Aqueous And Serum Melatonin Level In Myopes And Its Relation To Sun Exposure

Published 2023 - 41st Congress of the ESCRS

Reference: PO0976 | Type: Free paper | DOI: 10.82333/1te1-4m77

Authors: Hemant Jhajharia* ¹ , Noopur Gupta ¹ , Saumya Kumari ¹ , Vivek Gupta ¹ , M Vanathi ¹ , T Velpandian ¹ , Rohit Saxena ¹ , Praveen Vashist ¹ , Radhika Tandon ¹

¹Ophthalmology,Dr. R.P. Centre of ophthalmic sciences,New Delhi,India

Purpose

To explore the role of ultraviolet (UV) light exposure and circadian rhythm by estimating ocular sun exposure as measured conjunctival ultraviolet autofluorescence (CUVAF) and quantifying aqueous melatonin levels in myopes.

Setting

Cross-sectional, comparative study

Methods

30 emmetropes and 32 myopes were included in the study. Demographic profile, sun exposure questionnaires, morning serum melatonin, sleep pattern, degree of myopia, ocular biometry and area of CUVAF (objective biomarker for ocular UV exposure) were noted and analyzed. Aqueous melatonin was estimated in 32 myopes who underwent phakic IOL (intraocular lens) surgery.

Results

Mean duration of myopia was 15.7 ± 2.8 years with positive family history in 34.4%. Sleep duration was higher in myopes (p=0.01). Daily activity profile indicated a higher screen time amongst myopes (p=0.02). Mean axial length was significantly higher (p<0.0001) in myopes than emmetropes (27.35 vs 23.46 mm). Lifetime sun exposure and CUVAF area was higher among emmetropes (p =0.028;p<0.0001). Serum melatonin level was higher in myopes (1329.21 vs 39.73 pg/ml;p=0.0006). Aqueous melatonin was detectable in 40.26% (26/64) eyes with a mean value of 2.10 pg/ml and showed a rising trend with degree of myopia. There was no statistical association between aqueous melatonin and refractive error (p=0.29) or axial length (p=0.39) or age (p=0.40).

Conclusions

This study demonstrates an inverse relationship between serum melatonin and ocular UV exposure as measured by CUVAF in myopes. Ultraviolet exposure as measured by CUVAF area and through questionnaires was significantly more in emmetropes than in myopes, thus signifying a protective role of UV exposure in myopia. This study establishes the link between quantitative assessment of ocular UV exposure (CUVAF) and biochemical alterations (melatonin) in myopes. However, a link between aqueous melatonin levels and degree of myopia could not be established.