Comparison of Dorzolamide and Netarsudil on Intraocular Pressure and Ocular Perfusion in Early Glaucoma: A Randomized Controlled Trial.

Precis: Netarsudil shows promise as a second line drug in early glaucoma patients with an increase in most OCTA parameters as compared to Dorzolamide, with comparable rates of side effects.

Objective: To compare the effect of Netarsudil and Dorzolamide on macular and optic nerve head (ONH) perfusion changes on Optical Coherence Tomography Angiography (OCTA), and macular ganglion cell layer (mGCL) and peripapillary retinal nerve fiber layer (pRNFL) thickness on OCT in preperimetric/early glaucoma patients.

Participants and methods: In this prospective, randomized, parallel group, active controlled trial 90 preperimetric/early glaucoma eyes were recruited. The primary outcome measure was change in macular and ONH perfusion, and intraocular pressure (IOP). 45 eyes were randomised and prescribed Netarsudil 0.02% (Group 1) and 45 eyes were prescribed Dorzolamide 2% (Group 2). The IOP, ONH perfusion, ONH flux index (FI) and macular vessel density (mVD) on OCTA; pRNFL thickness and mGCL thickness on OCT of the two groups was recorded at baseline, 4 months, 8 months and 12 months.

Results: The mean baseline IOP in Group 1 was 19.52±3.2 mmHg and in Group 2 it was 19.5±2.97 mmHg. Group 1 showed 2.77 mmHg (13.23±8.27%) decrease in IOP (P<0.001), while Group 2 showed 1.85 mmHg (8.98±7.32%) decrease in IOP (P<0.001) at 12 months. Group 1 showed 1.58 mm/mm2 increase in mVD (P<0.001), and 0.03 (7.6%) increase in ONH FI (P<0.001) at 12 months. However, no trend in mVD or ONH FI was seen in Group 2. Group 1 showed 1.03% increase in ONH Perfusion (P<0.001) while Group 2 showed 1.16% increase in ONH perfusion (P<0.001). There was no significant difference in ONH perfusion between the two group. The OCT (pRNFL and mGCL) showed normal variability in both the groups. Congestion (40%) was the most common side effect observed in the Netarsudil Group while metallic taste (42.5%) was the most common side effect in the Dorzolamide group. The side effect profile of the two drugs was comparable (P=0.65).

Conclusion: Netarsudil causes an increase in all the OCTA parameters - mVD, ONH perfusion, and ONH FI whereas Dorzolamide causes an increase only in ONH perfusion in preperimetric/early glaucoma patients. Netarsudil monotherapy also showed a higher decrease in IOP as compared to dorzolamide therapy.