Positive predictive value of optic disc haemorrhages for open angle glaucoma

Area of Science:

• Ophthalmology
• Glaucoma Research
• Diagnostic Accuracy

Background:

• Disc haemorrhages (DHs) are a potential indicator for open angle glaucoma (OAG).
• Understanding the diagnostic value of DHs is crucial for efficient glaucoma screening and referral.
• Community optometrist referrals provide valuable insights into primary care diagnostic pathways.

Purpose of the Study:

• To determine the positive predictive value (PPV) of disc haemorrhages (DHs) in diagnosing open angle glaucoma (OAG).
• To evaluate the association between DHs and the likelihood of an OAG diagnosis.
• To assess the first visit discharge rate (FVDR) for patients referred with DHs.

Main Methods:

• Retrospective review of 618 new referrals to a hospital glaucoma service.
• Inclusion of 54 patients with noted DHs at referral.
• Comprehensive eye examination and diagnosis of OAG as the primary outcome.

Main Results:

• The overall PPV of DHs for OAG was 54% (95% CI 40-67%).
• For patients referred with DH alone, the PPV decreased to 24% (95% CI 8-47%).
• The FVDR was 57% for isolated DH referrals, significantly higher than for suspected glaucoma without DH (25%).
• FVDR decreased with additional glaucoma features: 35% with one other feature, 0% with two or more features.

Conclusions:

• Isolated disc haemorrhages have a notable, though not definitive, association with open angle glaucoma.
• The presence of additional glaucoma-related features alongside DHs significantly increases the probability of an OAG diagnosis.
• Referrals based solely on DHs result in a higher discharge rate, highlighting the need for careful interpretation in primary care.