|Year : 1960 | Volume
| Issue : 2 | Page : 47-51
Vindication of corneal incision and post-placed corneal sutures in cataract surgery
|Date of Web Publication||6-May-2008|
K J Dastur
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Dastur K J. Vindication of corneal incision and post-placed corneal sutures in cataract surgery. Indian J Ophthalmol 1960;8:47-51
Ever since the time of Daviel more than 200 years ago, technique of cataract surgery has undergone modification year after year, the underlying purpose being to make the surgery safe both for the surgeon and for the patient and thus reduce post-operative complications to a minimum. Thanks to the advances made in the last decade in pharmacology, the technique of akinesia local and general anaesthesia and the manufacture of delicate sharp needles and instruments, practically nothing is left to chance, and except for an occasional occurrence of retrobulbar and choroidal haemorrhages the rest of the post-operative complications have been considerably reduced.
Post-operative sepsis is almost a thing of the past. Vitreous loss during an uncomplicated cataract extraction can be prevented almost in all cases by (i) proper preoperative sedation of the patient; (ii) perfect anaesthesia; (iii) improved blepharostate of Arruga type; iv) introduction of alpha-chyrnotrypsin and (v) "patient" surgery. So much is this true that today an expert assistant can be done away with at least for cataract surgery. Thus all the 35 cases operated by me at the Petit Parsi General Hospital were without any help of an expert assistant, and in non" of these there was vitreous escape. The same factors in technique enable surgeons to perform ever larger number of intracapsular extractions and thus reduce the frequency of iritis phaco-anaphylactica
Hence, the present day complications after a cataract operation are mainly those arising from incomplete closure or delayed closure of the wound; e.g. iris prolapse, hyphaema, secondary glaucoma from blocking of the chamber angle, cystoid cicatrix and epithelial downgrowth into the anterior chamber.
| Merits of Corneal Incision|| |
While the conventional sclerocorneal incision with a limbus based conjunctival flap sutured with a perfectly placed sclero-corneal suture heals with firm union between the edges within 10-12 days, and thus effectively guards against all the above mentioned complications except hyphaema, the incidence of hyphaema is only reduced from 9.75% (Hughes and Owen,(1947) to less than 2% (Stallard, 1958). Corneal incision, therefore is the only effective safe guard against hyphaema.
Many surgeons are reluctant to make an incision in the clear cornea without a conjunctival flap for the following reasons:
(i) healing is very slow;
(ii) infection of the wound edges may occur;
(iii) preplaced appositional suture of the McLean type cannot be applied because an effective groove cannot he made in the cornea and one has to be satisfied with a preplaced mattress suture of Stallard type, which causes less perfect apposition of wound edges and/or posterior gaping; or a postplaced appositional suture wherein perfect apposition is difficult to obtain.
A well-apposed corneal wound, however, has several advantages :
(i) Post-operative hyphaema is ruled out.
(ii) The spur of the posterior lip is a more effective safeguard against late iris prolapse, that may occur any time after removal of cornea-scleral suture.
(iv) By routine tonography and gonioscopy pre- and post-operatively 17 cases of cataract operations, Miller, Keskey and Becker (1957) have found that section in clear cornea does not cause any measurable differences in topographic and gonioscopic alt0rations. This is probably because the ciliarv body is less disturbed than if the incision is limbal.
Regarding the disadvantages of a corneal incision it may be stated that (i) with proper technique it is possible to obtain as perfect apposition of wound edges with post-placed sutures as with preplaced ones; (ii) the memorable work of Dunnington (1951) and others on ocular wound healing on monkey's eyes has enabled ophthalmic surgeons` to revise their views on the merits of purely corneal incision without a conjunctival flap. The conclusions drawn from their work are briefly stated below:
(1) Limbal incision without a conjunctival flap and a purely corneal incision behave identically whether- with or without the suture application except that with the former incision however well apposed and stitched the incidence of post-operative hyphaema cannot be completely eliminated.
(2) Absence of conjunctival flap in a purely corneal incision does not significantly increase the incidence of such complications as fistula formation, epithelial (town growth, or cystoid cicatrix, provided that such a wound is well apposed and stitched properly.
(3) The tensile strength of the wound whether limbal or purely corneal, increases only after 4 or 5 days of the operation when fibroblasts, appear between the wound edges.
| Corneal Incision as Routine Procedure|| |
All the above considerations have led me to make a purely corneal incision without a conjunctival flap, as a routine procedure in cataract surgery since 1953. For the necessary courage required to adopt this procedure as routine, I am grateful to Dr.Arruga of Barcelona whose operative technique of incision and post-placed suturing as also the post-operative results of his cataract cases I had the good fortune to see personally.
[Table - 1] includes 35 cases operated by me at the Petit Parsi General Hospital, while [Table - 2] shows 15 cases operated by me in my private clinic. These latter 15 cases have been selected from a total of J3 cases and the remaining 38 private cases have been omitted because there was nothing unusual about their pre-operative condition and post-operative course.
