ABSTRACT
PURPOSE: To describe the topography and predictors of peripapillary choroidal thickness (PPCT) in highly myopic eyes of young, healthy, Asian subjects. METHODS: A total of 870 young male subjects aged 21.63 ± 1.15 years were recruited from the Singapore military. Choroidal imaging was performed using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT). Peripapillary choroidal thickness was manually measured at eight locations around the optic disc. RESULTS: We analyzed 448 subjects with high myopia (defined as spherical equivalent [SE] worse than -6.0 diopters [D]) and 116 with emmetropia (SE > -0.5 and < 0.5 D). The mean SE was -8.52 ± 1.20 D for the high-myopic group, and 0.11 ± 0.24 D for the emmetropic group. The mean peripapillary choroid was significantly thinner (142.62 ± 43.84 µm) in high myopes compared with emmetropes (181.90 ± 46.43 µm, P < 0.001). Likewise, PPCT showed further decrease with increase in degree of myopic refractive error. Distribution of PPCT showed a markedly different pattern in high-myopic eyes (thickest superiorly) and emmetropic eyes (thickest temporally). However, peripapillary choroid in both the groups was thinnest at the inferior location. Among the ocular factors studied, axial length, IOP, presence of posterior staphyloma, and chorioretinal atrophy were the factors significantly associated with PPCT. CONCLUSIONS: Highly myopic eyes have significantly thinner peripapillary choroid and showed different distribution of thickness, compared with emmetropes. Axial length, IOP, and presence of posterior staphyloma and chorioretinal atrophy significantly influence PPCT and should be taken into consideration during clinical interpretation of PPCT measurement.
Subject(s)
Asian People , Choroid/pathology , Myopia/ethnology , Myopia/pathology , Optic Disk/pathology , Adolescent , Adult , Corneal Dystrophies, Hereditary/ethnology , Corneal Dystrophies, Hereditary/pathology , Emmetropia/physiology , Fundus Oculi , Humans , Male , Optic Disk Drusen/ethnology , Optic Disk Drusen/pathology , Optical Imaging , Reference Values , Refraction, Ocular/physiology , Tomography, Optical Coherence/methods , Young AdultABSTRACT
BACKGROUND: Several studies have suggested racial differences in the prevalence of optic nerve head drusen (ONHD). We aimed to determine the percentage of patients with ONHD who are black and to describe the clinical, ophthalmoscopic, and perimetric findings in these patients. METHODS: We conducted a retrospective chart review of all patients with ONHD seen at our institution between 1989 and 2010. Only black patients with ONHD confirmed on either funduscopy or B-scan ultrasonography were included. Demographic and clinical findings in these patients were recorded and analyzed. RESULTS: Of the 196 patients with confirmed ONHD, 10 (5.1%) were black. This included 7 females and 3 males with ages ranging from 8 to 61 years. Six of the 10 patients had bilateral ONHD. The ONHD were buried in 11 of 16 eyes and exposed in 5 of 16 eyes. Fifteen of 16 eyes with ONHD had small cupless optic nerve heads. Visual fields were normal in 4 of 16 eyes with ONHD. In the remainder, visual field defects included an enlarged blind spot (5 eyes), constricted field (5 eyes), nasal defect (2 eyes), central defect (1 eye), and generalized depression (1 eye). Visual field defects were present in 4 of 5 eyes (80%) with exposed ONHD and 8 of 11 eyes (72.7%) with buried ONHD. None of the patients were related, and none of their examined family members had exposed ONHD on funduscopic examination. CONCLUSIONS: ONHD are rare in blacks, possibly due to the presence of a larger cup-to-disc ratio or a lack of predisposing genetic factors. Visual field defects are common in black patients with both exposed and buried ONHD.
