The effects of iridotomy size and position on symptoms following laser peripheral iridotomy

To evaluate visual disturbances following laser peripheral iridotomy (LPI). Patients sometimes note visual disturbances following laser peripheral iridotomy. The purpose of this study was to provide what we believe to be the first systematic evaluation of these visual disturbances, including a determination of whether or not they are associated with characteristics of a primary patent laser peripheral iridotomy, such as lid position and size of the iridotomy.

This was a case series of 93 consecutive (172 eyes) glaucoma patients who had had an Nd: YAG laser peripheral iridotomy. Patients returning for a follow-up visit after laser peripheral iridotomy were selected. A standardized questionnaire was prospectively administered to the study patients at least 1 month after their laser peripheral iridotomy had been performed, inquiring if they experienced any of the following either before or after the iridotomy: halo, lines, crescent, ghost image, glare, spots, shadows, blurring, or other unlisted visual disturbances. On the same visit when they answered the questionnaire, the patients were examined at the slit lamp to assess the location, lid coverage status, and size of the laser peripheral iridotomy. Selection for the performance of the LPI was not prospective. A series of 93 consecutive patients served as controls.

Seven (4%) of the 172 study eyes had postoperative visual symptoms of shadows, ghost images, crescents, or lines. Ninety (52.3%) of the laser peripheral iridotomies were covered by the upper lid, 40 (23%) were completely exposed, and 42 (24%) were partially exposed. Visual disturbances (those listed above plus glare, blurring, haloes, spots, and miscellaneous) occurred in 8 of the 90 (8.9%) eyes with completely covered laser peripheral iridotomies, in 11 of the 42 (26%) with partially covered laser peripheral iridotomies, and in 7 of the 40 (17.5%) with fully exposed LPIs.

Visual symptoms following laser peripheral iridotomy are more likely to occur in patients who have partially or fully exposed laser iridotomies than in those in whom the iridotomy is completely covered by the lid.