Financial disclosure: none Cyclophotocoagulation Transclerarl - PDF document

Ying Han, MD, PhD Associate Professor of Ophthalmology University of California, San Francisco Financial disclosure: none

Cyclophotocoagulation  Transclerarl approach (TCP)  Continuous mode: traditional TCP  Micropulse mode: Micropulse TCP  Endocyclophotocoagulation (ECP)  Anterior approach via limbus  Posterior approach via pars plana Traditional TCP  Two types:  Nd:YAG and Diode laser (810nm)  Laser is absorbed by melanin pigment of ciliary body  Mechanism:  Destruction of the ciliary bodies and decreasing aqueous production.  May increase outflow via blood autoregulation and immunologic response.

Traditional TCP  Mainly used to treat refractory glaucoma, including end ‐ stage painful eye.  High complication rate:  Unpredictable outcomes  Hypotony or Phthisis bulbi  Visual deterioration  Sympathetic ophthalmia (rare)  1.25 W and a 4.0 ‐ to 4.5 ‐ second duration were used. Eyes with other iris pigmentation received 1.5 W and a 3.5 ‐ to 4.0 ‐ second duration treatment Traditional TCP – slow coagulation  Traditional parameter:  1.75 W and 2.0 ‐ second duration  Slow coagulation parameter:  1.25 W and a 4.0 ‐ to 4.5 ‐ second duration for dark or light brown irises.  1.5 W and a 3.5 ‐ to 4.0 ‐ second duration treatment for other iris pigmentation.  Slow coagulation mode may lead to less postoperative inflammation Lee RK, Ophthalmology Glaucoma, 2018

Micropulse TCP Micropulse TCP  Diode laser emits 810 nm  Targeted to pigmented ciliary body epithelium  Either decrease aqueous production or increase uveal outflow Kuchar et al. Lasers Med Sci 2015

Micropulse vs Continuous TCP  On and off cycles  More selective  Less collateral damage – no histology damage  Nearly cause no inflammation Tan, et al. Clin Exp Ophthalmol, 2010 Micropulse TCP Continuous TCP

Settings for Micropulse TCP  Power: 2000mW  Duty cycle: 31.3%  Duration: 80s  1 ‐ 2 treatments per hemifield  Key: slow movement and press firmly to sclera Kuchar et al. Lasers Med Sci 2015

Indication for Micropulse TCP  Refractory glaucoma  Primary treatment for open angle glaucoma  High risk for incisional surgery  Patients s/p corneal transplant

Advantage of Micropulse TCP  No incisional surgery  Quick procedure– 5 mins  80% of patients have good response  IOP can be decreased to teens  No need for oral Carbonic Anhydrase Inhibitor. Disadvantage of Micropulse TCP  Still has complications (low risk)  Minimal inflammation  Minimal vision changes  Mydriasis  Vitreous hemorrhage (rare)  Peripheral vitreous traction(rare)  Hypotony (rare)  Corneal epithelial defect

Disadvantage of Micropulse TCP  Painful procedure  Requires full retrobulbar block  Or a quick general anesthesia  The laser effect may last 1 ‐ 2 years  Limited response in children

ECP Why do we need ECP?  Decrease laser energy: without barrier of sclera  2000 mW vs 200 ‐ 400 mW  Less complication  Direct visualization and treatment of the ciliary processes.

Anterior ECP • Laser probe enters via limbal incision • Aim for ciliary bodies process • Treat 270 ‐ 360 degree • Power: 0.25 ‐ 0.4 W  Treat until ciliary body shrink and turning white Indication for Anterior ECP • Refractory glaucoma • Primary treatment combining with cataract surgery • minimally invasive glaucoma surgery (MIGS) • Especially for patients with plateau iris or PAC or PACG

ECP Plus (via Pars Plana) • Requires pars plana vitrectomy and the insertion of the ECP probe via the pars plana • Treat the whole ciliary body and pars plana ECP Plus • Requires pars plana vitrectomy and the insertion of the ECP probe via the pars plana • Treat the whole ciliary body and pars plana

ECP Plus ECP Plus has better outcome

ECP Plus has better outcome • Higher success rate for refractory glaucoma • 80% success in 2 years follow up • Has potential to obtain IOP of 8 ‐ 12mmHg range • Clinical trial is needed to compare ECP plus vs standard approach to treat refractory glaucoma.

Disadvantage of ECP Plus • Requires pars plana vitrectomy • Complication as traditional anterior ECP • IOL dislocation • macular edema • postoperative inflammation Summary • Newer laser treatments, such as micropulse TCP, ECP plus, provide better approach to treat primary and refractory glaucoma.

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