Delhi Journal of Ophthalmology

A Color Doppler Imaging Study of Ocular Haemodynamic Parameters in Normal Tension Glaucoma

Atif Rahman Raini,1, Humayoun Ashraf2, Mohd. Ashraf2, Mohd. Khalid2, Ziya Siddiquif2, Mohd. Maroof2
1Department of Ophthalmology, Christian Medical Hospital, Kasganj, UP, India
2J N Medical College, AMU, Aligarh, UP, India

Editor-in-Chief, Delhi Journal of Ophthalmology, Dr R.P.Centre, AIIMS.


Corresponding Author:

Atif Rahman Raini MBBS, MS
Department of Ophthalmology,
ChristianMedical Hospital,
Kasganj,UP - 207123, India
Email id: atifraini1985@gmail.com


Received: 18-DEC-2019 Accepted: 05-MAR-2019 Published Online: 08-MAY-2019
DOI: https://dx.doi.org/10.7869/djo.443

Abstract
Context: Normal tension glaucoma (NTG) is a multifactorial optic neuropathy characterized by progressive retinal ganglion cell death and glaucomatous visual field loss, even though the intraocular pressure (IOP) does not exceed the normal range.Aim: To evaluate the retrobulbar hemodynamic parameters in NTG patients by Color Doppler Imaging (CDI).
Settings and Design: It was a hospital based cross-sectional institutional study carried out in the Medical College Out Patient Department (OPD).
Materials and Methods: Twenty patients with untreated NTG (mean age 53.27 ± 11.11 years) and 23 healthy volunteers (mean age 49.39 ± 9.56 years) were included in a prospective cross-sectional institutional study. Peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistivity index (RI = (PSV–EDV)/PSV) of the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were measured by means of CDI.
Statistical Analysis: Mean, standard deviation (SD) and Independent t- test was applied. Results: Patients with NTG showed significantly decreased PSV (P<0.001) and EDV (P<0.001) of the OA, significantly decreased PSV (P= 0.017) and EDV (P = 0.046) of the CRA, and significant decrease in EDV (P = 0.018) of SPCA. All the three vessels showed significantly increased RI; OA (P = 0.036), CRA (P = 0.008) and SPCA (P = 0.033).
Conclusions: We found decreased flow and increased resistivity index in the ocular vasculature in NTG and CDI may provide an effective and non-invasive method to evaluate vascular component in glaucoma.

Keywords :Color Doppler Imaging (CDI), Normal Tension Glaucoma (NTG), End Diastolic Velocity (EDV), Peak Systolic Velocity (PSV), Resistivity index (RI), Retrobulbar blood flow, Ocular Haemodynamic Parameters