Functional visual acuity captures disease severity in Stevens-Johnson syndrome

This study determined that functional visual acuity examination reflects the severity of clinical ocular surface findings and vision-related quality of life in patients with Stevens-Johnson syndrome (SJS) better than standard conventional visual acuity testing. The study's authors also found that SJS patients with good or intermediate visual acuity scores measured by conventional visual acuity testing suffered from lower vision-related quality of life, as assessed by functional visual acuity testing and National Eye Institute Visual Function Questionnaire (VFQ-25) scores.

The study included 59 patients (115 eyes) with SJS and toxic epidermal necrolysis (TEN), 104 healthy normal subjects (208 eyes), and 66 Sjogren syndrome (SS) patients (132 eyes). All subjects underwent tear function and ocular surface examinations, Landolt and functional visual acuity examinations, and the Japanese version of the VFQ-25.

The mean ocular surface grading scores were significantly higher and the mean score of all VFQ-25 subscales significantly lower in the SJS patients compared to SS patients and normal subjects (P < 0.05). Conventional and functional logMAR visual acuities in SJS patients with minimal corneal complications were significantly higher and the mean total composite VFQ-25 scores were lower compared to SS patients.

The conventional and functional logMAR visual acuities and the mean ocular surface grading scores in SJS with aqueous deficiency were significantly higher and the mean total composite VFQ-25 scores were lower compared to SS patients. Strong correlations between best-corrected logMAR functional visual acuities and either ocular surface grading scores or the composite VFQ-25 scores were observed.

The authors say that the strong correlation of functional visual acuity with ocular surface grading score in SJS patients suggests that, unlike conventional visual acuity testing, functional visual acuity testing may be detecting the effect of ocular surface disease severity on other visual functions, such as contrast, glare, or higher-order aberrations.