Sir,

We read with interest Hassaballa and Macky's1 article on phakic intraocular lenses (p-IOL) outcomes and complications. In their series significant complications resulting in elevation of intraocular pressure (IOP) requiring additional surgery occurred in two eyes (3%). As noted there are several possible mechanisms for increased IOP in patients implanted with a p-IOL. If IOP remains uncontrolled removal of a p-IOL may potentiate further pigment dispersion. There are case reports of intractable IOP elevation presumed secondary to pigment dispersion requiring surgery.2, 3 We performed non-penetrating glaucoma surgery for a similar case of bilateral severe IOP elevation post p-IOL implantation in a patient with high myopia.3 The authors report pigment dispersion occurring in 28.6% (Artisan) and 15.38% (Visian) in their series. They did not document whether all patients underwent pre- and post-operative gonioscopy to examine the anterior chamber angle. Stulting et al4 reported an incidence of iris pigment precipitates of 6.9%. A long-term incidence of pigment dispersion of 6.6% has also been described.5 This may be of significance as patients undergoing p-IOLs are generally from a younger demographic.

As the article stands, we agree with the authors on the need for long-term data on the efficacy and complications of p-IOLs. Evaluation of the possible effect on trabecular function from p-IOL-related pigment dispersion is warranted. Pigment dispersion is not always benign.