Hyperopia-Correcting Phototherapeutic Keratectomy and Its Comparison With Conventional Phototherapeutic Keratectomy.

Purpose: To evaluate hyperopia-correcting phototherapeutic keratectomy (HC-PTK) and to compare the visual and refractive outcomes of HC-PTK and conventional PTK. Methods: This study comprised a total of 72 eyes of 72 consecutive patients who underwent HC-PTK and conventional PTK for granular corneal dystrophy or band-shaped keratopathy. Preoperatively and 6 months postoperatively, we assessed visual acuity, manifest refraction, and mean keratometry, as well as postoperative corneal higher-order aberrations and adverse events in each PTK group, and compared these metrics between the two groups. Results: LogMAR BSCVA significantly improved from 0.43 ± 0.47 preoperatively to 0.21 ± 0.38 postoperatively in the HC-PTK group (Wilcoxon signed-rank test, p < 0.001). It was also significantly improved from 0.22 ± 0.21 preoperatively to 0.15 ± 0.12 postoperatively in the conventional PTK group (p = 0.031). Mean refraction significantly changed from 0.27 ± 1.55 diopter (D) preoperatively to 0.50 ± 1.77 D postoperatively, in the HC-PTK group (p = 0.313). By contrast, it was significantly hyperopic from -0.15 ± 2.41 D preoperatively to 1.45 ± 2.46 D postoperatively, in the conventional PTK group (p < 0.001). No significant complications occurred in any case during the follow-up period. Conclusion: Both HC-PTK and conventional PTK showed a significant improvement of BSCVA and no vision-threatening complications at any time in this series. HC-PTK significantly reduced a hyperopic shift in refraction compared with conventional PTK, suggesting its viability for patients requiring PTK, especially in consideration of preventing this hyperopic issue.

Clinical evaluation of flat peripheral curve design with aspherical-curve and multi-curve hard contact lenses for keratoconus.

Aspherical- and multi-curve rigid gas-permeable hard contact lenses (HCLs) have a flattened curve in the peripheral zone and are mostly used for patients with keratoconus who cannot wear glasses, soft contact lenses, or spherical HCLs. In this retrospective study, a total of 95 eyes of 77 patients who used aspherical- or multi-curve HCLs (mean age: 40.0 ± 11.0 years) were evaluated. This study examined the types of aspherical- and multi-curve HCLs, best-corrected visual acuity (BCVA) values before and after wearing HCLs, the association with the Amsler-Krumeich classification, duration of wear, corneal/conjunctival disorder, and the frequency of changing HCLs. There were 78 eyes that used aspherical-curve HCLs and 17 that used multi-curve HCLs. BCVA significantly improved from 0.42 logMAR to 0.06 logMAR after wearing either form of HCL. The Amsler-Krumeich classification showed that aspherical-curve HCLs were commonly used for patients with stage 2 keratoconus, and multi-curve HCLs were commonly used for stage 4 patients. The BCVA values were worse when the disease stage was more severe (stages 3 and 4) regardless of HCL type. The mean base curve of the lenses was steeper in multi-curve HCLs than in aspherical-curve HCLs. The more severe the disease stage, the steeper the base curve in both aspherical- and multi-curve HCLs. The duration of wear significantly improved from 2.1 h to 10.2 h, and corneal/conjunctival disorder similarly improved. The mean frequency of changing HCL types was 1.1 times. This study suggests that a flat peripheral curve design with aspherical- and multi-curve HCLs is useful for patients with keratoconus.

Morphological Changes and Potential Mechanisms of Intraocular Pressure Reduction after Micropulse Transscleral Cyclophotocoagulation in Rabbits.

INTRODUCTION: Micropulse transscleral cyclophotocoagulation (MP-TSCPC) is a method for intraocular pressure (IOP) reduction in patients with glaucoma; however, the specific mechanisms underlying its ability to reduce IOP remain unclear. We therefore investigated the morphological changes and mechanisms of IOP reduction after MP-TSCPC. METHODS: The right eyes of 4 pigmented rabbits were treated with MP-TSCPC with power setting corresponding to those used in glaucoma patients (1 power: 2,000 mW; time: 160 s; duty cycle: 31.3%). Power settings of 1, 1/8, 1/16, and 1/32 power were applied to the right eyes. The left eyes were used as controls. A light microscope and electron microscope were used to observe morphological findings after 1 week of MP-TSCPC. IOP and IOP reduction rate were compared before and after MP-TSCPC application on days 1, 3, and 5, and at 1 week. RESULTS: In the pre-MP-TSCPC, IOP was 16.7 ± 0.6 mm Hg. The IOP of rabbit treated with the 1 power was 3 mm Hg, with an IOP reduction rate of 80%; however, the eyes developed phthisis bulbi. The IOP was 7.0 ± 0.0 mm Hg 1 week after MP-TSCPC (IOP reduction rate: 59%) in rabbit treated with the 1/8 power. Reduction in IOP was observed, but there was significant tissue invasion to the ciliary body. The IOP was 10.3 ± 0.6 mm Hg (IOP reduction rate: 40%) 1 week after MP-TSCPC in rabbit treated with the 1/16 power, which was more effective to reduce IOP than that with the 1/8 power. Tissue invasion to the ciliary body was negligible, nonpigmented epithelial cells of the pars plicata were damaged, basal infoldings were destroyed, and repair was accompanied by proliferating tissue. No IOP reduction or tissue change was observed in rabbit treated with the 1/32 power. CONCLUSION: A potential mechanism for IOP reduction in pigmented rabbits is aqueous humor transport dysfunction due to damage to the nonpigmented epithelial cells of the pars plicata and destruction of basal infoldings. The power of MP-TSCPC was consistent with both morphological changes and IOP reduction.

