|Year : 1954 | Volume
| Issue : 3 | Page : 57-75
Results of Ridley's operation
SN Cooper, RJ Patel
Department of Ophthalmology, King Edward Memorial Hospital, Parel, Bombay, India
S N Cooper
Department of Ophthalmology, King Edward Memorial Hospital, Parel, Bombay
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Cooper S N, Patel R J. Results of Ridley's operation. Indian J Ophthalmol 1954;2:57-75
Since Ridley first presented his operation in 1951, three years have elapsed and it is now time to assess the results of the operation and ask ourselves the question should we continue doing Ridley's operation or not.
In this study not only do we present an account of 14 cases in which this operation has been tried by us and followed up for at least one year but have tried to critically review the literature available on the subject.
| Technique|| |
The technique that we have followed is the same as described so clearly by Harold Ridley ( 1951) with a few modifications to suit our usual method of cataract extraction. These are sufficiently different to merit a brief description.
A quiet cooperative patient and a rigid immobility of the eyeball are most desirable for a successful operation. The first is achieved by a suitable preanaesthetic and the second by retrobulber injection of 3% novocain with liq. adrenalin and hyalase.
As regards suturing of the wound, in the first eight cases we used a preplaced single limbal stitch of the Lindner type, but in the last six cases we have applied five conjunctival stitches only according to our usual practice in cataract extraction with no different result. We prefer these as they are quicker and easier to apply and to remove.
Iridectomy. In five cases no iridectomy was done at all whereas in the other nine a peripheral buttonhole type of iridectcmy was done.
A thorough washing out of the lens matter cannot be too emphasised. Efficient irrigation can be helped (1) by the use of a Hague cataract lamp which causes fluorescence of the unwashed out lens matter or (2) by the use of proflavin added to the saline solution for irrigation in the proportion of l in 1,000. Proflavin besides being an antiseptic, harmless to the tissues, stains the lens matter a faint straw-colour which makes its identification and irrigation comparatively easier.
Instead of the special forceps to hold the lens we made use of Traquair's forceps with double prongs which seemed to serve the purpose just as well. We tried to use a Bell's erisophake to pick up the lens and manipulate the same in position. It seemed to work very well if it was applied to the posterior surface of the lens. Properly modified it would make a very convenient instrument to pick up, introduce and manipulate the lens into correct position, because the greatest difficulty about introducing the acrylic lens is to manipulate it into proper position after introduction. We have experimented by trimming off the rubber cap of an empty insulin phial, into one side of which the stem of a Bell's erisophake was introduced upto the hollow cup. The device seems to work well, although this make-shift arrangement is a little big. To our mind an erisophake with a cup of plastic material probably should make the best possible device. Various modifications of the erisophake principle have already appeared in print. Guzman ( 1953 ), Palazon ( 1953) and others.
As regards introduction of the acrylic lens a useful preoperative step is to inject two drops of adrenalin sol. 1 in 1,000 subconjunctivally at the lower pole of the cornea. This retracts the iris at the lower pole and helps the introduction of the lens under the lower edge of the iris. The upper part of the iris not being retracted helps to retain the upper edge of the lens when it is slipped behind it as the tendency for the lens is to tilt forward at its upper pole, being opposite the incision. While introducing the lens one should not hesitate to push the lower edge of the acrylic lens sufficiently downwards, upto the edge of the retracted iris, so that the lens is gripped by the iris sphincter. Failure to do so tends to drive the lens back into the anterior chamber. The upper edge of the pupil can then be drawn over the lens in one of the many different ways. We use just an ordinary iris forceps and catch the iris at its pupillary border at 12 o'clock underneath the lens and draw it over the lens. This is a step where a surgeon can use his own ingenuity to achieve the end.
Before completing the operation the shape of the pupil gives an indication as to how the lens is placed in the hayaloid fossa. The pupil tends to retract towards that part where the lens has slipped. It is desirable to see a circular pupil at the end of the operation. This can be achieved by gentle stroking on the cornea or by an erisophake as described above.
We also prefer to inject a ¼ gr. of morphia intravenously immediately on completion of the operation to enable the pupil to contract evenly and ensure the correct position of the lens in situ. Besides, it ensures quietness of the patient after the operation. Morphia given intravenously does not produce any ill effect or vomiting.
Past Operative Management : Total immobility of the head between sand bags and on a thin pillow under the neck is essential at least for the first 3 days. The first dressing is done on the third day.
In our first case when we opened the bandage after 48 hours we saw some exudate in the anterior chamber which increased to an alarming extent in the course of the next two days. We withheld cortisone under the belief that it would interfere with the healing of the wound and did not use it till the 8th day of the operation. With the use of cortisone and injections of lens protein the patient made a good recovery. In our subsequent cases cortisone has been used from the 3rd day without any detrimental effect on the course of the healing of the wound. The uveitis in these cases was considerably less. It proves that without the use of cortisone perhaps this operation would be extremely hazardous.
On the other hand a little uveitis with iris adhesions to the lens is desirable to keep the lens in position.
Injections of lens protein mentioned above are given in the dose of 0.01 mg. (0.1 cc. of 1/10,000 dilution of whole lens) once every five days as is our custom of treating post operative iritis in extracapsular extractions.
The dose given above is safe and is arrived at by trial and error and to our mind it appears to be a useful weapon to counter the effects of phaco-anaphylaxis along with cortisone and antihistamins.
| Results|| |
REPORTS OF INDIAN OPHTHALMOLOGISTS
Between the 1st August 1952 and 14th May 1953 Ridley's operation was attempted in thirteen cases by us. In one case, lens implantation had to be abandoned because there was megalocornea and the lens could not be retained behind the iris as the pupil was actually bigger than the lens.
