Time filter

Source Type

Agrawal R.,National Healthcare Group Eye Institute

PURPOSE:: To evaluate choroidal vascularity index (CVI) in eyes with central serous chorioretinopathy (CSC) using an image binarization tool on enhanced depth imaging using spectral domain optical coherence tomography scans. METHODS:: In this retrospective cohort study, enhanced depth imaging optical coherence tomography scans of both eyes of patients with CSC were taken at baseline; they were segmented and compared with enhanced depth imaging optical coherence tomography scans of fellow eyes without CSC as well as age-matched healthy subjects. Subfoveal choroidal area (1,500 μm) was segmented into luminal area and stromal area using image binarization. Choroidal vascularity index was defined as the proportion of luminal area to the total circumscribed subfoveal choroidal area. RESULTS:: Eyes with acute CSC (32 eyes) had significantly higher CVI compared with their fellow eyes (27 eyes) (P < 0.0001), 19 eyes with resolved CSC (P < 0.0001) and with 30 eyes of age-matched healthy eyes (P < 0.0001). Fellow eyes of subjects with acute CSC also had significantly higher CVI compared with eyes with resolved CSC (P < 0.0001) and age-matched healthy eyes (P < 0.0001). CONCLUSION:: Increased CVI suggests increased vascular component compared with the stromal component in acute CSC. Increased CVI was noted in fellow eye of the subjects with acute CSC in comparison with age-matched healthy subjects. The CVI could be a useful index for early diagnosis of CSC and to assess the treatment response after laser photocoagulation or photodynamic therapy. © 2016 by Ophthalmic Communications Society, Inc. Source

Tan C.S.,Doheny Eye Institute | Tan C.S.,National Healthcare Group Eye Institute | Ouyang Y.,Doheny Eye Institute | Ruiz H.,Doheny Eye Institute | Sadda S.R.,Doheny Eye Institute
Investigative Ophthalmology and Visual Science

PURPOSE. To describe the pattern and magnitude of diurnal variation of choroidal thickness (CT), its relation to systemic and ocular factors, and to determine the intervisit reproducibility of diurnal patterns. METHODS. A prospective study was conducted on 12 healthy volunteers who each underwent sequential ocular imaging on two separate days at five fixed, 2-hour time intervals. Spectral domain optical coherence tomography (OCT) with enhanced depth imaging and image tracking was performed using a standardized protocol. Choroidal and retinal thicknesses were independently assessed by two masked graders. CT diurnal variation was assessed using repeated-measures ANOVA. RESULTS. A significant diurnal variation in CT was observed, with mean maximum CT of 372.2 μm, minimum of 340.6 μm (P < 0.001), and mean diurnal amplitude of 33.7 μm. Retinal thickness (mean, 235.0 μm) did not exhibit significant diurnal variation (P = 0.621). The amplitude of CT variation was significantly greater for subjects with thicker morning baseline CT compared with those with thin choroids (43.1 vs. 10.5 μm, P < 0.001). There were significant correlations between amplitude of CT and age (P = 0.032), axial length (P < 0.001), and spherical equivalent (P < 0.001). The change in CT also correlated with change in systolic blood pressure (P = 0.031). Comparing CT on two different days, a similar diurnal pattern was observed, with no significant difference between corresponding measurements at the same time points (P = 0.180). CONCLUSIONS. There is significant diurnal variation of CT, with good intervisit reproducibility of diurnal patterns on two different days. The amplitude of variation varies with morning baseline CT, and is correlated with age, axial length, refractive error, and change in systolic blood pressure. © 2012 The Association for Research in Vision and Ophthalmology, Inc. Source

Tan C.S.,Doheny Eye Institute | Tan C.S.,National Healthcare Group Eye Institute | Heussen F.,Doheny Eye Institute | Sadda S.R.,Doheny Eye Institute

