Design of ultra-wide-field scanning laser fundus imaging system with cascaded conicoid mirrors.

We propose and design a multi-stage cascaded scanning laser ophthalmoscope (SLO) for ultra-wide field (UWF), which uses conicoid mirrors, constructed by conjugation of pupil plane. The vergence uniformity and the angular magnification of a cascaded conicoid mirrors (CCM) system are analyzed recursively and optimized preliminarily to achieve high quality imaging with UWF, and the optimal system with the model eye are obtained by simulation and optimization. Two-stage and three-stage cascaded systems are designed with this method, and the formulas of beam vergence and angular magnification are obtained by theoretical derivation. As compared to the two-stage CCM system, the proposed three-stage cascaded UWF SLO has superior performance in imaging quality. Its average RMS radius of spot diagram is calculated to be 26.372 µm, close to the diffractive limit resolution. The image resolution of human retina can be up to 30 µm with 135° FOV in theory. The three-stage cascaded SLO is more suitable for UWF fundus imaging. This study will be helpful for early screening and accurate diagnosis of various diseases in the peripheral retina.

Changes in macular ultrastructural morphology in unilateral anisometropic amblyopia.

It is controversial that retina and photoreceptors are involved in amblyopic development. Lack of imaging devices for quantitative assessment of photoreceptors in vivo impedes further investigation. In this study we investigated the differences of macular thickness, outer nuclear layer (ONL) thickness and cone density among eyes with unilateral anisometropic amblyopia, amblyopic fellow eyes, and normal control eyes using high-definition spectral-domain optical coherence tomography and adaptive optics imaging system. Thicker fovea and parafovea with characteristic quantitative retinal changes in unilateral amblyopic patients indicated that the amblyopic process might involve the retina. Cones tended to be homogeneously distributed at 1.5° from the foveal center in all participants. However, we did not detect any significant differences in cone density and ONL thickness at 1.5° from the foveal center in patients with unilateral amblyopia when compared with the fellow eyes and the normal control eyes. This is the first study to explore whether photoreceptors are involved in amblyopic development in vivo that would help for understanding the underlying mechanisms of amblyopia. Whether macular changes relate to cone photoreceptors migration of the amblyopic eyes remains to be determined.

Neovascular glaucoma: a retrospective review from a tertiary center in China.

BACKGROUND: The purpose of this study is to report the prevalence, etiology, treatment and outcomes of neovascular glaucoma (NVG) in a tertiary care ophthalmic center in China. METHODS: Medical records of patients diagnosed as NVG at the Wenzhou Medical University between 2003 and 2014 were reviewed. Success was defined as IOP between 6 and 21 mmHg without topical or systemic glaucoma medications with retention of presenting visual acuity (VA). RESULTS: NVG was diagnosed in 483 of 8306 (5.8%) of all glaucoma patients. Etiology is reported for all 310 eyes of 284 patients managed in the department. Interventions depended on insurance as well as personal finances; outcomes are reported for the 149 eyes of 138 patients with complete data that met follow up requirements. Diabetic retinopathy (DR,39.7%) was the major cause of NVG. Kaplan Meier survival analysis showed a success rate of 84.8% at 1 year, 47.5% at 3 years and 21.9% at 5 years. Major interventions included glaucoma drainage device (GDD) in 103 eyes and trans-scleral cyclophotocoagulation (TSCPC) in 22 eyes. Complications were more common in the GDD group. CONCLUSIONS: NVG comprised 5.8% of glaucoma patients seen in a tertiary Chinese hospital. DR was identified as the commonest cause and probably reflects the increasing prevalence of diabetes in China. Surgical interventions were partly determined by insurance status and personal finances. GDD was the commonest surgical intervention used and also had the most complications.