Abstract
Abstract: :
Purpose: To analyze the topographic reproducibility and threshold repeatibility of a new automated, landmark–driven, fundus–related perimetry technique. Methods:A new system to automatically perform baseline and follow–up quantification of retinal fixation and fundus–related threshold (microperimetry; MP1, Nidek Technologies, Vigonza, Italy) was checked in this study. 24 eyes of 24 subjecs (8 normals and 16 affected by different degrees of age–related macular degeneration) were enrolled to evaluate the topographic reproducibility of retinal points tested during automatic fundus–related follow–up examination (group 1). Follow–up examination was performed one week after the baseline test. 28 eyes (14 normals subjects not involved in group 1 tests) underwent the threshold repeatibility study (group 2). Follow–up examination was performed 1 hour, 1 and 2 weeks after baseline test. Each test consists of a standard grid of retinal stimulated points. Retinal static threshold was quantified for each point with a staircase method. The fundus–related topographic reproducibility was evaluated computing the geometrical coordinates difference of two anatomical landmarks of follow–up vs baseline examination. Results: Each tested point (group 1) topographically varied between different examinations of 2.6 ± 1.1 pixels (range 1.1–4.5 pixels; 15 pixels = 1°). Intra and interindividual variation of retinal threshold in normal subjects (group 2) varied between 4 dB and 0 dB (mean 2 ± 0.5 dB). Conclusions: The value of an automatic system to perform fundus–related perimetry (microperimetry) rests one precise topographic reproducibility in follow–up examination, and limited variation of retinal threshold during follow–up test of normal eyes. The system we analyzed seems to be highly accurate in performing automated (standardized and customized tests) microperimetry, and useful in clinical practice of macular diseases.
Keywords: imaging/image analysis: clinical • macula/fovea • age–related macular degeneration