DIRECT PATTERN PROJECTED ANNULUS LASER FOR SCLEROCILIARY TREATMENT OF GLAUCOMA: AN ALTERNATE APPROACH
Published 2024 - 28th ESCRS Winter Meeting
Reference: P184 | Type: Presented Poster & Poster | DOI: 10.82333/frvf-ey66
Authors: Claudia Thieme* 1 , Verena Prokosch 2 , Carl Erb 3 , Ronald Krueger 4 , Satish Herekar 5
1Department of Ophthalmology,Klinikum Bielefeld Rosenhöhe,Bielefeld,Germany, 2Department of Ophthalmology,Oberärztin für Glaukomerkrankungen,Köln,Germany, 3Department of Ophthalmology,Augenklinik am Wittenbergplatz,Berlin,Germany, 4Department of Ophthalmology,University of Nebraska Medical Center,Omaha,United States, 5Medical Technologies,Senogen GmbH,Rodgau,Germany
Purpose
Glaucoma is a leading cause of blindness worldwide, and current surgical treatments are limited by precision, pain, and ease of use. A novel approach to address these limitations is the use of direct pattern projected annulus laser (DPPAL). The laser is applied to sclera to enhance uveoscleral outflow and angle anatomy without focal thermal damage.
Setting
Uni Wurzburg, Uni Lubeck, NNF Eye Hospital Bangalore, Uni Nebraska, UCLA Doheny Eye Institute
Methods
8 cadaver and 16 pig eyes were treated with an 810 nm DPPAL (annulus from 12 to 18 mm diameter) at 5 Watts, 625 Hz & 3 different duty cycle dosages (100%, 75%, 31.3%) for 0-120 sec. Temperature rise was recorded in all eyes and assessed for changes using AS-OCT and histology. IOP was measured during and post treatment, and IOP inflation-droop cycle tests recorded the time to reach 50% of peak pressure and IOP after 5 min. droop. ICG, fluorescein and riboflavin dye tests were conducted with multiple wavelength imaging analysis. Pre & post angle metrics were recorded with AS OCT, and H&E melanin reduction was correlated to laser dose. Ex vivo eyes were tested in a 36 deg C water bath at baseline.
Results
The DPPAL successfully altered uveal sclera outflow (dye and OCT images) and angle anatomy (OCT and H&E images) without causing focal thermal damage in both human donor and pig eyes across all duty cycles in a dose- dependent manner. H&E showed smooth, dose related shrinkage in stromal volume and ciliary body, and clear safety of non-treated tissue. Temperature rise varied depending on power and duty cycle dosages, with the highest at 25°C+- rise with 100% duty cycle (CW). Duty cycles of 75% led to 20°C+- increase and 31.3% duty cycle to 15°C+- increase. AS-OCT revealed ciliary muscle shrinkage, and histology confirmed intact conjunctiva and dosage-dependent ciliary melanin reduction.
Conclusion
The DPPAL demonstrates potential as a promising alternative for treating glaucoma across various duty cycles. Altered uveoscleral outflow & angle anatomy, melanin reduction, and scleral micro-blebbing without focal thermal damage indicate that efficient non-destructive (repeatable) ab externo laser scleroplasty may be achievable with this technique.