EFFECT OF EYE COLOR ON SELECTIVE LASER

TRABECULOPLASTY

Elaine M. MiglinoArusha Gupta, MD

Lawrence F. Jindra, MD

1st and 2nd authors have no financial

disclosure.

3rd author has independently conducted

and financed clinical research study

presented and provides technical advice and

consultant services to Lumenis Corporation.

Financial Disclosures

IntroductionSelective Laser Trabeculoplasty (SLT) uses a Q-Switched

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 MethodsTo 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 < 0.05

Data

Eye Color vs Decrease in Post-SLT IOP

% D

ecre

ase

in

IO

P

Blue Eyes(n = 53 eyes)

Brown 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.