Analysis of vision screening failures in a school-based vision program in Baltimore, MD

Abstract

Purpose : Vision screenings are often the way in which vision problems are identified in school-aged children. However, mandates for screening vary substantially by state, with many states requiring only one or two screenings over the entire elementary school period. We conducted a cross-sectional analysis to compare the rates of screening failure among Baltimore schoolchildren.

Methods : Between September 2016-June 2018, 32650 pre-kindergarten to eighth grade students in 82 Baltimore City Public Schools underwent vision screenings (distance acuity, Spot photoscreener, stereopsis, and alignment) conducted by Baltimore City Health Department staff. We examined the overall rate of screening failure, as well as the rate of failure by grade and the reason for failure (visual acuity vs. refraction). Screening failure due to visual acuity was defined as 20/50 or worse in either eye for students in pre-kindergarten, 20/40 or worse in either eye for students in kindergarten and older, or a ≥ 2 lines difference between eyes for all students. Failure by visual acuity and refraction were not mutually exclusive. A chi-square test was used to compare the rates of screening failure in state-mandated grades (pre-kindergarten or kindergarten, first, and eighth grade) to that in non-mandated grades.

Results : Over a two-year period, 10868 (33.3%) students failed vision screening. High failure rates were seen across all grades (range: 26.0% to 40.7%). Reduced visual acuity was the primary reason for screening failure. Among students who failed screening, 62% failed due to refractive error and 89% failed due to visual acuity, with a median visual acuity of 20/50 (range: 20/50 to 20/100 in pre-kindergarten; 20/40 to 20/160 in kindergarten and up). Failure by grade due to visual acuity ranged from 65% to 94%; failure by grade due to refractive error ranged from 53% to 81%. Failure rates were higher in non-mandated grades compared with mandated grades (34.5% vs. 30.6%, p<0.001).

Conclusions : Nearly one-third of Baltimore city grade school students failed vision screening, with failure rates higher in non-mandated grades compared with mandated grades. Screening only at select grade levels may not be sufficient in high-poverty urban school districts.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.