A 27-year-old woman with a history of slow intellectual development had congenital cataract surgery in 1974. Her aphakic condition was handled by contact lenses that were inserted and removed by the patient's mother. In 1987, she began to experience problems with the left eye and had progressive irregularity in her keratometry with continued steepening. In 1989, she was diagnosed as having keratoconus on the basis of fine apical striae and irregular keratometry readings measuring 55.00 + 60 + × 60. There was no corneal scarring. She had numerous contact lens trials including hard and soft lenses that were worn both on a daily and an extended-wear basis. Because of contact lens intolerance, the possibility of surgery was raised. Her posterior capsule was open, and there were areas of old synechiae. A penetrating keratoplasty with sutured posterior chamber lens implant was considered. The possibility of an epikeratophakia was also entertained and it was felt that this would be a safer procedure in view of her mental status.
We decided to use a keratoconic size 9-millimeter lenticle placed in an 8.5-millimeter keratectomy bed and predicted that her postop keratometry would be 45.00 D. Preoperatively, a hard contact lens of base curve of 52.00 D (6.50 mm) required a + 5.50 to correct her aphakia. With the predicted flattening from the keratoconic epikeratophakia of 45.00 D, an additional +7.00 in power would be required to make a total of + 12.50 for piano. An additional 1.50 D was added to try to compensate for any undercorrection. The final kerato-lens that was ordered was + 14.00 in power with a base curve of 45.00 and a lens diameter of 9 mm. The optical zone was 6 mm and center thickness of .47 mm. The surgery was performed on August 15, 1990. An 8.5-millimeter double Hessberg-Barron trephine was used to perform the keratectomy. Postoperatively, epithelial healing was completed within 5 days. In October 1990, with the sutures still in place, her keratometry reading was 46.00 + 48.50 × 40. A refraction of + 3.00 + 1.00 × 40 gave her 20/80 vision. She missed the next several appointments and was not seen again until January 1991. At that time, the lenticule appeared clear and all the sutures were removed. Her keratometry and refraction are now stable. As of July 15, 1991, her uncorrected visual acuity is 20/50 - . Her keratometry is 48.00 + 50.75 × 80, and a refraction of +1.75 +2.00 X 80 gives her 20/30 vision. The patient continues to do well and was last seen on December 13, 1991. Her uncorrected visual acuity is 20/50. Her keratometry is 49.50 + 51.00 X 65, and a refraction of + 1.00 + 2.00 × 65 gives her 20/30 vision. Although we underestimated the amount of postoperative flattening from the epikeratoplasty procedure, she still has been able to achieve a good functional visual result.