Many ODs remain at the front lines of glaucoma management, but a new study reports ophthalmologists still treat more glaucoma patients and prescribe a significantly wider range of medications than their OD counterparts.

A team of Chicago researchers conducted a cross-sectional observational study that examined all Medicare Part D claims of ocular hypotensive medications prescribed by practicing ophthalmologists and optometrists in the United States in 2014. Each claim represented a 30-day supply of a medication filled or refilled. The investigators compared claim rates between ophthalmologists and optometrists and also looked at trends by region, including on the state and county level.

The study identified 16,680 ophthalmologists, 16,333 optometrists, and 19 different medications that were prescribed. Latanoprost was the most common medication prescribed by both ophthalmologists and optometrists. Ophthalmologists’ second, third and fourth most frequently prescribed medications were timolol, bimatoprost and brimonidine, respectively. Optometrists’ second, third and fourth most frequently prescribed medications were bimatoprost, brimonidine and dorzolamide, respectively.

The study reported ophthalmologists’ prescription rates were higher than optometrists by a six-to-one ratio. Researchers noted ophthalmologists prescribed a wider variety of medications than optometrists with an average number of different medication types, averaging at 8.1 vs. 3.6 for optometrists. Additionally, optometrists were listed as the prescribing provider for fewer patients with an average of 60.4 beneficiaries per optometrist compared to 222.7 per ophthalmologist.

The investigators also noted claims rates in urban, large and small rural cities were significantly greater for ophthalmologists. Optometrists had the highest claim rates in isolated, small rural towns. Optometrists’ highest claims rates were in North Dakota and Iowa, while ophthalmologists highest claim rates were in Washington DC and Massachusetts—the only state that doesn’t allow optometrists to prescribe glaucoma medications.

“Medicare Part D claims data for ocular hypotensive medications indicate ophthalmologists used a significantly wider range of medications, derived from more medication classes and treated more patients than optometrists,” researchers said.

Although this suggests optometrists, in addition to treating fewer patients with glaucoma and ocular hypertension, are less likely to treat complex patients—for example, those who require multiple medications—future patient-oriented studies are needed to control for disease state and patient demographics, the study reported. “However, ophthalmologists prescribed nearly twice as many types of medications than optometrists, further supporting the concept that ophthalmologists may treat more complex patients who require multiple classes of medications,” researchers said.