CO₂, Excimer and Erbium:YAG Laser in Deep Sclerectomy

Abstract

Purpose: Deep sclerectomy is a non-penetrating filtering procedure that is not generally accepted, as tissue dissection is difficult and varying success rates have been reported. The purpose of the present study was to compare the use of CO₂, excimer and erbium:YAG lasers in dissection of the deep corneoscleral lamella. Methods: In enucleated porcine eyes a superficial lamellar scleral flap of 5 × 5 mm was surgically dissected. The deep lamella was removed using a pulsed erbium:YAG, a CO₂ or an excimer laser (10 eyes/group). All eyes were analysed histologically and 3 in each group by scanning electron microscopy (SEM). Results: It is feasible to ablate the deep corneoscleral lamella with the CO₂, excimer and erbium:YAG lasers without perforating the anterior chamber. The following histology and SEM showed a smoother surface after dissection with the CO₂ and excimer lasers compared to the erbium:YAG laser. There was no thermal damage after excimer laser treatment, compared to a damage zone of 10–30 µm using the erbium laser and one of 70–100 µm with the CO₂ laser. Conclusions: Excimer,erbium:YAG and CO₂ lasers allow the microsurgical dissection of the deep lamella. The excimer and CO₂ lasers achieve a more regular and smoother tissue surface. The excimer laser has the advantage to dissect without thermal tissue damage.

CO2 Laser-assisted Sclerectomy Surgery, Part II

“…Goniopuncture and needling were not considered to be failures or adverse events, as both are commonly used as normal postoperative interventions that are required to maintain or augment the operative results of glaucoma surgeries. [13][14][15] The number of hypotensive medications being used by each patient at the time of the 6-month and the 12-month visits was compared with the baseline situation.…”

“…The unique characteristics of this laser were used to develop the simplified CLASS procedure, in which inadvertent perforations are unlikely. 12,13 The CO 2 laser effect ceases once aqueous starts to percolate preventing perforation. When used in conjunction with a micromanipulating system, the OT-134 (IOPtiMate; IOPtima Ltd., Ramat Gan, Israel), it can be used to achieve effective fluid percolation in a minimal or noninvasive procedure.…”

CO2 laser‐assisted sclerectomy surgery compared with trabeculectomy in primary open‐angle glaucoma and exfoliative glaucoma. A 1‐year follow‐up

“…CO 2 laser energy has been found useful in sclerectomy as it provides accurate ablation of dry tissues and is absorbed by fluid, which means that the aqueous humour percolating through the intact TDM intrinsically prevents excessive ablation. Subsequently, the risk of intraoperative TDM perforation is reduced, and the whole procedure is less dependent on the surgeon's skills (Assia et al 2007;Klink et al 2008). CO 2 laserassisted sclerectomy surgery (CLASS) outcomes, in terms of IOP-lowering potential, have already been reported as comparable to classic NPDS over a period of up to 2-year follow-up Skaat et al 2014;Greifner et al 2016).…”

CO2 Laser-assisted Sclerectomy Surgery for Open-angle Glaucoma

“…8,24 Theoretically, laser-assisted glaucoma surgery offers the potential advantage of improved accuracy, repeatability and safety. An increasing number of different radiation sources were examined for penetrating [25][26][27][28] and non-penetrating 22,25,29 glaucoma surgery with various success rates.…”