Factors Influencing Threshold Energy in Subthreshold Photocoagulation for Diabetic Macular Edema

Area of Science:

• Ophthalmology
• Medical Devices
• Laser Therapy

Background:

• Subthreshold photocoagulation is a treatment for diabetic macular edema.
• Precise laser energy titration is essential due to a narrow therapeutic range.
• Identifying factors influencing threshold energy is critical for effective treatment.

Purpose of the Study:

• To investigate factors influencing threshold energy in subthreshold photocoagulation for diabetic macular edema.
• To refine treatment protocols for diabetic macular edema using Endpoint Management (EpM).

Main Methods:

• Multiple regression analysis was employed.
• Data from 20 consecutive cases (29 eyes) treated with EpM between April 2019 and June 2020 were analyzed.
• Analysis included factors such as surgical history, central macular thickness, and time intervals.

Main Results:

• Overall analysis (n=150) showed significance for prior vitrectomy/cataract surgery, central macular thickness, and interval post-panretinal photocoagulation.
• Further analysis (n=116) in patients with prior surgery highlighted central macular thickness, axial length, interval post-panretinal photocoagulation, and HbA1c as significant.
• Specific subfield measurements (superior/nasal 6 mm) were also significant in the overall analysis.

Conclusions:

• Threshold energy for diabetic macular edema is significantly influenced by prior vitrectomy/cataract surgery, central macular thickness, and the interval since panretinal photocoagulation.
• Ocular media transparency and intraocular inflammation are hypothesized contributors to these findings.
• These results aid in optimizing subthreshold photocoagulation parameters for diabetic macular edema.