Risk factors for neovascular glaucoma after vitrectomy in eyes with proliferative diabetic retinopathy.

PURPOSE: To investigate the potential risk factors for neovascular glaucoma (NVG) after vitrectomy in eyes with proliferative diabetic retinopathy. SUBJECTS AND METHODS: In this retrospective, observational, comparative study, patients with proliferative diabetic retinopathy who underwent vitrectomy at Toho University Sakura Medical Center between December 2011 and November 2016 and who were followed for ≥12 months after surgery were included. Subject parameters examined included age, glycated hemoglobin (HbA1c), fasting blood glucose, administration of insulin, and estimated glomerular filtration rate. Ocular parameters examined included preoperative best-corrected visual acuity, preoperative IOP, operative history (specifically panretinal photocoagulation), lens status, ocular pathology (eg, iris/angle neovascularization, tractional retinal detachment, diabetic macular edema, vitreous hemorrhage, combined tractional retinal detachment), intraoperative retinal tamponade use, vitrectomy gauge, combined lens extraction/vitrectomy procedure, subsequent surgical procedures, and pre- and postoperative intravitreal bevacizumab. Correlations between variables and postoperative NVG development were examined using logistic regression analyses (backward elimination method). RESULTS: A total of 254 eyes of 196 consecutive subjects (146 men [74.5%], 54.0±10.8 years old) were included. Sixty of 254 eyes (23.6%) developed NVG. Several preoperative factors increased the risk of developing NVG, including iris/angle neovascularization (P=0.042), preoperative high IOP (P=0.005), low HbA1c (P=0.004), and administration of insulin (P=0.045). Intraoperative retinal tamponade also increased NVG risk (P=0.021, backward elimination method). CONCLUSION: Preoperative parameters such as elevated IOP, iris/angle neovascularization, fasting blood sugar and HbA1c discrepancies, administration of insulin, as well as use of retinal tamponade during retinal surgery were identified as the risk factors for developing NVG.

Impairment of autoregulation of optic nerve head blood flow during vitreous surgery in patients with hypertension and hyperlipidemia.

PURPOSE: To examine whether hypertension (HTN) and hyperlipidemia (HL) affect autoregulation of optic nerve head (ONH) blood flow during vitrectomy. DESIGN: Cohort study. METHODS: Seventeen eyes from 17 subjects with HTN and HL and 19 eyes from 19 control subjects without systemic disorders underwent vitrectomy for the treatment of epiretinal membrane or macular hole. Following standard 25-gauge microincision vitrectomy, the mean blur rate (MBR), which is an index of relative ONH blood flow, in the vascular area (vascular MBR) and MBR in the tissue area (tissue MBR) were measured using laser speckle flowgraphy. Measurements were conducted before and 5 and 10 min after an approximately 15-mmHg rise in intraocular pressure (IOP). Both parameters represent relative values of ONH blood flow (%, compared to baseline). The recovery rate of blood flow to the ONH was calculated using the following equation: (MBR at 10 min - MBR at 5 min)/(MBR at baseline - MBR at 5 min). RESULTS: Ocular perfusion pressure in all subjects was reduced both 5 and 10 min after the increase in IOP. Vascular MBR in subjects with HTN and HL (75.5 ± 14.8) was significantly lower than that in control subjects (86.7 ± 12.1) 10 min after IOP elevation (P = 0.019). The recovery rate of vascular blood flow was significantly lower in the HTN and HL groups than in the control group (P = 0.002). CONCLUSIONS: Our results suggest that HTN and HL impair autoregulation in the vascular component of ONH blood flow during vitrectomy.

Impaired Autoregulation of Blood Flow at the Optic Nerve Head During Vitrectomy in Patients With Type 2 Diabetes.

PURPOSE: To determine whether type 2 diabetes mellitus (T2DM) influences autoregulation of optic nerve head (ONH) blood flow during vitrectomy. DESIGN: Cohort study. METHODS: Thirteen eyes of 13 subjects with T2DM and 30 eyes of 30 controls without T2DM undergoing vitrectomy for epiretinal membrane or macular hole were included. Following 25 gauge vitrectomy, we measured the mean blur rate (MBR), an index of ONH blood flow, in the vascular area (vascular MBR) and in the tissue area (tissue MBR) using laser speckle flowgraphy. We performed measurements before and 5 and 10 minutes after intraocular pressure (IOP) elevation of approximately 15 mm Hg; both parameters represent relative values (%, compared with baseline). We calculated the vascular MBR recovery rate as (vascular MBR at 10 min-vascular MBR at 5 min)/(vascular MBR at baseline-vascular MBR at 5 min). RESULTS: Vascular MBR in T2DM subjects was significantly lower than that in controls at 5 and 10 minutes after IOP elevation (P = .0328 and P < .0001, respectively). Tissue MBR was also significantly lower in T2DM subjects than in controls at both time points (P = .0253 and P = .0004, respectively). Vascular MBR recovery rate was significantly lower in the T2DM than in the control group (P = .0090). Furthermore, the vascular MBR recovery rate was significantly negatively correlated with hemoglobin A1c and fasting plasma glucose levels (P = .0284 and P = .0381, respectively). CONCLUSIONS: T2DM is associated with impaired ONH blood flow autoregulation in both vascular and tissue areas when subjected to change in IOP during vitrectomy.

