Peek Acuity vs Snellen Chart for visual impairment screening in leprosy: a cross-sectional study

Objective: Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which has a high incidence of ocular involvement. Due to the need for good vision for leprosy patients, visual acuity becomes an essential early screening examination. The Snellen Chart has been commonly employed as the standard for measuring visual acuity. Nevertheless, it is immobile and time-consuming. A smartphone-based application, Portable Eye Examination Kit (Peek Acuity), is already known to be accessible, reliable and easy to use for measuring visual acuity. This study examines the reliability of Peek Acuity in performing visual acuity screening for leprosy patients. Methods: A population-based cross-sectional study was carried out at a leprosy settlement village near Sitanala Hospital, Tangerang and Alverno Hospital, Singkawang. Participants' uncorrected visual acuity was measured using both the Snellen Chart and Peek Acuity. The scores were converted into logMAR. Results: This study involved 347 subjects which included 692 eyes (2 eyes were anophthalmic). The mean difference between the Snellen chart and Peek Acuity was 0.11 logMAR (95% CI, 0.096 to 0.13). Linear regression analysis showed no statistically significant difference between the Snellen Chart and Peek Acuity measurements (P =0.98). Cohen's Kappa and concordance rate of visual acuity measured with Peek Acuity and Snellen Chart were 0.65 and 0.83. Conclusion: Peek Acuity is an accurate and repeatable visual acuity screening tool as effective as the Snellen Chart, which also can be used for leprosy patients to overcome barriers in accessing eye health services, especially in rural areas.