Scanning laser ophthalmoscopy and angiography with a wide-field contact lens system

Abstract

Objective: To perform fluorescein and indocyanine green angiography for large or peripheral chorioretinal structures using a contact lens system that provides a 5-fold increase in the field of view of a confocal scanning laser ophthalmoscope (SLO).

Methods: Separate handheld contact and noncontact ophthalmoscopic lenses were manually aligned with the optical axis of a confocal SLO to demonstrate the feasibility of wide-field SLO angiography. An integrated, wide-field contact lens system was then designed and constructed to increase the SLO's 10 degrees , 20 degrees , and 30 degrees imaging fields to 50 degrees , 100 degrees , and 150 degrees , respectively.

Results: Simultaneous fluorescein and indocyanine green angiography was performed with the integrated, wide-field contact lens system for more than 50 patients with disorders that affect their peripheral retina and choroid. Retinal and choroidal abnormalities, including neovascularization and capillary nonperfusion, are easily detected and documented well beyond the range of conventional fundus cameras and SLOs. Peripheral retinal and choroidal hemodynamics can be readily observed and recorded.

Conclusions: A confocal SLO has adequate resolution for clinically useful reflectance and angiographic imaging even when its field size is increased 5-fold by a wide-field contact lens system. Dynamic and static wide-field angiography can be performed without the limitations of manual or computer-automated photomontages. Peripheral retinal conditions can be studied and recorded to confirm observations from indirect ophthalmoscopy and to facilitate retinal photocoagulation and vitreoretinal surgery.