Three‐Dimensional Orientation of Iris in an Ocular Prosthesis Using a Customized Scale

Abstract

The success of an ocular prosthesis depends largely on the correct orientation of the iris disk. Various methods have been put forth to achieve this. This article emphasizes one such simplified method, wherein a customized scale has been used to orient the iris disk mediolaterally, superoinferiorly, and anteroposteriorly in an ocular prosthesis. A scleral wax pattern was fabricated. The customized scale was used to measure the dimension and orientation of the natural iris. These measurements were then transferred to the scleral wax pattern with the customized scale. An iris disk was fabricated using black crayon on the scleral wax pattern according to the measurements. The scleral wax pattern, including the iris disk, was then placed in the eye socket to verify its dimension and orientation. A prefabricated iris disk was modified according to the measured dimensions and transferred to the final scleral wax pattern. The transfer of these dimensions to the definitive prosthesis was achieved successfully, ultimately improving the patient's social and psychological well being.

Positioning of iris in an ocular prosthesis: A systematic review

“…Gupta et al . used a customized scale for iris positioning[ 28 ] [ Figure 10 ]. This scale had markings from zero to four from left to right on top and vice a Versa at the bottom that helped to orient iris in all the three plans i.e., mediolaterally, superio-inferiorly and anteroposteriorly.…”

Alternative Technique of Iris Orientation in a Custom‐Made Ocular Prosthesis

“…As asymmetry may result in a squint‐eyed appearance, proper positioning of the iris is vital for success of the ocular prosthesis . The conventional use of visual assessment being subjective produces inaccurate results . The PD meter provides an accurate registration of alignment of an ocular prosthesis.…”

“…A PD ruler is relatively more convenient than the graph grid technique, since preparation of graph cutouts and transferring landmarks to graph grids is cumbersome . Construction of a customized scale is tedious and has chances of fabrication errors . Though the method described here is more precise, it may not be feasible to use the PD ruler in every clinical set‐up.…”

“…Various techniques regarding iris orientation in a custom‐made ocular prosthesis have been advocated. The use of a pupillometer, a plastic strip template, a millimeter rule, an ocular locator and fixed caliper, window light or light reflection viewed symmetrically in the eyes, inverted anatomic tracings, a Boley's gauge, a transparent graph grid, computer simulation approach with optical scanning technique, and computer‐aided design and a customized scale for assessing the position of the ocular prosthesis have been described in the literature …”

Rehabilitation of a defect secondary to sino-orbital mucormycosis- A prosthodontic challenge

“…Various methods for iris placement have been mentioned in the literature such as facial measurements using anatomic landmarks, ocular locator, inverted anatomic tracings, graph grid method, grid cutouts placed on spectacle frame, graph grid frame attached to spring bow, Modified Hanau wide view spring bow, cusyomised scale, optical vernier interpupillary distance ruler, Digital photograph. [9][10][11][12][13][14][15] Various methods of retention advocated in literature include spectacle frame, extensions from the obturator, magnets and buttons, engaging tissue undercuts, adhesives or osseointegrated implants. 16 In cases with multiple defects secondary to maxillectomy and orbital exenteration, obtaining retention between obturator bulb and orbital prosthesis with rigid connection such as magnets or buttons, results in movement of extraoral prosthesis when obturator is in function.…”