Pre-operative : Besides the - usual pre-operative investigations and treatment, special mention must be made of the condition of the cornea. Cornea must be examined under slit lamp for evidence of early endothelial dystrophy. This latter condition, corneal hvpoaesthesia or anesthesia and in extremely xerotic cornea, corneal incision is avoided.
After perfect anesthesia and akinesia, pre-operative sedation, and introduction of Arruga's Blepharostat, incision is made with a thin Graefe Cataract knife, (from 2 to 10 O'clock) in the clear cornea 1 mm. within the limbos. The incision is then enlarged with McGuire corneo-sclearal scissors from 2 to 3 and 10 to 9 O'clock positions.
Iridectomy either button-hole or broad peripheral is done next; before introduction of the suture.
Post-Placed Corneal Suture
In order to obtain perfect apposition with post-placed suture the following instruments are essential:
(i) A good binocular loupe.
(ii) A very delicate corneal suture forceps with pointed ends, e.g. St. Martin Corneal Suture Forceps.
(iii) Grieshaber corneal suture needles 7 mm. size.
(iv) Black silk suture -No. 000 British or No. 6xo American.
Method I :
A small triangular piece of conjunctiva with its base to the limbs at 12 O'clock, is excised and a small dotted mark of gentian violet is made on the sclera exactly at 12 O'clock, before making the incision [Figure - 1].
After the corneal incision and iridectomy have been done a threaded suture needle is passed through the anterior lip of the incision ½ mm. inside its anterior edge, exactly opposite the dotted mark [Figure - 2].
The point of the needle is made to emerge at the upper border of the anterior lip of the incision through the middle of its thickness. The needle is then introduced through the middle of the thickness of the border of the posterior lip of the incision, exactly at the dotted mark, and made to emerge mm. beyond the anterior edge of the posterior lip. [Figure - 2].
In all the 15 cases mentioned in [Table - 2], this method was applied.
Method II :
For this method a very delicate corneal suture forceps is absolutely indispensable.
Excision of the triangular piece of conjunctiva and marking of the sclera is omitted.
After the incision and iridectomy have been made the corneal suture is taken in exactly the same way as in Method I, except that the direction and point of entry of the needle through the posterior lip is determined by projecting the emerging suture (held taut) exactly in the 12 O'clock Meridian. The St. Martin's Corneal Suture Forceps is then applied contiguous to the point so projected [Figure - 3].
A loop is left temporarily on the temporal side and after the delivery of the lens the suture is made taut so as to obliterate the loop. Before it is tied the iris is properly reposited and iris repositor is passed through the lips of the incision in order to remove entangled lens matter, tag of iris or a strand of blood clot if any. The suture is then tied firmly enough to co-opt the edges of the section but never too tightly. The surgical knot is manipulated so that it sits on the posterior lip exit of the suture.
Method II was applied in all the 35 cases mentioned in [Table - 1].
| Discussion|| |
Incision way made corneal in all the 15 cases in [Table - 2] and in 29 cases in [Table - 1]. In the remaining 7 cases in [Table - 1] the incision was made limbal without a conjunctival flap for the following reasons :
Hypoesthesia of the cornea - 1
Old debilitated patients - 3
Trachomatous xerosis - 2
Prorminant arcus senilis - 1
A 2-10 O'clock incision with a cataract knife can be made slowly in the proper plane without the risk of cutting the iris. In none of the 50 cases mentioned in the series was iris cut by knife during incision.
The suture is placed after doing an iridectomy so that it may not be accidentally cut (luring the latter procedure.
In all the 35 cases in [Table - 1], the suture was introduced by Method II mentioned above. In this series there were two cases of wound leakage but in both these the incision was limbal. [Table 4] and [Table 5] give the comparative results in the two groups. It seems that more effective apposition is obtainable by employing Method I.
Posterior gaffing and wound leakage.
The experiments of Dunnington on ocular wound healing have demonstrated that in order to avoid posterior gaping of wound edges the sutures must pass through at least half the thickness of the wound edges. It is quite evident that depth of suture bite is better controlled when the suture is post-placed than when its is pre-placed. Pre-placed suture is very often likely to be placed too superficially and therefore gaping of the wound is fairly more frequent.
Cases 8 and 20 in [Table - 1] showed some evidence of posterior gaping with incarceration of iris. Pupils in both these cases were displaced upwards and anterior chambers were flat. These cases also showed wound leakage, tinder slit lamp on the 10th day. On the 10th day the sutures were removed and the leaking points were carbolized in both these cases. The shallow chambers became normal subsequently.
Gonioscopically after a month it was found that the iris prevented the view of the filtration angle in the upper segments in both these cases.
Two months after the operation the corrected vision was 6/q, without astigmatism in case 8 and with astigmatism of + 0.75 @ 30 0 in case 20. The intraocular tension was normal and the wound appeared completely healed. Case 20, however, came up 14 months subsequently for a tiny warty excrescence from the skin of the lid that obstructed his vision. That time to my surprise I found a pin point iris tissue in the otherwise firmly healed wound. The eye was however quiet and the vision remained 6/9 with the same glasses. Tension in the eye was 17 mm. Hg. Schiotz.
