Thinner Central Corneal Thickness is Associated with a Decreased Parapapillary Vessel Density in Normal Tension Glaucoma.

This retrospective cross-sectional study, which enrolled 124 normal tension glaucoma (NTG) eyes and 68 healthy eyes as the control, determined the association between central corneal thickness (CCT) and ocular parameters in NTG. CCT was measured using the Pentacam® system, optical coherence tomography angiography (OCT-A) was adopted to measure the peripapillary and macular area VDs, and spatial data were based on the Garway-Heath map as illustrated in OCT-A. Univariate and multivariate linear regressions were used to statistically analyze for associations between CCT and other factors. In this study, the mean age was similar for both the NTG and control groups. The mean CCT of the NTG group was significantly thinner than that of the control group (533.97 ± 33.11 µm vs. 546.78 ± 38.21 µm; p = .022). Considering all the factors, CCT negatively correlated with visual field (VF) pattern standard deviation (univariate, p = .045). To analyze structural and functional factors separately, we found a significant positive correlation between CCT and whole disc radial peripapillary capillary VD (VDRPC; multivariate, p = .019). To analyze the relationship between all factors and sectoral changes in VDRPC, a significant positive correlation was observed between CCT and inferior temporal VDRPC (univariate, p = .039) and inferior nasal VDRPC (VDRPC IN; univariate, p = .048). In conclusion, this novel study shows that among NTG participants, a thinner cornea correlated with weaker biomechanical properties susceptible to optic nerve tissue displacement, especially in response to mild transient elevation of IOP, leads to compromised ocular microcirculation.

Optic disc hemorrhage in nonglaucomatous eyes: A cross-sectional study with average 8-year follow-up.

PURPOSE: To characterize changes in the retinal nerve fiber layer (RNFL) and peripapillary vessel density (VD) at the site of disc hemorrhage (DH) in nonglaucomatous eyes. MATERIALS AND METHODS: This retrospective cross-sectional study included nonglaucomatous eyes diagnosed with unilateral DH. The change of DH was recorded using disc photography. Both anatomical data and functional visual field (VF) data were collected using optical coherence tomography angiography and Humphrey VF examination. RESULTS: Sixteen patients were included with average follow-up duration of 95 months. Almost half of DH episodes was initially presented at the inferotemporal area of the optic disc. Pigment formation at the previous DH site after resolution was noted in 12.5% of eyes. Sectoral radial peripapillary VD at the DH site was significantly lower in DH eyes than in the control group; however, the sectoral RNFL thickness at the DH site was not significantly decreased. Progression of the VF defect corresponding to the DH site was found in 81.3% of eyes despite regular use of antiglaucoma agents. The mean change in the VF mean deviation was -0.64 dB/year in DH eyes. CONCLUSION: During long follow-up periods, decreased peripapillary VD at the DH site and progression of the VF defect corresponding to the DH site were detected in nonglaucomatous eyes. Retinal pigmentation with an RNFL defect is a clue for DH, although RNFL showed no significant change. Antiglaucoma treatment may not prevent the deterioration of visual function.

Epidemiology and the Estimated Burden of Microbial Keratitis on the Health Care System in Taiwan: A 14-Year Population-Based Study.

PURPOSE: To investigate the epidemiologic characteristics of microbial keratitis and its overall burden on the health care system in Taiwan. DESIGN: Retrospective, population-based study. METHODS: We conducted a study using claims data in the Taiwan National Health Insurance Research Database in 2000-2013, employing diagnoses, drugs, and procedure codes to define diseases and procedures. Participants were classified into groups according to the requirement of hospitalization and surgical intervention. The main outcome measures were incidence, risk factors, predictive factors for hospitalization and surgical intervention, and health care expenditure. RESULTS: A total of 2,071 patients were included. The overall incidence significantly increased from 8.4 in 2000 to 20.2 per 100,000 person-years in 2013. The peak age range of incidence was between 18 and 40 years, but the peak age group for health care expenditures was those older than 65 years. A total of 704 patients (33.99%) had analyzable risk factors, of which the top 3 were diabetes mellitus (DM, 11.52%), eye trauma (10.55%), and dry eye (8.72%). Older patients, those using steroid and antiglaucoma agents, and those with ocular and systemic diseases were susceptible to further hospitalization and surgical intervention for the treatment of microbial keratitis. CONCLUSIONS: In Taiwan, DM, eye trauma, and dry eye were key predisposing factors for microbial keratitis. Older patients (>40 years) accounted for approximately 80% of health care expenditure for the management of infectious keratitis. Special care may be required for older patients with medication-related risk factors and ocular and systemic comorbidities because they are likely to have severe diseases leading to hospitalization and surgical interventions.

