[Morphological evaluation of the results of laser activation of scleral hydropermeability in the treatment of glaucoma]. / Morfologicheskaya otsenka rezul'tatov operatsii lazernoi aktivatsii gidropronitsaemosti sklery v lechenii glaukomy.

PURPOSE: The study attempted to experimentally substantiate the possibility of using the laser activation of scleral hydropermeability (LASH) technique in glaucoma treatment by morphological evaluation of treatment outcomes. MATERIAL AND METHODS: The pulsed-periodic radiation from an Er-glass fiber laser (λ=1.56 µm) was used. The model experiment consisted of evaluating ultrafiltration of fluid through the tissues of human sclera autopsy specimen according to the original technique using neodymium chloride-based labeling agent and scanning electron microscopy. The clinical part of the study consisted of optical coherence tomography (OCT) and laser confocal microscopy of the sclera and conjunctiva (CMSC) performed in vivo immediately after laser treatment in the laser application sites in 5 patients (5 eyes) aged 57 to 68 years with uncompensated advanced (IIIb-c) stage of glaucoma who had previously underwent LASH surgery. RESULTS: Results of morphological evaluation after LASH revealed structural changes indicating increased transscleral ultrafiltration: increased intrastromal hyporeflective areas in the sclera, thinning of collagen fibers, formation of porous structures. Using an original technique involving neodymium chloride-based labeling agent and scanning electron microscopy, we were able to prove the enhancement of transscleral ultrafiltration. The results of the experiment were confirmed by in vivo OCT images of the sclera and CMSC performed in 5 patients with advanced glaucoma after LASH surgery, in which tissue decompaction in the laser-exposed areas was clearly visualized. CONCLUSION: The revealed structural changes indicate the possibility of reducing intraocular pressure after LASH by the means of forming scleral porous structures and increasing transscleral ultrafiltration. Experimentally selected optimal mode of laser exposure (0.66 W with total exposure time of 6 seconds) during LASH helps avoid gross destructive changes in the eye tissues, making the proposed intervention a sparing approach to the treatment of glaucoma.

[Current possibilities of laser surgery on anterior eye segment]. / Sovremennye vozmozhnosti lazernogo vozdeistviya na struktury perednego segmenta glaza.

The article summarizes the experience of recent years in the development and implementation of novel original laser technologies used in surgery of the anterior segment of the eye. The presented technology of laser activation of scleral hydropermeability (LASH) in glaucoma is based on the effect of enhanced transscleral filtration and has been shown as effective and safe, which was confirmed by the results of a comprehensive clinical and experimental study. Development of another technique was associated with the need to improve the safety of laser interventions in anterior capsule contraction syndrome in pseudophakia, and resulted in a proposition to change the configuration of the anterior lens capsule incision from the usual linear-radial to T-shaped laser anterior capsulorhexis. The proposed technology of laser photomydriasis based on near-infrared radiation of the diode laser (0.810 µm) has shown its effectiveness and gentle nature (absence of atrophy of the iris stroma and post-burn pigmentation) in ectopias and pupil deformity.

[Clinical outcomes of laser activation of hydraulic permeability of the sclera in the treatment of advanced glaucoma]. / Klinicheskie rezul'taty lazernoi aktivatsii gidropronitsaemosti sklery v lechenii patsientov s dalekozashedshei stadiei glaukomy.

PURPOSE: This study evaluates the hypotensive effect and the outcomes of intravital morphological changes in the intervention site after laser activation of scleral hydro-permeability (LASH) by pulsed-periodic radiation from an Er-glass fiber laser (λ=1.56 µm) in patients with advanced glaucoma. MATERIAL AND METHODS: LASH surgery was performed in 19 patients (19 eyes) aged 48 to 73 years with uncompensated advanced stage (IIIb-c) glaucoma. In addition to standard methods of investigation, all patients were examined with optical coherence tomography (OCT) and laser confocal microscopy of sclera and conjunctiva (CMSC) at the laser treatment sites, and electronic tonography. RESULTS: The hypotensive effect after LASH in patients with advanced glaucoma was observed in 94.7% (n=18) of cases. The decrease in intraocular pressure (IOP) averaged 24.4% from baseline one month after intervention and 32.96% after six months of follow-up. In 15.7% (n=3) of cases, the recorded IOP decrease was insufficient as its target values were not achieved. However, in the vast majority of patients (n=16), the recorded IOP decrease corresponded to the target values and indicated compensation of the process. Results of complex morphological evaluation after LASH revealed structural changes indirectly indicating possible laser-induced influence on the processes of increased transscleral filtration and uveoscleral outflow. A high positive correlation dependence (r=0.848) was also revealed between the degree of IOP lowering and the increase in the coefficient of ease of aqueous humor outflow, attesting to the fact that IOP lowering was mainly due to the improvement of intraocular fluid outflow. CONCLUSION: The demonstrated efficacy of LASH technology indicates the possibility of its successful application as an independent method of IOP reduction in patients with advanced glaucoma.

[Technique for laser activation of scleral hydropermeability in the treatment of patients with refractory forms of glaucoma]. / Tekhnologiya lazernoi aktivatsii gidropronitsaemosti sklery pri refrakternykh formakh glaukomy.

Laser cyclodestructive interventions are considered the method of choice in the treatment of refractory glaucoma. However, the traumatic nature of cyclocoagulation makes it necessary to search for more gentle methods of laser treatment. One of the possible directions is the development of laser transscleral technologies that mainly affect the uveoscleral outflow. This article presents a new technique for laser activation of scleral hydropermeability (LASH) using pulse-periodic erbium glass (Er-glass) fiber-optics laser with wave length of 1.56 µm. The article describes the parameters of laser emission and the technique of LASH, and presents the mechanism of reducing intraocular pressure associated with increased transcleral drainage of intraocular fluid by forming new pores in the sclera. The effectiveness and safety of LASH is supported by a detailed example from clinical practice. This technology has proven itself as a possible alternative to the conventional contact transcleral cyclocoagulation.

[Transscleral laser therapy in the treatment of glaucoma]. / Lazernye transskleral'nye tekhnologii v lechenii glaukomy.

Nowadays glaucoma is one of the leading causes of irreversible blindness worldwide. The main goal in preservation of vision in glaucoma patients is reducing intraocular pressure (IOP), which is considered the main controlled risk factor for progression of glaucomatous optic neuropathy. The article discusses the effectiveness and safety of various transscleral laser technologies in the treatment of glaucoma. Modern transscleral laser technologies that affect the uveoscleral drainage and scleral hydro-permeability are less traumatic and more gentle making them promising in the treatment of patients with early stages of glaucoma, and not only in terminal glaucoma with pain syndrome resistant to conventional treatment ("last resort surgery").