Abstract
Purpose :
We have shown previously differences meassuring Electrical Spectral Impedance (ESI) among healthy and different pathologic corneal conditions . Our purpose is to assess a new device with a special sensor and a processing unit developed with new technology. Safety of the procedure and potential efficacy in differenciating pathologic from normal corneas are our main goals.
Methods :
A cohort of 62 patients was divided in 4 groups according to confirmed diagnosis: Sjogren Syndrome (antiRO and AntiLa positive test) , Penfigoid (biopsy and histology positive), Dry Eye Disease (OSDI and BUT positive) and healthy controls, also diagnosed by OSDI and BUT.
Each cornea was meassured twice in different loci with up to 2 min interval to evaluate reproducibility. By direct apposition of a sensor (200 micron diameter gold disk microelectrode) with the corneal surface for at least one second we got a unique register of resistance and capacitance to the electric current delivered. Patients were evaluated for any corneal distress.
Results :
Data from 244 meassures obtained from 122 corneas were analyzed.
Safety:Evaluation of corneas after the procedure was uneventful, showing it is safe to obtain ESI registers in patients with corneal diseases by this means.All the meassures resulted effective, so there was no need to repeat any.
Reproducibility: ESI determinations in each cornea resulted quite similar within a narrow range of dispersion, which demonstrated reproducibility of the tool.
Objectivity: Data from different subjects of the same group were consistent. Fig 1 and 2 show the consistency of the curve of different severe conditions as Penfigoid and Sjogren with significant differences from the controls curve. Dry Eye Disease patients showed a curve closer to controls (in the logaritmic scale but quite more differenciated in lineal scale -Fig 3), but consistently different, specially at low frequencies (Fig 1, 2 and 3)
Conclusions :
Meassuring ESI in corneas with our experimental device is a safe procedure and could be a new tool to differenciate corneal conditions from healthy corneas with an objective determination, which it would be of helping in improving the diagnosis of Dry Eye Diasease and other corneal pathologies.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.