Paul Zhao

Choroidal thickness and high myopia: a case-control study of young Chinese men in Singapore.

To determine the distribution of choroidal thickness (CT) and ocular factors associated with CT in high myopic eyes in comparison with emmetropic eyes of young healthy adults.

Peripapillary choroidal thickness in young Asians with high myopia.

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.

Choroidal thickness does not predict visual acuity in young high myopes

To investigate the influence of choroidal thickness (CT) on visual acuity (VA) in young persons with extremely high myopia.

Correlation of structural and electrophysiological changes in the retina of young high myopes

Despite a high prevalence of myopia among young East Asian adults, there is a lack of data on the myopic retina structure‐function relationship in this group. We examined the association between optical coherence tomography (OCT) and electroretinogram (ERG) measurements in highly myopic young Asian adults to provide this information and also determined if OCT can be used as an alternative screening tool to assess retinal function in young myopic adults.

Pearls & Oy-sters: Looking up the anatomy of looking up

A 46-year-old Chinese man with diabetes mellitus, hypertension, and hyperlipidemia, developed sudden onset of vertiginous dizziness and diplopia that was worse on looking up. His symptoms were not preceded by any antecedent infections, neither was there any headache. Blood pressure on arrival in the Emergency Department was 145/95 mm Hg and his neurologic examination revealed bilateral upward gaze restriction (video on the Neurology® Web site at Neurology.org). There was voluntary lid retraction by the patient. The pupils were 3 mm bilaterally and reactive to light and accommodation, there was no ptosis or nystagmus, and no fatigability could be elicited. Apart from esophoria and pseudo-6th nerve palsy, the rest of the eye movements were normal. Other cranial nerves, motor, sensory, and cerebellar examinations were unremarkable. The vertical optokinetic reflex was intact and there was no tremor of the upper limbs. On forced eye closure, there was upward deviation of his eyes consistent with the Bell phenomenon. ECG did not show any atrial fibrillation or ischemic changes. The basic blood investigations were unremarkable. He was initially diagnosed with myasthenia gravis with frontalis overactivity and complex ophthalmoplegia by the admitting emergency physicians.

Peripheral retinal changes in highly myopic young Asian eyes

To determine the type and prevalence of peripheral retinal changes and its relationship with axial length (AL) in a population of young Asian adult males.