COMPUTATIONAL PRINCIPLES IN PURKINJE I AND IV REFLECTION PATTERN EVALUATION FOR THE ASSESSMENT OF OCULAR ALIGNMENT

Purpose. To develop a standardized reasoning for the evaluation of Pur kinje I and IV Reflection Pattern data in primary, secondary, and tert iary positions of gaze in the diagnosis of strabismus with a mathemati cal approach. To demonstrate the applicability of certain mathematical relations and the appropriate graphic representation of computed ocul ar alignment data. Methods. Starting from the known Reflection Pattern Evaluation formulae, equations were derived that allowed for the comp utation of the relative and absolute positions of the optical and visu al axes of both eyes from original data in binocular and monocular fix ation. These equations were simplified for clinical use. Results. The authors obtained a set of equations that could be applied to the objec tive, quantitative analysis of eye alignment in screening for microtro pia, in concomitant and incomitant diagnoses of strabismus in primary and nonprimary positions. Conclusions. Purkinje I and IV Reflection Pa ttern Evaluation can be extended to the diagnosis of strabismus in non primary positions with sufficient clinical accuracy. The newly present ed principles and equations serve as a basis for a convenient graphic representation of Purkinje I and IV Reflection Pattern data. These pri nciples of evaluation may be applied to any data dealing with ocular a lignment, independently of the method.