The need for an alternative to filtration surgery is obvious. The problems associated with trabeculectomy include failure, flat chambers, choroidal effusions, endophthalmitis, bleb leaks, and hypotony. To date, however, I have not seen adequate controlled, scientific research in the peer-reviewed literature demonstrating that endoscopic cyclophotocoagulation (ECP) safely produces long-term, positive results with regard to decreasing IOP and, thus, facilitating the management of glaucoma in patients undergoing cataract surgery.

CYCLODESTRUCTION
We have destroyed the ciliary body for many decades in an effort to halt glaucomatous progression. We have burned this tissue with electrodes, frozen it with cryotherapy, and destroyed it with lasers. Among the first to use intraocular lasers in this capacity were Ronald G. Michels, MD; John T. Thompson, MD; and Arun Patel, MD, from the Wilmer Eye Institute at Johns Hopkins University in Baltimore. In patients with intractable glaucoma, they found it necessary to destroy 50% to 60% of the ciliary processes in order to lower pressure adequately.1 Such damage to the ciliary body breaks down the blood-aqueous barrier, which maintains the homeostatic nature of the eye. Destroying this barrier can cause chronic inflammation and cystoid macular edema. Because of these significant adverse events, one normally reserves destructive procedures as final treatments for glaucoma. We try to be constructive, rather than destructive, in glaucoma therapy.

SUCCESS RATES
ECP does not always adequately lower IOP. Many patients with glaucoma who have undergone ECP still need additional IOP-lowering medications after combined ECP and cataract surgery. Due to problems with compliance and adherence, this reliance upon medication is not ideal.

CAVEATS
I have not performed ECP. Although I am rarely conservative about new procedures, I hesitate to use ECP, because the potential ill effects of chronic inflammation trouble me. Perhaps a patient with neovascular glaucoma or uveitic glaucoma, who would experience inflammation postoperatively anyway, may benefit from ECP. The procedure may be an acceptable alternative to filtration surgery for some patients, such as those with endophthalmitis in their opposite eye who need cataract surgery as well.

CONCLUSION
ECP is clearly inappropriate in patients with ocular hypotension who have not exhibited glaucomatous changes to their optic discs or visual fields. In these patients, the risk of any intervention is certainly not worth the therapy. Before considering the procedure for my practice, I would like to review prospective results (particularly with regard to safety) from unbiased reviewers in well-controlled studies that compare of combined ECP/cataract surgery with phacotrabeculectomy.

Alan L. Robin, MD, is Clinical Professor of Ophthalmology at the University of Maryland in Baltimore. Dr. Robin may be reached at (410) 377-2422.; glaucomaexpert@cs.com.

1. Patel A, Thompson JT, Michels RG, Quigley HA. Endolaser treatment of the ciliary body for uncontrolled glaucoma. Ophthalmology. 1986;93:825-830.