Conjunctival Ultraviolet Autofluorescence: A Systematic Review of Factors Affecting Observed Ocular Damage

Abstract Purpose Conjunctival ultraviolet autofluorescence (CUVAF) is a marker for ocular sun damage. While its potential is recognised in research, factors influencing its development and temporal dynamics remain poorly documented. This systematic review evaluates whether the size of CUVAF reflects recent ultraviolet (UV) exposure, lifetime cumulative damage or both. Recent findings Google Scholar, PubMed, Embase, Scopus and ProQuest Global databases were searched for papers using defined search terms. Ninety-one articles were assessed and 35 studies using CUVAF as an indicator of sun exposure were analysed. Extracted data included study location, CUVAF area (mean/median, mm²)/presence or pattern, participant’s age, skin type, occupation, time spent outdoors, UV protection behaviour, the presence of UV eye disease and seasonal variations if assessed. Study quality was evaluated using the Newcastle–Ottawa-Scale. A locally weighted scatterplot smoothing (LOWESS) and polynomial curve were generated to visualise age-related trends. CUVAF area peaked in young adults and followed nonlinear, oscillating pattern with age. High ambient UV regions like Australia showed greater weighted average CUVAF (28.8 mm², range: 0.6–45.4 mm 2 ) compared to moderate or lower UV regions such as India (6.8 mm², range: 4.3–11.1 mm 2 ), the USA (7.5 mm², range: 5.5–9.2 mm 2 ) and Europe (5.3 mm², range 0.4–6.4 mm 2 ). Outdoor work and fair pigmentation were associated with larger CUVAF area. CUVAF size did not vary with season. Myopes had smaller average CUVAF areas than non-myopes (14.5 vs. 21.5 mm²). Eyes with UV-related eye disease exhibited larger average areas (43.4 vs. 20.7 mm 2 ) compared to healthy eyes. There was no reported correlation between sunglass use and CUVAF. Artificial UV irradiation temporarily increased CUVAF area. Summary Age-related oscillations in CUVAF, larger values in high-UV regions and transient increases following artificial UV exposure suggest that CUVAF may reflect both acute conjunctival responses and cumulative UV exposure. However, its ability to capture dynamic changes under natural environmental UV remains uncertain without longitudinal data.