Year : 1990 | Volume
: 38 | Issue : 3 | Page : 139--144
Radial keratotomy in India untoward consequences and complications
RP Dhanda, V Kalevar
R P Dhanda
R.K. is a surgery of tomorrow. It is still in the stage of evolution. It should be under-taken only for precise indications. Case evaluation and honest advice to the patient is important. The patient should be explained that the worst can happen. The surgery should be limited to moderate degrees of myopia, not less than -3.0 D sphere and not more than 8 to 10 D. It has no place for myopia with degenerative retinal changes. Surgery should be interrupted at the first sign of a significant operative complication. It will be unfortunate if a healthy eye is lost due to complications of R.K. done with indiscriminate approach and ignorance of possible post-operative consequences.
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Dhanda R P, Kalevar V. Radial keratotomy in India untoward consequences and complications.Indian J Ophthalmol 1990;38:139-144
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Dhanda R P, Kalevar V. Radial keratotomy in India untoward consequences and complications. Indian J Ophthalmol [serial online] 1990 [cited 2022 May 17 ];38:139-144
Available from: https://www.ijo.in/text.asp?1990/38/3/139/25520
There are a few important considerations in the evolution of Radial Keratotomy Surgery:
(1) No surgery has been publicised the world over as R.K. Fullpage advertisements in the press were and continue to be a medium of public education consequently creating a public pressure on the ophthalmologists. Statement like "all optical shops will close down if R.K is adopted by all Eye Surgeons" is a misplaced and misguiding statement to make.
(2) R.K. is a surgery on a healthy eye and on healthy cornea of an eye which improves to vision 6/6 with contact lens or with glasses. The surgery therefore does not permit scope for complications. This is the reason that ophthalmologists have not been enthusiastic to take up this surgery and are waiting for newer methodology to minimise the chances of complications and the unpredictability of results.
(3) R.K. in India is primarily a demand for social rehabilitation in majority of cases, further misguided by a comment by the surgeon that it is an out-door surgery and helps give up glasses in all cases.
Radial Keratotomy practised at present is the result of increasing incidence of myopia and an anxiety to find a permanent answer to cure it rather than treating it with glasses or by contact lenses. Removal of the transparent crystalline lens was for long considered a treatment to neutralise myopia. Sato (1953) developed a surgery with a corneal approach to cure myopia. It was however Fyodorov (1974) who gave the extensive publicity to convince the public and the profession for adoption of his technique of radial keratotomy for moderate degrees of myopia which affected a large urban and literate population the world over and high minus glasses were considered a cosmetic and optical handicap. Contact lenses were cosmetically better but economically taxing. The U.S. Government considering the increasing demand for this new surgery organised a multicentre collaborative 5 years' study called "Prospective Evaluation of Radial keratotomy(PERK) study in 1979, the report of which was available in 1984. The follow up of the study is being discussed in the literature.
The complications of radial keratotomy as practised by Fyodorov and adopted by PERK study are listed in three groups:
(1) Transient complications, present in most cases but resolve within a few months. These include pain in the eye, photophobia, persistant glare and diurnal fluctuating vision.
(2) Complications which persist longer but are mild in nature: i) under-correction of myopia. ii) over-correction of myopia. iii) thick incision scars. iv) blood vessels along the R.K. scars v) secondary astigmatism.
(3) Complications which are damaging and can make the eye worse than before: i) corneal perforations described as micro and macro perforations have been reported in 2.29% of PERK series but none of them needed suturing or termination of surgery. ii) unpredictable poor visual results.. iii) infection.
We have been referred a number of cases where radial keratotomy was done and eyes developed complications involving the cornea, the lens and causing raised intraocular tension, not reported in literature. These are:
i) anterior synechia to R.K. scars. ii) iris prolapse. iii) secondary glaucoma iv) cataract. v) gross damage following attempts at surgical repair.
Most of these complications, we have observed, are due to: a) asymetrical incisions unequal in extent, depth and often obliquely placed. b) perforation at operation, ignored by the surgeon. c) secondary glaucoma. d) consquences of secondary surgery following R.K. complications. e) infection.
