Investigators reviewed data from a Medicare claims database containing a random sample of 5% of all beneficiaries to evaluate risk factors for glaucoma progression and surgical burden in patients with presumed mild disease.
Study design
The analysis included patients diagnosed with ocular hypertension, pre-glaucoma, mild-stage glaucoma, primary open-angle glaucoma (POAG) with borderline findings, or unspecified POAG. Eyes with a history of laser trabeculoplasty were matched to eyes from individuals without a history of trabeculoplasty (2435 unique eyes for each group), controlling for demographic variables (e.g., race, ethnicity, gender, age) and disease severity. The patient data were analyzed for 2 years after the index date. The primary outcome measure was risk of requiring incisional glaucoma surgery; the secondary outcome was progression to moderate- or severe-stage glaucoma.
Outcomes
There was no statistically significant difference in the risk of requiring incisional glaucoma surgery between the trabeculoplasty and non-trabeculoplasty groups. Black patients were at much higher risk of receiving incisional glaucoma surgery than White patients. There was no difference in achieving the secondary outcome measure between the two surgery groups, but Black patients were at greater risk of progression compared with White patients.
Limitations
There are inherent limitations in retrospective studies that rely on insurance claims databases, as true clinical information is not always available. For example, it is impossible to know whether the trabeculoplasty was performed for 180 or 360 degrees, or whether argon (ALT) or selective laser (SLT) was used. Diagnostic coding errors also cannot be ruled out, even though the authors tried to validate their data appropriately.
Clinical significance
This study demonstrates the need for continued monitoring of patients with even mild open-angle glaucoma despite successful performance of laser trabeculoplasty, as the baseline need for surgical intervention may still exist. As has been shown in other studies, Black patients are at higher risk of both need for incisional glaucoma surgery and disease progression, so appropriate follow-up strategies should be implemented.