Re­spon­se ­to ­la­ser­iri­do­to­my ­in ­Hi­spa­nic­ and­ Cau­ca­sian­ pa­tients­­ with ­nar­row,­ oc­c­lu­da­ble ­fil­tra­tion­ an­gles

Introduction
Laser iridotomy (LI) is the standard procedure to relieve relative pupillary block in patients with narrow occludable filtration angles. We have observed a difference in response to this procedure in declared Hispanic and Caucasian patients. In this study an attempt is made to compare the effectiveness of an LI in this two ethnic groups.

Material and methods
In a prospective study an LI was performed in 21 (42 eyes) Hispanic and 14 (23 eyes) Caucasian patients with narrow, occludable filtration angles. A standard clinical examination along with evaluation of the filtration angles (goniscopy and/or ultrasound biomicroscopy) was performed in each patient before and after the LI.

Results
Age range for Hispanic patients was 47 to 83 (mean 66) years, 37 to 76 (mean 57) years in Caucasians. Non-occludable filtration angles following LI were observed and documented in 17/36 eyes (47.2%) of Hispanic and 17/23 eyes (73.9%) of Caucasian patients. Those with plasteau iris syndrome were similarly compared: 2/4 eyes (50.0%) in Hispanics and 9/12 eyes (75.0%) in Caucasians were non-occludable after LI. The remaining patients with occludable filtration angles form causes other than plateau iris, responded positively to LI in 15/32 eyes (46.9%) in the Hispanic cohort, and 8/11 eyes (72.7%) in the Caucasian.

Conclusions
Non-occludable filtration angles following LI are achieved more frequently in Caucasians when compared with Hispanics.