Abstract
Purpose :
Panretinal photocoagulation (PRP) may be associated with pain that can adversely affect the number and quality of retinal laser spots delivered and indirectly increase the number of treatment sessions required to achieve regression of proliferative diabetic retinopathy (PDR). We assessed comfort in patients undergoing treatment with green (532 nm) versus yellow (577 nm) PRP for PDR using the laser indirect ophthalmoscope delivery system.
Methods :
A prospective, single-center, randomized crossover clinical trial of patients with PDR with high risk characteristics was performed. Patients were equally randomized to first receive PRP either with green (Iridex IQ 532, Mountain View, CA) or yellow (Iridex IQ 577, Mountain View, CA) laser followed by additional treatment with the alternate laser using standardized duration and interval settings in the superior hemisphere of a single treatment eye per patient during the same treatment session. Topical anesthetic was used in all study eyes prior to each treatment. Power was titrated with each laser until moderate grey-white retinal burns were achieved. The primary outcome measure was perceived patient pain as measured with a standardized 10-point pain scale. Secondary outcome measures included laser power, treatment time, and number of treatment shots with each laser.
Results :
Forty eyes of 40 patients with a mean age of 54.0 years were enrolled. There was no statistical difference in visual acuity (P = 0.441) or central macular thickness (P = 0.392) before and 1 month after PRP. There was no significant difference in the mean pain score between green and yellow wavelengths (2.8 ± 2.6 versus 3.1 ± 2.3, P=0.401). Additionally, there was no significant difference when comparing minimum laser power required (243.2 ± 74.2 versus 234.0 ± 59.6 mW, P=0.549), treatment time (5.1 ± 3.6 versus 5.6 ± 3.9 min., P=0.384), and number of treatment shots (257.6 ± 12.6 versus 258.0 ± 2.3, P=0.682). Independent of laser wavelength, there was no difference in reported pain scores when comparing the first and second round of laser treatment (2.9 ± 2.4 versus 2.9 ± 2.5, P=0.960). No adverse events occurred.
Conclusions :
Patient comfort during panretinal photocoagulation for proliferative diabetic retinopathy using the laser indirect ophthalmoscope delivery system is similar for green and yellow wavelengths.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.