Laser Scanning Imaging for Macular Disease. A Report by the American Academy of Ophthalmology

Objective: To evaluate currently available data in the published literature to answer the question of whether laser scanning imaging is a sensitive and specific tool for detecting macular disease when compared with the current standard technique of slit-lamp biomicroscopy or stereoscopic fundus photography. Methods: Literature searches conducted in December 2004 and in August 2006 retrieved 370 citations. The Retina Panel members selected 65 articles for the panel methodologist to review and rate according to the strength of the evidence. Of the 65 articles reviewed, 6 provided level I evidence, 9 provided level II evidence, and 50 provided level III evidence. A level I rating was assigned to studies that reported an independent masked comparison of an appropriate spectrum of consecutive patients, all of whom had undergone both the diagnostic test and the reference standard. A level II rating was assigned to an independent masked or objective comparison; a study performed in a set of nonconsecutive patients or confined to a narrow spectrum of study individuals (or both), all of whom had undergone both the diagnostic test and the reference standard; or an independent masked comparison of an appropriate spectrum, but the reference standard had not been applied to all study patients. A level III rating was assigned when the reference standard was unobjective, unmasked, or not independent; positive and negative tests were verified using separate reference standards; or the study was performed in an inappropriate spectrum of patients. Results: There are high-level studies of the use of laser scanning imaging to quantify macular thickness and, thereby, macular edema in patients with diabetic retinopathy and to examine patients with a macular hole. There is lower-quality evidence on the use of laser scanning imaging for other diseases of the macula. There is insufficient evidence to compare the different instruments. Conclusions: There is level I evidence that laser scanning imaging can accurately and reliably quantify macular thickness in patients with diabetic retinopathy. There is level I evidence that optical coherence tomography provides additional information to clinical examination when used in patients with a macular hole. Laser scanning imaging provides important information that is helpful in patient management by allowing objective serial quantitative measurements. Although further studies are needed to develop an optimal testing strategy using these imaging modalities, laser scanning imaging is a sensitive, specific, reproducible tool for diagnosing macular edema and, therefore, is likely to be useful for managing diseases that result in macular edema.