In one case an intracapsular operation was done [Table - 1] and as the eventual result was disappointing, we have never used the intracapsular method after that for Ridley's implant. It has now become an established contraindication for Ridley's operation.
For the study of the results, it leaves us therefore with twelve cases in which Ridley's lens was implanted after an extracapsular operation.
The cases have been followed up for a sufficiently long time to allow us to draw some tangible conclusions. At the final checking of the result an astigmometric reading was taken on a keratometer and the binocular vision was determined on a synoptophore.
In two cases the eye was lost because of an injury after the patient went home after an apparently successful operation, and are described separately.
In one case the lens got subluxated spontaneously on the fifth day.
In one case, the twelfth one, the result was really bad. It appears to be due to allergy to the plastic material of the lenticulus along with phaco-anaphylaxis. The details of the case are given below.
Two cases after making an uneventful recovery and in whom the vision without glasses at the time of discharge was 6/36 and 6/60, in spite of all our efforts could not be traced. The final result should definitely be better.
In six cases the results have been quite satisfactory, as can be seen from [Table - 1]. The , corrected vision was 6/6 in two cases, 6/9 in two cases, 6/12 in two cases. All cases showed a moderate degree of brown iris pigment on the anterior surface of the acrylic lens. The first case had a very large amount of pigment in the beginning but it got reduced after cortisone instillation was started. Five of these six patients showed good stereoscopic vision, whereas one with 6/12 vision had simultaneous perception but no stereoscopic vision.
Corneal astigmatism varied from 1 to 7 diopters, and the cylinders accepted were more or less in keeping with the corneal astigmatism, indicating that astigmatism due to a probable shift or tilt of the implanted lens was negligible and the implanted lenses after extracapsular surgery remained in their central places.
On the synoptophore not much heterophoria was detected to suggest any great displacement of the lens either vertically or horizontally.
As will be seen all the cases that have been followed up have been reported after an observation, period of at least one year. All of them have been wearing their lenses comfortably and are not conscious of its presence inside the eye. One of these reported recently in the out patients' department for a foreign body sensation. On shining the inspection light into he pupil the peculiar yellowish glow of the acrylic lens implant was noticed. On questioning the patient, who is quite intelligent, whether a lens was implanted in his eye, he flatly refused, but acknowledged that a lot of fuss had been made about his case. On biomicroscopy the lens was distinctly visible, the patient being happily unaware of its presence. He said he carries on with his work as a fitter as easily as he did before the operation.
PATWARDHAN ( 1955) has operated on three patients, one of them on both his eyes. No iridectomy at all or no type of suturing was done, as is his practice in extracapsular extractions. In one eye the acuity is 6/9 in two 6/12 and in the fourth 6/12 without correction. All had an uneventful recovery. The first case was operated more than two years ago, the last four months back. No complication has been encountered and the eyes have made an uneventful recovery.
GUPTA ( 1953) has operated on 12 cases. In the published report, the results in five of his cases have been given as 6/60 to 6/36 at the time of discharge on the eighth day. In a personal communication he states that in ten of the 12 cases the vision had improved upto 6/12 and 6/9 in the course of time although the exact number of cases giving 6/12 and 6/9 vision is not stated. He adds, the only bad complications he had were in two cases, one in which the lenticulus got dislocated into the anterior chamber by hand injury and had ultimately to be removed, and in the second case, high tension developed although he was seeing very well with that eye for one year. The fundus showed definite glaucomatous cupping and atrophy and complete loss of vision. The case being a noncongestive one, no definite cause can be given for the glaucoma and the presence of the acrylic lens inside the eye cannot be incriminated as cause of glaucoma.
All cases showed acute plastic iridocyclitis which responded very well to cortisone therapy.
REPORTS OF CONTINENTAL AND SOUTH AMERICAN OPHTHALMOLOGISTS
PAUFIQUE ( 1954) giving his report on his first 32 cases considers his results on the whole favourable. He advises injection of air at the end of the operation to prevent prolapse of the iris. Amongst the difficulties he mentions first the impossibility of placing the lens due to an extensive removal of the capsule in three of his cases with hypermature cataracts. This leaves him with 29 cases to report on the result. He prefers to cut the secluded pupil, when it occurs, obtaining marked improvement in vision.
Tabulating his results we find acuity from 6/12 to 6/6 in 15 cases, 6/15 in three cases, 6/20 in two cases, 6/60 in two cases. In three cases where the acuity was lower than 6/60, one was due to a congenital cataract with amblyopia and the second was a dystrophic cataract, both of them with good anatomical result. In the third case the eye was totally lost with anterior segment inflammation and secondary glaucoma. This case was particularly sensitive to eczema. Three cases of luxation of the lens, described below had eventually good visual acuity. In one case the acuity was not tested although the anatomic result was good.
In the post operative complications he encountered ocular hyper-tension twice, controlled by medical treatment with 6/9 vision in one case and the second was controlled by operative treatment with 6/15 vision.
In two cases iritis resulting in occlusion of the pupil had reduced the vision to less than 6/60 which improved to 6/9 and 6/12 after an artificial pupil was made (coreoprexy).
Keratitis occurred in those cases where there was a prolonged handling of the case.
Mal position of the lens was noted 5 times. There was atrophy of the iris in two and sphincter inefficiency after traumatic mydriasis in the third. In the remaining two there was an exaggerated dilatation of the pupil with atropin. Although the actual visual acuity is satisfactory in these cases the author is cautious in his statement and wonders whether it will not end in a true luxation of the lenticulus later.
Luxation of the lenticulus took place twice in the anterior chamber when the lenticulii were extracted. In one case the luxation was in the vitreous where it has been well tolerated. The visual acuity is quite good in all the three cases after correction.