Purpose: To characterize peripheral fundus autofluorescence (FAF) abnormalities in patients with age-related macular degeneration (AMD), correlate these with clinical findings, and identify risk factors associated with these FAF abnormalities. Design: Clinic-based, cross-sectional study. Participants: A total of 119 consecutive patients: 100 patients with AMD (200 eyes) and 19 patients without AMD (38 eyes). Methods: In a prospective study performed at the Doheny Eye Institute, University of Southern California, widefield 200-degree FAF and color images were obtained by the Optos 200Tx Ultra-Widefield device (Optos, Dunfermline, Scotland) using a standardized imaging protocol. The FAF images were captured centered on the fovea, and additional images were captured after steering the field of view inferiorly and superiorly. All FAF and color images were graded independently by 2 masked ophthalmologists with respect to the presence, location, extent, and type of peripheral (defined as outside the central 30 degrees) FAF abnormality. Main Outcome Measures: Presence and type of peripheral FAF abnormalities. Results: Peripheral FAF abnormalities were evident in 164 eyes (68.9%), with several distinct FAF patterns identified: granular (46.2%), mottled (34.0%), and nummular (18.1%). A 90% concordance of FAF patterns was observed between both eyes. Abnormal FAF occurred more frequently in neovascular compared with non-neovascular AMD or normal eyes (86% vs. 72.8% vs. 18.4%, respectively, P<0.001). Significant risk factors for peripheral FAF abnormalities were AMD type (neovascular AMD odds ratio [OR], 12.7 and non-neovascular AMD OR, 6.2 compared with normal eyes, P<0.001), older age (OR, 6.5; 95% confidence interval [CI], 2.4-17.8; P<0.001 for the oldest quartile compared with the youngest), and female sex (OR, 4.1; 95% CI, 1.9-8.9; P<0.001). Clinical features on color photography were detected in 174 eyes (73.1%): peripheral drusen (51.7%), retinal pigment epithelium (RPE) depigmentation (34.9%), RPE hyperpigmentation (branching reticular pigmentation) (22.7%), and atrophic patches (16.8%). There was a high correlation between specific FAF and clinical findings: granular FAF with peripheral drusen (P<0.001) and mottled FAF with RPE depigmentation (P<0.001). Conclusions: Several distinct patterns of peripheral FAF abnormalities were observed in 68.9% of patients, with AMD type, female sex, and age being independent risk factors. The peripheral FAF patterns correlate strongly with specific clinical features seen in eyes with AMD. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references. © 2013 American Academy of Ophthalmology. Source

Ng A.W.,National University of Singapore | Teoh S.C.,Eagle Eye Center | Teoh S.C.,National Healthcare Group Eye Institute
Survey of Ophthalmology

Dengue fever, a viral disease epidemic in some parts of the world, is of considerable international concern, with a growing incidence owing to developing urbanization, tourism, and trade. Ocular manifestations of dengue fever are uncommon, but of great significance. Proposed mechanisms include direct viral infection as well as immunologic phenomena. Common manifestations include subconjunctival, vitreous, and retinal hemorrhages; posterior uveitis; optic neuritis; and maculopathies such as foveolitis, hemorrhage, and edema. Main symptoms include blurring of vision, scotomata, metamorphopsia, and floaters. Diagnostic and monitoring investigations described included optical coherence tomography, fundus fluorescein and indocyanine green angiography, visual field analysis, and electrophysiologic tests. Management is based on clinical presentation and includes active surveillance as well as various anti-inflammatory and immunosuppressive therapies. There have been no prospective, randomized therapeutic trials, and it is unclear if the disease is self-limiting or if treatment is actually beneficial. Prognosis varies, ranging from full resolution to permanent vision loss despite intervention. © 2015 Elsevier Inc. Source

Tan C.S.H.,National Healthcare Group Eye Institute | Wong H.K.,National Healthcare Group Eye Institute | Yang F.P.,National Healthcare Group Eye Institute
Journal of Cataract and Refractive Surgery

Purpose: To describe the incidence of postoperative endophthalmitis after cataract surgery in a multiethnic Asian population over an 11-year period, compare the endophthalmitis rates before and after the use of intracameral antibiotic agents, and identify potential risk factors for endophthalmitis. Setting: Department of Ophthalmology, Tan Tock Seng Hospital, Singapore. Design: Cohort study. Methods: The incidence and risk factors for postoperative endophthalmitis in patients who had cataract surgery over 11 years were reviewed. Subconjunctival antibiotic agents only were administered over 7 years; in the subsequent 4 years, intracameral cefazolin (1.0 mg/0.1 mL) was used. Results: The overall incidence of postoperative endophthalmitis in 50177 was 0.042%. Over the 7 years without intracameral antibiotics, the endophthalmitis rate was 0.064% (19/29539). With the use of intracameral cefazolin, the incidence decreased to 0.01% (2/20638) (multivariate odds ratio [OR], 13.6; 95% confidence interval [CI], 3.15-58.58; P<.001). The independent risk factors for endophthalmitis were age (OR, 1.05; 95% CI, 1.01-1.09; P=.025) and male sex (0.06% versus 0.02%; OR, 2.96; 95% CI; 1.15-7.65; P=.025). Conclusions: There was a significant reduction in the rate of postoperative endophthalmitis in a multiethnic Asian population with the use of intracameral cefazolin. Men and older patients were at a higher risk for endophthalmitis. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. © 2012 ASCRS and ESCRS. Source

Discover hidden collaborations