Complications of refractive surgery - A nightmare to a corneal surgeon

D.C. Bansal, Neelima Sodhi & J.P.S. Sodhi
(Dr. Bansal Eye Institute & Research Centre, Patiala)

The current status of refractive surgery is mainly based on invasion of corneal tissue. Cornea is a unique delicate wonder of nature. It is so thin, perfectly transparent, bloodless and has a smooth surface. At all times it is exposed to hot and cold winds and still it resists all infections. For ametropia, cornea is very rarely at fault but still it gets the beating. Various refractive procedures came with a huge bang but faded away with passage of time due to serious corneal complications. The procedures in earlier days were:

This involved placement of a lenticule on or within cornea to alter its refractive power usually by changing its anterior curvature. Epikeratoplasty is graft on top of cornea, Keratomileusis is carving the cornea, Keratophakia is lens in the cornea, Keratectomy is excision of a piece of cornea, Penetrating Keratoplasty is transplantation, Thermokeratoplasty is application of heat

Radial keratotomy was considered as a revolutionary procedure in late seventies and early eighties. Millions of operations were done and there was mad rush to practice this procedure. Intraoperative complications were normally underplayed by surgeons. Post operative complications encountered were:

Mild like : Glare, Diminished night vision, Photosensitivity, Undercorrection, Overcorrection, Distortion of image perception.

Major like peratitis : reputured Globe, cataract due to heavy corticosteroids, transient Central Corneal steepening even leading to Keratoconus, Glaucoma and Corneal recurrent erosions, incision cysts.

The later version of Mini R.K. and Midi R.K. with shorter incision though do not suffer from major structural weakening of cornea as compared to earlier forms of R.K. but other complications were still encountered. The opinion of Webmaster that standard R.K. has too many risks as cornea is seriously weakened and frequently continues to change shape with time. The introduction of PRK came as the operation of choice.

Early nineties saw the advent of Photorefactive Keratectomy. Rather than making cuts in the cornea the PRK process uses an Excimer Laser to sculpt an area of 5-9mm in diameter and upto 30% thickness on the surface of cornea. Although PRK sculpts only a partial amount of tissue from the surface of cornea but the all important and resistant Bowmans membrane was sacrificed.

Late onset Haze associated with Keratoconjunctivitis, Keratitis leading to gross distortion of corneal contour, Bacterial Keratitis, Central steep islands after PRK, inflammatory cell invasion and tissue reactions leading to permanent corneal haze, Disability glare as a result of change of corneal topography and haze after PRK, Anterior chamber flare. Endothelial cell loss.

PRK surgeons claimed 100% success in the field of refractive surgery. The complications were noticed but ignored may be for commercial reasons. This euphoria lasted for few years and now LASIK YUG has come.

It is more complex procedure than PRK. The surgeon uses a microkeratome to cut a flap of corneal tissue, removes the targeted tissue beneath it with laser and then replaces the flap. Skill of surgeon is important in Lasik as compared in PRK.

Surgical, Post operative and Refractive

Surgical a complications related to use of Microkeratome are:-

Epithelial complication, Bleeding, Thin flap, Button hole, Free flap, Corneal perforation, Incomplete cuts and irregular cuts, Corneal abrasion and Decentered ablation 2-6%

Post operative complications are :-

Flap detachment-(10%), Epithelial ingrowth-
(2-7%), Diffuse Lamellar Keratitis (DLK), F.B's under flap, Infection with serious complications, Melting of flap after extensive epithelial ingrowth and partial Keratolysis.

Refractive complications are :-

Decentration, Central steep islands-Keratoconus, Halos and glare, Decreased night vision, Loss of 2 lines BSCVA-4-9%, Error of +1D in 47-86%

Lasik, the latest craze in refractive procedure is not exempt from Corneal complications. Being a relatively new procedure not many cases of corneal complications have presented to us. But still stray cases of serious complication do present occasionaly.

An interesting event came across of a young man who underwent lasik in both the eys. A few months later he died in a road accident. His parents very sentimently donated his eyes for PKP. The history of lasik was not revealed, the examination of the donor eyes revealed a clear and healthy cornea of both eyes with no suspicision of lasik. But on applying the trephine on the epithelial surface, the lasik flap just separated and PKP had to be postponed.

Also we have to ponder on the possibility of late complications which may appear after many years. We have removed almost anterior 2/3 thickness of the cornea leaving behind a little more than 1/3 thickness to do the function of the full thickness cornea. After all, nature has given just the right amount of tissue to do the body function, how can we expect to defend the eye with the reduced thickness. Many workers have reported the development of keratoconus in many of these eyes. There are also reports of loss of endothelial cells during the laser procedure. The procedure may be reasonably safe and effective but

should be undertaken cautiously and judiciously balancing the need of the patient and the risk that can be taken i..e cost benefit ratio.

1. Sanders, Haufman-Refractive Corneal Surgery printed by Jaypee Brothers page 21-25, 1989.

2. Sandeep Jain, Dimitri T. Azar-Eye infections after refractive keratotomy, Journal of refractive surgery Vol. 12 (1) Jan/Feb. 1996.

3. Kurt A. Buzard, Bradly R. Fundingsland, Transient Corneal Steepening after R.K. Journal of Refractive Surgery Vol. 12 (4) May/June 1996.

4. Ashram Amayan, Ahmed Tawfik Ali: Bacterial Keratitis after PRK-Journal of refractive surgery Vol 12(5) July/Aug 1996.

5. Alfredo Castillo, Francisco Romero-Management and treatment of central steep Islands after Excimer Laser PRK. Journal of refractive surgery Vol 12(6) Sept/Oct 1996.

6. Roberto Pineda, Jonathan H. Talamo-Late Onset haze with Viral Keratoconjunctivitis following Photorefractive Keratectomy. Journal of refractive surgery-Vol 14(2) Mar/April 1998.

7. Anita Panda, Namarata Sharma, Abhujan Kumar, Ruptured Globe 10 years after R.K., Vol 15(1) Jan/Feb 1999. Journal of Refractive surgery.

8. Jorge L. Alio, Jaun J. Peroz Santoja-Post operative inflammation Microbial Complications and Wound Healing following Laser in situ Keratomileusis-Journal of refractive surgery. Vol 16(5) Sept/Oct 2000.

9. Shard Lakhotia-Complications of Lasik Laser-Ophthalmology Today Vol 11 No. 3-4, May-Aug 2001 Jan.

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