Pascal panretinal laser ablation and regression analysis in proliferative diabetic retinopathy: Manchester Pascal...

Area of Science:

• Ophthalmology
• Diabetic Retinopathy Treatment
• Laser Photocoagulation

Background:

• Proliferative diabetic retinopathy (PDR) is a severe complication of diabetes that can lead to vision loss.
• Panretinal laser photocoagulation (PRP) is a standard treatment for PDR, but optimal dosage for regression is debated.
• The 20-ms Pattern Scan Laser (Pascal) offers precise ablation, but its effectiveness in PDR regression requires further quantification.

Purpose of the Study:

• To quantify the 20-ms Pascal laser ablation dosage needed for PDR regression.
• To explore factors influencing long-term PDR regression after PRP.
• To assess the relationship between PDR severity and required laser dosimetry.

Main Methods:

• Retrospective analysis of a cohort from the Manchester Pascal Study (36 eyes, 22 patients).
• 18-month follow-up assessing visual acuity (VA) and PDR regression.
• Analysis of laser burn dosimetry, retinal ablation areas, and patient-related factors.

Main Results:

• No significant changes in logMAR VA over time.
• Regression rates varied by PDR severity: 75% (mild), 67% (moderate), 43% (severe) after top-up PRP.
• Dosage increased with severity: mild PDR (2187 burns, 264 mm²), moderate PDR (3998 burns, 456 mm²), severe PDR (6924 burns, 836 mm²).

Conclusions:

• Multiple 20-ms PRP treatments do not negatively impact visual outcomes.
• Favorable PDR regression rates were observed with minimal laser burn expansion.
• Higher laser dosimetry and ablation areas are significantly associated with worsening PDR severity for complete regression.