Digital eye strain in young screen users: A systematic review.

Digital eye strain (DES) or computer vision syndrome (CVS) is a phenomenon linked to ever increasing digital screen use globally, affecting a large number of individuals. Recognizing causative and alleviating factors of DES may help establish appropriate policies. We aimed to review factors that aggravate or alleviate DES symptoms in young, i.e. pre-presbyopic (< 40 years old), digital device users. We searched PubMed, Scopus, EMBASE, Cochrane, Trip Database, and grey literature up to 1st July 2021. Among a plethora of studies with heterogeneous diagnostic criteria for DES, we only included those using a validated questionnaire for the diagnosis and evaluating associated factors in young subjects. Relevant data were extracted, risk of bias assessment of the included studies and GRADE evaluation of each outcome were performed. Ten studies were included (five interventional, five observational) involving 2365 participants. Evidence coming from studies with moderate risk of bias suggested that blue-blocking filters do not appear to prevent DES (2 studies, 130 participants), while use of screens for > 4-5 h/day (2 studies, 461 participants) and poor ergonomic parameters during screen use (1 study, 200 participants) are associated with higher DES symptoms' score. GRADE evaluation for the outcomes of blue-blocking filters and duration of screen use showed low to moderate quality of evidence. It appears advisable to optimize ergonomic parameters and restrict screen use duration, for minimizing DES symptoms. Health professionals and policy makers may consider recommending such practices for digital screen users at work or leisure. There is no evidence for use of blue-blocking filters.

Efficacy of Topical Levofloxacin 0.5% in Treating Levofloxacin-Resistant Pseudomonas aeruginosa-Induced Keratitis.

PURPOSE: To evaluate the efficacy of topical levofloxacin 0.5% in treating levofloxacin-resistant Pseudomonas aeruginosa-induced keratitis. DESIGN: Longitudinal study. METHODS: The study was conducted in 21 New Zealand White rabbits whose corneas were inoculated with 0.1 mL of 1000 colony-forming units of levofloxacin-resistant P. aeruginosa. After 24 hours, the rabbits were randomized into 3 groups: 9 were treated with levofloxacin 0.5%, 6 were treated with ceftazidime 50 mg/mL, and 6 were treated with a placebo. The rabbits were given a loading dose once every 5 minutes in the first hour and continued to receive a dose once an hour in the next 11 hours. Afterward, 3 rabbits treated with levofloxacin were killed. Their corneas were examined for levofloxacin concentration. The remaining rabbits continued to receive 6 regular doses for 4 more days, each of which was administered at a 2-hour interval. Levofloxacin concentration was examined. Treatment efficacy was evaluated based on 4 clinical characteristics: corneal infiltrate, conjunctival edema, conjunctival injection, and discharge. RESULTS: All clinical characteristics, except conjunctival edema, improved significantly in rabbits treated with either levofloxacin or ceftazidime, compared to the placebo group. At the last follow-up (120 hours), all clinical characteristics improved significantly in both treatment groups. Mean corneal levofloxacin concentration in the treatment groups was 6.25 (0.32) µg/g, which declined significantly to a mean of 2.15 (1.23) µg/g after another 120 hours. CONCLUSIONS: Topical levofloxacin 0.5% improved the clinical characteristics of keratitis induced by levofloxacin-resistant P. aeruginosa. Such improvement could be attributed to a high concentration of levofloxacin that was above the minimum inhibitory level.