Long-term follow-up shows stable results with epikeratophakia for keratoconus

The procedure flattens the cornea, reducing cylinder and surface asymmetry. Visual acuity was improved markedly, with no progression of the disease.

Issue: March 15, 2001

ByMichela Cimberle

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CANNES, France — Epikeratophakia is an effective alternative keratoconus treatment, especially for patients who are contact lens intolerant, according to a retrospective study on 53 patients with a minimum follow-up of 5 years.

“We reported a high success rate. The ectatic corneas were reinforced, results were stable in time and the keratoconus did not progress,” said Finnish ophthalmologist Risto Uusitalo, MD, at the European Society of Cataract and Refractive Surgery winter meeting here.

Epikeratophakia is a partially re versible surgical procedure in which donor tissue is sutured over the recipient cornea, reproducing the effects of a contact lens. After the recipient epithelium has been scraped away, a shallow groove is produced by a trephine in the stroma and the donor graft is sutured into place with radial tight sutures to reform the cornea. The procedure flattens the ectatic cornea and makes it more regular.

High success rate

chart All 53 patients examined by Dr. Uusitalo had keratoconus and were contact lens intolerant. They were divided in two groups according to visual acuity, to evaluate what means of optical correction they were using after 5 years.

Data were collected at years 1, 2 and 5 of the follow-up. “The anatomic success of the procedure was 94% at 1 year, due to 3 cases of failure (5%) which had to be regrafted,” said Dr. Uusitalo. “At a later stage, 12 eyes (23%) required penetrating keratoplasty (PKP), reducing the final success to 76% at 5 years. Three of these cases (6%) were due to postoperative failure of the epikeratophakic graft, and 9 (17%) to inadequate visual acuity results.”

Visual acuity improved significantly in all successful cases. “Preoperatively, 74% of patients had uncorrected visual acuity (UCVA) less than 20/400. At 5 years, none had remained at these low values and 23% had UCVA better than 20/40,” he said.

“Preoperative best corrected visual acuity (BCVA), taken with a hard contact lens placed on the eye for diagnostic purposes, was 20/40 or better in 47% of the eyes. The follow-up data 1 to 5 years are not comparable to preoperative data because these (postop data) were taken with spectacles (BCVA). Two years after epikeratophakia, 85% of these eyes had achieved BCVA better than 20/40. At 5 years 65% had BCVA of 20/40 or better.” chart

Refractive results were also good. The spherical equivalent was reduced in the range of –5.5 D to –3 D, due to a mean flattening of the cornea of 9.4 D, Dr. Uusitalo reported. The mean manifest spectacle cylinder, as well as corneal astigmatism measured by keratometry, showed a significant decrease in the first year after surgery, which remained stable over the entire follow-up period.

Photokeratoscopy revealed that the irregular astigmatism had become more regular in all cases (P<.01). The surface asymmetry index (SAI), which was a mean 4.6 preoperatively, de creased to 1.7 at 1 year and to 1.5 at 5 years. In 10 eyes, SAI was 1.0 at 5 years. SAI is measured with TMS-1 (Topographical Modeling System, Computed Anatomy). A modern version of the equipment is Tomey.

“The implanted corneas looked strong and stable, and the disease seemed absolutely quiescent,” Dr. Uusitalo said.

Improving in time

chart As an example, Dr Uusitalo illustrated the case of a 22-year-old patient operated in January 1987. He had bilateral keratoconus, quite irregular cornea and was contact lens intolerant. Preoperative BCVA was less than 20/200 and he was unable to read. The keratometry showed high levels of cylinder and the surface asymmetry index was 3.95.

“Postoperatively, topographic maps showed a more regular cornea, which maintained throughout the follow-up. The irregular astigmatism had become regular and, at 1 year, keratometric values had considerably decreased and SAI was 1.13. At 2 and 5 years, we could observe increased regularity of the cornea, and final SAI was 0.65,” Dr. Uusitalo said.

“We realized that almost all cases of failure measured with hard contact lensfor visual acuity were in the group that had BCVA less than 20/40. Of the patients who were successfully treated in this group, one didn’t need optical correction, nine wore spectacles and two wore contact lenses. In the second group, BCVA better than 20/40 measured with hard contact lens, three patients didn’t need correction, 17 wore glasses and two wore contact lenses.

Preoperative data showed patient had bilateral keratoconus, quite irregular cornea and was contact lens-intolerant. Preoperative BCVA was less than 20/200 and he was unable to read. The keratometry showed high levels of cylinder and the surface asymmetry index (SAI) was 3.95.	The irregular astigmatism had become regular and, at 1 year, keratometric values had considerably decreased and SAI was 1.13.	An increased regularity of the cornea was observed at 2 years. SAI was 0.80.
Regular astigmatism and stable corneal shape on the follow up was shown at 5-year postop. The SAI was 0.65.

For Your Information:
Risto J. Uusitalo, MD, can be reached at the Department of Ophthalmology, Helsinki University Central Hospital, P.O. Box 220, 0029 HYKS, Finland; (358) 9 57175561; fax: (358) 9 47175569; e-mail: risto.uusitalo@hus.fi. Dr. Uusitalo has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.