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ARTICLE
Year : 1967  |  Volume : 15  |  Issue : 4  |  Page : 139-144

Corneal surgery in India


Corneal Surgery Unit and Regional Eye-Bank, M.G.M. Medical College and M. Y. Hospital, Indore (M.P.), India

Date of Web Publication21-Jan-2008

Correspondence Address:
R P Dhanda
Corneal Surgery Unit and Regional Eye-Bank, M.G.M. Medical College and M. Y. Hospital, Indore (M.P.)
India
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Source of Support: None, Conflict of Interest: None


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How to cite this article:
Dhanda R P. Corneal surgery in India. Indian J Ophthalmol 1967;15:139-44

How to cite this URL:
Dhanda R P. Corneal surgery in India. Indian J Ophthalmol [serial online] 1967 [cited 2020 Dec 2];15:139-44. Available from: https://www.ijo.in/text.asp?1967/15/4/139/38795

Table 2

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Table 2

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Table 1

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Table 1

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Corneal blindness is a national pro­blem in India when we realise that of the 3 million estimated blind in the country, 650,000 are corneally blind due to the ravages of small pox and malnutrition and sequelae of trachoma and infective conjunctivitis. Worse still, these are mostly preventable causes.

To an ophthalmic surgeon it poses two problems. Either he has to surgi­cally treat these cases or he has to guide them on proper lines which might help their rehabilitation.

The purpose of this talk is to avoid wrong conventions in keratoplasty in this country as has happened say for example in relation to cataract surgery. It takes 5 years for a new thing to be accepted but it takes 25 years for old conventions to die out.

It is ironical that unlike other sciences, technical advances in kerato­plasty preceded the scientific under­standing of the subject. That is why it is often mentioned as corneal carpen­try. The WHY and HOW of graft failures have only started being under­stood very recently. That cornea iso­lated from the donor eye and before being finally accepted or rejected by the host can live on its own reserve of nutrition even upto 15-20 days, ex­plains that grafts unless technically complicated mostly remain transparent during the first 15 days. The critical period of life and death of donor graft from a physiological point of view is therefore the end of the third week when tissue exchanges with the host surroundings have started and donor cornea becomes dependent on the mercy of the host. Any reactions of tissue incompatibility are therefore most frequently observed about this time. It is correctly said that if a graft has remained transparent for one month after operation it is most likely to remain so for the rest of the life.


  Etiological Considerations Top


The common etiological factors for corneal pathology in India, you will appreciate, are radically different from those in Western countries. If one went through the literature, a lamellar kera­toplasty is most frequently done for herpetic keratitis and epithelial dys­trophy and a penetrating graft for kera­toconus and Fuch's endothelial dys­trophy, interstitial keratitis having been excluded from the clinical picture by steroids and antibiotics. The pro­blem that you and I have to face are however radically different. We in India know that infected corneal ulcers, trachoma, small pox and mal­nutrition are the conditions for which corneal grafting is most frequently re­quired.


  Age considerations Top


Nearly 60% of the causes of corneal opacity have their origin before the acre of 12 years, and this poses a ques­tion, how soon can corneal grafting be safely done. It is commonly advised that a child with corneal opacity should better wait till he grows up to adoles­cence but it is little realised that the introduction of nystagmoid movements and a concomitant squint will seriously jeoparadise the visual recovery in that case. To be more precise, 113 out of 571 recipients during 1963-64 i.e. 19.5% were considered unsuitable by us because of associated squint or nys­tagmus. I may emphasize that the history of onset of pathology is ex­tremely important because a pathology developing after the age of 15 years and ocular deviation if present is likely to be a heterophoria temporarily con­verted to heterotropia but of a rever­sible nature and therefore of good visual prognosis.


  Depth and Density of the Corneal Opacity Top


Another difficulty is the preopera­tive assessment of the depth of corneal opacity. You will often experience that you plan a lamellar surgery for a superficial looking opacity but on dis­section leave behind an unexpectedly large amount of deeper extension. There are occasionally pleasant sur­prises also that a dense looking opacity may not have extended more than 0.3 mm. in depth, so that a slit lamp ex­amination is imperative for a proper assessment of this point. One should of course realise that in total corneal opacity judgment may have to depend more on intuition or observations dur­ing actual surgery.

I may also emphasize the falacy of applying a tonometer on a scarred cornea. This is still more undepend­able in adherent leucomata and par­tial staphylomata. It is therefore wise to presume a raised intraocular tension in all cases where more than half the angle of anterior chamber is narrowed.


