News

A study comparing the 30-kHz femtosecond laser (IntraLase, Advanced Medical Optics) and the mechanical microkeratome (Zyoptix XP, Bausch & Lomb) showed both created thinner-than-intended flaps, but with similar variance and independent of preoperative SE, keratometry, or pachymetry, reports one physician.

The early results after use of pre-cut tissue for Descemet stripping automated endothelial keratoplasty (DSAEK) indicate that there is rapid restoration of good vision with no difference in complications compared with tissue that is cut by the surgeon. The tissue dislocation rate is low (1%), as is the loss of donor endothelial cells.

Femtosecond lasers and mechanical microkeratomes both have advantages and limitations. These features provided subject matter for a point-counterpoint discussion on choosing technology for LASIK flap creation.

Whether a cornea-or lens-based method is preferred for presbyopic surgery is a subject of ongoing debate in ophthalmology. Proponents of each discuss progress to date with the two approaches and look to the future for further advances.

An ongoing multinational study is evaluating LASIK for myopia and myopic astigmatism performed with a new-generation excimer laser (Schwind Amaris, Schwind eye-tech-solutions) using its aspheric, aberration-free ablation profile.

Femtosecond lenticule extraction (FLEx) is an all-laser procedure for the treatment of myopia performed using a femtosecond laser system (VisuMax, Carl Zeiss Meditec) to cut a flap and intrastromal lenticule. Results from 6 months of follow-up in 45 eyes suggest that it is a safe and effective refractive surgery modality.

A new laser application (IntraLase-Enabled Keratoplasty [IEK], IntraLase Corp.) used with a femtosecond laser (IntraLase, IntraLase Corp.) to cut donor and host incisions is considered a significant advance in transplantation surgery. Initial experience using the laser to cut zig-zag incisions indicates the procedure has several advantages and is associated with favorable refractive and visual outcomes

Advanced surface ablation and sub-Bowman's keratomileusis (SBK) were compared in a randomized, prospective study enrolling 200 patients who underwent bilateral surgery using the same procedure in both eyes. At 1 year, predictability, visual acuity, quality of vision, and safety outcomes were excellent. SBK had significantly faster visual recovery.

Innovations in diagnostic technology have implications for improving the screening and follow-up of refractive surgery patients. An ophthalmologist reviews equipment and features that are newly available and others that are on the near horizon.

Sub-Bowman's keratomileusis (SBK) aims to combine the advantages of LASIK with the biomechanical stability of surface ablation. Results of a prospective study comparing SBK with advanced surface ablation in fellow eyes suggest it may be fulfilling its goals.

Topography-guided ablation is an effective technique for managing highly distorted corneas, such as those with keratoconus, corneal ectasia, corneal trauma, and irregularities caused by previous surgery.

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.

A better visual outcome can be achieved after corneal transplantation surgery in pediatric patients with Peters' anomaly type 1 if the surgery is performed when the patients are aged approximately 10 to 15 weeks and if the glaucoma and astigmatism are well controlled.

An accommodating IOL (NuLens, NuLens Ltd.) is one of the most exciting IOL technologies under development and research. This lens differs from single-optic and dual-optic accommodating IOL designs in that it changes its power during accommodative effort not by a movement in IOL optic position, but by a change in the radius of curvature of the optic surface.

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.

Use of an implantable contact lens may be a safe and reasonably accurate refractive option in patients with pseudophakia and myopia, according to an ophthalmologist who describes one case.

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.

The winners of the fifth annual Ophthalmology Times Resident Writer's Award program were announced during the annual meeting of the American Academy of Ophthalmology.

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.

Outcomes from a long-term study of patients with small, suspicious choroidal melanoma suggest that observation is an effective strategy that is associated with very low melanoma-specific mortality rates and preservation of visual acuity.

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.