Secondary cataract occurred in only one case due to the thickening of the posterior capsule which the author opens up in the centre by a special cistotome which can be inserted through an incision, through the iridectomy opening and behind the lens.
Binocular vision was present in 15 of the 18 cases so studied.
DOLCET (1953) picked seven most unfavourable cases for this operation and admits that the bad results were due to the bad condition of the eyes and not to the method itself. Even in his series, one had 6 / 12 vision with correction, a second had 6/36 vision with a good surgical result. In two cases the lenticulus had to be extracted, one because the lens formed too big a bulge on the iris and the other, a case of retinitis pigmentosa which developed severe cyclitis, but the ultimate fate of the eyes was not bad. Two cases of old iritis developed occlusio pupil. In the last case the vision could not be ascertained.
H. ARRUGA AND A. ARRUGA (1954) conclude that where the eye was normal and the technique correct, the results were generally good, a little more than 50% of patients reaching a vision of 6/12 to 6/9 after 2-3 months and some of them 6/6 a few months later. Not so favourable results were reported in complicated cases.
In a similar earlier report by the same authors (1953) three cases of dislocated lenses are reported, one while manoevering through a rigid pupil, and the other two after intracapsular extraction. The lenses were well tolerated in the vitreous with corrected vision 6/12, 6/12, and 6/6 respectively.
MALBRAN AND SALLERAS ( 1953) reporting on 15 cases after 6 months, found luxation of the lens into the vitreous in all the three intracapsular extractions. Out of the remaining 12 cases, 6 cases had vision better than 6/12, in two cases it was between 6/60 and 6/18 and in four cases it was less than 6/60. The details of the bad results cannot be ascertained. In a 20 year old girl whose vision after operation was 6/6 and who had an exotropia, the exotropia disappeared.
ANTON ( 1953 ) stresses the importance of study of the vitreous and prefers to insert the lens in a second operation. In two of his four cases the implant was made months after an intracapsular operation was done. The implant was well tolerated in all his cases.
MILLER ( 1953) prefers to do his operation under general anaesthesia and advises antihistamins pre and post operatively to reduce vomiting. Incidentally it may help to control the anaphylactic manifestations from liberated lens matter. Toal iridectomy, he believes is not a contraindication for lens inclusion for he has done it twice without any untoward incident. A combined extraction therefore, with inclusion of the lens at a second operation is possible in cases of cataract with glaucoma. He injects cortisone in the anterior chamber at the time of the operation. He is very cautious in the after care, and his patients do not leave the hospital for 3 weeks. He advises sub-conjunctival injections of adrenal preoperatively to dilate the pupil. He reports on 5 cases followed for six months and more, with corrected vision nearly 6/6 in 4 cases and 6/10 in the 5th.
Amongst complications and the way to avoid them he suggests inclusion of the lens at a second operation a few weeks later at the least difficulty, i.e. persistent lens masses, a thick capsule or too much removal of the capsule, bleeding, old injury, old iritis, hypertension etc. He has not come across any subluxation of the lens, if these precautions are followed.
He feels that post-operative reaction takes at least 2 months to subside, which in spite of his use of cortisone from the day of the operation seems too long a period.
For the rise of tension, if it occurs he suggests instillations of neosynephrine 5%.
There are other results published by several other surgeons. These are not reviewed because the series is either too small or the details of the results are not available. On the whole it works up to an average of 6/12 and better vision in 50% of cases operated by the extracapsular method with implantation of Ridley's lens.
REPORTS OF HAROLD RIDLEY
Harold Ridley ( 1954) in his latest report on more than 100 cases done with his operation reports a progressive improvement in results. The best vision is not attained till two or three months after he operation. He advises picking up the remnant of the anterior capsule and cutting the same with iris-scissors instead of pulling it out, lest it disrupts the protecting posterior capsule. A light final irrigation helps to centralize the lens.
He describes his results under intracapsular and extracapsular. Out of the 18 intracapsulars - 10 deliberate and 8 inadvertent - in as many as ten the lens got dislocated into the vitreous. They were well tolerated in this dislocated position and the corrected vision remained good. In spite of the eventual good result, some of these patients were disappointed because of the loss of the other optical advantages they had experienced previous to the dislocation. Implantation after an intracapsular operation, however, is unsatisfactory and should not be done under the existing technique.
Out of 91 extracapsulars, three suffered from post-operative injuries and the lenses got dislocated, one in the anterior chamber which was removed, one was corrected satisfactorily and in the third the dislocation was in the vitreous.
Out of 91 extracapsulars 66% had 6/9 and better vision, out of which over half can see 6/6 or 6/5. In the others the vision is expected to improve. "Only five cases. other than those which are amblyopic or contain dislocated lenses, seem beyond reasonable hope of 6/9", but the author does not state the reasons why.
Among the complications, although he mentions about occlusion of the pupil and secondary glaucoma, he seems to make light of the post operative iridocyclitis, and does not seem to lay enough emphasis on this complication. True it is that this can be countered effectively though a little irksome, with modern means.
He believes that cataract with heterochromia (Fuch's cataract) is no contraindication for the operation. On the other hand constitutional diseases are contraindications to all but the simplest operation.
RESULTS OF SURGEONS OF THE U.S.A.
Comparatively few results have been published by surgeons of the U.S.A.
J. A. McLean ( 1953 ) reports on 17 insertions, the final results being the equivalent of 6/12 or better in 9 cases, between 6/36 and 6/18 in 4 cases and 6/60 or less in two cases. In 2 cases the results are not known.
