Study of clinical applications and safety for Pascal® laser photocoagulation in retinal vascular disorders


Paulo E. Stanga
Consultant Ophthalmologist and Vitreoretinal Surgeon
Honorary Reader in Ophthalmology
Manchester Royal Eye Hospital
University of Manchester
Oxford Road
Manchester M139WH
Tel: + 441612761234
Fax: + 441612765555


Purpose:  To establish safe laser parameter standards for 10–30 ms Pascal® laser in clinical practice and to evaluate clinical and visual outcomes using this 532-nm multi-spot photocoagulation system.

Methods:  Retrospective observational case series of 313 patients treated between 2006 and 2008. Evaluation of eight groups: A – panretinal photocoagulation (PRP) for proliferative diabetic retinopathy (PDR); B – focal laser treatment for clinically significant diabetic macular oedema; C – grid laser for diffuse diabetic macular oedema; D – sector PRP for ischaemic branch retinal vein occlusions (I-BRVO); E – full PRP for ischaemic central retinal vein occlusions (I-CRVO); F – macular laser treatment for macular oedema secondary to non-ischaemic BRVO; G – full PRP for rubeosis iridis and/or neovascular glaucoma (NVG) secondary to I-BRVO, I – CRVO or PDR; H – laser retinopexy for retinal breaks/degenerations.

Results:  Mean LogMAR visual acuity for all procedures improved postlaser (p = 0.065), and laser prevented visual loss in 85% eyes. Topical anaesthesia was only required. At mean follow-up of 5 months, 72% procedures had a successful clinical outcome. Significantly higher powers were required for PRP using Pascal® compared to conventional laser (p = 0.001) in PDR, I-BRVO, I-CRVO and NVG. Sixty-seven per cent of patients (15/20) were successfully treated with single-session 20-ms PRP using a mean 1952 burns. There were no laser-associated adverse effects or ocular complications associated with multi-spot PRP or macular Pascal® arrays.

Conclusions:  The clinical efficacy using 10- to 30-ms pulse duration Pascal® laser is comparable to conventional standard protocols used for the treatment of vascular retinal disorders. Higher power, 10- to 30-ms pulse duration laser may be safely and effectively used in clinical practice.