Analysing diagnostic practices and referral pathways for glaucoma in Australian primary eye care

Background: Glaucoma is the leading cause of irreversible blindness globally, posing a significant public health challenge in Australia, particularly among individuals aged 55 years and older. As primary health care providers, optometrists play a crucial role in the early diagnosis and management of glaucoma, making them central to efforts aimed at reducing the burden of this sight-threatening condition. This study investigates the practice patterns of Australian optometrists in diagnosing and managing glaucoma, focusing on test utilisation, diagnostic confidence, referral practices and intra- and inter-observer variabilities in grading glaucomatous optic neuropathy (GON). Methods: A mixed-method cross-sectional design was conducted, involving 50 Australian optometrists who graded 120 colour digital retinal photographs for GON and completed an online survey regarding their diagnostic methods and confidence levels. Statistical analyses assessed inter- and intra-observer agreement in GON grading. Results: The results showed that 82% of optometrists surveyed possessed optical coherence tomography (OCT) instruments and 96% had visual field analysers. Despite a majority expressing confidence in glaucoma detection, only 8% felt capable of independently diagnosing the disease and initiating treatment. Inter-observer agreement for glaucoma detection from retinal photographs was moderate (kappa = 0.53, 95% CI 0.50–0.54), while intra-observer agreement was substantial (kappa = 0.73, 95% CI 0.70–0.77). Inter-observer agreement of optometrists was similar to that of ophthalmologists. Conclusion: Most optometrists have access to advanced diagnostic tools, know how to appropriately diagnose and manage glaucoma and have similar inter-observer variability when assessing fundus photographs to that of glaucoma sub-specialists, but few feel confident in independently diagnosing and managing glaucoma.