Anterior and posterior segment photography. An alternative approach using a dSLR camera adaptor.

The research presents a newly developed digital single lens reflex (dSLR) camera adapter that facilitates improved photography of anterior and posterior segment of the eyes. It has been utilized on dogs, cats, and horses, producing high-resolution images at a considerably lower cost than traditional imaging systems.

Methodology

• The researchers used the adapter to evaluate the eyes of canines, felines, and equines attending Tufts Ophthalmology service.
• For imaging the anterior part of the eye (such as cornea, iris, and lens), the adapter was affixed between a dSLR camera body (Canon 7D) and a macro lens (Canon EF-S 60mm/f2.8).
• In order to image the posterior part (like retina, optic disc, and macula), an indirect ophthalmic lens was mounted in front of the macro lens with the help of the adapter.
• The adapter includes a single white light-emitting diode (LED) providing coaxial illumination for viewing. Concurrently, illumination during image capture was facilitated either by the built-in flash or an accessory flash.
• Employing a pair of linear polarizers with their azimuths at right angles to each other, the adapter was able to eliminate reflections from the cornea and/or lens.

Results

• The dSLR camera adapter effectively generated high-resolution, reflection-free images of both anterior and posterior segments of the eye.
• The lightweight, easy to assemble and transportable design allowed for simple manoeuvring and adjustments required for quality images with minimal effort.

Conclusion

• The dSLR camera adapter provides an affordable alternative to existing imaging systems.
• It enabled acquisition of high-quality images, especially of the posterior segment of the eye, at a fraction of the cost of other established imaging systems.