  Vascularisation Top


70% of long standing corneal opa­cities in India are vascularised, tracho­matous or non-trachomatous. Vascu­larisation therefore is a matter of con­sideration in the assessment of suit­ability of corneal surgery. A pre-ope­rative intensive antitrachoma therapy in trachomatous cases, help of steroids and peritomy in more pronounced vas­cularisation should adequately help making the case more suitable and operable. It may be mentioned that radiation as a pre-operative therapy is now considered a disadvantage.

It is thus to be appreciated that ad­vice for keratoplasty cannot be very lightly given. Observations that I have made should help my ophthalmic col­leagues to study the case before under­taking a corneal surgery or advising the same.

Accurate projection of light in all directions of gaze is imperative for consideration of corneal grafting or for that matter any surgery on the eye. Similarly it is important to widely dis­seminate to the lay public that corneal transplantation is not transplantation of the eye ball as a whole. It will re­lieve us of a great strain and avoid disappointment to the patient if it was well understood that transplantation of an eye ball is not a practical proposi­tion nor is it likely to be in near future because of the peculiar physiology of the optic nerve.

"When to do and when not to do a keratoplasty".

In the sea of corneal blindness in this country, the most deserving indi­cation of corneal grafting is a patient with bilateral corneal scars of an active corneal pathology. Corneal grafting will not be rewarding surgery even if successful in long standing uniocular pathology if the vision in the other eye is 6/12 or better because the bino­cularity of the vision in such cases is a difficult and slow process. Again in cases with one eye totally blind, phthi­sical or staphylomatous, and the other with a gross leucoma adherens, pene­trating kerotoplasty should be under­taken with great hesitation and only after carefully balancing the prospect of good visual recovery if all goes well, and losing what the patient has if an unexpected complication ruins the graft. Prudence may some­times lead us to an optical iridectomy rather than a penetrating surgery in such cases. Except this one indication, an optical iridectomy should be con­sidered misplaced eye surgery. An en­thusiastic iridectomy of a big size is a great hazard during penetrating surgery responsible for anterior dislocation of lens through a large ragged coloboma and difficulty in injection of air and restoration of anterior chamber at the end of operation. It is important to emphasize that iridectomy should not be done in any case where corneal grafting can be a consideration at the time or in future. The gravity of the problem will be evident to you when I tell you that 66 out of 571 cases referred to us, (11.5 0%) had a big iridectomy coloboma and this was a cause for our hesitation for surgery in those cases.

I may also explain what I have often called and which is being more often accepted, "mercy keratoplasty". Who can refuse surgery when one eye is incurably blind and the other eye has a partial or a total staphyloma with perfect projection of light. A situation like this particularly in a developing child is an every day challenge in India and will need a total penetrating keratoplasty which means replacement of the whole cornea, removal of all tags of iris and extraction of lens even if transparent. It is a surgery which has a prospect of improvement in not more than 10-15% of cases. Often the graft may remain perfectly transparent, but a deeply cupped atrophic disc discover­ed after surgery may explain the failure in improvement of vision. However the excitement of an occasional suc­cess is an ample reward where nothing else could have been done.

There is also a distinct place for cosmetic keratoplasty in India where rehabilitation in life may be as import­ant as the rehabilitation of blind. Cos­metic surgery must however be limited to lamellar surgery because penetrating surgery may in some give positive re­sults while in others may make it cos­metically worse.


  Surgical Consideration Top


The days of 4 and 5 mm. size grafts are a past history and in the patholo­gies like the one we face in this coun­try, it should have still less considera­tion. These small grafts were done when means of securing a graft were the cris-cross overlying stitches or sup­port by an amniotic membrane or a conjunctival flap. The common size of a penetrating graft should be 6.5 or 7 mm. and may have to be even 8 or 9 mm. or even more in cases of sub­total and total penetrating grafts. A lamellar graft should preferably be 8 mm. in size and 9 to 11 mm. is an equally practical possibility. These large sized grafts can however be se­cured only by direct edge to edge stitching because that alone can help attaining the final step of surgery, that is restoration of anterior chamber on the table by injection of air or saline, a step if not attained will account for at least 50% failures. To accomplish this, a stitch every mm. in a penetrating graft is necessary and is an acceptable possibility with the fine needles and finer silk now available. The import­ance of this statement can be assessed from the following table:

A lamellar graft can however be more lightly undertaken. In properly selected patients lamellar graft should be the first choice when it can serve even a limited purpose as compared to the risky penetrating surgery. A lamel­lar dissection is surgically a more intri­cate procedure but a fascinating piece of surgery in conditions like epithelial dystrophies, scarred trachomatous cor­neas in quiet eyes and in cosmetic in­dications. A donor therapeutic tissue effect on the resolution of the deeper opacity that may not have been includ­ed in lamellar dissection of recepient cornea is a known biological pheno­menon. An eye operated by lamellar keratoplasty may look very much dif­ferent 6 months to a year later.

