METHODS: A population-based survey of refractive errors in a cohort of 15,095 military conscripts between July 1996 and June 1997 using noncycloplegic autorefraction and a standard questionnaire. Prevalence rates of myopia (
PURPOSE: The present study aims to look at the association between CH and severity of OSAS, and whether CH could be another link between OSAS and the development of glaucoma.
METHODS: This was a cross-sectional, observational study at the University Malaya Medical Centre, Kuala Lumpur. Patients undergoing polysomnography for assessment of OSAS were recruited. We measured central corneal thickness (CCT) using optical biometry, and CH using ocular response analysis. Intraocular pressure (IOP) and Humphrey visual field (HVF) indices were also measured. The Apnea Hypopnea Index (AHI) divided patients into normal, mild, moderate, and severe OSAS categories. The normal and mild categories (47.9%) were then collectively called group 1, and the moderate and severe categories (52.1%) were called group 2. T tests, Pearson correlation tests, and general linear model analysis were performed, with P .05). CH correlated negatively with AHI (r = -0.229, P = .013) and positively with lowest oxygen saturation (r = 0.213, P = .022).
CONCLUSIONS: CH is lower in moderate/severe OSAS than in normal/mild cases. This may be another link between OSAS and the development of glaucoma; further studies are indicated to determine the significance of this connection.
PURPOSE: The purpose of this study was to compare habitual visual acuity in a sample of young children using two versions of the single Lea symbols charts with different crowding features.
METHODS: Monocular habitual visual acuity was measured in a sample of 77 young children aged between 4 and 6 years using crowded Lea symbols charts with either flanking bars separated from the central symbol by 0.5 optotype width or flanking Lea optotypes separated from the central symbol by 1.0 optotype width.
RESULTS: Mean visual acuity was higher (i.e., lower logarithm of the minimum angle of resolution) with the Lea symbols crowded using flanking optotypes, equivalent to about 1.5 optotype difference. Visual acuity measured with the two charts was significantly correlated; however, the 95% limits of agreement were larger than expected from repeatability studies using Lea symbols.
CONCLUSIONS: Lea symbols with flanking optotypes resulted in higher visual acuity than the Lea symbols with flanking bars, probably as a result of differences in the crowding effect. The two charts showed insufficient agreement, and we do not recommend their use interchangeably. We recommend using the Lea symbols with flanking bars because of the closer flanker-target separation.
PURPOSE: Little is known about the effect of e-cigarettes on the eyes except for reported eye irritation among individuals who were exposed to e-cigarette vapors and e-liquids. This study aims to investigate the effect of vaping on ocular surface health of long-term vapers.
METHODS: Twenty-one vapers and 21 healthy nonsmokers who are all male underwent measurements of the Ocular Surface Disease Index, noninvasive tear breakup time, fluorescein breakup time, ocular surface staining, tear meniscus height, and the Schirmer test. The effect of voltage used during vaping was also evaluated against the measurements.
RESULTS: Vapers experienced moderate-to-severe eye dryness (25.0 [interquartile range, 14.6 to 43.7]) as indicated by the Ocular Surface Disease Index. Significant reductions of noninvasive tear breakup time (3.13 ± 0.97 vs. 6.57 ± 2.31 seconds; P < .0001), fluorescein breakup time (2.68 [interquartile range, 2.33 to 3.18] vs. 4.12 [3.56 to 5.07] seconds; P < .0001), and tear meniscus height (203.0 [193.0 to 225.5] vs. 235.0 [210.0 to 253.50] μm; P = .002) were noted in vapers, but the Schirmer test showed higher results (14.5 [12.0 to 17.0] vs. 8.0 [7.0 to 11.0] mm; P = .001) compared with nonsmokers. Increase in vaping voltage aggravated the dry eye symptoms and tear instability (P < .05). Higher Schirmer test result was also noted as voltage increases.
CONCLUSIONS: Vapers showed moderate-to-severe symptomatic dry eye and poorer tear film quality compared with nonsmokers. High vaping voltage may have aggravated the dry eye syndrome because of hazardous by-products from pyrolysis of the e-liquid constituents. Investigation of the ocular surface health at cellular and molecular levels is warranted to gain a deeper understanding on the effect of e-cigarette to the eyes.