Advanced topography-guided (OcuLink) treatment of irregular astigmatism after epikeratophakia in keratoconus with the WaveLight excimer laser.

PURPOSE: To evaluate the feasibility, safety, and predictability of treatment for high irregular astigmatism with advanced topography-guided laser epithelial keratomileusis in symptomatic eyes after epikeratophakia (EP) for keratoconus. METHODS: In a prospective case series, 10 consecutive eyes (10 patients) with high irregular astigmatism after epikeratophakia for keratoconus received OcuLink laser-assisted subepithelial keratectomy (LASEK) using the Allegretto Wave excimer laser. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifestation and refraction, corneal topographic examination with asphericity, and regularity were evaluated. All patients could not tolerate contact lens wear and had subjective symptoms. RESULTS: The UCVA improved from 0.61 ± 0.27 logarithm of the minimum angle of resolution (logMAR) (range, 0.3-1.0 logMAR) to 0.27 ± 0.07 logMAR (range, 0.2-0.4 logMAR), and the BSCVA improved from 0.25 ± 0.14 to 0.15 ± 0.09 logMAR (range, 0-0.3 logMAR) at 6 months after surgery. One patient had reduced UCVA (1 line), but no patients had reduced BSCVA. The refractive cylinder improved from -3.82 ± 2.43 diopters (D) (range, -0.75 to -7.75 D) to -1.43 ± 0.95 D (range, -0.25 to -2.50 D). The index of surface variance (an indicator of corneal surface irregularity) reduced from 115.1 ± 21.1 (range, 90-153) to 68.4 ± 18.2 (range, 39-95). Subjective symptoms, such as glare, halos, ghost images, starbursts, and monocular diplopia, were either not present or obviously alleviated. CONCLUSIONS: Advanced topography-guided (OcuLink) LASEK can significantly reduce irregular astigmatism and increase the UCVA and BSCVA.

Long-term microstructural changes following epikeratophakia: in vivo confocal microscopy study.

The unilateral epikeratophakic eye of a 20-year-old woman with a history of congenital cataracts was examined using laser scanning in vivo confocal microscopy 17 years after transplantation. In vivo confocal microscopy demonstrated a reduced keratocyte density in the grafted lenticule and the host stroma, with unusual elongated and tortuous hyperreflective branching structures in the anterior stroma of the host cornea. The sub-basal nerve plexus was present in the lenticule, although with a reduced nerve density. The appearance of the host endothelium was similar to that observed in Fuchs endothelial dystrophy. Dramatic microstructural changes were observed in almost all layers of the cornea 17 years after epikeratophakia. Although no longer performed as routine practice, in vivo confocal microscopy examination of epikeratophakia has provided fascinating insight into the potential corneal adaptations at a cellular level.

Long-term outcomes of photorefractive keratectomy in eyes with previous epikeratophakia for keratoconus.

PURPOSE: To determine the long-term safety and effectiveness of photorefractive keratectomy (PRK) in the treatment of refractive errors after epikeratophakia (EP) for keratoconus. METHODS: Ten patients (14 eyes) who had refractive errors after EP for keratoconus received PRK surgery. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refractive error, corneal astigmatism, pachymetry, corneal topography, and complications were monitored. RESULTS: Mean follow-up after PRK was 63.4 +/- 19.8 months. Mean spherical equivalent was -5.5 +/- 3.9 D before PRK, -0.9 +/- 0.5 D at 1 month after PRK, and -1.5 +/- 1.0 D at 3 years. Mean astigmatism was 4.2 +/- 2.1 D before PRK, 1.2 +/- 0.5 D at 1 month after PRK, and 1.5 +/- 0.6 D at 3 years. Thirteen (93%) eyes had an UCVA <20/40, and 12 (86%) had a BSCVA of 20/40 or better before PRK. At 1 year, the UCVA was 20/40 or better in 8 (57%) eyes, and the BSCVA was 20/40 or better in all eyes. Mean central corneal thickness was 749 +/- 35 microm before PRK and 621 +/- 56 mum at 3 years. During the follow-up period, haze (grade no more than 1.0) was observed in 2 eyes. No immune rejection episode or recurrent keratoconus was found. CONCLUSIONS: PRK appears to be reliable and safe for the correction of residual ametropia after EP for keratoconus, and the visual acuity can remain stable after PRK for a long time.

Corneal sensitivity 10 years after epikeratoplasty.

