Proposed methodology for the examination of the Corneal Specular Microscopy and the profile of the performed examinations

Abstract

 

Purpose

 

Non-Contact (NC) Corneal Specular Microscope (CSM) acquire endothelial mosaic (EM) images when the patient sets the target light, each model of this type of CSM has fixed positions. Contact (C) CSM (CSM) can acquire EM images of any area of the endothelial surface by sliding the objective lens on the cornea. The EM according to the author can be classified into three models: Regular Pattern, Irregular Pattern or Chameleon Pattern. Considering the different patterns and the way the NC and C CSM perform the Specular Microscpy (SM), this study is in order: 1 - Present algorithm to guide the selection of the best type of CSM to perform the SM ; 2 - Know the amount of SM done with NC and C CSM, and the related information for each of these types CSM.

 

Methods

 

All SM done in 2013 at the Eye Clinic Dr. Fernando Abib, Curitiba, Brazil. The type of the CSM was determined by the algorithm (Figure). NC CSM (CSO, Italy) and C CSM (BioOptics, USA) were utilized. SM results were calculated by considering the CSM endothelial sampling with a minimum number of endothelial cells counted in each sampling process, for orientation of Reliability Indexes of the Cells Analyzer _{USA Patent}software program (Technicall, Brazil). The results are reported in terms of gender, number of examinations performed with NC and C CSM, indications and diagnoses, utilizing descriptive statistics.

 

Results

 

879 patients, 634 (72%) female and 245 (38%) male. 606 (69%) SM with NC CSM and 273 (31%) SM with C CSM. 19 out of 606 (3%) designed with NC CSM had to be performed with C CSM, the NC CSM, as it was not able to capture endothelial images. Indications for SM with NC and C CSM are listed in the Table 1: The most frequent with NC CSM: refractive evaluation, contact lens wearers and pre cataract surgery; The most frequent with C CSM: Fuchs Endothelial Dystrophy, penetrant keratoplasty and cornea guttata.

 

Conclusions

 

With the proposed algorithm, the NC CSM is not enough to perform the SM in all the patients, as the C CSM was required for SM in 31% of the patients with clinical diseases and complex situations. It is recommended that cases of endothelial mosaic Irregular or Chameleon Pattern be assigned for the performance of SM with C CSM, as this type is a more objective SM for the results and versatile for carrying out the examinations.