Biomedical subjects

W A Lyle

Publications and source records attributed to W A Lyle.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Initial results of automated lamellar keratoplasty for correction of myopia: one year follow-up.

PURPOSE: To report our initial results with automated lamellar keratoplasty (ALK) to correct myopia and to evaluate the short-term efficacy, safety, and predictability of this procedure. METHODS: A prospective series of 128 eyes of 81 consecutive patients who had ALK were reviewed for a mean follow-up of 13.6 months (range 12 to 19 months). Preoperative data, intraoperative parameters, and postoperative visual acuity, refraction, keratometric readings, and complications at 1 day, 1 week, 1, 3, and 6 months, 1 year, and last follow-up visit were used for analysis. The procedure was performed for myopia in 120 eyes (-4.50 to -13.25 diopters [D]) and for residual myopia following radial keratotomy (RK) in eight eyes (-1.75 D to -3.75 D). A hinged-flap technique was used in 17 cases (13%) once this method was introduced. RESULTS: Preoperative mean uncorrected visual acuity was 0.04 +/- 0.05 (20/500). Postoperatively (12 to 19 months), overall uncorrected visual acuity was 20/40 or better in 86.4% of eyes with a mean uncorrected acuity of 0.68 +/- 0.22 (20/30) 76.2% of eyes were within 1.00 D of emmetropia and 93.6%, within 2.00 D. After the initial ALK procedure, 77% of eyes had RK or astigmatic keratotomy (AK). Among the 29 eyes with ALK alone, 86% had 20/40 or better uncorrected visual acuity, with mean uncorrected acuity and mean corrected acuity of 0.69 +/- 0.21 (20/30) and 0.95 +/- 0.10 (20/21), respectively; 72% of eyes were within 1.00 D of emmetropia and 90%, within 2.00 D. In 4%, astigmatism increased more than 1.00 D from the preoperative value and 4% of eyes (5/128) had persistent irregular astigmatism. Four percent of eyes (5/128) had overcorrection, with a final spherical equivalent greater than +1.00 D. Epithelial growth in the interface requiring surgical removal occurred in 2% of cases. One eye with residual myopia from a previous RK lost the cap after ALK. A homologous donor graft was performed, which resulted in 20/30 uncorrected visual acuity. Best corrected visual acuity of two lines or more was lost in 6.3% of eyes (8/128). This was caused by irregular astigmatism in 63% of cases. CONCLUSIONS: The results of our initial experience indicate that ALK is a reasonably safe, effective, and predictable procedure for correction of high myopia and myopia following previous RK. With additional enhancement with RK/AK, good visual and refractive outcome can be expected.

Adult↗

PubMedDate not supplied

Long-term stability of refraction after intrastromal suture correction of hyperopia following radial keratotomy.

BACKGROUND: Our first series of nine cases using circular and interrupted sutures for hyperopia from overcorrected radial keratotomy was reported 2 years ago. Additional cases and long-term follow up with this technique are presented here. METHODS: Thirteen eyes of 12 patients with symptomatic hyperopia underwent corneal suturing with pursestring and interrupted sutures and were followed for 3 years. There were six original overcorrections and seven overcorrections after reoperation. The mean preradial keratotomy refractive spherical equivalent refraction was -3.85 +/- 1.40 RESULTS: The mean preoperative refractive spherical equivalent was +2.55 +/- 0.93 D (range +1.125 to +5.375 D). The mean follow up after the suturing procedure was 40 +/- 14.3 months with a range of 10 to 72 months. The change in refraction following suturing procedures averaged -1.84 D, resulting in an overall correction of 72% of the overcorrection. The mean increase of postoperative central keratometric power was 1.42 +/- 0.95 D. All eyes reduction of hyperopia. Uncorrected visual acuity was improved from 0.367 +/- 0.11 (20+60) preoperatively to 0.712 +/- 0.25 (20/30+) postoperatively. The average improvement was 3.3 Snellen lines. using the visual function score to assess the effectiveness of the procedure, we found 85% (11/13) of eyes obtained excellent or good results and 15% appeared fair or poor. In the 3 years since the study began, eight eyes had follow-up data from the previous study and the present study. During this period, an average change of refraction of only -0.19 D was observed. A refractive change less than 0.50 D was observed in 62.5% of the eyes, and all of the eyes had a refractive change within 1.00 D. There were no new complications and no loss of effect during the mean 43 months of follow up for those patients. CONCLUSION: Based on the 3-year follow up, we concluded that intrastromal pursestring and interrupted techniques are stable, safe, and effect procedures for correcting hyperopia following radial keratotomy, especially for less than +3.00 D.

Adult↗

PubMedDate not supplied

Circular and interrupted suture technique for correction of hyperopia following radial keratotomy.

BACKGROUND: Hyperopia is a possible complication following radial keratotomy. In this article, we describe a circular and interrupted corneal compression suture technique for the correction of hyperopia induced by radial keratotomy. METHODS: A retrospective study was performed to evaluate the effectiveness of this procedure in nine consecutive patients. RESULTS: The procedure achieved an average of -1.70 diopters change in spherical equivalent refraction. This accounted for an overall correction of 68% of the hyperopia caused by radial keratotomy after a minimum 3-month follow up. Seven of nine eyes (78%) were within 1.00 D of emmetropia after surgery. Uncorrected visual acuity of 20/40 or better was present in only two eyes (22%) preoperatively, and nine eyes (100%), after the corneal suturing procedure. The mean improvement of uncorrected visual acuity was 4.0 Snellen lines (P = .0004). All patients were pleased with their visual outcomes. CONCLUSIONS: We found that this technique is an easy, safe, and reasonably successful treatment for radial keratotomy overcorrection.

Adult↗