Utilization of eye care services among those with unilateral visual impairment in rural South India：Andhra Pradesh Eye Disease Study(APEDS)

AIM：To report on the utilization of eye care services and its associated factors among those with unilateral visual impairment（VI）in a rural South Indian population.METHODS：A population based cross-sectional study was conducted in three districts（Adilabad,Mahbubnagar and West Godavari）in the state of Andhra Pradesh,India.A detailed interview and a comprehensive eye examination were conducted. Those with unilateral VI were asked questions about noticing any change in vision and on utilization of eye care services. The most important reason reported by the participant for not utilizing the services was used for the analysis. Multiple logistic regression models were used to examine the association between noticing a change in vision and socio-demographic variables such as age,gender,education and area of residence,severity and causes of VI.RESULTS：Among the 4456 participants aged ≥16y who were administered the questionnaire,53.2% were women,and 54.7% had no education. Of the 489（11%; 95% CI：10.1-11.9）people with unilateral VI,399（81.6%）participants reported noticing a change in their vision over the last five years but only 136（34.1%）participants had soughteye care consultation. Those who had any education（OR：1.9; 95% CI：1.1-3.2）,had blindness（OR：2.7; 95% CI：1.4-5.2）,and cataract（OR：2.1; 95% CI：1.0-4.3）as a cause of unilateral VI were more like to seek eye care consultations. The most commonly reported reasons for not seeking eye care services were ＂do not have money for eye checkup＂ in 30.7% of the participants followed by ＂do not have a serious problem＂（30.0%）.CONCLUSION：A large proportion of rural population though noticed a change in their vision did not seek eye care due to financial and person-related reasons. Eye care service providers need to address these barriers to enhance the uptake of eye care services among those with unilateral VI.

Unilateral visual impairment in rural south India-Andhra Pradesh Eye Disease Study(APEDS)

AIM： To report the prevalence and causes of unilateral visual impairment（UVI） in rural population of all ages in rural Andhra Pradesh, India.·METHODS： A population-based cross sectional study using a multi-stage cluster sampling methodology was carried out in West Godavari, Adilabad and Mahbubnagar districts in south India. A comprehensive eye examination that included presenting and best corrected visual acuity and dilated fundus examination was conducted by trained professionals. UVI is defined as presenting visual acuity 6/18 in one eye but ≥6/18 in other eye. Multiple logistic regression analysis was used to test association of UVI with socio-demographic risk factors.· RESULTS： Data were analyzed for 6634/7771 participants after excluding those with bilateral visual impairment. The mean age of the participants was 27.4y（Standard deviation： 17.9y）, 51.9% were women and49.1% were educated. The prevalence of UVI was 7.8%（95% CI： 7.2%- 8.5%）. Uncorrected refractive error（60.8%）, cataract（17.4%） and retinal causes（6.6%） were the leading causes of UVI. On multiple logistic regression analyses, older age, not having education, living in welloff district had significantly higher odds of being associated with UVI. UVI was not associated with gender.·CONCLUSION： UVI is common in rural south India.Most of it is due to cataract and refractive errors, both of which can be addressed at primary and secondary levelsof eye care. Burden of UVI should also be considered in planning eye care services.

Comparison of ocular modulation transfer function determined by a ray-tracing aberrometer and a double-pass system in early cataract patients

Background The evaluation of retinal image quality in cataract eyes has gained importance and the clinical modulation transfer functions （MTF） can obtained by aberrometer and double pass （DP） system. This study aimed to compare MTF derived from a ray tracing aberrometer and a DP system in early cataractous and normal eyes. Methods There were 128 subjects with 61 control eyes and 67 eyes with early cataract defined according to the Lens Opacities Classification System II1. A laser ray-tracing wavefront aberrometer （iTrace） and a double pass （DP） system （OQAS） assessed ocular MTF for 6.0 mm pupil diameters following dilation. Areas under the MTF （AUMTF） and their correlations were analyzed. Stepwise multiple regression analysis assessed factors affecting the differences between iTrace- and OQAS-derived AUMTF for the early cataract group. Results For both early cataract and control groups, iTrace-derived MTFs were higher than OQAS-derived MTFs across a range of spatial frequencies （P 〈0.01）. No significant difference between the two groups occurred for iTrace-derived AUMTF, but the early cataract group had significantly smaller OQAS-derived AUMTF than did the control group （P 〈0.01）. AUMTF determined from both the techniques demonstrated significant correlations with nuclear opacities, higher-order aberrations （HOAs）, visual acuity, and contrast sensitivity functions, while the OQAS-derived AUMTF also demonstrated significant correlations with age and cortical opacity grade. The factors significantly affecting the difference between iTrace and OQAS AUMTF were root-mean-squared HOAs （standardized beta coefficient=-0.63, P 〈0.01） and age （standardized beta coefficient=0.26, P 〈0.01）. Conclusions MTFs determined from a iTrace and a DP system （OQAS） differ significantly in early cataractous and normal subjects. Correlations with visual performance were higher for the DP system. OQAS-derived MTF may be useful as an indicator of visual performance in early cataract eyes.