Central Retinal Venous Pressure in Eyes of Normal-Tension Glaucoma Patients with Optic Disc Hemorrhage

OBJECTIVE: To compare central retinal venous pressure (CRVP) among eyes with and without optic disc hemorrhage (ODH) in bilateral normal-tension glaucoma (NTG) patients and NTG eyes without an episode of ODH. METHODS: In this prospective study, 22 bilateral NTG patients showing a unilateral ODH and 29 bilateral NTG patients without an episode of ODH were included. Eyes were categorized into group A (n = 22, eyes with ODH), group B (n = 22, fellow eyes without ODH), and group C (n = 29, NTG eyes without an episode of ODH). A contact lens ophthalmodynamometer was used to measure CRVP and central retinal arterial pressure (CRAP). RESULTS: Intraocular pressure (IOP) measured on the day of contact lens ophthalmodynamometry showed no difference among groups. However, the mean baseline IOP in group A was significantly lower than that in group C (P = .008). The CRVP in group A (29.1 ± 10.8 mmHg) was significantly lower than that in group C (40.1 ± 8.8 mmHg, P = .001), but similar to that in group B (30.5 ± 8.7 mmHg, P = .409). A similar relationship was noted for CRAP. No significant eye-associated variable for ODH was found in group A and B by conditional logistic regression analysis (all P > 0.05). However, multivariate logistic regression analysis in groups A and C revealed that low mean baseline IOP (odds ratio [OR] = 0.69, 95% confidence interval [CI] 0.49-0.98, P = 0.043) and low CRVP (OR = 0.88, 95% CI 0.80-0.95, P = 0.003) were associated with ODH. CONCLUSIONS: CRVP was lower in NTG eyes with ODH than in eyes without an episode of ODH, but similar to that of fellow eyes without ODH. These imply less likelihood of association between increased central retinal venous resistance and ODH.