The panel for cataract surgery of the American Academy of Ophthalmology has expressed a general disapproval of the operation though a minority of it feels that further investigational work be continued by experienced ophthalmic surgeons.
REESE ( 1954) who has also reported to the panel on the 29 cases he has operated is quite enthusiastic about the operation. He is surprised at the amount of opposition to this operation by some of the older American ophthalmologists to the idea of introducing a foreign body into the eye. Unfortunately Reese's results in 29 cases are not given in detail.
On the other hand the results of FINLAY and ROMAINE ( 1954) who have not expressed too favourably have been tabulated. "Nine cases were operated by various residents and attending physicians", which means, the most experienced surgical skill was not available in every case. Out of the nine cases, two had diabetes mellitus, and two had bronchial asthma with hypertensive cardiovascular disease compensated. That means, four of these nine cases were poor operation risks. Out of the remaining five, one has not reported although he is supposed to have had a severe plastic irido-cyclitis. That leaves us with four cases. Out of these, two had vision 6/12, one 6/9 and in one there was "postoperative iritis, secondary glaucoma and prolapse of the iris". (See discussion.)
The fourth study from the United States comes from ANDREW B. ROETTH, Sr. (1953) who perhaps has not performed a Ridley's operation himself, for he does not give any of his results in Ridley's operation. He has selected the best possible results of Ridley's operation that is by Ridley himself ( 1953 ) and matched them with the results in his own and other reported series of intra- and extracapsular operations. Thus with intracapsular operation a result of 6/9 and better can be had in 85 to 91% of cases if cases with poor visual acuity due to extraneous causes are excluded, e.g. corneal opacity, choroiditis etc. A similar result can be had in 59.3% in regular extracapsular extractions and only 50% in Ridley's operation, as reported by Ridley ( 1953 ). This weighs heavily against Ridley's operation, but we shall examine the merits of this analysis later.
| Discussion|| |
It may appear that only twelve cases in our series left for final comparison is too small a number to draw conclusions from. The very nature of the operation is such that although a bit dramatic it demands caution in its universal applicability. To leave a foreign body purposely inside the eye indefinitely, the thought is sufficiently arrestive. We had decided to do a dozen selected operations and then wait and watch the results before we could go further. Under the circumstances a dozen operations seem to be sufficient unto the day.
Should not the results have been watched for a longer time ? These cases we hope to review again after two or three more years, but sufficient satisfaction has been provided from these results over a period of 1 to 2 years to undertake a fresh spurt of Ridley's operation in selected cases in the light of the experience gathered.
Up to now we have selected only those men who we gathered could be traced and be relied upon for reporting when asked to do so. Again we selected comparatively young subjects with unilateral cataract without any trace of an inflammatory lesion like presence of old K.P.'s or posterior synechia and were considered good risks for a cataract operation. Such cases may have been of traumatic origin and as we have observed previously - Cooper, Lakhani and Javeri ( 1948 ), traumatic cataracts present the least trouble in the post-operative period. Antigenically they produce practically no allergic activity. It is possible that this run of good luck may be due to the fact that our selection of cases in young, unilateral cataractous eyes without inflammation may have led us to an unconscious selection of traumatic cataracts at least 'in some cases, although only a vague history of trauma in some of the cases could be ascertained.
In only one case, four keratic precipitates were seen previous to the operation. The eye stood the operation well, but could not stand up to an injury nine months after the operation (case 13 ).
Reading the results of this operation by different operators outside India, one sees two distinct groups of observers (1) surgeons of the U.S.A. and ( 2 ) the others. That is why we have described the results as coming from different continents. All of them exercise a certain degree of caution, but on the whole the European group appears to be more enthusiastic than the North American group.
It is extremely difficult to faithfully compare the different series of results, reported by different surgeons with different standards of determining visual acuity between clinics, different groupings, different time-lapse etc. All that one can gather is that in the initial stage of the experience of different skilled surgeons, the visual result is 6/12 or better in at least 50 % of cases. Ridley's own results stand out in a group by itself. His initial results were also 6/ 12 or better in 50% of cases but in his latest series the results have improved to nearly 74%, showing that with more, experience and practice the results are bound to be better.
A better way of comparing the results would be to critically analyse the results of the group who have expressed themselves against the operation. Two such studies present themselves, one by Finlay and Romaine ( 1954) and the other by de Roetth Snr. ( 1954 ), both reviewed under results by surgeons of the U.S.A.
Finlay and Romaine have made mention of nine cases operated by various residents and attending physicians in a clinic. Not all have been operated by one skilled surgeon as should have been the case. Out of the nine, four were definitely bad operation risks, two diabetics and two asthmatics with compensated hypertensive vascular disease. Out of the five good operation risks the result was 6 / 12 or better in 3. In one there was "postoperative iritis, secondary glaucoma and prolapse of the iris". It appears that the complication was more due to prolapse of the iris and so the blame may not be laid down at the door of Ridley's lenticulus.
Scanning the results in the poor-operation risk cases, we find one case with bronchial asthma having 6/6 vision six weeks after the operation. Then "the lenticulus was displaced forward by residual lens cortex". This seems unlikely six weeks after the operation and 6/6 vision; there must be precious little lens matter remaining behind. More likely the subluxation may be due to a bout of coughing in the patient who was asthmatic. A secondary glaucoma resulted which was controlled by 2% pilocarpin. Then she developed an asthmatic attack and bilateral iridocyclitis which improved with steroid therapy etc. The lenticulus was then extracted and even then the final corrected vision was 6/9.
The second asthmatic case had 6/9 vision.
One case of diabetes had 6/24 with a low grade iritis. The fundus could not be seen.