PURPOSE: To assess corneal sensitivity in patients 10 or more years after epikeratoplasty for myopia, aphakia, hyperopia, and keratoconus. METHODS: A total of 45 eyes of 33 patients (age range at examination 33 to 55 yr) were included in the study. Corneal sensitivity thresholds using an electromagnetic aesthesiometer (Draeger) were measured at various locations on the lenticule and the recipient cornea. Measurements were evaluated regarding the corrective purpose, surgical technique, age, and gender of the patients and the area of measurements. RESULTS: The mean corneal sensitivity threshold in the center of the epikeratoplasty lenticule was significantly lower than on the peripheral recipient cornea (320.0 +/- 365.1 x 10(-5) N versus 0.1 +/- 0.5 x 10(-5) N). Corneal sensitivity at the 3 and 9 o'clock positions was significantly higher compared to the values at the 6 and 12 o'clock positions on the lenticule. No correlations of these values with age, gender, type, and primary indications for the surgery were observed. CONCLUSIONS: These results indicate a relative hypesthesia of the epikeratoplasty lenticule as compared to the peripheral host cornea, even 10 years after surgery. In our patients no clinically significant changes were observed that could be attributed to the reduced sensitivity over this follow-up period.

Phototherapeutic keratectomy for anterior scarring in an epikeratophakia lenticule.

PURPOSE: To present a case of anterior scarring in an epikeratophakia lenticule and its partially successful treatment with the excimer laser. METHODS: Excimer laser phototherapeutic keratectomy (PTK) was used to reduce corneal scarring in an epikeratophakia lenticule. RESULTS: Visual acuity improved after two sessions of PTK. CONCLUSIONS: PTK is an alternative to epikeratophakia lenticule removal.

Epithelial interface cysts after epikeratophakia.

BACKGROUND: Epithelial interface cysts have been occasionally observed after lamellar keratoplasty. The authors report the incidence, clinical significance, and management of this complication in epikeratophakia patients. METHODS: From August 1987 to January 1991, 108 consecutive patients undergoing epikeratophakia entered a prospective study aimed at evaluating both clinical results and changes in corneal physiologic parameters. After an average hospitalization of 6 days, all patients underwent complete ophthalmologic examinations at regular intervals after surgery. All postoperative complications, including the development of epithelial interface cysts, were recorded and photographed. RESULTS: Over a 3-year period, epithelial interface cysts were observed in 8 eyes, with an overall incidence of 7.4%. All cysts originated under the periphery of the epilens. In five patients, the cysts enlarged centripetally but eventually ceased to grow, causing no visual impairment. In two patients, after an initial increase in size the cysts slowly regressed and finally disappeared. In only one patient, a cyst migrated over the visual axis, thus necessitating surgical removal. The cyst did not recur during an observation time of 18 months after debridement, allowing full recovery of visual acuity. CONCLUSION: The incidence of epithelial interface cysts after epikeratophakia is relatively high. Because of their peripheral location and self-limited growth, the clinical significance of this complication is low. The possibility of spontaneous regression of the cysts supports a conservative approach, as long as the visual axis is not affected. Surgical removal is possible without compromising the epi-lens and is compatible with an excellent visual outcome.

Combined epikeratoplasty and homoplastic keratophakia for correction of aphakia: double curve effect.

BACKGROUND: Having used the nonfreeze Barraquer-Krumeich-Swinger set for refractive lamellar keratoplasty since January 1987, the authors found the results of this procedure to be disappointing for correction of aphakia. Insufficient refractive gains for epikeratoplasty (+39% of initial refraction at 12-month follow up) persuaded the authors to look for a more effective refractive corneal surgery technique for correcting aphakia. METHODS: We describe a new technique consisting of the insertion of a plano-convex homoplastic donor cornea meniscus between the patient's cornea and a hypermetropic epikeratoplasty. A nonfreeze Barraquer-Krumeich-Swinger set was used to fashion the two donor lenticules. This double surgery, called the "double curve effect," because it uses two convex surfaces to increase the converging power of the cornea, has been performed in 15 eyes. RESULTS: We report the results of 10 eyes with a 6-month follow up. The average refractive gain was +11.75 D, 90% of the needed correction. But there was a loss of approximately 46% of best spectacle-corrected visual acuity. CONCLUSION: Three problems should be emphasized: the existence of two interfaces, the difficulty of perfectly centering the two lenticules, and the induced irregular astigmatism. Despite these problems which can reduce the level of best spectacle-corrected visual acuity, the double curve effect may offer an effective solution for treating certain cases of unilateral aphakia.

Epikeratophakia for keratoconus. Long-term results using fresh, free-hand made lamellar grafts.

Epikeratophakia using fresh, free-hand made corneal grafts was done in 16 patients with keratoconus. The follow-up period averaged 27.8 months (range 13-45 months). A significant improvement of visual acuity was obtained (p = 0.002), and 14 of the 16 eyes (87.5%) achieved a corrected visual acuity greater than or equal to 6/12. The spherical equivalent and the cylindrical refractive error were reduced (p less than 0.05), and a significant flattening of the central corneal curvature was obtained (p less than 0.002). The mean postoperative central corneal astigmatism was 4.25 D. Postoperatively, the mean central corneal thickness was 0.670 mm, and the mean central thickness of the epithelialized graft was 0.336 mm. Six patients reported some postoperative glare or blurring of vision, despite a visual acuity greater than or equal to 6/9 on the Snellen chart. No significant subjective or objective changes were noticed after the 6-month postoperative follow-up visit.