Only a few representative cases are reported to emphasise that R.K. is a surgery which should not be taken lightly and every cave should be made to prevent complications rather than to have to treat complications.
(I) ASYMETRICAL AND IRREGULARLY SPACED INCISIONS
a) S.18 years male Uniocular myopia L.E.-7.0 Dsp, R.K. Done L.E. 8-6-84. Incisions irregulary placed, some short ending 3 mm from limbus, some long encroaching the pupilarly zone.
Post-operative : (1-7-88)-Vision L.E.1/60-8-0, retinoscopy L.E. -10.0 irregularly placed, no improvement with glasses.
Poor surgery, no benefit to patient, myopia increased
b) P.26 years male
Myopia R.E. -1.5 Dsp, L.E.-6.0 Dsp.
Identical R.K. procedures done in both eyes at the same sitting.
R.E. became hypermetropic by +1.5 Dsp, L.E myopia reduced to -2.5 Dsp.
Surgery done disregarding the anisometropic myopia, anisomemetropia after operation worse than before operation, patient regretted having gone for surgery.
c) A Jain Muni, 48 years, male
Myopia both eyes -2.5 D sp. Using glasses only for distance, R.K. done in both eyes at one sitting.
Eyes became hypermetropic by +1.5 D sp after R.K. Patient now needed glasses both for distance and near.
(II) R.K. DISASTERS:
Worse are the complications where the eye was perforated, perforation was neglected, flat anterior chamber persisted, anterior synechia developed and the result was secondary glaucoma.
Still worse are the cases where R.K. was either not indicated or should not have been done and result was loss of the eye.
(a) S.27 years Female
Pre-operative myopia: RE -7.0 Dsp, LE - 8.0 Dsp.
R.K. done November 1983 both eyes in same sitting. Perforation in B E at operation resulting in anterior synechia and secondary glaucoma in both eyes. Filtering operations for glaucoma were done both eyes, same sitting,10 days after radial keratotomy.
Vision both eyes reduced to : RE-PR 4+, LE CF 2 Ft No improvement with glasses.
FIRST EXAMINED BY AUTHORS ON 6-3-1985.
RE Irregular R.K. scars more than 30 in number. Majority of the scars were obliquely placed crossing the limbal circle and some encroaching the pupillary zone. Anterior chamber absent. Iris plastered to posterior corneal surface at places. Central corneal opacity. Large glaucoma filtering bleb at 12 O'clock.
LE Irregularly irregular R.K. Scars. Central corneal opacity A.C. shallow, Ant. synechia to the R.K. Scars. Organised exudates in the pupillary area. Large filtering glaucoma bleb.
MANAGEMENT BY AUTHOR
RE Penetrating corneal graft 7 mm done on 7-8-85 During operation, some R.K. scars started gaping and were sutured. Anterior synechia separated at operation. Exudative membrane in the pupillary area peeled off. Cataractous lens removed. Vitreous presented and aspirated. Graft remained clear for one month, then became oedematous andopaque.
A re-graft, 8.5 mm done on 12-2-86 (on an aphakic eye.)
A second regraft was done on 7-8-87. This graft remained clear but vision did not improve beyond CF 2 Ft. because of previous intraocular complications.
A disastrous result of R.K. done on both eyes at the same sitting. Perforations in both eyes were neglected. Glaucoma surgery done on both eyes instead of treating the cause of secondary glaucoma. The patient has suffered an irrepairable loss of vision in both eyes and became cosmetically seriously handicapped.
(b) V.9 years child
Pre-operative myopia not known. R.K. done both eyes same sitting on 22-6-86. First seen by the authors on 8-8-86 (6 weeks after RK). Patient had severe photophobia both eyes. Vision record not possible. Anterior segment examination was possible only under general anaesthesia.
R.E. Irregular R.K. scars extending beyond limbus. Central cornea in the pupillary area melted out. Exposed iris covered with organised membrane.
L.E. irregular R.K. scars. Diffuse corneal haze. Ant.synechia to R.K. scars at places. A.C. shallow. Secondary cataract.
