The immediate IOP response of Nd-YAG-laser iridotomy and its prophylactic treatability.

The response of IOP in the normotensive human eye to Neodym-YAG-laser iridotomy was investigated in this study. In 2 series of 10 patients, each unilateral laser iridotomy was performed with a YAG-laser prior to cataract surgery. In one group laser iridotomy was done without pre-treatment, in the second group laser iridotomy was preceded by treatment with 1% pilocarpine. Close follow-up of IOP before and after surgery was carried out with the Non-Contact-Tonometer. Laser iridotomy caused average IOP rises of 10 mmHg, which could be identified as early as 20 min after surgery, with a maximum of response after 80 min, and a declining IOP from 100 min post-operatively onwards. Pre-treatment with pilocarpine eyedrops could be reduce the laser-mediated IOP rise to less than one fourth. These results recommend a mild miotic for routine pre-treatment for iris laser surgery in order to cope with acute pressure rise as one of the major problems in these procedures.