Clinical trial NCT04332133: Outcomes of Subthreshold Laser Versus Intravitreal Injection of Ranibizumab in Diabetic Macular Edema
Official title: Anatomical and Functional Outcomes of Subthreshold Micropulse Laser Versus Intravitreal Ranibizumab Injection in Treatment of Diabetic Macular Edema
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Diabetic Macular Edema
Keywords: DME, mfERG, SML, ranibizumab,IV.injection
Lead sponsor: Minia University
Sponsor class: OTHER
First posted: 2020-04-02
Enrollment: 80
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The aim of this study is To compare the anatomical and functional results of intravitreal( IV) injection of ranibizumab with sub threshold micropulse laser ( SML) in treatment of Diabetic macular edema (DME) both anatomically by spectral domain optical coherence tomography (SD OCT) and functionally by best-corrected visual acuity (BCVA) and multifocal electroretinogram (mfERG).

Detailed description: Diabetic macular edema (DME) causes significant visual loss in diabetic patients. About 20% and 40% of patients with Type 1 and Type 2 diabetes mellitus (DM), respectively, develop DME. One-third of diabetic patients who have had DM for more than twenty years will develop DME . Early impairment in the function of the middle and inner layers of the retina has been reported in diabetic patients before appearance of vascular complications . A good independent guide of macular function in patients with DME is multifocal electroretinogram (mfERG) readings from the macular area, which strongly associate with morphologic alterations in the macula. Some investigators suggested that temporal characteristic (implicit time) of mfERG waves are more important than amplitudes for evaluation of retinal function in diabetic patients. They concluded that patients with DM show temporal changes indicating delayed neural transmission due to local impairment of blood glucose metabolism. In contrast, others emphasize the importance of both parameters (implicit time and amplitude) in identifying retinal affection in DM.

Intravitreal (IV) injections of anti-vascular endothelial growth factor (VEGF) agents provided good visual outcomes in treatment of DME. However, IV anti-VEGF injections are expensive, need to be repeated many times and have the potential risk of causing endophthalmitis . Subthreshold micropulse laser (SML) treatment of DME has the same effect as conventional laser treatment, nonetheless, there is less damage to adjacent tissues of the burn area in the retinal pigment epithelium (RPE). SML allows laser emission to be divided into bursts of short cyclic pulses that remain for microseconds permitting substantial cooling amid these short pulses .

Eligibility criteria: Inclusion Criteria:

* DME with BCVA\<0.5 decimal Snellen acuity.
* Controlled blood glucose (HbA1c) \<6.5%.

Exclusion Criteria:

* History of previous intraocular surgery,
* History of previous laser treatment,
* History of previous IV injection,
* Macular disease or ischemia,
* Proliferative diabetic retinopathy,
* Vitreoretinal traction,
* Interruption of external limiting membrane (ELM) or ellipsoid zone (EZ).
* Dense media opacity,
* Optic disc pathology
* History of strokes or ischaemic heart diseases.
* patients with (CST) \> 400 µm on OCT .

Primary outcomes:
measure: central subfield thickness in micrometer
timeFrame: 6 months
measure: p1 amplitude of mfERG
timeFrame: 6mnths
measure: BCVA
timeFrame: 6 months
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: ophthalmology department,faculty of medicine, minia university
name: Raafat Abdallah, A.professor
role: PRINCIPAL_INVESTIGATOR
affiliation: ophthalmology department,faculty of medicine, minia university
name: Mahmoud Genidy, professor
role: STUDY_DIRECTOR
affiliation: ophthalmology department,faculty of medicine, minia university
name: Wagiha Massoud, professor
role: STUDY_CHAIR
References:
citation: Klein R, Knudtson MD, Lee KE, Gangnon R, Klein BE. The Wisconsin Epidemiologic Study of Diabetic Retinopathy XXIII: the twenty-five-year incidence of macular edema in persons with type 1 diabetes. Ophthalmology. 2009 Mar;116(3):497-503. doi: 10.1016/j.ophtha.2008.10.016. Epub 2009 Jan 22.
citation: Lung JC, Swann PG, Wong DS, Chan HH. Global flash multifocal electroretinogram: early detection of local functional changes and its correlations with optical coherence tomography and visual field tests in diabetic eyes. Doc Ophthalmol. 2012 Oct;125(2):123-35. doi: 10.1007/s10633-012-9343-0. Epub 2012 Jul 25.
citation: Yamamoto S, Yamamoto T, Hayashi M, Takeuchi S. Morphological and functional analyses of diabetic macular edema by optical coherence tomography and multifocal electroretinograms. Graefes Arch Clin Exp Ophthalmol. 2001 Feb;239(2):96-101. doi: 10.1007/s004170000238.
citation: Fortune B, Schneck ME, Adams AJ. Multifocal electroretinogram delays reveal local retinal dysfunction in early diabetic retinopathy. Invest Ophthalmol Vis Sci. 1999 Oct;40(11):2638-51.
citation: Abdelrahman A, Massoud W, Elshafei AMK, Genidy M, Abdallah RMA. Anatomical and functional outcomes of subthreshold micropulse laser versus intravitreal ranibizumab injection in treatment of diabetic macular edema. Int J Retina Vitreous. 2020 Dec 3;6(1):63. doi: 10.1186/s40942-020-00265-6.