EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/1148281
AUGUST 2019| EYEWORLD | 63 G lations such as primary open angle patients," Dr. Noecker said. "This study demonstrated that micropulse can lower IOP significantly in a manner that is less traumatic and inflammatory than other modalities such as traditional transs- cleral cyclophotocoagulation." Other milder technologies such as MIGS are not indicated or will not deliver the desired efficacy, Dr. Noecker said. Questions remain Pulsed TSCPC can be titrated to minimize the occurrence of hypotony. However, it is not known how often the treatment can be repeated if the IOP is not sufficiently reduced, the study authors noted. To varying degrees, the laser is applied blindly to the internal structures of the eye and may be treating either the cili- ary body or the trabec- ular meshwork, and where the treatment is actually applied could influence the effect of subsequent treatments. The authors said further research is needed to determine whether breakdown of the blood-aqueous barrier is less intense with TSCPC than it is with a trabeculectomy or aqueous shunts and to further assess graft survival and endothelial cell loss in eyes that are not as severely compromised as many of the eyes were in this study. "Interestingly, the TSCPC treatment re- duced IOP in our eyes with total angle closure, indicating that either the iris tissue covering the trabecular meshwork becomes more porous to fluid transfer across it or production of aqueous fluid by the ciliary body decreased," the authors wrote. (range, 0–4) versus 2.2 (range, 0–4) at the last follow-up. Many eyes in the study had already under- gone glaucoma filtration surgery, which is a major risk factor for graft failure. At baseline, seven grafts were decompensated and five of 54 clear grafts (9%) had endothelial cell density <700 cells/mm. Graft survival was 94% at 1 year and 81% at 2 years after the initial laser treatment. "This study found that pulsed TSCPC was generally an effective noninvasive alternative to glaucoma filtration surgery in keratoplasty eyes; it reduced IOP by a mean of 35% at 12 months and was well-tolerated by most treated subjects," the authors wrote. Management of post-keratoplasty glaucoma is crucial because high IOP is detrimental to both optic nerve fibers and endothelial cells of the corneal graft. IOP control is often more complicated in post-keratoplasty eyes because the long-term use of topical corti- costeroids to prevent transplant rejection causes IOP elevation, noted the authors. Surgeon's view Robert Noecker, MD, said this study addressed an important niche for use of micropulse and that it was a good study with a good number of patients treated. "This is a very difficult population of patients to treat and the alternatives are not good," Dr. Noecker said. Dr. Noecker noted that tubes can achieve similar IOP lowering but are also associated with high rates of corneal failure. "The IOP lowering that was achieved with micropulse was similar to that in other popu- Financial interests Noecker: None Reference 1. Subramaniam K, et al. Micro- pulse transscleral cyclophotoco- agulation in keratoplasty eyes. Cornea. 2019;38:542–545. "This study demonstrated that micropulse can lower IOP significantly in a manner that is less traumatic and inflammatory than other modalities such as traditional transscleral cyclophotocoagulation." —Robert Noecker, MD