Weakened Corneas

"Ruptures along RK incisions occurring 7and 10 years after RK suggest that some eyes with RK may never re gain full strength. Therefore, in addition to the commonly accepted risks inherent in RK, the potential candidates for RK must be apprised of the increased risk of ruptured globe after blunt trauma."

Ruptured Globes Following Radial and Hexagonal Keratotomy Surgery
(Arch Ophthalmol. 1996;114:129-134).

Paul F. Vinger, MD; William F. Mieler, MD; James H. Oestreicher, MD; Michael Easterbrook, MD

"Persons with occupations or, hobbies that increase the risk of trauma to the eyes should be excluded. This would include boxers, karate practitioners, race car drivers, etc." 

Dr Charles Casebeer, Incisional Keratotomy - 1995

"Radial keratotomy is a procedure that may permanently alter the corneal epithelium and endothelium, that certainly does scar the stroma, and that demonstrably weakens the eye wall's resistance to blunt trauma."

Dr Irving Schwab, Refractive Keratoplasty - 1987

Air Bag-related Corneal Rupture After Radial Keratotomy

Goldberg M., Valluri S. and Pepose J.

Amer Jour Ophthalmol , 120(6):800-802, 1995 Dec.

The authors report a case: a 29 year old state police officer status post 8 incision RK (to the limbus) with 3.0 and 3.5 mm optical zones was involved in a MVA at 35 miles per hour. His airbag deployed. He suffered a ruptured globe with dehiscence of 7 of the 8 RK incisions in addition to a full thickness corneal laceration. He required 31 10-0 nylon sutures for repair. Five months post operatively he achieved 20/25 vision with a comforatably fitting hard contact lens. The authors suggest PRK may be a better refractive choice for those persons at a higher risk for sustaining trauma and RK patients should be advised to wear protective lenses when driving.

Discussion:

Newer RK techniques that have larger optical zones and incisions not extending to the limbus have been reported in cadaver studies to have similar tensile strength as an unoperated eye. PRK may indeed be more advisable in persons at higher risk for trauma but the degree of myopia, planned surgical technique and surgeon skill also play significant roles when evaluating a patient for a refractive procedure.


Rupture Of Two Radial Keratotomy Incisions 19 Years Later, During A Clear Corneal Cataract Surgery

Audrey Baudot, Jean M. Perone, Adina Agapie, M Lacusteanu, P Lasota, S Kurun, H Mnasri and P J. Bertaux

Ophthalmology, Regional Hospital Center Bon-Secours, Metz, France

Commercial Relationships: Audrey Baudot, None; Jean M. Perone, None; Adina Agapie, None; M. Lacusteanu, None; P. Lasota, None; S. Kurun, None; H. Mnasri, None; P. J. Bertaux, None

Support: None Abstract

Purpose:The authors report the case of a multiple rupture of radial keratotomy (RK) incisions which occurred during a clear corneal microcoaxial phacoemulsification 19 years after refractive surgery.

Methods:Operated 19 years earlier by RK for a bilateral moderate myopia (about - 5 D), a 62- year-old woman was referred to us for the decline of her left one-sided visual acuity because of evolved cataracts. Realized in 1991, RK happened without particular incident. 4 incisions of 3mm of length and 500μ m of depth were made from the edge of the outer clear zone to the periphery, leaving a small margin of uncut cornea at the limbus. The BCV A were of 160/200 P2 for her right eye with a correction of -4.00 (0° -1.50) D and 80/200 P3 for her left eye with -7.00 ( 160° -2.75 ) D. The patient presented evolved bilateral nuclear cataracts so an indication of clear corneal cataract surgery of her left eye was retained. The scars of RK were noted down as almost hard to see in preoperative.

Results:The microcoaxial clear corneal phacoemulsification (2.2mm incision, stellaris Bausch&lomb,Rochester, NY) happened without incident until the end of the phase of divide and conquer where a sudden collapse of the anterior chamber was noted, complicated with a break of the posterior capsule. After the interruption of the operation, it appeared that both superior corneal incisions located on the axes of 70 and 110° had completely opened, explaining the collapse of the anterior chamber. After a suture of the two worn-out sections, each by two separated points of nylon 10/0, the intervention could start again and allowed a cleaning of the anterior chamber, a complementary anterior vitrectomyand a final implantation with a MTA4UO IOL of 17 D ( Alcon labs, Forth Worth, TX). Post operatively, no complications were noted. After sutures ablation 2 months later, the BCV A on this left eye was of 120/200 with a correction of -1.00 (100 ° + 2.00) D.Conclusions:Only two similar cases were described in literature: in 1998 by Budak and in 2001 by Behl. In both cases, the break of RK scar concerned only a single scar and had arisen very early after the KR for the first case (9 months later), and 11 years later for the second. Our clinical case shows that even 20 years after RK, the corneal fragility is such that a break may arise during clear corneal phacoemulsification. When the main met problem concerns today the biometric calculation of the implants, we warn against the rupture always possible of old RK incisions, even 20 years after the procedure.