The second diabetic case had severe postoperative iridocyclitis and an extraction of the lenticulus was advised. Her eye was then tinkered with by another ophthalmologist who was unaware that a Ridley lens was implanted. She developed severe intraocular haemorrhage.
Although the authors have tried to show up the bad results of the operation, they have incidentally shown the results to be more than satisfactory.
This series appear to be too severe a test for the Ridley operation. Even then, in the bad operation risks the results are not bad. These are not cases that can enter into a list of strictly comparable results and to condemn the Ridley operation on the report of these cases seems a little unfair. Perhaps this series was selected to find out whether Ridley's operation can stand up to its merits in unselected cases, and that it certainly does not, in its present technique.
These authors also seem to make a point of inability to see the fundus after this operation. In two of their own cases (cases l & 4) the vision is 6/12 and 6/9 respectively and the fundus is not visible. This however is not an uncommon experience even at a stage when the patient has already started seeing well, and as Miller ( 1953 ) points out, this is due to the defraction of light from the several pigment deposits on the lenticulus. These tend to clear and fundus details can be seen fairly clearly in the course of time. They are not incompatible with good vision.
The second study is by de Roctth, Snr. ( 1953 ) who declares that with intracapsular operation a result of 6 / 9 and better can be had in 85 to 91 % of cases, in extracapsular extractions 59.3% of cases, and in Ridley's operation - Ridley's own series 1953 - 50% of cases.
The results as stated do not show whether the extracapsular operations done by him were planned extracapsulars or accidental ruptures in attempted intracapsulars. If the latter is the case, which appears to be more likely, the results of intra and extra capsulars should not be taken apart, and the total results be considered the results of attempted intracapsular surgery which will reduce the average results from 90% to 75%. Admittedly the results are still better by at least 25% when Ridley's lens is not introduced.
There is yet another point to be considered. It is elementary knowledge that the retinal image after aphakia is magnified by one and one-third times approximately and a visual acuity of 6/6 after aphakia should be considered equivalent to 6/9 and of 6/9 to 6/12 after the implanted lens technique because that does not magnify the retinal image. Hence visions with 6/9 or better with unimplanted correction should be matched with 6/12 and better with Ridley's operation. This easily adds about 8 % more to the credit side of Ridley's operation.
In the latest survey of his results in over a hundred cases Ridley ( 1954) gives the percentage of results 6/9 and better as 66% and 6/12 and better as 74%. Thus the correct way to match the results would be this figure 74% as against 75% to 85% for intracapsulars, worked out in the second paragraph above.
Besides, intracapsular surgery today is the result of perfection through at least two generations by people who believe in this operation. Ridley's operation is still running in its third year and adopted by surgeon's with a certain degree of reserve and diffidence which is not conducive of rapid progress. As can be seen from Ridley's successive reports better and better results will be obtained with experience and practice.
To this mathematical results of central visual acuity should also be added the other advantages of a Ridley's technique, viz. a larger field of vision, binocular, unmagnified natural vision and the absence of disadvantages of wearing a thick lens. As Ridley mentions, patients prefer to have 6/12 with binocular vision than have 6/12 in one eye and 6/6 with an aphakic lens in the other eye which is not tolerated.-Ridley ( 1952 ).
Thus the optical, cosmetic and psychological advantages of a Ridley's lens implant are obvious. The only difficulty would be the correction of the unequal accommodation between the two eyes of a unilateral aphakic patient operated with Ridley's technique.
Several other questions suggest themselves in the discussion. (1) Have we any evidence to feel that the insertion of acrylic material inside the eye is harmful ?
Naturally, time alone will show whether the material can be tolerated indefinitely. For the present Ridley's cases have been followed the longest and he - Ridley ( 1954) feels that the longer the lens is worn the better it is tolerated. There is no indication so far that the lenticulus will not last a life time. From those who have reported, no one has experienced so far, any late irritation in their successful cases, although they all mention of this possible danger.
Baron ( 1954) mentions the experimental evidence of Virenque who has studied its effect when left under the conjunctiva in animals.
(1) It produces little reaction in the conjunctiva; (2) this reaction does not progress. The fibrous tissue formation is not progressive or evolutive as in other foreign body reactions.
In tissue culture, the growth appears equally augmented with or without the acrylic. Pure methacrylate of methyl is therefore not cytotoxic.
However three possible, sources of danger appear before us.
(1) Infection during introduction. The lens is sterilized by immersion in citavlon solution for 30 minutes and washed in sterile saline before introduction. It is better to wash it in saline solution to which a little Penicillin is added.
(2) "Acrylic" is soluble in alcohol, and though the possibility seems remote, its intolerance in chronic alcoholics should be watched. An interesting study would be to compare its tolerance in alcoholics and non-alcoholics.
(3) Allergy from "acrylic". Though Ridley, Paufique, Miller and others have not encountered any such case, Case 12 in cur series and the one reported by Jonkero (1953 ), suggests that the possibility exists. In both these cases the reaction became progressive and subsided only after removal of the lens. Perhaps a co-existing lens or other allergy may be a contributory cause.
Far from discouraging us in the use of the acrylic implant these few adverse experiences should stimulate us to further research.
From a resume of the literature on this subject the principle of implanting acrylic material inside the eye has taken firm root. Perhaps Ridley's original technique may undergo a wide metamorphosis in future but his operation will always remain the pioneer of further research.
(2) Is there any optical disadvantage of a Ridley lens ?
It has a fixed refractive power and cannot make allowance for any existing refractive error, nor can it correct the astigmatism consequent to the operation. It is very important therefore, to determine in every available way the approximate refractive error, otherwise artificial and unnecessary myopia may be introduced say in a myopia of over 6D. This can be overcome by a two stage operation as suggested by Miller (1953).
(3) Does not the lens , get luxated ?
