There is a prescribing trend toward earlier more aggressive therapy for better IOP control. A fixed-combination drug may improve treatment adherence.
He commented that the reasons for the trend toward adding a fixed-combination drug to a prostaglandin are the greater IOP lowering effect, fewer copays and visits to measure the IOP if there are no allergic reactions, more consistent IOP lowering during the day, and the complementary action of inflow inhibition to the prostaglandin’s outflow enhancement.
In addition, with a fixed-combination therapy there is less exposure to preservatives, reduced washout effects, fewer total drug instillations, and the dosing is still twice daily as with single agents added to a prostaglandin.
A third option to add to prostaglandin therapy is SLT, which eliminates a number of potential problems by reducing compliance issues, side effects, allergies, and drug costs in young patients who may not understand the need for treatment compliance and in elderly patients who may have impaired memory, arthritis, and a large medication burden.
SLT may be applied in patients with narrow angles with elevated IOP with compression gonioscopy after laser iridotomy. Finally, the procedure can reduce IOP fluctuations, which is important because the risk of glaucoma progression in five years is six times greater in eyes in which the IOP fluctuates 5.5 mm Hg compared with 3 mm Hg, Dr. Asrani explained.
SLT also can be beneficial in patients with low and normal tension glaucoma, in whom lowering the IOP and controlling fluctuations are vital.
“I typically perform SLT as the second-line therapy if the patient is already taking a prostaglandin,” he said, adding that topical CAIs can be considered as a second-line therapy in these patients because the CAIs do not affect the BP while they increase the DOPP.
“The considerations for the choice of a second-line agent are side effects, compliance, cost, effect on IOP fluctuations, effects on DOPP, and quality of life,” Dr. Asrani said. “Rho kinase inhibitors will soon be available for adjunctive therapy and they show great promise. A recently completed study of Rhopressa [Aerie Pharmaceuticals] showed stable efficacy at three months and the drug was not inferior to timolol instilled twice daily.”