Limiting Screen Time Improves Foveal Responses in Computer Vision Syndrome

Limiting screen time may improve foveal responses in individuals with computer vision syndrome (CVS), according to a study published in Clinical Ophthalmology. These findings suggest that foveal dysfunction resulting from excessive screen time may be reversible, according to the report.  

Researchers included 49 medical school students in the prospective cohort comparative study consisting of individuals with CVS (n=24; mean age, 21.36 years; 14 women) and age- and sex-matched control group participants without a CVS diagnosis (n=25; mean age, 21.56 years; 13 women). Participants underwent ophthalmic examinations, fundus and multifocal electroretinogram (mfERG) assessments, and completed the CVS-Form 3 (CVS-F3) questionnaire at baseline and 4 weeks after limiting their daily screen time to 1 hour or less per day. 

Individuals with CVS reported significantly more daily screen time compared with individuals without CVS (5.48 vs 2.32 hours; P <.0001).

Baseline mfERG assessment revealed that patients with CVS had smaller amplitudes in rings 1 through 5 (mean difference [MD] range, -32.40 to -1.50 nV/deg²; P ≤.07 for all) and quadrants 1 through 4 (MD range, -2.60 to -1.82 nV/deg²; P ≤.05 for all) compared with control group participants.

At the 4-week follow-up visit, no significant differences in corrected distance visual acuity were noted between the 2 groups (MD, 0.04; 95% CI, -0.006-0.08 logarithm of the minimum angle of resolution [logMAR]; P =.09).

The mfERG examination revealed that the amplitudes in rings 2 (P =.57) and 3 (P =.25) were similar between the groups at the follow-up visit, but the amplitudes in rings 1 (MD, -17.64 nV/deg²; P <.0001), 4 (MD, -1.50 nV/deg²; P =.03), and 5 (MD, -2.34 nV/deg²; P =.0004) remained significantly lower among individuals with CVS. Similarly, the amplitudes in quadrants 1 (P =.49) and 3 (P =.31) were similar between groups at follow-up, but lower in quadrants 2 (MD, -2.96 nV/deg²; P =.0001) and 4 (MD, -2.14 nV/deg²; P =.002).

A subgroup assessment of individuals with CVS revealed that reducing the screen time improved visual outcomes and mfERG amplitudes in rings 1, 2, 3, and 5 (P ≤.02 for all) and in quadrants 1 and 3 (P ≤.04 for both), indicating better foveal response compared with baseline.

“The current study outcomes proved the existence of screen-induced foveal dysfunction as mfERG sign of CVS,” according to the researchers. “We think that the mfERG changes elicited by the screen-induced foveal dysfunction are reversible with strict reduction of screen-time to ≤1 screen-hour daily resulting in significant post-reduction improvements in the foveal responses.”

Study limitations include a small sample size and the use of convenience sampling.