Far too many luxations, have taken place with intracapsular surgery to merit a persistence of this procedure. On the other hand a two-step operation may be risked even after an intracapsular operation after the condition of the vitreous is determined. The "floating" lens and Strampeli's lens (see below) may be the answer to this contraindication under the present technique.
As regards extracapsular surgery, the irido-cyclitis and the iris adhesions to the lens that follow Ridley's operation in almost every case, which eventually disappears, we feel actually helps the retention of the lens in position postoperatively. No iris adhesions may allow the subluxation of the lens downwards.
In any case, luxations of the lens take place readily with trauma, direct or indirect. In our brief experience and gathering from the literature available we feel that eyes operated by Ridley's method cannot withstand post-operative trauma easily. Such cases must be cautioned against trauma and straining, as we generally do in cases of detachment surgery. Chronic cough, asthma and chronic constipation should be definite contraindications for Ridley's operation.
(4) Is not there an alarming amount of irido-cyclitis ?
Although Ridley himself does not make much of the post-operative iridocyclitis, it is definitely much more than after ordinary extracapsular extractions. In fact it is the main obstacle in promoting the popularity of this operation. At the same time it is not so uncontrollable as to merit Miller's opinion that it takes at least two or two and a half months for the eye to become quiet.
Always partial to the role of lens proteins in the causation and treatment of post-operative iridocyclitis we have used this as an extra tool in our own cases besides the existing ones, viz. cortisone, protein therapy, antihistamins and vitamins, particularly ascorbic acid, to counter the effects of phaco-anaphylaxis. We have not had the chance of comparing series where lens proteins have and have not been used, but we feel that the post-operative inflammation subsides more readily. Although the intensity of inflammation is great the period of subsidence does not appear to be much greater than in regular extra capsular extractions.
Although Posner (1953) has much to say against the use of lens proteins, we have to state that if lens protein is to be used as a therapeutic measure in the relief of post operative irido-cyclitis (and not ever in the prevention of cataract formation) it is very essential to stick to the dosage. Anything more than 0.01 mg. may easily cause an adverse reaction.
The dose mentioned 0.01 mg. and the technique of desensitization described previously are safe and are arrived at by trial and error.
Only one case did not yield to the usual measures and subsided only after the lenticulus was extracted. This case (case 12) is somewhat like the one described by Jonkero (1953) and may be considered likely to be directly due to the presence of acrylic material in the eye. Case 5 done intracapsularly also suggests a possibility of a mild inflammatory reaction (see details in appendix) to "acrylic" in some individuals. If that is the case one can ask the question is it possible to desensitize effectively such patients by adequately small doses of the acrylic antigen?
Although we ourselves have not encountered complete seclusion of the pupil, Paufique, Ridley, Arruga and some others have come across this complication. Surprisingly good results have been reported on freeing the pupil surgically. Our one case of a near seclusio-pupil (case 4) followed the injury to the eye that took place after going home. He reacted badly to the attempt to free the pupil.
A two stage operation should definitely cut down the incidence of such severe end results of irido-cyclitis.
(5) What is the risk of secondary glaucoma ?
We have not come across this complication, but temporary rise of tension has been reported, which can be controlled by miotics or by surgery in the usual way. In view of the incidence of seclusio-pupil with secondary glaucoma it is wise to do a small peripheral iridectomy, at least to prevent glaucoma if seclusion takes place.
(6) From what day should cortisone be used ?
The myth about non-closure of the wound with the use of cortisone is exploded. Some surgeons use it from the first day and even inject it in the anterior chamber. We prefer to use it from the third day when the first dressing is done, and subsequently daily in the form of an eye ointment.
(7) How does the alternative of a contact glass after aphakia compare with an intraocular implant of the lenticulus ?
Rougier (1954) in a comparative study of correction of unilateral aphakia with contact glasses and by Ridley's lenticulus conclusively proves the superiority of the latter not only in tolerance but in the quality of vision. He adds however that the indications for Ridley's lens are limited to unilateral cataracts in a healthy eye, and requires skilled surgery. On the other hand there is a large number of aphakics who can be fitted with contact glasses with excellent prospects of good binocular vision if the ophthalmologist institutes early enough an orthoptic examination and treatment of existing deviations.
Ridley ( 1954) states that the irritation, discomfort, veiling and the patience required to fit the contact lens and learn to wear it makes it far inferior to the intraocular implant.
Fritz (1954) considers the suppleness of the contact glass important in the ability to wear the same throughout the day. He recommends that the contact glass should not be more than 0.2 mm. thick.
(8) Are there any modifications made in Ridley's lens?
French and Italian ophthalmologists have been devising ingenious variations to the Ridley lens to overcome its optical defect. Baron (1954) has devised square lenses of varying refractive powers to be placed in front of the iris at a second operation, but the great disadvantage is that it causes striate keratitis, sometimes leaving a permanent leucoma. Strampelli (1954) prepares an acrylic strip with the lens in the centre which can be introduced through a small limbal incision, and placed in front of the pupil. He reports on 5 cases in which the post-operative inflammation was insignificant. According to him such a lens has obvious advantages - (1) no risk of posterior dislocation; (2) can be introduced even years later; (3) a needling can be done with the lens in position; (4) correction of marked ametropia with the crystaline lens in position; (5) can be easily removed if required.
We foresee three more advantages. (1) Exact dioptric correction can be calculated and prepared to suit each individual person. (2) It can be used even after an intracapsular operation, or where a complete iridectomy has been performed. (3) By introducing it in the required axis an astigmatic correction is also possible.
Bietti (1954) has also expressed himself favourably on the use of such lenses in his experience.