Autoregulation of Optic Nerve Head Blood Flow Induced by Elevated Intraocular Pressure during Vitreous Surgery.

PURPOSE: To investigate optic nerve head (ONH) blood flow changes resulting from intraocular pressure (IOP) elevation in subjects without systemic disorders. MATERIALS AND METHODS: Eighteen eyes of 18 patients who underwent vitrectomy to treat an epiretinal membrane or macular hole at Toho University Sakura Medical Center were included. Following standard 25-gauge microincision vitreous surgery, mean blur rate (MBR) in tissue (MT), an index of ONH blood flow, was measured using laser speckle flowgraphy. Measurements were taken before and 5 and 10 minutes after a 15 mmHg IOP elevation. RESULTS: The ONH blood flow was initially lower than baseline (P = 0.001) after elevating IOP from 14.8 ± 2.8 mmHg to approximately 30 mmHg. Between 5 and 10 minutes after elevating IOP, ONH blood flow partially recovered (P = 0.004), even though ocular perfusion pressure was 20.2% lower than at baseline. CONCLUSIONS: The ONH blood flow in subjects without systemic disorders was initially lower, but began to recover 5-10 minutes after a 15 mmHg elevation in IOP. These results indicate that autoregulatory mechanisms of ONH blood flow may help to minimize the effects of IOP elevations and fluctuations during vitreous surgery.

Changes in the blood flow of the optic nerve head induced by different concentrations of epinephrine in intravitreal infusion during vitreous surgery.

PURPOSE: We investigated whether intravitreal infusion solution containing epinephrine affects optic nerve head (ONH) blood flow during vitreous surgeries. METHODS: The subjects were 22 patients with epimacular membrane or idiopathic macular hole. During vitreous surgery, ONH blood flow was examined before and 10 minutes after intravitreal infusion of solution containing epinephrine, via a laser speckle flowgraphy (LSFG) technique modified for acquiring measurements in a supine position. Epinephrine concentration was set at 1.0 mg/500 mL (1:500,000) or 0.5 mg/500 mL (1:1,000,000), with each concentration assigned to 11 consecutive patients. Relative pupil diameter, IOP, blood pressure, and pulse rate also were measured. RESULTS: A significant reduction in blood flow throughout the ONH was induced by intravitreal infusion of epinephrine at 1:500,000, but not at 1:1,000,000. Blood flow in ONH tissue was diminished at both concentrations, while that in vessels of the ONH was not altered significantly by either concentration. Both epinephrine concentrations induced significant pupillary dilatation, but no significant changes in IOP, blood pressure, or pulse rate. CONCLUSIONS: This study suggests that epinephrine, used in combination with intravitreal infusion solution, may decrease ONH blood flow during vitreous surgeries, as indicated by measurements obtained via a modified LSFG technique. Attention must be paid to the effects of intravitreal infusion of epinephrine on ocular circulation, particularly ONH blood flow.

[Nocturnal dipping of heart rate in patients with proliferative diabetic retinopathy and iris and/or angle neovascularization].

PURPOSE: To evaluate the relationship between nocturnal dipping in heart rates and iris and/or angle neovascularization (NV) in patients with proliferative diabetic retinopathy(PDR). SUBJECTS AND METHOD: One hundred fifty-one patients with PDR who underwent surgery were divided into groups based on either the presence or absence of iris and/or angle NV (NV group, 37; non-NV group, 114 patients). Pulse oximetry was conducted overnight and the heart rates were measured both before and during sleep; the resting and nocturnal heart rates and the resting-nocturnal heart rate dip ratio were calculated. RESULTS: The resting and nocturnal heart rates did not differ significantly between the two groups. The resting-nocturnal heart rate dip ratio was significantly lower in the NV group than in the non-NV group (p = 0.006). In the NV group, the frequency of insulin therapy (p = 0.003) and a history of coronary artery disease were significantly (p = 0.033) higher than in the non-NV group. Pearson's correlation analysis showed that only the NV group was significantly negatively correlated with the resting-nocturnal heart rate dip ratio (r = -0.18, t value = -2.2, p = 0.028). CONCLUSION: In patients with PDR, the non-occurrent of nocturnal dip in heart rate may be a related factor for iris and/or angle neovascularization.

[A case of a corneal disorder after lung cancer treatment with erlotinib].

BACKGROUND: We report a case of a severe corneal disorder after lung cancer treatment with the epidermal growth factor receptor (EGFR) inhibitor, erlotinib hydrochloride (Tarceva). CASE: A 59-year-old man, who was referred to our cornea service, presented with blurred vision and pain OD. Visual acuity was 6/20. Slit-lamp examination showed a severe corneal epithelial defect and ocular inflammation OD. Eighteen months previously, he had been diagnosed with lung cancer and had been undergoing treatment with erlotinib for 6 months. He had no history of ocular surgery, trauma or diabetes. After topical antibiotic therapy was started and the erlotinib treatment was discontinued for 1 week, the corneal findings resolved completely. The visual acuity recovered to 20/20 after 8 weeks. CONCLUSION: An EGFR inhibitor used to treat lung cancer can cause severe corneal disorders including severe corneal defects and ocular inflammation. Clinicians should consider the possibility of erlotinib in cases of corneal disorders of uncertain etiology.