Correlation Between Optical Coherence Tomography Angiography and Photopic Negative Response in Patients With Glaucoma

Study Overview
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Brief Summary
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Open angle glaucoma (OAG) is considered a common cause of irreversible vision loss worldwide. It is an optic neuropathy associated with progressive loss and degeneration of the retinal ganglion cell layer (RGC) and its axons (retinal nerve fiber layer; RNFL), which lead to neuroretinal rim excavation and corresponding visual field defects.

Detailed Description
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Open angle glaucoma (OAG) is considered a common cause of irreversible vision loss worldwide. It is an optic neuropathy associated with progressive loss and degeneration of the retinal ganglion cell layer (RGC) and its axons (retinal nerve fiber layer; RNFL), which lead to neuroretinal rim excavation and corresponding visual field defects. OCT Angiography (OCTA) is a promising tool for diagnosing and monitoring glaucomatous patients. It can evaluate glaucomatous damage and assess the ganglion cells' health by measuring blood flow within the optic nerve and the retina Correlation between vascular , structural and functional changes of the peripapillary retinal nerve fiber (RNFL) and macular/ganglion cell complex (GCC) can lead to early detection of glaucomatous changes.

Official Title
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Correlation Between Optical Coherence Tomography Angiography and Photopic Negative Response in Patients With Primary Open Angle Glaucoma

Conditions
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Open Angle Glaucoma

Intervention / Treatment
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* Diagnostic Test: Optical Coherence Tomography- Angiography
* Diagnostic Test: Photopic negative response


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age of 30 years or older for both control and glaucoma groups. Spherical equivalent (SE) between -2 and +2 D. No history of previous eye surgery, trauma, or systemic diseases. Exclusion Criteria: Spherical equivalent greater than +/- 2.00 diopters (D). Media opacity as (cataract or corneal scar). Any history of ocular surgeries or trauma. Optic nerve anomaly or other retinal diseases. Unreliable visual field tests (33% fixation losses, false positive, and false- negative results).

Ages Eligible for Study
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Minimum Age: 35 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| mild Primary Open Angle Glaucoma group (Group I)<br>28 eyes of 16 patients with mild primary open angle glaucoma as group I. | Diagnostic Test: Optical Coherence Tomography- Angiography<br>* Peripapillary retinal nerve fiber layer thickness, ganglion cell complex, superficial and deep capillary plexus vessel density were measured.<br>* Other names: OCT-A;Diagnostic Test: Photopic negative response<br>* Both the implicit time and amplitude of PhNR were recorded.<br>* Other names: PhNR;|
| moderate to severe Primary Open Angle Glaucoma group (Group II)<br>44 eyes of 24 patients with moderate to severe primary open angle glaucoma as group II. | Diagnostic Test: Optical Coherence Tomography- Angiography<br>* Peripapillary retinal nerve fiber layer thickness, ganglion cell complex, superficial and deep capillary plexus vessel density were measured.<br>* Other names: OCT-A;Diagnostic Test: Photopic negative response<br>* Both the implicit time and amplitude of PhNR were recorded.<br>* Other names: PhNR;|
| Control Group<br>80 eyes of 40 healthy subjects as control group. | Diagnostic Test: Optical Coherence Tomography- Angiography<br>* Peripapillary retinal nerve fiber layer thickness, ganglion cell complex, superficial and deep capillary plexus vessel density were measured.<br>* Other names: OCT-A;Diagnostic Test: Photopic negative response<br>* Both the implicit time and amplitude of PhNR were recorded.<br>* Other names: PhNR;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between vascular, structural and functional changes of the peripapillary retinal nerve fiber and macular ganglion cell complex in patients with open angle glaucoma. | Correlation between RNFL thickness and GCC measured by OCT-A with implicit time and amplitude of Photopic Negative Response (PhNR) measured by electroretinogram. | Immediately after OCTA and electroretinogram diagnostic tests for each eye. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess the validity of OCTA parameters and PhNR in early detection of glaucoma changes. | Changes in the parameters were measured by OCT-A as Superficial and deep vessel Density. | Immediately after OCTA and electroretinogram diagnostic tests for each eye. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Open angle glaucoma, Optical coherence Tomography, Photopic negative response