Abstract
Purpose:
To determine if the method of anesthesia (topical versus retrobulbar) and the type of laser (Pascal versus conventional green laser) affect the completion rate of panretinal photocoagulation (PRP).
Methods:
This was a retrospective chart review study from a single institution. All patients undergoing PRP in previously untreated eyes for the diagnosis of diabetic retinopathy or central retinal vein occlusion during the past four years were identified. Eyes were included in the study if the type of laser and anesthetic used, the number and size of laser spots, and the presence or absence of vitreous hemorrhage were obtainable from the medical records for the first PRP session and all subsequent visits within 90 days. Eyes were excluded if they underwent vitrectomy or developed new vitreous hemorrhage within 90 days of the first laser treatment. Completed treatment was defined as 1200 or more laser burns with retinal spot size of 500 microns or 1800 burns with spot size of 400 microns within 90 days of the first PRP treatment. Completion rate was defined as the percentage of treated eyes receiving complete PRP.
Results:
132 eyes (109 patients) were treated with conventional green laser using topical anesthesia (CGT), 26 eyes (23 patients) with conventional green laser using retrobulbar anesthesia (CGRB), 48 eyes (43 patients) with Pascal laser using topical anesthesia (PT), and 1 eye with Pascal laser using retrobulbar anesthesia (PRB). The completion rates were as follows: CGT 46 of 132 (34.8%), CGRB 25 of 26 (96.2%), PT 21 of 48 (43.8%), and PRB 1 of 1 (100%). The relative risks of incomplete treatment were: CGT vs. CGRB 16.9 (CI, 2.5 to 116.3, P=0.004), CGT vs. PT: 1.5 (CI, 1.055 to 2.1, P=0.023), and PT vs. CGRB: 11.4 (CI, 1.6 to 79.8, P=0.0145).
Conclusions:
Conventional green laser with retrobulbar anesthesia and Pascal laser with topical anesthesia both have higher completion rates than conventional laser using topical anesthesia. The magnitude of this difference suggests that the use of retrobulbar anesthesia or Pascal laser should be strongly considered when performing PRP.
Keywords: 578 laser •
499 diabetic retinopathy •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials