Comparison of LogMAR Eye charts with angular vision for visually impaired: the Berkeley rudimentary vision test vs LogMAR One target Landolt ring Eye chart

Abstract

It is not common to quantify visual acuity worse than 2.0 logarithm of the minimal angle resolution (logMAR) (commensurate with decimal visual acuity 0.01) at ophthalmology clinics. Recently, the Berkeley rudimentary vision test (BRVT) was developed as a simple measurement tool of logMAR with angular vision for quantifying poor levels of visual acuity. We compared the difference between BRVT and conventional Landolt ring logMAR chart with angular vision measured by the logMAR one target Landolt ring eye chart (LogMAR LEC). We reviewed 110 patients with best-corrected visual acuity (BCVA) in the better eye from light perception (LP) to 0.8 logMAR measured by LogMAR LEC. The reproducibility of the log MAR LEC and BRVT was evaluated on 39 eyes from 20 patients, and 33 eyes from 20 patients respectively. The comparison of logMAR between BRVT and logMAR LEC was evaluated by surveying 61 eyes from 70 patients. In addition, regardless of their BCVA, the eyes from patients with worse than 2.0 logMAR by LogMAR LEC were re-evaluated by BRVT. The logMAR of patients examined by BRVT or logMAR LEC did not show any significant difference between the first and second examinations, and there was a strong correlation between the examinations in both eye charts. The BRVT significantly produced better logMAR compared with logMAR LEC, and the strong correlation was shown between both eye charts. Although 35 eyes from 28 patients among 110 patients could not be quantified by logMAR LEC, 18 eyes of 35 eyes could be quantified logMAR by BRVT. The BRVT and logMAR LEC are reliable visual acuity measurement tools. Moreover, the BRVT is potentially effective in quantifying visual acuity of the more severe visually impaired patients.