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PURPOSE: To study the prevalence of the prescription glasses given to first-grade students due to the "Good Sight for Thai Children" (GSTC) policy. METHODS: This was a cross-sectional study that examined all prescription glasses given to first-grade students throughout Thailand, after visual screening due to the GSTC policy between 2016 and 2017. Trained class teachers screened their students' visual acuity and referred children who had less than 20/40 visual acuity in either eye to a hospital for an eye examination and prescription glasses. RESULTS: A total of 786,729 students were screened. Of these, 20,401 (2.59%) students were referred to hospital. However, only 9867 (48.37%) students presented to a hospital. Glasses were prescribed for 5324 (53.96%) students following cycloplegic refraction by ophthalmologists or trained refractionists. The mean spherical equivalent was -1.08 (-19.00 to +10.00, SD 2.32) diopters. There were 1626 (30.54%) children at amblyopic risk without glasses. A 5.49% had high myopia (< -6 diopters), 5.22% had high hyperopia (> +5 diopters) and 27.82% had high astigmatism (>2 diopters). A cylindrical lens analysis showed that 81.53% had with-the-rule astigmatism, 4.07% had against-the-rule astigmatism, and 14.40% had oblique astigmatism. CONCLUSION: Although the reliable prevalence of refractive error cannot be estimated, the prevalence of visual impairment may be estimated. There were a number of students who required glasses. The astigmatism was the most common refractive error on prescription glasses for first-grade children. With-the-rule astigmatism was the most prevalent. The visual screening program of school children proved to be valuable and should be continued and developed.
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PURPOSE: To analyze radiological characteristics of the extraocular muscles (EOMs) in myasthenia gravis (MG) patients with ocular manifestations. PATIENTS AND METHODS: This retrospective case-control study included all MG cases with ocular manifestations, who attended a neuro-ophthalmology clinic at a university hospital, Bangkok, from April 2009 to June 2018. They experienced double vision and ophthalmoplegia. Control participants had normal eye movements. Orbital scans were thoroughly reviewed. We measured muscle thickness (MT) of the superior rectus, inferior rectus, medial rectus and lateral rectus muscles in both eyes using magnetic resonance imaging or computed tomography scan. The sum of the muscle thickness at all sites was calculated (MTsum). Comparisons of the mean MT of each muscle type and the mean MTsum between the MG and control groups were performed by using Student's t-test. MRI signal intensities of the EOMs were also recorded. RESULTS: Twenty MG cases and 20 controls were included in the study. The mean MTsum was 23.7 (standard deviation 4.8) mm in the MG group and 32.6 (3.5) mm in the controls. There were statistically significant differences between the two groups with respect to the mean MT and mean MTsum (p <0.001). In the MG group, there was a negative correlation between the MTsum and disease duration (p= 0.03). By using coronal T2-weighted orbital MRI with fat suppression (T2W/FS), the most frequent finding was isointensity with central hypointensity of the EOMs in the MG group. CONCLUSION: Atrophic EOMs were frequently found in the MG group, particularly in chronic cases. Isointensity with central hypointensity of EOMs on T2W/FS was also common in the MG group. These findings highlight the importance of muscle involvement in MG and may be helpful for clinical decision-making.
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Vertebrobasilar dolichoectasia (VBD) is a rare dilative arteriopathy defined as elongation or widening of the intracranial vertebral and/or basilar arteries. The prevalence ranges from 0.06% to 5.8%. The majority of VBDs are asymptomatic. Downbeat nystagmus has been reported as a component of an infrequent ocular movement disorder in VBD. Nevertheless, oculopalatal tremor (OPT), delayed sequelae of a brainstem lesion, has never been demonstrated in VBD cases. Synchronized rhythmic involuntary contractions of the soft palate with an ocular pendular nystagmus, predominantly vertical pendular nystagmus, are the hallmark presentation. Our case demonstrated a 50-year-old female who presented with 3-month history of oscillopsia. Examination showed binocular conjugate torsional jerk nystagmus simultaneous with a contraction of the soft palate, defined as an atypical OPT, resulting from dolichoectatic left vertebral artery compressing on medulla, demonstrated by magnetic resonance imaging. Bilateral conjugate torsional jerk nystagmus simultaneous with palatal tremor, considering as an atypical OPT, should be included as one of the symptomatic presentations of vertebral artery dolichoectasia in spite of its rarity.
