Epikeratoplasty For Keratoconus Research Articles

Penetrating Keratoplasty vs. Epikeratoplasty for the Surgical Treatment of Keratoconus

Penetrating keratoplasty and epikeratoplasty have been utilized in the surgical treatment of keratoconus. Comparison of the relative efficacy of each procedure in achieving visual outcomes has not been achieved due to limited numbers of cases and follow-up in previous series. All patients who underwent either penetrating keratoplasty or epikeratoplasty for keratoconus between January 1987 and December 1997, and for whom at least 24 months of postoperative follow-up data for visual acuity was documented in the medical record, were included in this retrospective, nonrandomized, sequential comparative trial. The sole criteria for outcome in each group, as well as for comparison of the two groups, was Snellen visual acuity measured at the time of each follow-up with the presenting optical aid. Inclusion criteria were met for 443 eyes treated with penetrating keratoplasty and 161 eyes treated with epikeratoplasty. Mean follow-up was 4.3 years for penetrating keratoplasty and 4.5 years for epikeratoplasty. In each group, approximately 50% of the patients chose rehabilitation with optical correction with either spectacles or contact lenses and 50% chose no optical correction. Final median logMAR visual acuity for all patients, irrespective of means of visual rehabilitation, was 0.30 (20/40) for penetrating keratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). In 209 penetrating keratoplasty and 77 epikeratoplasty eyes with optical correction, the final median logMAR visual acuity was 0.18 (20/30) for penetrating keratoplasty and 0.40 (20/50) for epikeratoplasty (P < .00005). The final median logMAR visual acuity in 234 penetrating keratoplasty and 84 epikeratoplasty eyes without optical correction was 0.48 (20/60) in both groups (P-value was not statistically significant). Although penetrating keratoplasty was statistically superior to epikeratoplasty with respect to visual outcome, results with epikeratoplasty were adequate to recommend its use as a surgical alternative in cases when it is not desirable to perform penetrating keratoplasty.

Epikeratoplasty for keratoconus using manually dissected fresh lenticules: 4-year follow-up.

Epikeratoplasty for keratoconus, in the absence of apical scarring, aims at reducing high irregular myopic astigmatism and provides an ectatic cornea with mechanical support. We performed epikeratoplasty on 11 keratoconic corneas using fresh or McCarey-Kaufman preserved, manually dissected donor lenticules. A disparity of 0.5 mm was maintained between the host and the donor. Patients with keratoconus having a preoperative spectacle-corrected visual acuity of less than 6/60 and intolerance to contact lens wear were included in this prospective study. Spectacle-corrected visual acuity, keratometry, and refraction were analyzed over a 4-year follow-up period. Four year follow-up was completed on 10 eyes. Of these, 80% achieved a postoperative spectacle-corrected visual acuity of 6/12 or better. Average postoperative keratometry was 45.79 +/- 2.07 D and a decrease of 4.60 +/- 0.09 D was observed in refractive cylinder. Spherical equivalent showed a significant decrease in myopia of -4.35 +/- 0.26 D. Mean time to stabilization was 8 +/- 2.3 weeks. Epithelial defects occurred in three eyes; two were successfully treated by patching. One lenticule was removed due to graft infection following a persistent epithelial defect. Epikeratoplasty for keratoconus is a useful procedure with good long-term visual acuity results and an early stabilizing period.

Management of perforations during epikeratoplasty for keratoconus

Epikeratoplasty (EKP) in keratoconus generally has few intraoperative complications. Perforations during EKP are rare but may force the surgeon to abandon the procedure. We developed a special suture technique to manage this problem. Several deep mattress sutures are placed by taking shallow bites of the central corneal rim and deep bites of the peripheral corneal rim. This leaves the peripheral corneal rim projecting forward by approximately one third the corneal thickness. Slight stretching of this peripheral corneal rim allows adaptation of the epilenticule to form a smooth tissue plane. This method was used in two patients with significant corneal scarring and led to satisfactory visual results.

Relaxing Incisions With Compression Sutures to Reduce Astigmatism After Epikeratoplasty

Relaxing incisions with compression sutures were performed in seven eyes with high astigmatism following epikeratoplasty for keratoconus and in one case of posttraumatic aphakia. Mean preoperative keratometric astigmatism was 7.64 +/- 2.51 diopters (range 5.50 D to 13.00 D) in the epikeratoplasties for keratoconus and about 10.00 D in the hyperopic epikeratoplasty. The surgical procedure consisted of a free-hand dissection perpendicular to the steeper meridian along the scar between the edge of the epikeratoplasty lenticule and the recipient cornea, with an additional incision into the recipient stroma to an approximate depth of 80%. Following the incisions, compression sutures were added 90 degrees away in the flatter meridian. After surgery, the net decrease in keratometric astigmatism was 6.50 D +/- 2.90 D (range 5.00 to 13.00 D) in the eyes with epikeratoplasty for keratoconus and 6.50 D in the eye with hyperopic epikeratoplasty. Uncorrected visual acuity improved in six eyes and remained unchanged in two eyes. Spectacle-corrected visual acuity improved in every eye and contact-lens-corrected visual acuity improved in seven eyes and was unchanged in one eye. This procedure, already employed for astigmatism correction after penetrating keratoplasty, was effective in decreasing astigmatism after epikeratoplasty.