Relationhip of the actual thick intraocular len optic to the thin len equivalent Original Reearch Article

PURPOE: To theoretically derive and empirically validate the relationhip between the actual thick intraocular len and the thin len equivalent. METHOD: Included in the tudy were 12 conecutive adult patient ranging in age from 54 to 84 year (mean ± D, 73.5 ± 9.4 year) with bet-corrected viual acuity better than 20/40 in each eye. Each patient had bilateral intraocular len implant of the ame tyle, placed in the ame location (bag or ulcu) by the ame urgeon. Preoperatively, axial length, keratometry, refraction, and vertex ditance were meaured. Potoperatively, keratometry, refraction, vertex ditance, and the ditance from the vertex of the cornea to the anterior vertex of the intraocular len (AVPC1) were meaured. Alternatively, the ditance (AVPC1) wa then back-calculated from the vergence formula ued for intraocular len power calculation. REULT: The average (±D) of the abolute difference in the two method wa 0.23 ± 0.18 mm, which would tranlate to approximately 0.46 diopter. There wa no tatitical difference between the meaured and calculated value; the Pearon product-moment correlation coefficient from linear regreion wa 0.85 (r2 = .72, F = 56). The average intereye difference wa −0.030 mm (D, 0.141 mm; EM, 0.043 mm) uing the meaurement method and +0.124 mm (D, 0.412 mm; EM, 0.124 mm) uing the calculation method. CONCLUION: The relationhip between the actual thick intraocular len and the thin len equivalent ha been determined theoretically and demontrated empirically. Thi validation provide the manufacturer and urgeon additional confidence and utility for len contant ued in intraocular len power calculation. Article Outline