Monocular Drug Trial Poor Long-Term Predictor

July’s Ophthalmology

For decades, ophthalmologists have accepted the monocular drug trial as a viable way of providing an estimate of long-term IOP reduction when initiating therapy with topical IOP-lowering medication. However, a study by Tony Realini questions the usefulness of this practice.The investigator studied 26 patients with ocular hypertension or open-angle glaucoma who each made five study visits: two on no therapy, one on monocular therapy with latanoprost and two on bilateral therapy. The monocular therapeutic drug trial did not provide clinically relevant information regarding long-term IOP reduction after starting IOP-lowering medication. Even the unadjusted IOP change in first-treated eyes—not incorporating the monocular trial adjustment—showed poor correlation with long-term IOP reduction.The author concludes that the monocular trial was no more informative than using the unadjusted IOP in the treated eye. Consequently, there is no value in leaving one eye untreated when trying to estimate efficacy.