Association between Mean Ocular Perfusion Pressure and Diabetic Retinopathy in a Northeastern Chinese Population

Objective To evaluate the association between diabetic retinopathy(DR) and mean ocular perfusion pressure(MOPP) in patients with type 2 diabetes mellitus(T2 DM).Methods Patients from the Fushun Diabetic Retinopathy Cohort Study(FS-DIRECT), a communitybased prospective cohort study conducted in northeast China, were included in this study. The presence and severity of DR were determined by grading fundus photographs according to the Early Treatment Diabetic Retinopathy Study(ETDRS) retinopathy scale. Systolic and diastolic blood pressure(SBP and DBP) were recorded using an electronic sphygmomanometer. Intraocular pressure(IOP) was measured using an iCare rebound tonometer. MOPP was calculated using the formula MOPP = 2/3 [DBP + 1/3(SBP-DBP)]-IOP.Results In total, 1,857 patients who had gradable fundus photography and MOPP data were enrolled in this study. Male patients had a higher MOPP than female patients(52.25 ± 8.75 vs. 50.96 ± 8.74 mmHg, P = 0.002). Overall, both male and female patients with any type of DR, non-proliferative DR(NPDR), or non-sight-threatening DR(non-STDR) had significantly higher MOPP relative to patients without DR. Increased MOPP(per 1 mmHg) was in turn associated with the presence of any type of DR[odds ratio(OR) = 1.03, 95% confidence interval(CI) : 1.02–1.04], NPDR(OR = 1.03 95% CI: 1.02–1.04),and non-STDR(OR = 1.03, 95% CI: 1.01–1.04) after adjusting for confounders. Increased MOPP(per 1 mmHg) was also associated with an increased likelihood of macular edema(OR = 1.02, 95% CI:1.01–1.04).Conclusions The results suggest that increased MOPP was associated with DR and macular edema in northeastern Chinese patients with T2 DM.

Paracentesis following intravitreal drug injections in maintaining physiologic ocular perfusion pressure

A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide.These patients were previously diagnosed as having glaucoma,ocular hypertension,or had responded previously with sustained elevated intraocular pressure.Of 1661 procedures were performed.Totally 219（13%） of the injections were on phakic patients.A median（SD） of 210 μL（40 μL） of aqueous was removed during each paracentesis.There were no reported incidences of any complications.We propose performing a paracentesis immediately following intravitreal injections for patients at risk for ocular hypertension,glaucoma,and retinal vein or artery occlusion.

Retinal vessel diameter changes induced by transient high perfusion pressure

·AIM: To investigate the effects of transient high perfusion pressure on the retinal vessel diameter and retinal ganglion cells.·METHODS: The animals were divided into four groups according to different infusion pressure and infusion time(60 mm Hg-3min, 60 mm Hg-5min, 100 mm Hg-3min, 100 mm Hg-5min). Each group consisted of six rabbits. The left eye was used as the experimental eye and the right as a control. Retinal vascular diameters were evaluated before, during infusion, immediately after infusion, 5min, 10 min and 30 min after infusion based on the fundus photographs. Blood pressure was monitored during infusion. The eyes were removed after 24 h.Damage to retinal ganglion cell(RGC) was analyzed by histology.·RESULTS: Retina became whiten and papilla optic was pale during perfusion. Measurements showed significant decrease in retinal artery and vein diameter during perfusion in all of the four groups at the proximal of the edge of the optic disc. The changes were significant in the 100 mm Hg-3min group and 100 mm Hg-5min group compared with 60 mm Hg-3min group(P 1=0.025, P 2=0.000).The diameters in all the groups recovered completely after 30 min of reperfusion. The number of RGC)showed no significant changes at the IOP in 100 mm Hg with5 min compared with contralateral untreated eye(P 】0.05).·CONCLUSION: Transient fluctuations during infusion lead to temporal changes of retinal vessels, which could affect the retinal blood circulation. The RGCs were not affected by this transient fluctuation. Further studies are necessary to evaluate the effect of pressure during realtime phacoemusification on retinal blood circulation.