METHODS:Seventy consecutive patients with BRVO and 70 age- and sex-matched controls were evaluated retrospectively. All participants underwent Berlin questionnaire and full-night respiratory polysomnography(PSG)for estimating risk of OSAS and monitoring apnea-hypopnea index(AHI), minimal oxygen saturation(MOS).

RESULTS: Of the 70 BRVO patients, 49(70%)had OSAS,average AHI was(19.74±7.59), MOS was(82.45±9.17)%. For controls, only 23(33%)of 70 subjects had OSAS, average AHI was(13.69±6.35), average MOS was(88.44±8.72)% in controls. Incidence of OSAS, AHI and MOS between BRVO patients and controls were different significantly(χ2=19.331, t=5.115, 3.954, all P<0.01). There was a positive correlation between OSAS and BRVO(rs=0.319, P=0.033). Of the 39 patients with acute BRVO, average AHI was(16.905±6.31), average MOS was(85.14±8.22)%. For the 31 patients with chronic BRVO, average AHI was(17.84±5.47), average MOS was(83.81±7.87)%. There were no significantly differences between acute BRVO patients and chronic BRVO patients in average AHI or MOS(t=0.653, 0.685, P=0.516, 0.496).

CONCLUSION: OSAS could be a trigger in the pathogenesis of BRVO or an important risk factor of CRVO development.