ABSTRACT
PURPOSE: We report a previously unrecognized mechanism of secondary glaucoma due to iridescent crystalline particles released from an irradiated iris melanoma. It masqueraded as refractory hypertensive uveitis following uncomplicated phacoemulsification. MATERIALS AND METHODS: A 58-year-old gentleman had an iris melanoma that underwent successful regression following irradiation with proton beam radiotherapy. Three years later an uncomplicated phacoemulsification with intraocular lens implant was performed and subsequently the patient presented with apparently "refractory hypertensive uveitis." Closer examination identified unique iridescent crystalline particles originating from a disintegrating tumor and dispersing within the anterior chamber and drainage angle. The patient developed a unilateral secondary open-angle glaucoma attributable to these particles. Ultrasound biomicroscopy of the anterior segment confirmed absence of tumor recurrence or intrascleral spread and systemic investigations ruled out distant metastases. RESULTS: The intraocular pressure was refractory to maximal medical treatment, but was eventually controlled with trans-scleral diode laser cyclo-photocoagulation. CONCLUSIONS: This is the first report of a secondary glaucoma attributable to trabecular blockage with iridescent crystalline particulate material released from a disintegrating, previously irradiated, iris melanoma. Proton beam radiotherapy and possibly phacoemulsification may have played a role in triggering the release of these previously undescribed particles from the atrophied tumor surface. This unique mechanism of secondary glaucoma needs to be kept in mind in such rare cases. Trans-scleral cyclodiode laser may be used as a good initial option in such cases to minimize potential risk of tumor seeding with incisional glaucoma surgery.
