Clinical trial NCT04976361: Macular Vessels Density Before and After PRP in Patients With Proliferative Diabetic Retinopathy
Official title: Macular Vessels Density Before and After Panretinal Photocoagulation in Patients With Proliferative Diabetic Retinopathy
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: PRP
Keywords: OCTA
PRP
Lead sponsor: Minia University
Sponsor class: OTHER
First posted: 2021-07-26
Enrollment: 21
Sex: ALL
Minimum age (years): 40
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: OTHER

Brief 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.

Detailed 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.

Eligibility criteria: 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.

Primary outcomes:
measure: Measurement of vessel density
timeFrame: 6 months
measure: Measurement of retinal thickness
timeFrame: 6 months
Secondary outcomes:
Other outcomes:
Locations:
city: Minya
country: Egypt
facility: Minia University Hospital
Study officials:
affiliation: Minia University Hospital
name: Ahmed Shawkat, Prof Dr
role: STUDY_DIRECTOR
affiliation: Minia University Hospital
name: Mohamed Farouk, Prof Dr
role: STUDY_DIRECTOR
affiliation: Minia University Hospital
name: Mohamed Salah, Doctor
role: PRINCIPAL_INVESTIGATOR
affiliation: Minia University Hospital
name: Asmaa Anwar, Doctor
role: STUDY_DIRECTOR
References:
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, 9th edition. Diabetes Res Clin Pract. 2019 Nov;157:107843. doi: 10.1016/j.diabres.2019.107843. Epub 2019 Sep 10.
citation: 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.
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.
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.
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. doi: 10.1167/iovs.04-0077.
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. doi: 10.1007/s004170000207.
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.
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.
citation: Abdelhalim AS, Abdelkader MFSO, Mahmoud MSE, Mohamed Mohamed AA. Macular vessel density before and after panretinal photocoagulation in patients with proliferative diabetic retinopathy. Int J Retina Vitreous. 2022 Mar 14;8(1):21. doi: 10.1186/s40942-022-00369-1.