Effect of Smartphone Usage on Intraocular Pressure and Evaporative Dry Eye Changes in Healthy Adults

Abstract Clinical Relevance: With the growing concern of excessive screen use during pandemic era, there is an increasing need to determine the effect of smartphone use on intraocular pressure (IOP) and ocular surface in healthy adults for future targeted preventive measures. Purpose: To investigate the effect of smartphone usage in terms of IOP and evaporative dry eye changes at the different lighting conditions. Methods: A prospective comparative study involving 112 eyes of 56 healthy adults (age <40 years) was conducted in a suburban community. The participants were requested to watch preselected videos on the smartphone (Google PIXEL 2XL) for 20 min, under standardized bright room and dim room conditions on different examination days. Three sets of IOP examinations were performed each day using the Goldmann Applanation tonometer: pre-work, during smartphone work [10 min], and immediately post-work [20 min]. Tear break up time (TBUT) was recorded before every IOP measurement. Results: Under the bright light, the mean pre-work IOP was 13.3 ± 1.9 mmHg, and after 10 min of work, the mean IOP increased to 14.0 ± 2.3 mmHg. When the smartphone use lasted for 20 min, the IOP showed a further significant increase (14.4 ± 2.4 mmHg; P < 0.001). Under the dim-light condition, the mean IOP significantly increased after 10 min (from 13.6 ± 1.9 to 14.1 ± 2.0 mmHg) and further increased to 15.0 ± 2.2 mmHg ( P < 0.001) at 20 min. The percentage of IOP rise is significantly higher in dim light conditions than in bright light (mean difference = 3.1%, P = 0.011). The mean TBUT significantly declined over the 20 min in both bright and dim light (from 8.1 to 4.0 seconds from 7.0 to 3.5 sec respectively; P < 0.001). Conclusion: In healthy adults, smartphone usage for 20 min induced a small but significant elevation in IOP, which is still within the physiological fluctuation range. IOP rise and reduced tear film stability is more prominent under dim light conditions.