Image-derived conjunctival hyperemia and clinical ocular surface changes after initiation of topical glaucoma therapy: a prospective longitudinal pilot study

Abstract Topical glaucoma therapy can affect the ocular surface, but objective longitudinal data on conjunctival hyperemia are limited. We prospectively followed 31 patients naive to topical antiglaucoma therapy for 24 weeks after treatment initiation, analyzing one baseline severity-selected eye per participant. All 31 participants contributed complete analyzable conjunctival image series at baseline and 6, 12, and 24 weeks. Automated image processing quantified strong red area as the primary hyperemia metric and blood vessel area as a secondary metric. Tear breakup time (TBUT), Schirmer I testing, National Eye Institute (NEI) corneal staining, Ocular Surface Disease Index (OSDI), and NEI Visual Function Questionnaire-25 were also assessed. Strong red area increased numerically by 2.56 percentage points at 24 weeks (95% CI − 1.06 to 6.18; P = 0.165), while blood vessel area remained stable. NEI staining decreased, TBUT and Schirmer I showed no significant overall change, OSDI scores decreased (overall P = 0.002), and NEI-VFQ-25 scores improved. Over 24 weeks, image-derived conjunctival hyperemia showed no statistically significant persistent increase, whereas clinical ocular-surface signs and patient-reported outcomes followed differing trajectories. These preliminary findings characterize ocular-surface changes after initiation of topical glaucoma therapy, although the small uncontrolled design precludes causal or equivalence conclusions.