Risk Factors for Diagnostic Change from Glaucoma Suspect to Primary Open-Angle Glaucoma and Vice Versa Over 2 Years.

Objective: This study investigates the incidence and causes of diagnostic changes from primary open-angle glaucoma suspect (POAGS) to primary open-angle glaucoma (POAG), and vice versa, in clinical practice.

Design: This is a retrospective, single-site, case-control study.

Participants: It includes patients > 40 years of age diagnosed with either POAG or POAGS between 2013 and 2020. Controls had a minimum of 24 months of follow-up without a diagnostic change, whereas cases underwent a diagnostic change from glaucoma to suspect (POAG to POAGS) or from suspect to glaucoma (POAGS to POAG) within 2 years.

Methods: At initial and follow-up visits, diagnosis, treatment, type of ophthalmic provider, and performance of pachymetry, visual fields (VFs), OCT, disc examination, and gonioscopy were recorded.

Main outcome measures: Data were then analyzed to determine if baseline characteristics, type of provider seen, or ophthalmic testing performed were protective or risk factors in regards to diagnostic change.

Results: Nine hundred twenty-two subjects were included, and the incidence of diagnostic changes was 13.8% (127/922), of which 99 (78%) were upstaged from POAGS to POAG and 28 (22%) changed from POAG to POAGS. Pre-existing nonglaucomatous VF defect (P < 0.001) was significantly higher in cases than controls. Cases were significantly less likely to be seen by a glaucoma specialist at the initial visit compared with controls (P < 0.001), and less cases underwent VF testing (P < 0.001), OCT testing (P = 0.017), or gonioscopy (P = 0.013) at the initial visit. On multivariate analysis, performing VFs or OCT at both visits reduced the odds of short-term diagnostic change, whereas changing providers from a nonglaucoma specialist to a glaucoma specialist between visits increased the odds of diagnostic change. In the POAG-to -POAGS cases, 39% (11/28) were treated with either medications or laser trabeculoplasty, whereas 72% (71/99) of the POAGS-to-POAG cases were left untreated between visits.

Conclusions: It is important to understand risk factors for diagnostic changes in glaucoma, in order to prevent undertreatment of disease and overtreatment of suspects. Here we find specialist type and adherence to American Academy of Ophthalmology (AAO) recommended testing to be important factors in preventing short term diagnostic changes.

Financial disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.