Baseline clinical features predict visual outcome in young patients with central retinal vein occlusion.

PURPOSE: To evaluate prognostic factors in young patients with central retinal vein occlusion (CRVO). METHODS: Retrospective case series. CRVO patients aged ≤ 50 and follow-up ≥ 6 months were enrolled. The best corrected visual acuity (BCVA) and central retinal thickness (CRT) at baseline, 3 months, 6 months, and last visit were documented. Severity of retinopathy was graded by comparing to standard photos. Prognostic factors associated with visual outcome at 6 months were evaluated by multiple linear regression models. RESULTS: A total of 73 eyes from 69 patients with mean age 37.6 ± 8.5 were enrolled. Forty-seven (68%) patients were male. The mean follow-up duration was 25.9 ± 23.0 months. LogMAR BCVA improved from 0.979 ± 0.785 at baseline to 0.594 ± 0.748 at the 6 months (p < 0.001) and CRT improved from 475 ± 222 µm to 299 ± 104 µm (p < 0.001). Forty-eight (66%) eyes required anti-vascular endothelial growth factor (anti-VEGF) treatment. The mean number of injections was 2.25 ± 1.41 in the first 6 months and 75% of eyes received ≦ 3 injections during the clinical course. The baseline BCVA (coefficient 0.518, p < 0.001), grade of retinal hemorrhage (coefficient 0.230, p = 0.006), grade of retinal venous engorgement (coefficient 0.238, p = 0.011), grade of optic disc edema (coefficient - 0.226, p = 0.005), and diabetes mellitus (coefficient 0.264, p = 0.047) were the independent factors associated with visual outcome at 6 months. CONCLUSIONS: Baseline clinical features are useful for the prediction of visual outcome at 6 months in young CRVO patients.

Normal tension glaucoma in obstructive sleep apnea syndrome: A structural and functional study.

This study characterized and evaluated normal tension glaucoma (NTG) in obstructive sleep apnea syndrome (OSAS).In this retrospective, cross-sectional study, all participants were examined with polysomnography (PSG). Functional parameters of standard automated perimetry (SAP) were recorded. Structural parameters in optical coherence tomography angiography (OCTA) included peripapillary superficial vessel density (VD RPC), peripapillary whole-layer (VD NH), and superficial and deep macular area VD. Participants were categorized into perimetric and nonperimetric groups by SAP result. Low reliability of SAP and signal strength index <50 in OCTA were excluded.Severity of OSAS was graded by apnea-hypopnea index (AHI) in PSG. Those with moderate/severe OSAS (AHI ≥ 15, n = 39) had longer neck circumference and shorter ocular axial length than mild OSAS (AHI < 15, n = 14). Furthermore, there was significantly higher AHI and larger neck circumference in the NTG perimetric group (n = 27) than in the control group (n = 26; p < 0.001 and p = 0.047, respectively). Superficial and deep-layer peripapillary and macular area VD significantly decreased in the perimetric group. Overall, structural and functional parameters show that VF PSD was negatively correlated with VD NH and VD RPC (p = 0.007, p = 0.015); and VF MD was positively correlated with VD NH (p = 0.029), but not significantly to VD RPC (p = 0.106).OSAS is a risk factor of NTG. With aid of OCTA, whole-layer retinal capillary dropout supports that the vascular dysregulation of OSAS leads to NTG.