Macular Vessels Density Before and After PRP in Patients With Proliferative Diabetic Retinopathy

PRP Clinical Trial

Official title:

Macular Vessels Density Before and After Panretinal Photocoagulation in Patients With Proliferative Diabetic Retinopathy

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04976361
• Other study ID #: VD befor and after PRP
• Status: Completed
• Phase: N/A
• Start date: March 1, 2019
• Est. completion date: May 1, 2021

Study information

• Verified date: July 2021
• Source: Minia University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

In this study, OCTA is used to study the vascular changes following PRP in patients with PDR; regarding vessels density at 1 month and 6 months follow up period and measure superficial, deep, and outer retina for fovea, para-fovea and whole image.

Description:

The global prevalence of diabetes mellitus in 2019 is estimated to be 9.3% (463 million people).1 Diabetic retinopathy (DR) is microangiopathy characterized by capillary non- perfusion, microaneurysms (MAs), and retinal ischemia. 2It may cause many complications, such as diabetic macular edema (DME) and diabetic macular ischemia (DMI).3 Capillary ischemia decreases the nutrition of the retina and causes hypoxia which results in increased level of vascular endothelial growth factor (VEGF), which promotes angiogenic responses causing both neovascularization (proliferative diabetic retinopathy, PDR) and vascular permeability (macular edema).

Panretinal photocoagulation (PRP) by argon or diode laser is the standard treatment for proliferative diabetic retinopathy. It improves oxygenation to the ischemic retina. Destruction of the highly active photoreceptor cells is the suggested mechanism of action for PRP. Subsequently, production of vascular endothelial growth factor (VEGF), the key player in neovascularization process, is reduced leading to regression of new vessels.5

PDR eyes have an overall lower blood flow than normal or non-PDR eyes, parallel to the higher level of retinal ischemia and disease severity. With regression of these neovascular and shunt vessels following PRP, normalization of flow in the macula may reverse the ischemia and decrease the stimulus for new blood vessel formation. Closure of intraretinal microvascular abnormalities and neovascularization would theoretically increase overall resistance to flow and, combined with the constriction of the large vessel in response to increased oxygen in the inner retina, collectively decrease the overall blood flow.6 While most previous studies have explored the large vessel effects of PRP, the development of ocular coherence tomography angiography (OCTA) allowed the study of microvascular retinal changes in a detailed manner. It is a non-invasive modality that allows vascular mapping with high speed and quality and promotes visualization of vascular system in different retinal and choroidal levels. Several investigations have demonstrated the competence of OCTA in the quantification of microvascular density, choroidal flow area, and foveal avascular zone (FAZ) area in diabetic patients.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 21
• Est. completion date: May 1, 2021
• Est. primary completion date: April 1, 2021
• Accepts healthy volunteers: No
• Gender: All
• Age group: 40 Years to 60 Years

Eligibility

Inclusion Criteria:

• patients with type 2 diabetes with PDR

• treatment-naive PDR diabetic patients diagnosed clinically and by the presence of neovascularization on optic disc (NVDs) or elsewhere (NVEs) on fluorescein angiography.

Exclusion Criteria:

• Patients with significant media opacity decreasing image quality

-. Eyes with significant macular edema

• patients with glaucoma, uveitis, previous intraocular surgery, and history of previous treatment for diabetic retinopathy including anti-VEGF and laser

• patients with low signal strength index (SSI; <50)

• presence of 1 or more blink artifacts

• poor fixation leading to motion artifacts.

Related Conditions & MeSH terms

• Diabetic Retinopathy
• PRP

Intervention

Other:
• PRP was done using visulas green laser machine (Carl Zeiss Meditec AG Geoschwitzer Str. 51-52,07745 jena, Germany)
PRP was done using visulas green laser machine (Carl Zeiss Meditec AG Geoschwitzer Str. 51-52,07745 jena, Germany)

Locations

Country	Name	City	State
Egypt	Minia University Hospital	Minya

Sponsors (1)

Lead Sponsor	Collaborator
Minia University

Country where clinical trial is conducted

Egypt, 

References & Publications (8)

Adhi M, Brewer E, Waheed NK, Duker JS. Analysis of morphological features and vascular layers of choroid in diabetic retinopathy using spectral-domain optical coherence tomography. JAMA Ophthalmol. 2013 Oct;131(10):1267-74. doi: 10.1001/jamaophthalmol.2013.4321. — View Citation

Cuypers MH, Kasanardjo JS, Polak BC. Retinal blood flow changes in diabetic retinopathy measured with the Heidelberg scanning laser Doppler flowmeter. Graefes Arch Clin Exp Ophthalmol. 2000 Dec;238(12):935-41. — View Citation

Ghassemi F, Fadakar K, Bazvand F, Mirshahi R, Mohebbi M, Sabour S. The Quantitative Measurements of Vascular Density and Flow Areas of Macula Using Optical Coherence Tomography Angiography in Normal Volunteers. Ophthalmic Surg Lasers Imaging Retina. 2017 Jun 1;48(6):478-486. doi: 10.3928/23258160-20170601-06. — View Citation

Lee R, Wong TY, Sabanayagam C. Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss. Eye Vis (Lond). 2015 Sep 30;2:17. doi: 10.1186/s40662-015-0026-2. eCollection 2015. Review. — View Citation

Miwa Y, Murakami T, Suzuma K, Uji A, Yoshitake S, Fujimoto M, Yoshitake T, Tamura Y, Yoshimura N. Relationship between Functional and Structural Changes in Diabetic Vessels in Optical Coherence Tomography Angiography. Sci Rep. 2016 Jun 28;6:29064. doi: 10.1038/srep29064. — View Citation

Photocoagulation for diabetic macular edema. Early Treatment Diabetic Retinopathy Study report number 1. Early Treatment Diabetic Retinopathy Study research group. Arch Ophthalmol. 1985 Dec;103(12):1796-806. — View Citation

Saeedi P, Petersohn I, Salpea P, Malanda B, Karuranga S, Unwin N, Colagiuri S, Guariguata L, Motala AA, Ogurtsova K, Shaw JE, Bright D, Williams R; IDF Diabetes Atlas Committee. Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: Results from the International Diabetes Federation Diabetes Atlas, 9(th) edition. Diabetes Res Clin Pract. 2019 Nov;157:107843. doi: 10.1016/j.diabres.2019.107843. Epub 2019 Sep 10. — View Citation

Savage HI, Hendrix JW, Peterson DC, Young H, Wilkinson CP. Differences in pulsatile ocular blood flow among three classifications of diabetic retinopathy. Invest Ophthalmol Vis Sci. 2004 Dec;45(12):4504-9. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Measurement of vessel density	Measurement of vessel density at superficial, deep, and outer retina at base line, after 1 month, and after 6 months.	6 months
Primary	Measurement of retinal thickness	central retinal thickness at base line, after 1 month, and after 6 months.	6 months