Images of intravitreal objects projected onto posterior surface of model eye

Abstract

ABSTRACT.Purpose: To try to recreate the images reported by patients during vitreous surgery in a model eye. Methods: A fluid-filled model eye with a posterior frosted translucent surface which corresponded to the retina was used. Three holes were made in the model eye through which an endoillumination pipe and intraocular forceps could be inserted. A thin plastic sheet simulating an epiretinal membrane and an intraocular lens (IOL) simulating a dislocated IOL were placed on the retina. The images falling on the posterior surface were photographed from the rear. The images seen through the surgical microscope were also recorded. Results: The images from the rear were mirror images of those seen through the surgical microscope. Intraocular instruments were seen as black shafts from the rear. When the plastic sheet was picked up, the tip of the forceps was seen more sharply on the posterior surface. The images of the dislocated IOL from the posterior were similar to that seen through the surgical microscope, including the yellow optics and blue haptics. Conclusion: Intravitreal objects can form images on the surface of a model eye. Objects located closer to the surface are seen more sharply, and the colour of the objects can be identified.

Images created in a model eye during simulated cataract surgery can be the basis for images perceived by patients during cataract surgery

“…The outlines of the tips of these instruments were not as sharp as those seen during vitreous surgery. [12][13][14] In addition, they were not as sharp as the images recorded during simulated vitrectomy in the model eye, 16,17 in which the instruments were closer to the posterior surface. The greater distance of the instruments in the anterior chamber to the posterior surface made the images cast on the posterior surface more blurred.…”

“…At present, the best evidence suggests that these sensations are created by the shadows cast by the instruments inserted into the anterior chamber during cataract surgery or during vitrectomy. 17 Similarly, the entopic images of the eyes have been reported to arise from the shadows cast by tissue fragments floating in the vitreous of the eye. 18 However, the exact images falling on the retina during the different phases of cataract surgery have not been determined.…”