Another kind of lens that is under experimentation is the "floating" lens, with a lower specific gravity so that it does not sink in the vitreous.
(9) Should the operation be performed in two stages?
Such a procedure has obvious advantages - (1) after the subsidence of the post-operative inflammation, the introduction later of a lenticulus has a better chance of success; (2) the capsule can be needled and (3) the integrity of the vitreous determined by slit-lamp in intracapsular surgery before the lenticulus is introduced (See Anton's results on page 64 ). (4) the refrective error can be ascertained prior to implanting lenticulus. As already quoted from Miller the least difficulty in the introduction of the lens at the time of the operation should be an indication for a two-stage operation.
(10) Should we continue to do Ridley's operation ?
Progress in any scientific procedure can only be achieved by imagination, courage and readiness to look at our bad results in the face. Sufficient time has elapsed to make us feel more and more confident of leaving the acrylic foreign body in the eye. Yes, let us go on with this operation at the highest possible level of surgical skill and experience. Let our adverse experience guide the way not only to better visual results but also to a better knowledge of physiological, optical and allergic principles involved.
| Conclusions|| |
- It is not an operation for the occasional operator and the comparatively inexperienced one.
- Ridley's operation should not be done with intracapsular surgery. The most accepted indication is unilateral ripe cataract in young subjects requiring stereopic vision. This rigidity in the selection of cases may be relaxed with further experience.
- In our present experience it is better to confine ourselves to cases that may be considered good operative risks.
- It appears to be a safe operation in selected cases, and its value in other types of senile, cyclitic and black cataracts is yet to be tested. It is undoubtedly an operation with many advantages, particularly where stereopsis in industrial workers is essential, after extraction of a unilateral cataract.
- Such operated eyes withstand post operative trauma rather badly, and should be given the same advice in post-operative care as a case of operated separation of the retina.
- In most cases the acrylic material is well tolerated inside the eye even after its dislocation into the vitreous.
- Allergy to the acrylic material is a possibility.
- Post-operative irido-cyclitis holds out, for the present, an obstacle to promote the general popularity of this operation.
- Comparative studies of visual results should be critical. An allowance for the magnification of the retinal image in aphakia corrected with spectacle lenses should be made, so that a 6/9 visual acuity after aphakia corrected with spectacle lenses should compare with 6/12 visual acuity after a Ridley operation.
- Besides the quantity of vision, the quality of vision should also be considered e.g. field of vision, apparent sizes of objects, stereopsis.
- Even if the operation fails, the ultimate visual result is not discouraging.
- Several avenues of research have been opened up, which when pursued with faith and imagination may ultimately lead to the general progress in cataract surgery.
Finally may we express our appreciation to the grand team-work that has made this operation hazard a successful possibility - Ridley for his imagination to think of the possibility of implanting a lens into the eye to take the place of the crystalline lens, the physicist who may have calculated the suitable radii of curvatures, the chemists who worked out the formula for the acrylic material. the technician who made the manufacture of the lens possible, the biochemists who gave us cortisone, without which the operation could easily be a flop, the allergists who have contributed to our knowledge of allergy, and finally Ridley again for his courage to put his conviction into practice and evolve a technique to present to the ophthalmic world what is perhaps the most imaginative and dramatic eye operation of the day.
DETAILS OF SELECTED CASES
Case 4. We were curious to compare the results of Ridley's operation in eyes with a lightly pigmented bluish iris with those with an highly pigmented brown iris of an average Indian. This case had light blue iris. After a most successful operation, perhaps the best result we had, directly on reaching home he banged his eye against an object and immediately returned with a severe hyphema and pain. An iridocyclitis followed. The condition improved with treatment. Annular synechiae were threatening and we decided to free the iris for fear of secondary glaucoma before the eye was quite quiet. The uveitis flared up with vengence and the lenticulus had to be removed. Even with a vectis a hard pull was needed to take the lenticulus out because strong adhesions had taken place between the iris and the lenticulus. The end result was an atrophy bulbi, a most unlucky termination to an operation which had shown such good promise. Perhaps freeing of the pupil should have been deferred till the eye was quiet.
Case 5. It is the only case which was done intracapsularly. After fifteen days the lens had shifted to the nasal side. Four months later the lens got completely dislocated in the posterior chamber. The anterior face of the vitreous appeared to be covered with a fine membrane, which was circular with a sharply defined edge on one side. Two months later the membrane had disappeared, suggesting a possible inflammatory reaction due to contact with the acrylic lenticulus. At the time of the posterior dislocation the vision was 6/24 with correction. Ten months later vision had deteriorated to finger counting from 10 feet and large vitreous opacities had appeared. (See discussion point 4).
Case 11. This operation was done with a sclero-corneal incision without cutting the conjunctival bridge. Some difficult was experienced in bringing the lenticulus in position. On the third day moderate injection and slight keratitis were present, the lenticulus being in good position.
On the fifth day the lenticulus got tilted and sub-luxated to the temporal side; the temporal edge was in front of the iris. On the same day the lenticulus was extracted under sodium pentothal. There was much bleeding at the time of the second operation. Hyphema persisted for 6 days. Eye became quiet within 6 weeks. Vision six weeks later was 6/18 with correction. Vision one year later 6/6 with +9.Osph +4.Ocy1 @ 100° .
Slit-lamp examination shows a hiatus in the posterior capsule with a slight bulge of vitreous in the anterior chamber. It is not possible to say whether the hiatus in the posterior capsule was present before the implantation and was responsible for the difficulty in bringing the lenticulus into position and its subluxation subsequently or was produced at the time of removal of the lenticulus.