MANAGEMENT BY AUTHORS
Penetrating graft done RE on 10-8-86.(8.5 mm donor on 8.0 mm recipient window). Iris was densely adherent to the cornea, separated with difficulty. Exudative membrane peeled off from the pupillary area. Graft has remained clear with few posterior synechia and thin anterior capsular lens opacity. Vision with -2.5 Dsp improves to 6/60.
Disastrous result of radial keratotomy. Child should not have been operated at this age because myopia would have been in progressive phase at this age. Perforation at operation in both eyes were neglected. Melting of cornea in the RE needed an emergency corneal graft. Patient is partially rehabilitated by corneal graft RE, and is awaiting P.K. left eye.
C.L. 37 years male
Pre-operative myopia not known. R.K. done both eyes same sitting in October 1985. Glaucoma surgery B.E. done December 1985.
SEEN BY AUTHORS ON 30-1-86 RE Good optical result.
Vision 6/12 without glasses.
R.K. scars irregulary placed. Filtering blebs at 12 O'clock
LE Corneal scars irregular and encroaching pupillary area Cornea oedematous. Iris prolapse through lower cornea. A.C. absent. Filtering glaucoma bleb at 12 O'clock. Pupil occluded with organised membrane. Ultra-sonography suggestive of a cataractous lens.
MANAGEMENT BY AUTHORS
Penetrating keratoplasty done LE on 10-2-86. (11.0 mm donor on 10.5 mm recipient window). Exudative membrane peeled off the pupillary area. Iris diaphragm maintained intact. Cataractous lens removed. Graft oedema ++ with deep vascularisation. A.C. well formed. Chronically inflamed iris caused graft failure. Advised regraft but patient did not report back.
One eye benefitted by R.K. but other eye had a disastrous result. Glaucoma surgery done rather pre-maturely.
N.18 years female
Pre-operative myopia both eyes only -1.5 Dsp Vision both eyes 6/6 with corrections. R.K. done both eyes at the same sitting on 24-5-86. Infection on fourth postoperative day in RE. PK done on the RE by the RK Surgeon 2-8-87 resulting in opaque and scarred cornea. lensectomy done (by the RK surgeon) on 10-6-87.
SEEN BY AUTHORS ON 1-7-88.
RE Opaque graft
LE Vision 6/6 without correction, 8 incisions marks, unequal in depth and asymetrically placed.
Patient should not have opted for R.K. Surgeon should not have offered to do R.K. Patient could do without glasses and instead lost vision in one eye and invited a cosmetic disaster.
Most of the untoward results and complications following R.K. seen by the authors in the last 5 years were in cases operated by the same surgeon. The paper includes results of R.K. done without consideration to the optical status of the eye, cases where incidents at operation were overlooked and cases where post-operatively the eyes became worse than before. The observations have been from simple surgical errors to most tragic complications.
(1) IRREGULAR INCISION MARKS:
The irregularities noted are:
(a) Number of incisions not related to degree of myopia. (b) Incision marks not equidistant. (c) Incisions encroaching optical pupillary zone. (d) Incisions going across the limbus with blood vessels growing along the incision scars.
The result of irregular incisions were:
(1) No improvement following surgery. (2) Introduction of corneal astigmatism when there was none before operation. (3) Vision becoming poorer than before surgery.
It is important that in countries where trachoma prevalent, the incision should not encroach the limbus from where new blood vessels can grow along the incisions which will result in evident scarring and cosmetic blemish. The incisions for R.K. in tropical countries and in countries where trachoma is prevanlent should end at the intra-limbal zone.
Micro perforations have been reported by various surgeons practising R.K. and discussed by Dietz et al in 1984. As long as the anterior chamber maintains its depth and the eye does not become hypotonic, the micro-perforation may not cause damage. (Waring et al 1985.) It however invites possible consideration for interruption of surgery and its postponement.
Macro perforations, reported by Rowsey et al 1983 in 9 out of 102 cases of R.K. is however a different proposition. The surgery should be interrupted, the perforations should be sutured and anterior chamber restored.
