News

The pros and cons of surface ablation procedures were reviewed at the opening session of the refractive surgery subspecialty day at the American Academy of Ophthalmology annual meeting.

Refractive surgery has followed an evolving course over the past 20 years based on the availability of new technologies and understanding of the mechanisms for problems underlying various procedures. Into the future, surgeons can expect a continued move back to the surface with sub-Bowman's keratomileusis and pharmacologically modulated PRK.

John P. Berdahl, MD, a third-year resident at the Duke Eye Center, Duke University, Durham, NC, was named the winner of the fifth annual Resident Writer's Award program at the 2007 annual meeting of the American Academy of Ophthalmology in November in New Orleans.

Established and up-and-coming treatments for wet age-related macular degeneration (AMD); a controversial announcement by Genentech that the company would stop selling bevacizumab (Avastin) to compounding pharmacies effective Jan. 1, 2008, and the impact this decision would have on patients with wet AMD and other intraocular neovascular diseases; and combination therapies for AMD were topics of high interest to retina specialists in 2007.

Although 2007 did not present groundbreaking news for the specialty of glaucoma, several small advances occurred-particularly in the area of diagnostics. In addition, some new or investigational surgical modalities are showing promise as safe and effective methods for controlling IOP. The year also was a time for consolidation as specialists took stock of emerging knowledge, reassessed existing dogma, and determined what directions to pursue in the future.

There are doubts that Genentech is stopping bevacizumab sales to compounding pharmacies purely because of FDA-raised concerns and also by the company's recent history, which includes a series of disturbing actions. However, comments made by a Genentech executive in a personal appearance after the closing session of the Retina Subspecialty Day at the annual meeting of the American Academy of Ophthalmology (AAO) together with assurances provided by Genentech in an earlier meeting between several of its leaders and representatives from the AAO and the American Society of Retina Specialists (ASRS) offered some hope that the impending threat of lack of access to bevacizumab (Avastin) may have a satisfactory resolution.

Experiments have shown that oxidative stress is an early event following acute hydrostatic pressure elevation in vitro or IOP elevation in vivo. These findings suggest that oxidative damage could be an underlying mechanism for glaucomatous optic neuropathy.

Mouse model studies explore role of matrix metalloproteinase 9 (MMP9) in glaucoma-related axon loss. Initial findings revealed a significant difference in relative axon loss between the MMP9 knockout mice and wild-type control mice.

The year 2007 was successful for cataract surgery; many developments in technology and pharmaceuticals provided benefits to surgeons and their patients, and others to come promise even better things to come. Only the ongoing story of fee reductions from Medicare seems able to temper the positive outlook of cataract surgeons.

ISTA Pharmaceuticals Inc. has licensed North American rights to nasal dosage forms of bepotastine, an investigational product from Tanabe Seiyaku Co. Ltd. ISTA said it expects to complete the formulation of nasal bepotastine next year and begin clinical development in late 2008 or early 2009.

Monocyte chemoattractant protein 1 (MCP-1) seems to be responsible for apoptosis of the photoreceptors in certain visual disorders. MCP-1 seems to have a critical role in mediating photoreceptor apoptosis after retinal detachment in an experimental murine model. Specifically, MCP-1 causes macrophages and microglia to accumulate and generate oxidative stress in the retina.

New research in a large family affected with autosomal dominant juvenile-and adult-onset primary open-angle glaucoma has shown that age of onset can predict severity of disease. Researchers also have demonstrated that at least one modifier gene or locus alters the severity of glaucoma caused by a particular myocilin mutation.

A visual illusion known as the induced twinkle after-effect (TAE) can accurately identify the location and breadth of scotomas in those with retinal disease, according to a small study.

Combination therapy using photodynamic therapy and verteporfin (Visudyne, Novartis) as well as bevacizumab (Avastin, Genentech) can be effective in patients with age-related macular degeneration (AMD), particularly when patients are naïve to treatment, according to results from a patient registry.

A new screening service (Retasure, Digital Healthcare Inc.) is available to identify in primary-care and endocrinology practices those patients with diabetes who are at risk of developing diabetic retinopathy.

A new lens-positioning system (Optiflex Surgical Assistant, Volk Optical) for vitreoretinal surgery has a wide field of view and features such as powered and manual controls designed to provide maximum focus capability.

Spectral-domain optical coherence tomography (OCT) collects data that are extensive and allow software to generate displays that are clinically far superior to the data obtained using time-domain systems, according to one ophthalmologist.

An advance in posterior segment imaging technology (Cirrus HD-OCT, Carl Zeiss Meditec) brings clinicians and researchers useful advantages compared with previous-generation optical coherence tomography (OCT) equipment and holds promise for valuable expanded capabilities in the future.

The less is more approach has been successful when applied to treating retinal disease with lasers. The best example of this is a laser therapy (2RT – Retinal Regeneration Therapy, Ellex) that uses extremely short (3-nanosecond) pulses of laser energy to stimulate the retinal pigment epithelium (RPE) to create a sort of renewal process within the retina.

New wet AMD agent tested

A fusion protein that is an anti-vascular endothelial growth factor agent (VEGF Trap-Eye, Regeneron Pharmaceuticals) significantly reduced retinal thickness from baseline and significantly improved visual acuity in a double-masked, randomized trial with five dosing arms and both monthly and quarterly dosing intervals. Although improvements occurred in all dosing arms, the effects were more consistent in the monthly groups.

High doses of bevacizumab

A small group of patients given 2.5-mg injections of bevacizumab (Avastin, Genetech) to treat age-related macular degeneration had less frequent injections and slightly better visual acuity than those receiving a 1.25-mg injection over an 8-month follow-up period.

An international, phase II, randomized, double-blind, sham-controlled study evaluated pegaptanib sodium (Macugen, OSI Eyetech/Pfizer) for the treatment of macular edema secondary to central retinal vein occlusion. Results after 30 weeks showed significant benefits of treatment for improving vision and reducing edema.

Two-year results of an exploratory study using an optical coherence tomography-guided variable dosing regimen with ranibizumab in patients with age-related macular degeneration showed that patients maintained visual acuity improvements achieved after an initial series of three monthly injections.

A phase I trial has begun investigating intravitreal injection with a complement inhibitor (POT-4, Potentia Pharmaceuticals) in patients with active choroidal neovascularization secondary to age-related macular degeneration. There is a solid scientific basis for developing complement inhibition as a therapeutic strategy, particularly for treating patients with early disease to prevent progression.