Case No.4 in [Table - 1] showed that the chamber remained flat till the 7th day, but became normal after the removal of the corneo-scleral suture on the 9th day. In none of the 50 cases in the series did the anterior chamber flatten on removal of the suture; a complication that has been reported by Hughes and Owen (1947) in man and by Dunnington (1951) in monkeys when sutures are placed too deeply.
None of the 52 cases sutured by Method I showed any eccentricity of pupil. The anterior chamber formed either on the operation table or by the third day, that is at the time of the first dressing. Cases No. 2 and 15 in [Table - 2] however showed chamber formation not till the 5th day. In case 2, however, an iridoencleisis of Holth had been clone previous to the cataract extraction.
Except for case No. 32 in [Table - 1] there -vas no case of hyphaema in the whole series. This case in which a limbal incision was made because of very prominent arcus senilis, showed bloodtinged iris on the third day of the operation with a thin brownish exudate in the pupillary area. The patient was a case of chronic bronchitis and had developed severe cough following the operation.
Even in the hands of seasoned surgeons e.g. Stallard (1958) and Escapini (1958) hvphaema occurs in 2 to 3% of cataract operations when the incision is limbal. A corneal incision is the only effective way to prevent this complication.
Case No, 20 in [Table - 1] already described, was the only case of iris prolapse that occurred several months after the operation. Here the incision made was limbal because of the trachomatous xerotic conjunctiva. It is possible that the spur of the posterior lip effectively guards against iris prolapse and therefore the prolapse is rarer with corneal than with limbal incision.
Case No. 7 in [Table - 1], a diabetic developed high tension 15 days after needling for the after-cataract. Following cyclodialysis and under pilocarpin the tension has remained 22 mm. Hg Schiotz to date.
Case 3 in [Table - 2] was operated for hypermature cataract. Preoperatively tension in each eye was 19 mm. Hg.Sch. Three months after of acute glaucoma in other eye following accidental instillation of atropine eye drop in that eye instead of in the operated (left) eye. The glaucoma was controlled with miotic eye drops and acetazolamide.
8 months after the operation tension in the operated eye was found to be 40 mm. Hg. Cyclo-dialysis was ineffective and cyclo-diathermy was advised but the patient refused any further operation on the eye; and thereafter attended irregularly.
2 1/2 years after the operation tension in the right eye was 25 mm. Hg. and in the left eye was 40 mm. Hg.
In view of the high tension in RE (under mydiatic), it is probable that the glaucoma in the operated eye might not be post-operative secondary glaucoma but a primary glaucoma that escaped detection for lack of detailed examination for glaucoma.
| Results|| |
[Table 4] and [Table 5] give the operative results of the cases in [Table - 1] and [Table - 2] respectively.
Out of the 35 cases in which sutures were applied by Method II there were two cases showing leakage of the wound and posterior gaping. In 26 of the 29 cases in this series as also in the 15 cases in [Table - 2] where the incision was corneal, A.C. formed either on the operating table or by the third post. operating day. While in the remaining 7 cases with limbal incision there were 2 cases of wound leakage and/or posterior gaping. Out of these 7 cases one had hyphaema on the third post-operative day. Striate keratitis appears to be more frequent when the incision is corneal.
One case of post-operative glaucoma in this series followed cyclitis after needling; while the other in the other series [Table - 2] was really a case of chronic simple glaucoma with cataract. There was no significant difference in the amount of post-operative corneal astigmatism between limbal (average .82D) and purely corneal incision (average .98D).
| Summary|| |
(i) The present day complications of cataract surgery are mainly those due to defective wound healing.
(ii) Corneal incision made in the proper plane and sutured accurately with post-placed sutures healed uneventfully.
(iii) Hyphaema and Iris Prolapse are totally eliminated while the incidence of post-operative glaucoma due to blockage of filtration angle is much reduced, when incision is made in clear cornea.
(iv) Two methods of post-placed corneal suturing have been described in detail.
| References|| |
Callahan A. (1950, South .
Med. J 44, 179.
Dunnington (1951), Amer. J. Ophth., 34, 36.
Dunnington (x952), Amer. J. Oplith., 35, 167.
Dunnington (1955), Trans. Ophth. Soc. of U. K. 75,
Dunnington (1957), Amer. J. Ophth., 43, 667.
Dunnington and Regan (1958) Arch. of Ophthal. 59, 315
Escapini (1958), Arch, of Ophthal.. 59, 653.
Hughes and Owen (1947), Arch. of Ophth. 38, 577.
Miller, Keskev, Becker (1957), Arch. of Ophth. 58, .101.
Stallard I-I. B. (1958), Eye Surgery p. 521, B. J. Wright & Sons, London.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]
[Table - 1], [Table - 2]