Characteristics of Rare Inherited Retinal Dystrophies in Adaptive Optics-A Study on 53 Eyes.

Inherited retinal dystrophies (IRDs) are genetic disorders that lead to the bilateral degeneration of the retina, causing irreversible vision loss. These conditions often manifest during the first and second decades of life, and their primary symptoms can be non-specific. Diagnostic processes encompass assessments of best-corrected visual acuity, fundoscopy, optical coherence tomography, fundus autofluorescence, fluorescein angiography, electrophysiological tests, and genetic testing. This study focuses on the application of adaptive optics (AO), a non-invasive retinal examination, for the assessment of patients with IRDs. AO facilitates the high-quality, detailed observation of retinal photoreceptor structures (cones and rods) and enables the quantitative analysis of parameters such as cone density (DM), cone spacing (SM), cone regularity (REG), and Voronoi analysis (N%6). AO examinations were conducted on eyes diagnosed with Stargardt disease (STGD, N=36), cone dystrophy (CD, N=9), and cone-rod dystrophy (CRD, N=8), and on healthy eyes (N=14). There were significant differences in the DM, SM, REG, and N%6 parameters between the healthy and IRD-affected eyes (p<0.001 for DM, SM, and REG; p=0.008 for N%6). The mean DM in the CD, CRD, and STGD groups was 8900.39/mm2, 9296.32/mm2, and 16,209.66/mm2, respectively, with a significant inter-group difference (p=0.006). The mean SM in the CD, CRD, and STGD groups was 12.37 µm, 14.82 µm, and 9.65 µm, respectively, with a significant difference observed between groups (p=0.002). However, no significant difference was found in REG and N%6 among the CD, CRD, and STGD groups. Significant differences were found in SM and DM between CD and STGD (p=0.014 for SM; p=0.003 for DM) and between CRD and STGD (p=0.027 for SM; p=0.003 for DM). Our findings suggest that AO holds significant potential as an impactful diagnostic tool for IRDs.

Canaloplasty - Efficacy and Safety in an 18-Month Follow Up Period, and Analysis of Outcomes in Primary Open Angle Glaucoma Pigmentary Glaucoma and Pseudoexfoliative Glaucoma.

PURPOSE: Open-angle glaucoma (OAG), accounting for 90% of all glaucoma cases, is a progressive optic nerve neuropathy. It may lead to irreversible loss of visual field and complete blindness. When conservative treatment becomes insufficient to stop OAG progression, a surgical intervention is considered. Currently, canaloplasty procedure is being introduced instead of conventional trabeculectomy for invasive OAG treatment. The aim of the study is to asses safety and efficacy of canaloplasty. METHODS: This prospective study included 67 eyes that received 360° canaloplasty with placement of a tensioning suture. Primary OAG (n = 35), secondary OAG in pseudoexfoliative syndrome (n = 13), and pigmentary glaucoma (n = 19) patients were included. Control check-ups were conducted pre-operatively and in a 18-month follow-up time. Study endpoints involved reduction in IOP values and in the number of glaucoma medications after the intervention. RESULTS: The intervention led to a significant 38% reduction in IOP value from the preoperative baseline to 18 months after the intervention. The number of medications decreased significantly by 89%. At 18 months postoperative, 79% eyes did not require any glaucoma medications. The incidence of complications after canaloplasty was low, and none of the adverse effects were vision threatening. A surgically-induced astigmatism was the most frequent complication. Pigmentary glaucoma patients were the most beneficial subgroup, with 50% reduction in IOP, the highest success rate, and 98% reduction in the number of medications used. CONCLUSION: This study proved that canaloplasty is an efficient and safe procedure in OAG eyes.

Immersion Biometry for Intraocular Lens Power Calculation with Fourth-Generation Formulas.

BACKGROUND: Fourth-generation formulas for intraocular lens power calculations, including the Barrett Universal II formula, the Olsen formula or the Holladay 2 formula, were thoroughly validated with optical biometry measurements. They precisely predict the effective lens position not only in normal eyes but also in eyes with unusual anatomy. However, in the setting of dense nuclear or posterior subcapsular cataracts, optical biometers fail to obtain accurate measurements and third-generation formulas, i.e. the Hoffer Q or the SRK/T, combined with ultrasound measurements are a method of choice. Considering that optical biometry was fine-tuned to immersion ultrasound, we hypothesize that fourth-generation formulas will yield precise intraocular lens power calculations with immersion ultrasound measurements. METHODS: We retrospectively analyzed 50 eyes of 50 patients who underwent uneventful cataract surgery. All patients had intraocular lens power calculated based on immersion ultrasound measurements. Refractive error predictions were compared between third-generation formulas and fourth-generation formulas. RESULTS: There were no statistically significant differences in the median absolute error between formulas. In the study, 86%, 88%, 86%, 84%, 88% and 80% of eyes were within 1 D of target refraction for the SRK/T, the Barrett II, the Hoffer Q, the Holladay 1, the Holladay 2 and the Olsen formula respectively. CONCLUSION: Fourth-generation formulas combined with immersion ultrasound produced similar results to third-generation formulas. However, the percentage of eyes within 1 D of target refraction remains inferior to previously reported results for optical biometry measurements.