Does severe obstructive sleep apnea syndrome alter retrobulbar blood flow? A color Doppler ultrasound study.

PURPOSE: To evaluate extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of severe obstructive sleep apnea (OSA) on retrobulbar blood flow. METHODS: Between February 2014 and September 2015, 30 patients with severe OSA (apnea-hypopnea index (AHI) > 30) and 28 controls were prospectively included in this study. Intraocular pressure (IOP) was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels. RESULTS: The mean AHI score for the OSA group was 63.2 ± 21.5 per hour. The IOP values were significantly higher in the severe OSA group (p < 0.05). The central retinal artery peak systolic velocity (PSV) (p < 0.05) and end-diastolic velocity (EDV) (p < 0.02), and the ophthalmic artery (OA) PSV and EDV, were found to be significantly lower in the OSA group (p < 0.05). CONCLUSION: Severe OSA causes an increase in IOP and a decrease in flow velocity in the retrobulbar circulation.

The effect of bariatric surgery on the retrobulbar flow hemodynamic parameters in patients with obesity: color Doppler evaluation.

PURPOSE: To evaluate the effect of weight loss on the retrobulbar hemodynamics in patients who had undergone bariatric surgery for obesity using color Doppler ultrasound (CDU) and to evaluate correlations with intraocular pressure (IOP) changes measured using Goldman applanation tonometry. METHODS: Thirty-two patients were included in this prospective study. Body mass index (BMI), IOP measurements, and retrobulbar CDU examination were performed on all individuals 6 months before and after bariatric surgery. RESULTS: The preoperative mean BMI value was 48.8 ± 2.27 kg/m2, and mean IOP value was 18.2 ± 2.06 mmHg. At 6 months postoperatively, mean BMI and IOP were 36.28 ± 5.41 kg/m2 and 16.1 ± 1.81 mmHg which was statistically significantly lower than the preoperative measurements (p < 0.001). In the comparison of pre- and postoperative orbital CDU value, the preoperative OA PSV (30.16 ± 5.31 cm/s) and OA EDV (10.93 ± 3.04) values were significantly lower than the postoperative OA PSV (36.21 ± 5.56) and OA EDV (12.84 ± 3.38) values (p < 0.001 and p < 0.05, respectively). A significant correlation was determined between BMI and IOP (r = -0.443; p < 0.05). CONCLUSIONS: Decrease in body weight resulting from bariatric surgery performed on morbid obese patients causes alterations in both IOP and retrobulbar hemodynamics. Morbidly obese patients who undergo bariatric surgery have statistically significantly lower IOP values and increase in OA Doppler parameters (PSV, EDV) than in the preoperative period, which reflects a better retrobulbar and ocular blood flow.

Effects of obesity on retrobulbar flow hemodynamics: color Doppler ultrasound evaluation.

PURPOSE: To evaluate intraocular pressure (IOP) and extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of obesity on retrobulbar blood flow. METHODS: Fifty-nine patients were included in this prospective study. Patients were divided into two groups according to body mass index: Group 1 (31 obese patients) and Group 2 (28 non-obese patients). IOP was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels. RESULTS: The mean IOP was 18 ± 6.68 mmHg in the obese group and 13.71 ± 1.60 mmHg in the control group (p<0.001). When the CDU values for the central retinal artery were compared between the groups, the pulsatility index was found to be significantly lower in the obese group than in the control group (p<0.001). When the CDU values for the ophthalmic artery (OA) were compared between the groups, the peak systolic velocity (p<0.001) and end-diastolic velocity (p=0.002) values were found to be significantly lower in the obese group than in the control group. CONCLUSIONS: Obese patients have a higher mean IOP and lower flow velocity than non-obese patients. Increased IOP together with decreased retrobulbar blood flow, particularly in obese individuals, may increase the risk of glaucoma development.