Ocular blood flow velocity in primary open angle glaucoma - A tropical african population study

Abstract

Purpose:To assess blood flow velocity in newly diagnosed indigenous black-skinned Africans with primary open angle glaucoma (POAG).Materials and Methods:Prospective case-control study at Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria on 50 newly diagnosed POAG patients (POAG group) and 50 control patients (control group). Ocular Doppler Color Imaging was performed on subjects in the supine position using 9 MHz linear array transducer of a Fukuda Denshi Ultrasound. The Peak Systolic Velocity (PSV) and End Diastolic Velocity (EDV) values were obtained by finding the average of two readings each for the ophthalmic artery (OA) and central retinal artery (CRA). Resistive Index (RI) was calculated as (PSV − EDV)/PSV. Data were analyzed and statistical significance was defined at P < 0.05.Results:The mean intraocular pressure (IOP) for the POAG group and control group was 28.1 ± 7.4 mmHg and 16.6 ± 2.0 mmHg, respectively (P < 0.001). The mean PSV for OA was 31.35 cm/s in POAG group and 37.61 cm/s for the control group (P < 0.001). The EDV for both OA and CRA were significantly lower in glaucoma patients as compared with the corresponding values in the control group (P < 0.001, both comparisons). The mean RI in the OA was 0.71 ± 0.05 and 0.63 ± 0.03 for the POAG and control group groups, respectively (P < 0.001). The increase in IOP in the POAG group was statistically significantly negatively correlated with PSV and EDV and positively correlated with RI for both OA and CRA.Conclusion:The outcomes of this study indicate that ocular blood flow alterations including reductions in PSV and EDV and increase in RI of the OA and CRA are present in black-skinned Africans with POAG.

Comparison of Color Doppler Imaging Criteria for the Ophthalmic Artery and Central Retinal Artery in Infants with Retinopathy of Prematurity with and Without Plus Disease

“…Hauch et al (23) also reported no significant difference regarding this parameter. Olufemi Adeyinka et al (26) also found that the EDV of OA and CRA in glaucoma patients was significantly lower than the control group. Moreover, Ozcan et al (24) reported no significant difference between patients with and without ROP regarding EDV.…”

Comparison of ophthalmic artery blood flow between open-angle glaucoma and nonglaucomatous eyes of Indian patients

“…studied the correlation between arterial resistance and PI in glaucoma patients. [ 15 ] Forty-nine cases of POAG, 62 cases of Normal Tension Glaucoma (NTG), and 48 healthy controls were taken. The RI in OA was found to be 0.81 in normal cases, 0.79 in NTG, and 0.79 in POAG.…”

“…in the Tropical African Population in 2013 on 50 cases of newly diagnosed cases of POAG and 50 healthy adults revealed an increase in RI of patients with POAG (0.71 ± 0.05) as compared to normal adults (0.63 ± 0.03) in the OA. [ 15 ]…”

Vascular considerations in glaucoma patients of African and European descent

“…These differences were found despite statistically similar IOP (Siesky et al 2013). Similarly, a newly published prospective study by Adeyinka et al measured retrobulbar blood flow velocities in African patients with OAG in Nigeria and found reduced peak systolic and end diastolic velocities and increased resistivity in the ophthalmic and central retinal arteries of OAG patients compared to controls (Adeyinka et al 2013). Previous studies have demonstrated a reduction in blood flow velocities in the retrobulbar vessels of glaucoma patients in general (Sergott et al 1994; Nicolela et al 1996; Chiou et al 1999; Akarsu and Bilgili 2004; Abegão Pinto L et al 2012), and lower retrobulbar blood flow within in OAG patients of AD may be a mechanism which contributes to their OAG disease disparity.…”