EFFECT OF EYE COLOR ON SELECTIVE LASER TRABECULOPLASTY

EFFECT OF EYE COLOR ON SELECTIVE LASER TRABECULOPLASTY Elaine M. Miglino Arusha Gupta, MD Lawrence F. Jindra, MD

Financial Disclosures 1 st and 2 nd authors have no financial disclosure. 3 rd author has independently conducted and financed clinical research study presented and provides technical advice and consultant services to Lumenis Corporation.

Introduction Selective Laser Trabeculoplasty (SLT) uses a QSwitched frequency-doubled (532 nm) Nd: YAG laser which targets melanocytes in the pigmented trabecular meshwork. 1, 2 When treated with SLT, a primarily biologic response is induced in the trabecular meshwork which involves the release of cytokines that trigger macrophage recruitment and other changes leading to IOP reduction. 2 It treats the meshwork without causing any thermal or coagulative damage to surrounding structures. 1, 2 1. Latina MA, et al. Selective targeting of trabecular meshwork cells: in vitro studies of pulsed and cw laser interactions. Exp Eye Res. 1995; 60: 359 -372. 2. Latina MA, et al. Q-switched 532 -nm Nd: YAG laser trabeculoplasty (selective laser trabeculoplasty): a multicenter, pilot, clinical study. Ophthalmology. 1998; 105: 2082 -2090.

Objective and Methods To examine the effect of eye color (blue or brown) on SLT, in decreasing intraocular pressure (IOP) in patients with glaucoma. A retrospective chart review was performed on 137 eyes treated with SLT over 5 years; eyes were grouped as blue or brown. Two-tailed paired t-test and ANOVA were used to compare maximum pre- and post-SLT IOP.

Results: Blue Eyes 53 blue eyes were treated with SLT for glaucoma; mean follow-up was 388 days. IOP decreased from a mean of 18. 5 to 13. 6 mm Hg; this represents a 26% decrease in IOP. Data were significant with P < 0. 05.

Results: Brown Eyes 84 brown eyes were treated with SLT for glaucoma; mean follow-up was 306 days. IOP decreased from a mean of 19. 5 to 13. 3 mm Hg; this represents a 32% decrease in IOP. Data were significant with P < 0. 05.

Data Blue Eyes Brown Eyes Number of eyes (n) 53 84 Mean follow-up (days) 388 306 Pre-SLT IOP (mm Hg) 18. 5 19. 5 Post-SLT IOP (mm Hg) 13. 6 13. 3 IOP change (mm Hg) 4. 9 6. 2 % ↓ IOP 26% 32% P-value < 0. 05

Data % Decrease in IOP Eye Color vs Decrease in Post-SLT IOP Blue Eyes Brown Eyes (n = 53 eyes) (n = 84 eyes)

Summary Mean Post-SLT Reduction in IOP: Blue Eyes 26% Brown Eyes 32% The results were significant with P < 0. 05.

Conclusion In this series, SLT significantly lowered mean IOP more in brown eyes and less in blue eyes, suggesting a direct relationship between eye pigment and post-SLT reduction of IOP in patients with glaucoma.