Abstract
Purpose :
Detailed evaluation of the retina is a challenging aspect of ophthalmic examination. Reusable contact lenses are difficult and costly to maintain during sterilization. We aim to describe a single use disposable miniaturized lightweight high-refractive-index contact lens and evaluate it for diagnostic and therapeutic visualization of the retina during vitreoretinal surgery.
Methods :
The lens system has two lens groups with a net radius of curvature (ROC) of 7.7 mm for placement on the patient's cornea. The refractive index of the material used for both lens groups is 1.49. The diameter of the lens system is 21.0 mm and the overall height is 14.5 mm. As the ROC of this lens system is nearly identical to the ROC of the anterior corneal surface, a coupling agent is not required. The group I lens system consists of a biconcave lens and acts to collimate and direct light rays originating from the retina to the second lens group (group II) for focusing. The group II lens is biconvex and is located in a spaced-apart relationship with respect to group I, allowing an air space between them. This group focuses the light rays from group I and provides magnification. Image contrast of the lens is further improved by incorporating a circular or disc shape stop in the lens system at the air space between the two groups I and II. This stop is opaque and prevents light rays from propagating through the central region of the group II, thus stopping superfluous and aberrant light from propagating the posterior segment.
Results :
The lens system provides a real and inverted panoramic 360 degree image of the retina. We express the optical performance of the new single use vitrectomy lens through its magnification (0.59x) and field of view relative to the center of the globe (180 degrees). The light weight (14g) allows for easy handling during surgery and provides 210 degrees of dynamic view.
Conclusions :
The novel design of this low weight, single use disposable, miniaturized, wide-field lens allows high resolution peripheral retinal visualization, and likely increases patients’ comfort compared with previous generations of wide-field contact lenses. The reduced-size profile of the lens simplifies manipulation of the lens within the orbit leading to shortened procedure time. Lastly, due to being resuable, this lens avoids complications of maintaining lenses which costs time and resources.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.