Clinical Analysis of Fringe Acuity by Lotmar Visometer

ABSTRACT

In cases of opacity of ocular optical media, we can predict postoperative visual outcome vaguely with electroretiongram, Visual evoked potential, Two point discrimination, Blue field entoptoscope, Laser interferometer, Lotmar visometer, Potential acuity meter, Visual display terminal. The Lotmar visometer which is attached to the slit lamp provides simple and inexpensive method to check for fringe acuity. It distinguishes the interval of changeable moire fringes for the measurement of postoperative visual acuity in spite of opacity in ocular media. We compared the preoperative Lotmar visometer fringe acuity with the postoperative final corrected visual acuity in 82 cases of cataract and 15 cases of vitreous opacity at the department of Ophthalmology, Pusan Paik Hospital, Inje University Medical college from January to August 1989. We tested the clinical use of the Lotmar visometer and the results were as follows 1. The visual acuity when checked by preoperative Lotmar visometer acuity and postoperatIve visual acuity differed in mature cataract and dense vitreous opacity cases. 2. The preoperative Lotmar visometer acuity was within one line of postoperative visual acuity in 47.4% with ECCE only, 34.1% with ECCE and PCL, 53.3% with vitrectomy. 3. The preoperative Lotmar visometer acuity which is included +/-25% of postoperative visual acuity in cases with ECCE only is 58.62%, in cases with ECCE and PCL is 46.15%, in cases with vitrectomy is 66.6% except in mature cataract and dense vitreous opacity. 4. There is a high correlation(r=0.8407)in the cases of vitreous opacity between preoperative Lotmar visometer acuity and postoperative visual acuity except in mature cataract and dense vitreous opacity.