Sutureless superficial anterior lamellar keratoplasty for recurrent corneal haze after repeat excimer laser surface ablation.

BACKGROUND/AIMS: To evaluate the 5-year outcomes of sutureless superficial anterior lamellar keratoplasty (SALK) in the treatment of surface ablation-related corneal haze recurring after phototherapeutic keratectomy (PTK). METHODS: Prospective interventional study at a tertiary referral centre in Forli, Italy. Ten consecutive eyes with corneal haze following photorefractive keratectomy, recurring after treatment with PTK with or without mitomycin C, undergoing sutureless SALK. Sutureless SALK was performed using a microkeratome in donor and recipient. MAIN OUTCOME MEASURES: best spectacle-corrected visual acuity (BSCVA), surgically induced astigmatism (SIA), rate of recurrence and complications. RESULTS: There were no intraoperative complications and there was no recurrence of haze in any eye postoperatively. BSCVA showed significant improvement at all postoperative time points. Mean preoperative visual acuity improved from 0.46 logMAR units (SD=0.12) to 0.12 (SD=0.12, p=0.0001) at 5 years. At 6 months, SIA was 2.50±1.04 with no further significant change at 5 years (2.53±1.39, p=0.95). There was no significant change in mean spherical equivalent and no significant difference between preoperative and postoperative astigmatism vector values at 5 years. CONCLUSIONS: Sutureless SALK provides a useful treatment option in patients with recurrent haze after excimer laser treatment. It can eliminate haze recurrence for at least a period of 5 years and can improve BSCVA, although there may be significant SIA.

Comparison of single-step reverse transepithelial all-surface laser ablation (ASLA) to alcohol-assisted photorefractive keratectomy.

PURPOSE: To evaluate postoperative pain, corneal epithelial healing, development of corneal haze, refractive outcomes, and corneal aberrations in a novel one-step, modified transepithelial photorefractive keratectomy (PRK), termed All-surface laser ablation (ASLA), compared to conventional, alcohol-assisted PRK. MATERIALS AND METHODS: Sixty eyes of 30 myopic patients were prospectively recruited to a randomized fellow eye study. Patients underwent conventional alcohol-assisted PRK in one eye (control group) and ASLA-modified transepithelial PRK in the other (30 eyes in each treatment arm). Primary endpoints were postoperative pain and haze scores at 1 day, 3 days, 1 week, and 1, 3, 6, and 12 months. Secondary endpoints included visual acuity at 1, 3, 6, and 12 months, corneal aberrations at 3, 6, and 12 months, and early and late onset haze. Refractive predictability, safety, and efficacy of the two methods were considered. RESULTS: The average age of the cohort was 29 years (standard deviation [SD]: 9; range: 18-46), and the average spherical equivalent refractive error was -4.18 diopters (SD: 1.9). At 3 days after surgery, the average pain score was 64% lower in the ASLA group (P < 0.0005). At this point, 96% of ASLA eyes had no epithelial defect, whereas 43% in the alcohol-assisted group did not achieve complete epithelial healing, and required replacement of bandage contact lens. The haze level was consistently lower in the ASLA group at all time points from 1 to 6 months. CONCLUSION: This study shows that the ASLA technique may have a future role in refractive surgery, due to the fact that it offers faster epithelial healing, lower pain scores, and significantly less haze formation.

Stability of therapeutic retreatment of corneal wavefront customized ablation with the SCHWIND CAM: 4-year data.

PURPOSE: To evaluate the long-term outcomes of aspheric corneal wavefront ablation profiles for excimer laser retreatment. METHODS: Eighteen eyes that had previously undergone LASIK or photorefractive keratectomy (PRK) were retreated with LASIK using the corneal wavefront ablation profile. Custom Ablation Manager (SCHWIND eye-tech-solutions, Kleinostheim, Germany) software and the ESIRIS flying spot excimer laser system (SCHWIND) were used to perform the ablations. Refractive outcomes and wavefront data are reported up to 4 years after retreatment. Pre- and postoperative data were compared with Student t tests and (multivariate) correlation tests. P<.05 was considered statistically significant. A bilinear correlation of various postoperative wavefront aberrations versus planned correction and preoperative aberration was performed. RESULTS: Mean manifest refraction spherical equivalent (MRSE) before retreatment was -0.38±1.85 diopters (D) and -0.09±0.22 D at 6 months and -0.10±0.38 D at 4 years postoperatively. The reduction in MRSE was statistically significant at both postoperative time points (P<.005). Postoperative aberrations were statistically lower (spherical aberration P<.05; coma P<.005; root-mean-square higher order aberration P<.0001) at 4 years postoperatively. Distribution of the postoperative uncorrected distance visual acuity (P<.0001) and corrected distance visual acuity (P<.01) were statistically better than preoperative values. CONCLUSIONS: Aspheric corneal wavefront customization with the ESIRIS yields visual, optical, and refractive results comparable to those of other wavefront-guided customized techniques for the correction of myopia and myopic astigmatism. The corneal wavefront customized approach shows its strength in cases where abnormal optical systems are expected. Systematic wavefront customized corneal ablation appears safe and efficacious for retreatment cases.

The effect of static cyclotorsion compensation on refractive and visual outcomes using the Schwind Amaris laser platform for the correction of high astigmatism.

PURPOSE: To compare the refractive and visual outcomes using the Schwind Amaris excimer laser in patients with high astigmatism (>1D) with and without the static cyclotorsion compensation (SCC) algorithm available with this new laser platform. METHODS: 70 consecutive eyes with ≥1D astigmatism were randomized to treatment with compensation of static cyclotorsion (SCC group- 35 eyes) or not (control group- 35 eyes). A previously validated optimized aspheric ablation algorithm profile was used in every case. All patients underwent LASIK with a microkeratome cut flap. RESULTS: The SCC and control group did not differ preoperatively, in terms of refractive error, magnitude of astigmatism or in terms of cardinal or oblique astigmatism. Following treatment, average deviation from target was SEq +0.16D, SD±0.52 D, range -0.98 D to +1.71 D in the SCC group compared to +0.46 D, SD±0.61 D, range -0.25 D to +2.35 D in the control group, which was statistically significant (p<0.05). Following treatment, average astigmatism was 0.24 D (SD±0.28 D, range -1.01 D to 0.00 D) in the SCC group compared to 0.46 D (SD±0.42 D, range -1.80 D to 0.00 D) in the control group, which was highly statistically significant (p<0.005). There was no statistical difference in the postoperative uncorrected vision when the aspheric algorithm was used although there was a trend to increased number of lines gained in the SCC group. CONCLUSIONS: This study shows that static cyclotorsion is accurately compensated for by the Schwind Amaris laser platform. The compensation of static cyclotorsion in patients with moderate astigmatism produces a significant improvement in refractive and astigmatic outcomes than when not compensated.

Proteoglycan alterations in the rabbit corneal stroma after a lamellar incision.

PURPOSE: To investigate proteoglycans under minimally damaged epithelium after a lamellar microkeratome incision. SETTING: Collaborating university departments. METHODS: Anterior lamellar caps were excised from rabbit corneas and then resutured in place. Healing tissue was examined by electron microscopy with proteoglycan staining. RESULTS: In the weeks after surgery, regions of disorganized stromal matrix were populated by sulfated proteoglycan filaments that were much larger (up to 300 nm long) than those in quiescent stroma. CONCLUSIONS: Large, sulfated proteoglycans existed in rabbit corneas healing from lamellar incisions. These molecules appear to be a normal feature of corneal wound healing; because of their water-binding capacity, they might aid tissue restructuring.