Comparison of Optical Coherence Tomography Angiography Microvascular Changes in Primary Open Angle and Primary Angle Closure Glaucoma

After approval of the local institutional ethics committee and local institutional review board, all patients presenting to the outpatient clinic of the department of Ophthalmology in the universities has been subjected to routine ophthalmological examination including: best corrected visual acuity (BCVA), Slit-lamp evaluation of anterior segment, IOP by Goldmann applanation tonometer, Gonioscopy using gonio contact lens, Fundus examination by indirect opthalmoscope with history taking focusing on positive family history of glaucoma after a detailed informed consent was signed by eligible patients and investigated by OCTA of the Peripapillary and Macular vascular density on presentation using AngiVue (Optovue, Inc., Fremont, CA, USA).

Data analysis performed using the Statistical Package of Social Science (SPSS) software version 22 in windows 7 (SPSS Inc., Chicago, IL, USA) Simple descriptive statistical analysis in the form of numbers and percentages of qualitative data, and arithmetic means as central tendency measurement, standard deviations as a measure of dispersion of quantitative parametric data.

For quantitative parametric data: Independent samples test was used to compare quantitative measures between two independent groups, One-way analysis of variance ANOVA test used to compare quantitative measures between more than two independent groups of quantitative data with the benferroni Post-HOC to test the significance between each two groups, Paired t-test used to compare two dependent quantitative data.

For qualitative data Chi square test used to compare between two or more than two qualitative groups.

Bivariate Pearson correlation test to test the association between variables The probability value (P-value) < 0.05 was considered as statistical significant

Inclusion criteria

• Age ≥ 18 years old.
• Fulfilling Diagnostic criteria of PACG patients :occluded angle by gonioscopy in which > 180˚ of trabecular meshwork cannot be seen , IOP>21, Optic disc and RNFL damage due to glaucoma
• Diagnosed POAG patient: open anterior chamber angle ,IOP>21 ,Optic disc and RNFL damage due to glaucoma
• Healthy patient: normal anterior chamber, open angle and normal fundus.

Exclusion criteria

• History of other causes of optic neuropathy.
• History of systemic diseases. (HTN, DM, Cardiac).
• Previous ocular surgeries or Laser iridotomy.
• Poor quality of OCTA image less than 4/10.
• Refractive errors > 6 diopters sphere, >3 diopter cylinder
• Poor cooperation or fixation with the OCTA examination.
• Secondary causes of glaucoma
• Media opacity that interfere with quality of image (dense cataract,corneal opacity,…)
• Previous acute attack of ACG