Gross perforations neglected at operation are followed by anterior synechia and secondary glaucoma which are responsible for serious consequences reported here.
The worst case was melting of the optical zone of the cornea following multiple perforations near the pupillary zone resulting in ischaemia and necrosis of the central cornea.
(3) Secondary glaucoma
Secondary glaucoma is a serious complication and usually the result of neglected perforation at operation and its consequences. Anterior synechia to the corneal perforation, exudative iritis and secondary cataract add to the cause of raised intra-ocular tension.
It is important to prevent a secondary glaucoma by identifying a perforation at the earliest and saving the eye from its consequences by interrupting surgery, suturing the perforations if necessary and restoring the anterior chamber by injection of air or saline on the table.
Secondary glaucoma should be treated conservatively and one should not rush the eye to glaucoma surgery because the glaucoma is secondary and the treatment should be directed to the factor which has caused secondary glaucoma like anterior synechia.
A post-operative infection is a most unexpected and disastrous complication. Although an ambulatory surgery, R.K. should be done with complete aseptic precautions. Clean corneal incisions get epithelialised soon and therefore there is very little chance of infection except due to negligence and carelessness.
(5) Irrepairable loss of vision
This is the result of any of the above complications made worse by damage to the tissues in the posterior segment and loss of function of retina and the optic nerve.
This should be a rare situation following R.K. surgery and is tragic indeed because the patient came for giving up glasses and returned with loss of vision and grossly damaged eye.
Prevention of complications
As already mentioned, some complications are inevitable in an surgery. Complications which make the eye worse than before are however a serious consideration. It is extremely important that in a cosmetic and socially rehabilitative surgery like Radial keratotomy, complications are to be prevented. The most important considerations are:
(1) A careful case selection. One should not advise R.K. in every myope. Indications should be only cases where an optical or a social rehabilitation is extremely important.
(2) A precise evaluation of the case by pachometry is important to prevent undesirable complications.
(3) The surgeon should be fully trained and conscious of his responsibility of operating on a healthy eye. There is no scope for making a patient worse than what he was before operation.
(4) Readiness to interrupt surgery at the first sign of a macro perforation should be uppermost in the : mind of the surgeon.
(5) The surgery should be done only under an operating microscope and in a unit properly equipped.
(6) Surgery should not be done in both eyes at the same sitting. It is still more important if there is a perforation in the first eye at operation.
(1) R.K. does reduce myopia but the results are unpredictable and variable.
(2) R.K. should not be done simply because the patient wants it. The risk factor should be very carefully evaluated and explained to the patient.
(3) Case study and evaluation should be practised with emphasis on history of myopia and its progress.
(4) R.K. should not be done for myopia of less than -3.0 Dsp. of fear of making the eye hypermetropic.
It has very limited scope in myopia of more than 8 to 10 D. It is contra-indicated in degenerative myopia.
(5) Operative complications if any should be identified and taken care of promptly. This is obligatory where the perforation is large.
(6) Any repair of the complication should be undertaken immediately and not postponed to a later date.
(7) There is no place for mis-placed enthusiasm or complacency on the part of the surgeon.
RELEVANT REFERENCES OF RADIAL KERATOTOMY
|1||Sato T et al- "Anew surgical approach to myopia" Am. J. Opthal. 36, (1953).|
|2||Fyodorov S.N. "Operation of Dosaged Dissection of corneal circular ligament in cases of myopia of a mild degree" Ann. Ophthal 11-(1979)..|
|3||Waring GO. et aI-"Retionale for and design of PERK study" Ophthalmology -90(1983)|
|4||Waring G.O. et al- "Results of PERK study-one year after surgery" PERK cordinating centre, Emory clinic, 1365-clifton Road, NE Atlanta GA. 303221984|
|5||Rowsey J.J. et al- "Preliminary results and complications of radial keratotomy". Am J. Ophthal-93-(1982)|
|6||Deitz M.R et al-"Radial keratotomy, an overview of Kansas city study"-Ophthalmology 91-(1984)|