Effect of Angle Opening Parameters on Corneal Endothelial Cell Density and Intraocular Pressure after Posterior Chamber Phakic Intraocular Lens Implantation.

This study aimed to investigate the time courses of angle opening parameters and the relationships of these with the corneal endothelial cell density (ECD) and the intraocular pressure (IOP) after posterior chamber phakic intraocular lens (Visian ICLTM, STAAR Surgical) implantation. We evaluated 116 eyes of 59 consecutive patients (mean age ± standard deviation, 34.0 ± 8.8 years) who underwent V5 implantable collamer lens (ICL) implantation. Preoperatively and 1 day, 1 week, and 1, 3, and 18 months postoperatively, we quantitatively measured the angle opening distance at 500 µm (AOD500), the trabecular-iris space area (TISA500), and the trabecular iris angle (TIA500), using anterior segment optical coherence tomography (CASIA 2, Tomey), and assessed the relationships of these measurements with ECD and IOP in ICL-implanted eyes. All angle parameters (AOD500, TISA500, and TIA500) significantly decreased 1 day postoperatively but remained stable thereafter. At 18 months postoperatively, we found no significant correlations of the angle parameters with ECD (Pearson correlation coefficient r = -0.108, p = 0.249 for AOD500; r = -0.162, p = 0.083 for TISA500; r = -0.022, p = 0.815 for TIA500) or between the angle parameters and IOP (r = -0.106, p = 0.256 for AOD500; r = -0.021, p = 0.826 for TISA500; r = -0.018, p = 0.850 for TIA500). The angle opening metrics significantly decreased immediately after ICL implantation but remained stable thereafter. Narrowing of the angle did not significantly affect ECD or IOP in ICL-implanted eyes during the 18-month postoperative period.

Long-term clinical results of trabectome surgery in patients with open-angle glaucoma.

PURPOSE: To evaluate the 72-month clinical results of trabectome surgery (TOM) in patients with primary open-angle glaucoma (POAG), secondary OAG and childhood glaucoma. METHOD: A total of 305 eyes from 249 glaucoma patients were analyzed in the current retrospective single-center study. Kaplan-Meier analysis was performed using three criteria: criterion A (postoperative intraocular pressure [IOP] ≤ 21 mmHg and ≥ 20% reduction from baseline IOP); criterion B (postoperative IOP ≤ 18 mmHg and ≥ 20% reduction from baseline IOP); and criterion C (postoperative IOP ≤ 16 mmHg and ≥ 20% reduction from baseline IOP). The changes in IOP, medication score, success probability, results of the multivariate analysis for success and failure risk factors, and complications were analyzed. RESULTS: The baseline IOP in all glaucoma patients decreased from 29.2 ± 9.8 mmHg with a 5.3 ± 1.7 medication score to 16.4 ± 5.8 mmHg (- 43.8%) with a 4.2 ± 1.5 medication score at 72 months (p < 0.01). The success probabilities in all cases for 72 months based on criterion A, B, and C were 44%, 35%, and 17%, respectively. For criterion A, no significant differences were found in the success probability according to the glaucoma subtype for 72 months. The combined surgical procedure significantly decreased the failure risk (hazard ratio [HR]: 0.59). On the other hand, the presence of POAG (HR: 1.6) and a history of past selective laser trabeculoplasty (HR: 2.2) significantly increased failure risk. One patient (0.3%) demonstrated endophthalmitis after TOM but recovered through appropriate treatment. CONCLUSION: At the 72-month time point, approximately half of the glaucoma patients maintained an IOP ≤ 21 mmHg with ≥ 20% IOP reduction. TOM is a safe surgery but may not yield sufficient IOP reduction in patients who have received SLT or have POAG.