Pigmentation may be contraindication for selective laser trabeculoplasty

This case report found that previous inflammation or pigmentation could be a potential contraindication for selective laser trabeculoplasty (SLT).

The subject was a 40-year-old woman with open-angle glaucoma. Visual acuity was 6/6 in both eyes, while IOP was 11 mmHg in the right eye and 30 mmHg in the left eye. Both anterior segments were quiet during examination, except for some pigment on posterior corneal surfaces bilaterally.

Gonioscopy revealed open angles with Shaffer Classification Grade 4. Cup-to-disc ratio was 0.5 in the right eye and 0.8 in the left eye. Humphrey visual field test revealed a wide visual field constriction in the left eye. Specular microscopic evaluation showed dark spots/patches on the left corneal endothelium.

One week after SLT, IOP was 12 mmHg in the right eye and 13 mmHg in the left eye without any inflammation. At three weeks, the patient was admitted with cloudy vision and photophobia when visual acuity was 6/12 in right eye and 6/15 in the left eye. There was bilateral uveitis with +3 cells in the anterior chamber, bilateral posterior synechia and corneal haze. Specular microscopy demonstrated multiple dark spots/patches bilaterally on corneal endothelium. Symptoms resolved after two weeks of topical prednisolone, cyclopentolate HCl and tropicamide.

Dark spots/patches seen on the specular microscopy after SLT has been recently reported.This change in the corneal endothelium may be due to edema, subendothelial inflammatory cells or adjacent endothelial cell damage and is assumed to resolve after resolution of the inflammation.

The authors conclude that SLT is usually a safe procedure, but signs of past intraocular inflammation or pigment on the posterior surface of the cornea should be considered a relative contraindication for SLT therapy.