Case 12. The operation was uneventful. Post-operative iritis was seen on the first day of the dressing. It began to gain momentum and we were unable to curb it with all the means at our disposal viz., cortisone locally, milk injections, injections of lens proteins and antihistamins. By the seventh day the wound had healed, there was no prolapse of the iris, but the chamber was shallow. A peculiar appearance was developing. The outline of lenticulus could be visualised through the inflammed iris. It appeared as if swollen vitreous was pushing the lenticulus forwards. There was no dislocation of the lens. By the fourteenth day the iris appeared distinctly in two parts - the part opposite the lenticulus showed yellowish patches of atrophy, the perifheral part showed a brown-grey colour as in an inflamed brown iris. The lenticulus was extracted on the seventeenth day as no form of treatment seemed to do him any good. The eye rapidly became quiet. On discharge the vision was hand-movements only. A month later his vision had improved to finger counting at 3 meters, but the patient was not reported since. We consider that this stormy course must be due to the presence of the lenticulus itself in which anaphylaxis from lens proteins may or may not have played a supporting role, as it showed no response to the usual treatment.
Case 13. Age 39, male, unilateral ripe cataract right eye, with brisk reaction, normal tension. With the slit-lamp four fine pigmented keratic precipitates were seen. Since no cause could be detected for a previous cyclitis he may have had and as he was otherwise a very good operative risk he was selected for the Ridley operation. An extracapsular operation was done. After introduction of the lens there was a tendency for the lens to slip downwards. At the time of discharge there was a slight flare in the anterior chamber which disappeared within 2 weeks. The lens had remained in the slipped position, and there was no tendency to correct itself. A shred of capsule could be seen between the upper edge of the lens and the upper border of the dilated pupil. However, when the pupil was undilated the pupillary edge covered the upper lens border. The corrected vision was 6/12 with -5.0 cyl at 105˚. The surprising part was that the astimgatic correction corresponded with the corneal astigmatism in spite of the subluxation. The difficulty was to prescribe near glasses with aphakia in one eve. An unequal addition which brought the near point to 12 inches proved to be comfortable for near work. The subluxation may be due to an error in technique, because there was a piece of capsule hanging over the upper border of the lenticulus, which should have been excised.
Three months after the operation the eye was accidentally injured by his baby's hand, which caused partial dislocation of the lenticulus into the anterior chamber. Extraction of the lenticulus was advised but he delayed it for a month during which time it got completely dislocated in the anterior chamber. During extraction of the lenticulus there was slight vitreous disturbance. An iridectomy had to be done for a rise of tension which followed five months after the operation. After this he developed a severe diffuse striate keratitis, which got controlled with treatment, but a dense corneal opacity has developed in the parenchyma of the cornea in the upper part. The final result is finger counting at 3 meters.
| References|| |
Anton, M. ( 1953 ), Arch. Soc. Cubana Oftal. 3, 93-95, abstract 3685 Ophth. Lit. 7, No. 5.
Arruga, H. J., Arruga, A., ( 1953) Arch. Soc. Oftal. hisp.-amer. 13, 731-745, abstract 2693 Ophth. Lit. 7, No. 4.
( 1954) Rev. esp. Oto-neuro-oftal. abstract 1363 Ophth. Lit. 8, No. 2.
Baron, A., ( 1954) Bull et Mem. Soc. France d'Ophth. 67, 386-390.
Bietti, M.G. B., ( 1954) Bull. et Mem. Soc. France d'Ophth. 67, 405.
Cooper, Lakhani and Javeri, ( 1948) Trans. All-India Ophth. Soc. 9, 47.
de Roeth., A. Snr. ( 1953) Amer. J. Ophth. 36,
Dolcet, L., ( 1953) Arch. Soc. oftal, hisp.-amer., 13, 665-671, abstract 1674 Ophth. Lit 7, No. 3.
Finlay, J. R. and Romaine, H., ( 1954) Trans. Amer. Acad. of Ophth. Otol. 58, 57-59.
Fritz, (1954) Bull. et Mem. Soc. France d'Ophth. 67, 400.
Gupta, M. K., ( 1953) Ophth. J. Gandhi Eye Hosp. 3, 13-17 and personal communication.
Guzman, A. D., ( 1953) Arch. Soc. Cubana Oftal. 3, 96-99, abstract 3689 Ophth. Lit. 7, No. 5.
Jonkero, G. H., ( 1953) Ophthalmologica 126,
Malbran, J. L. and Salleras, A. Arch. Oftal. B. Aires ( 1953 ) 28, 134-135, abstract 2694, Ophth. Lit. 7, No. 4.
McLean, J. A., ( 1953) Trans. Can. Ophthal. Soc. 6, 119-128.
Miller, H. A., ( 1953) Ann. d'Occulist., Paris 186, 312-332.
Pallazon, ( 1953) Arch. Soc. Oftal. hisp.-amer. 13, 306-308.
Patwardhan, D. G., ( 1953) Medical Digest 21, 398-400 and personal communications.
Paufique ( 1954) Bull. et Mem. Soc. France d'Ophth. 67, 378-383.
Posner, Eye, Ear, Nose, Throat, Mon. ( 1953 ) 32, 43.
Reese, Warren, S., ( 1954) Trans. Amer. Acad. Ophth. Otol. 58, 55-57.
Ridley, H., ( 1951) Trans. Ophth. Soc. U.K. 71, 617-621.
( 1952) Brit. J. Ophth. 36,
( 1953) Trans. Amer. Acad. Ophth. Otol. 57, 98-106.
( 1954) Brit. J. Ophth. 38,
Rougier, ( 1954) Bull. et Mem. Soc. France d'Ophth. 67, 371-398.
Strampeli. ( 1954) Bull. et Mem. Soc. d'Ophth. 67, 401-404.
[Table - 1]