A lack of a significant refractive error and visiting an optometrist rather than an ophthalmologist were factors associated with a missed diagnosis of primary open-angle glaucoma, according to a recent analysis.
More than half of primary open-angle glaucoma (POAG) cases remained undiagnosed in a recent cohort study despite patients having undergone a visit to an eye care provider within the past 12 months.1
The investigative team, led by Azadeh Doozandeh, MD, from the research Institute for ophthalmology and vision science at the Shahid Beheshti University of Medical Sciences, suggested a lack of significant refractive error and being seen by an optometrist rather than an ophthalmologist were factors significantly associated with the risk of undiagnosed POAG.
“An essential healthcare implication of this study is that further strategies are required to encourage eye care providers to improve their screening skills for glaucoma,” study investigators wrote. “Raising public awareness of glaucoma and informing close relatives of affected patients can also help reduce the burden of missed cases of glaucoma.”
The majority of cases of glaucoma are detected through opportunistic case finding among individuals presenting to eye clinics due to visual complaints or routine eye check-ups. The available infrastructure for screening benefits cost-saving measures and suggests an advantage. However, case finding may be insufficient by itself for glaucoma detection, particularly in developing countries, where eyes present with more advanced impairment and undergo infrequent check-up visits.2
A further risk of a case-finding approach is the risk of missed glaucoma diagnoses by eye care professionals. As a result, Doozandeh and colleagues looked to analyze the performance of eye care providers related to glaucoma detection and referral. The cross-sectional investigation enrolled new patients with POAG diagnosed at presentation or within 1 year prior to referral to Labbafinejad Medical Center from June 2018 to October 2020, including only those with no other ocular disease.
Diagnosis of POAG was made by the presence of glaucomatous changes of the optic disc, an open iridocorneal angle on gonioscopy, the presence of retinal nerve fiber layer (RNFL) defects on spectral-domain optical coherence tomography (SD-OCT), and presence of glaucomatous visual field defects, with or without high intraocular pressure (IOP).
Investigators sought to gather data regarding a participant’s demographic characteristics, medical history, medication use, history of eye disease, glaucoma awareness, and family history of glaucoma in an interview. In addition, the type of eye care provider, the principal reason for the visit, and the exact time of the visit were queried. Two outcomes were presumed for patients who met an eye care provider in the past year: diagnosed versus undiagnosed glaucoma.
A total of 154 newly diagnosed patients with POAG were enrolled in the study, with a mean age of 58 years and 84 male patients (54.5%). At presentation, the majority (92.3%) of patients had moderate (70.2%) or severe (22.1%) glaucoma. Moreover, the analysis found 132 patients (85.7%) had a documented eye care provider visit over the past 12 months before presentation.
Of this population, 59 patients (46%) were correctly diagnosed with POAG in the index visit; however, 73 participants (54%) remained undiagnosed after the examination. Among undiagnosed participants, data showed 15 patients (19.6%) sought a second eye care visit which ultimately led to a diagnosis of POAG.
Although there were no significant differences observed between groups regarding age or gender, undiagnosed glaucoma was more common in patients examined by an optometrist rather than an ophthalmologist (P <.001). No significant differences were noted between groups regarding mean best-corrected visual acuity and/or the spherical equivalent of refractive error. However, investigators found significant refractive errors were more prevalent in subjects with a correct diagnosis of POAG.
The analysis also suggested the mean IOP at presentation was not statistically significant in the worse eyes of undiagnosed glaucoma cases versus diagnosed subjects (P = .64). It identified no significant difference between groups in factors defining glaucoma severity, including vertical cup-to-disc ratio, the severity of visual field defects, visual field mean deviation, and RNFL loss on OCT.
Regarding family history, 32 patients (20.8%) reported a family history of glaucoma and only 4 patients (12.5%) with a positive family history were aware of the familial risk of glaucoma. Based on these findings, investigators note that family history alone may not be sufficient to lead to an early glaucoma diagnosis.
“Unless public awareness of the importance of family history is increased and close family members of affected patients are adequately informed, positive family history by itself may remain an unhelpful clinical feature in glaucoma detection,” investigators wrote.1