Secondary glaucoma common in Acanthamoeba keratitis patients

Patients with Acanthamoeba keratitis frequently develop secondary glaucoma, a retrospective study found. Additionally, such patients often need surgery to control IOP and preserve vision, the study indicated.

“The development of secondary glaucoma is not uncommon in Acanthamoeba keratitis and is a poor prognostic sign ... because most [eyes] progress to light perception or no light perception vision,” the authors said in the study.

H. Dwight Cavanagh, MD, PhD, and colleagues at the University of Texas Southwestern Medical Center reviewed the medical records for all suspected Acanthamoeba keratitis patients treated at the center’s Aston Ambulatory Center. The study included 20 eyes of 20 patients followed for at least 6 months. All patients had Acanthamoeba keratitis diagnoses confirmed by either confocal microscopy or culture and either glaucoma or ocular hypertension secondary to their keratitis, according to the study.

The researchers found that six eyes (30%) developed secondary glaucoma during follow-up. Surgeons managed four of these six eyes using medication alone. However, visual acuity for three eyes (75%) decreased to light perception or no light perception. Another three of six patients required glaucoma drainage device implantation to control their IOP. For one of these three eyes, visual acuity decreased to no light perception. But the remaining two eyes maintained better than 20/100 visual acuity, according to the study.

Histopathologic examinations identified chronic trabecular meshwork inflammation as well as angle closure. However, no Acanthamoeba organisms were present in any angle structures, which suggests “an inflammatory angle-closure mechanism, apparently without direct infiltration of the organism,” the authors said.

The study was published in the July issue of Eye & Contact Lens.