A Precise Iris Positioning Technique Using a Modified Occlusal Plane Analyser - A Case Report

Abstract

The eye is a vital organ, a key aspect of facial expression and the essence of cosmetic appearance in human beings.[1] Surgical intervention and removal of the eyeball may be required due to accidental trauma, pathology or congenital defects.[2] The disfigurement associated with the loss of an eye can cause immense physical, psychosocial and emotional disturbance.[3] The surgery involved can vary from minimal surgical intervention, such as evisceration or enucleation, to extensive radical treatment, such as exenteration.[4] The associated psychological distress can be reduced by timely rehabilitation with a prosthetic eye.[5] An ocular prosthesis can be either stock or custom-made. Typical stock ocular prostheses come in a variety of standard sizes, contours, forms, and colours. They tend to be used for interim or postoperative purposes.[6] Although prefabricated ocular prostheses are easily available, poor fit, poor aesthetics, and poor eye movements are the inevitable disadvantages associated with them. All these can be overcome by fabricating a customized ocular prosthesis that provides a more intimate contact with the tissues.[7] There are various methods described in literature for iris positioning in a custom ocular prosthesis such as, use of eyewear with graphic grid positioning,[8] use of facebow with graphic grid method,[9] McArthur’s ocular locator and fixed calliper,[10] Robert’s pupilometer,[11] Benson visual judgement.[12] All these techniques help in locating the iris position in an ocular prosthesis. However, the Benson visual judgment is subjective in nature, and both the graph grid and the ocular locator techniques pose difficulty in stabilization and cannot be used in patients with facial asymmetry.[13] To overcome the limitations of the existing techniques, a simple and efficient method using a modified occlusal plane analyser has been described in this article.