Intervention of laser periphery iridectomy to posterior iris bowing in high myopic eyes

For some high myopic patients with posterior iris bowing, laser periphery iridectomy should be performed pre-operation to prevent pupil block glaucoma if these patients would have phakic intraocular lens implantation to correct high myopia. So we had the opportunity to analysis the influence of laser iridectomy on posterior iris bowing.

Eighteen high myopic patients with posterior iris bowing (11 males and 7 females) were involved in the study in Beijing Tongren Eye Center from March 2008 to July 2008. Phakic intraocular lens were implanted to correct their ametropia. The mean age was (32 ± 6) years (range, 25 - 40 years). The center anterior chamber depth, the pupil diameter, the posterior iris bowing depth and the anterior chamber angle were measured with anterior segment coherence tomography (AS-OCT) under the normal condition, myosis condition induced by 2% pilocarpine, laser periphery iridectomy after myosis, and 2% pilocarpine eluting condition respectively.

There was no significant difference of center anterior chamber depth under the four conditions (P = 0.512). The pupil constricted after pilocarpine (P = 0.001). After laser iridectomy performed and pilocarpine eluted, posterior iris bowing depth reduced more than that in normal condition (P = 0.003). The anterior chamber angle reduced significantly after laser periphery iridectomy and pilocarpine eluted (P = 0.012).

Laser periphery iridectomy can reduce the posterior iris bowing, which might be due to the change in aqueous circulate pathway.