Posters

Bilateral morphometric analysis of corneal sub-basal nerve plexus in patients undergoing unilateral cataract surgery: an in vivo confocal microscopy study

Poster Details

First Author: M.Roda ITALY

Co Author(s): M. Pellegrini   F. Bernabei   P. Versura   C. Torrazza   F. Guaraldi   G. Giannaccare     

Abstract Details

Purpose:

It is known that the full-thickness corneal incisions performed during cataract surgery result in severing of stromal nerves and reduced sub-basal nerve plexus (SNP) density in the operated eye. Recently, evidence of bilateral coordinated interactions between the nervous and the immune systems of affected and unaffected eyes in several ocular surface diseases is incresing. Taking into account the nervous interdependence between both eyes, we hypothesize that also micro-incisional cataract surgery may determine contralateral corneal nerves changes. Therefore, the purpose of this work was to evaluate the morphometric analysis of corneal SNP in both eyes of patients undergoing unilateral cataract surgery.

Setting:

Ocular Surface Center of S.Orsola-Malpighi University Hospital, Bologna, Italy.

Methods:

This prospective study enrolled 30 patients who underwent first-eye phacoemulsification and intraocular lens implantation. In vivo confocal microscopy (IVCM) was performed before and 1 month after surgery in either operated eyes (OEs) and unoperated eyes (UEs). Corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fiber area (CNFA), corneal nerve fiber width (CNFW), corneal nerve fractal dimension (CNFrD) and dendritic cells (DCs) density were calculated using the automated software “ACCMetrics”. The Wilcoxon test was used to compare IVCM parameters before and after surgery.

Results:

In OEs, the mean CNFD, CNBD, CNFL, CTBD, CNFA and CNFrD significantly decreased after surgery (respectively, 21.21±6.56 to 15.35±7.00n/mm2; 26.79±16.91 to 13.57±12.16n/mm2; 13.49±3.42 to 9.67±3.44mm/mm2; 42.25±24.64 to 22.81±18.77 n/mm2; 0.0058±0.0020 to 0.0207±0.0016mm2/mm2; 1.470±0.037 to 1.418±0.058; always P<0.05). In UEs, the mean CNFD, CNBD, CNFL, CTBD, CNFA and CNFrD significantly decreased after surgery (respectively, 23.20±7.26 to 20.11±6.69n/mm2; 29.76±15.25 to 24.28±14.88n/mm2; 14.02±3.82 to 12.53±3.60mm/mm2; 43.93±22.27 to 38.06±20.52n/mm2; 0.0057±0.0019 to 0.0049±0.0016mm2/mm2; 1.477±0.036 to 1.466±0.040; always P<0.05).

Conclusions:

Patients undergoing unilateral micro-incisional cataract surgery exhibit bilateral changes of corneal SNP one month postoperatively. Similar contralateral effects have been described following peripheral nerve lesions in other regions of the body. This phenomenon implies the presence of signaling mechanisms that link the two sides of the body at a central and/or peripheral level. Since age-related cataract is often bilateral, this finding could have broad implications in the setting of sequential cataract surgery in terms of identification of the proper interval time between the two surgeries.

Financial Disclosure:

None