Effects of Melatonin Supplementation on Sleep Quality in Patients with Advanced Glaucoma: A Randomized,...

To evaluate the effect of oral melatonin administration in patients with advanced glaucoma on sleep-wake cycle variables recorded by actigraphy on a single night and sleep quality assessed by specific questionnaires.

Prospective, randomized, parallel, crossover, double-masked therapeutic-type.

Sixty-four patients aged between 40 and 80 years, diagnosed with advanced primary open-angle glaucoma, were included.

Participants received 5 mg of melatonin or placebo daily for 30 days, 1-week washout period; all assessments were repeated after each treatment phase. Subjective sleep was evaluated using the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS). Objective sleep parameters total sleep time (TST), wake after sleep onset (WASO), number of awakenings, and sleep efficiency (SE) were measured by actigraphy. Vision-related quality of life was assessed using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Standardized ophthalmologic exams, visual field testing (Swedish Interactive Threshold Algorithm Standard 24-2), and OCT-based retinal nerve fiber layer analysis were also performed.

The primary outcomes were PSQI and actigraphy-measured SE. The secondary outcomes included TST, WASO, number of awakenings, ESS, and NEI VFQ-25 scores.

All 64 participants completed the study. No significant differences were found between melatonin and placebo for any sleep or quality of life outcomes. However, both groups showed improvements over time: PSQI scores decreased (-1.36 points; P < 0.001) and NEI VFQ-25 scores increased (+3.09 points; P < 0.001), indicating a temporal effect. Poor sleep quality (PSQI > 5) and reduced SE were associated with worse objective sleep parameters and lower vision-related quality of life. No carryover or sequence effects were observed, and melatonin did not significantly impact actigraphy measures such as TST, WASO, or number of awakenings.

Melatonin supplementation did not significantly improve sleep quality compared to a placebo in patients with advanced glaucoma, based on both subjective and objective measures. The improvements observed in the sleep questionnaires during the treatment phases suggest that patient perception may play a significant role in sleep-related outcomes, underscoring the importance of considering placebo effects in clinical trials.

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