Surgery for a recurrent pterygium of a malignant type has taxed the inge­nuity of eye surgeons for long the pa­tients having been operated repeatedly by best of eye surgeons. There is no final answer. A deep dissection of the pterygium and a partial peripheral corneo-scleral lamellar grafting follow­ed by repeated doses of β-radiation is, I think, best when everything else fails.


  Post-operative Complications and Results Top


Anterior synechia to the graft mar­gin is a most potent danger to the transparency of a graft. A larger inci­dence of post-operative iridocylitis in India should be anticipated because of flaring up of hidden septic foci in the body which are difficult to detect and often impossible to erradicate. A per­sistent iridocylitis will cause endothe­lialitis leading to a very disturbing complication like a bullous kerato­plasty.


  Results of Corneal Grafting Top


Results of corneal grafting depend on the clinical condition of the cornea for which it is planned and on the type of surgery that is undertaken.

Penetrating surgery will undoubtedly have a better outlook in simple partial leucomatous opacities with minimal or no anterior synechia and where a round pupil can be maintained after synechio­tomy. More extensive the iris incar­ceration, poorer will be the result. Other intraocular changes like a cata­ractous lens and degenerative changes in posterior segment NOT discovered before surgery will materially influence the results. Lamellar grafting however is very safe surgery and carries, where suitably indicated and performed, a high degree of success.

I want to emphasize that the state­ment `Graft has taken' is not only mis­placed but is deceiving one's own self. Every graft `takes', stitches or no stitches because of the gluing secretions of the raw corneal edges. What is im­portant is whether the graft remains transparent or has become cloudy. Kerato-plasty could be as confidently undertaken in children as in adults, provided a good anesthesia is available and the surgical considerations are ap­propriate and where possible, a lamel­lar surgery should be preferred in children.


  Eye Bank and the Donor Material Top


An eye bank is an incompletely un­derstood term. It is an organisation where donor human eyes are received, processed and made available to cor­neal surgeons. An eye bank is also a research organisation in experimental studies aimed at prolonging the viabi­lity of donor cornea. It is also a centre of training to the paramedical staff, and a nucleus of organisation for publicity of donation of eyes. The position till todate is that a fresh donor cornea re­moved soonest after death and used within 24 hours, occasionally longer is alone a suitable donor material for pe­netrating keratoplasty. The viability of donor cornea depends on the viability of its endothelial layer which in turn is influenced by factors like the cause of death of donor, the environmental conditions in which the body was lying till the eyes were enucleated, the sea­sonal variations of tropical climate and the interval between death and enu­cleation and between enucleation and surgery. For lamellar surgery how­ever, a donor eye can be used after much longer periods of preservation. Excised corneas preserved in glycerine and molecular sieve can be used for lamellar surgery even after 6-9 months of preservation at room temperature or ever longer.

Having made the long subject a really short story indeed it is not for me to say, "who should do corneal grafting?" I would only state that dexterity in cataract surgery, special instrumentation and practice in their use and willingness to face and handle complications are the foundations of a good corneal surgeon. The rewards of corneal surgery are as great as the stakes and it should be a profession rather than fulfiling a curiosity. No surgery is more unpredictable pre­operatively, no surgery involves more uncertainties on the operation table, no surgery is more out of control of the eye surgeon once the patient has left the operation table and no surgery is more uncertain in the final outcome. The surgery invites popularity but it should be a popularity which is not run after but which is born of justice in pursuit of noble ends by noble means.


  Summary Top


In this lecture the following aspects of keratoplasty have been dwelt upon:

1. Etiological and age considera­tions with special reference to Indian conditions.

2. Indications for penetrating and lamellar keratoplasty with reference to vascularization and depth of opacity, and their limitations.

3. Cosmetic and "mercy" kerato­plasty.

4. Techniques and results.

5. Eye banks and requisites of a good corneal surgeon.



 
 
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