ABSTRACT
Purpose: To evaluate the safety and efficacy of 532 nm frequency-doubled Nd-YAG green laser for treatment of retinopathy of prematurity (ROP). Methods: This retrospective interventional case series included infants undergoing treatment for ROP with 532 nm green laser between January 2012 and March 2017 at a single tertiary-care referral center. Review of clinical records was done to identify baseline ROP characteristics, procedural difficulties, complications related to the laser procedure and outcome of treatment at ? 1 year of follow-up. Results: There are about 347 eyes of 182 infants were included in this present study. ROP presented in zone I in 76 eyes (21.9%) and zone II in 271 eyes (78.1%). Tunica vasculosa lentis (TVL) was present in 43.8% and pre-existing vitreous hemorrhage in 4.6% of the eyes. 532 nm green laser could be performed as a primary procedure in all eyes, including those with TVL. 322 eyes completed a minimum follow up of 1 year with a mean follow up of 22.8 months (range, 12–54 months). At the last follow-up visit, 298 (92.5%) of the 322 eyes had a favorable outcome. On logistic regression analysis, pre-existing fibrovascular proliferation (p = 0.04) and new-onset fibrovascular proliferation after treatment (p = 0.001) were the most significant independent predictors of poor outcome. Complications encountered were new-onset hemorrhage in 36 eyes (11.2%), anterior segment ischemia in two eyes (0.006%) and cataract in one eye (0.003%). Conclusion: 532 nm frequency-doubled Nd-YAG green laser appears to be safe and effective in the treatment of ROP.
ABSTRACT
PURPOSE: The solid-state, continuous-wave, frequency-doubled neodymium:yttrium-aluminum-garnet (Nd:YAG) laser pumped by diode laser has several advantages, including air cooling, higher electrical to optical efficiency ratios, and portability. The authors evaluated the use of the frequency-doubled Nd:YAG laser for peripheral iridotomy and compared with the argon blue-green laser. METHODS: Laser peripheral iridotomy was performed on 64 eyes of 47 patients with acute or chronic primary angle-closure glaucoma and narrow angles capable of closure. Thirty-one eyes of 25 patients were treated with frequency-doubled Nd:YAG laser and 33 eyes of 22 patients were treated with argon laser. Postoperative intraocular pressure, visual acuity, preoperative and postoperative medication, number of laser spots, and failure of patency were compared. RESULTS: Postlaser 1hr intraocular pressure elevation greater than 10 mmHg 1hr was seen in one (3.2%) of frequency-doubled Nd:YAG laser treated eyes and six (17.6%) of argon laser-treated eyes (p=0.055). The failure of patency was seen less often in frequency-doubled Nd:YAG laser than in argon laser (9.7% vs 27.3%, p=0.081). The number of laser spots was greater in frequency-doubled Nd:YAG laser than in argon laser (p=0.069). Preoperative, postoperative 1hr, 1day, 1mon, 3mons intraocular pressure, visual acuity, preoperative and postoperative antiglaucomatous medication, number of laser spots, and failure of patency were similar in the two groups. CONCLUSIONS: The above results suggest that the frequency-doubled Nd:YAG laser was at least as effective and appears to be as safe as the argon laser. However, laser iridotomy with frequency-doubled Nd:YAG laser may be more difficult than the argon laser.
Subject(s)
Humans , Argon , Glaucoma, Angle-Closure , Intraocular Pressure , Lasers, Semiconductor , Lasers, Solid-State , Neodymium , Visual AcuityABSTRACT
We investigated the effect of trabeculoplasty using Q-switched,frequency doubled Nd: YAG laser (Selecta 7000, Coherent,U.S.A.) which was developed to selectively destroy pigmented trabecular meshwork cells without producing collateral or thermal structural damage to adjacent structure. Twenty eyes of 14 patients with medically uncontrolled primary open angle glaucoma were enrolled in this study. The mean prelaser intraocular pressure (IOP) was 20.5 +/-5.0 mmHg (12-32mmHg) and the decrease of IOP was 5.8 +/-5.3 mmHg (26.7%) at 1 week, 5.9 +/-3.7 mmHg (27.7%)at 1 month and 5.4 +/-4.7 mmHg 22.9%) at 6 months. Moderate anterior chamber inflammation was noted in 7 cases but resolved in 1 week and peripheral anterior synechia was not noted in any case until 6 months.