OCT a good AMD screenig tool

June 1, 2007

OCT a good AMD screening tool

OCT a good AMD screening tool

Optical coherence tomography (OCT) is an effective screening tool for wet age-related macular degeneration (AMD), according to the results of a study published in the May issue of the British Journal of Ophthalmology.

James Talks and colleagues from the Royal Victoria Infirmary, Newcastle Upon Tyne, UK, carried out a retrospective audit of a consecutive series of 134 new patients referred with suspected wet AMD. If visual acuity (VA) was 6/60, an OCT was performed and if the OCT was consistent with wet AMD, the patient underwent simultaneous fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA). The number of additional diagnoses made using ICGA were recorded.

OCT had a sensitivity, in this clinic, of 1 and a specificity of 0.65 for detecting wet AMD. ICGA provided additional diagnoses in 19 (14.17%) patients and detected specific vascular abnormalities in 58% of the occult lesions.

Although ICGA can provide an additional diagnosis it does not define vascular abnormalities in all occult cases. OCT, however, has proved to be an effective method of screening wet AMD.

No benefit seen with repeat Avastin injections in CNV

Patients who are repeatedly treated with bevacizumab (Avastin) for choroidal neovascularization (CNV) experience visual improvements similar to patients who received their first treatment with the drug, according to a report published in the April/May issue of Retina.

Mitchell Goff, MD and colleagues from the Alta Bates Summit Medical Center, California, USA, conducted a retrospective study to examine whether there is a difference in treatment effect between initial and repeated intravitreal injections of bevacizumab.

Of the 51 patients (54 eyes) with CNV secondary to age-related macular degeneration (AMD), 70% had previously been treated for CNV. A total of 178 injections (mean: 3.3 per eye) were performed. In 20% of the cases, surgeons also performed photodynamic therapy (PDT) at the time of the initial injection. Mean follow-up was 138 days and 91% of subjects were followed for at least 90 days post-injection.

The results showed that central macular thickness significantly decreased after treatment (baseline: 362 μm; one-week follow-up: 235 μm; one-month: 244 μm). Although thickness had increased slightly by month three it was still significantly lower compared with baseline (three months: 235 μm). Mean VA improved from 20/125 at baseline to 20/100 at final follow-up.

The results suggest that previously treated and treatment-naïve patients have similar outcomes.

Gene therapy could treat blindness

A Phase I/II clinical trial has been initiated to evaluate an innovative gene therapy in patients with progressive deterioration in vision caused by an abnormality in the RPE65 gene.

Researchers from University College London's (UCL) Institute of Ophthalmology, Moorfields Eye Hospital, London, UK and Targeted Genetics Corporation will evaluate the effectiveness of an adeno-associated virus (AAV) vector to deliver a normal copy of the RPE65 gene into the cells of the retina. Research in animal models has demonstrated that the AAV-mediated delivery can improve and preserve vision.

The trial, which is the first of its kind and is being funded by the UK Department of Health, involves adults and children who have progressive vision deterioration caused by the genetic defect.

The purpose of this study is to evaluate the safety and efficacy in human patients.

But it's looking good in DME...