Ocular Surface Alteration After Radiofrequency Thermocoagulation Therapy In Trigeminal Neuralgia

Background and ObjectiveTrigeminal neuralgia (TN) is characterised by attacks of recurring, paroxysmal, shock-like pain within the distribution of one or more branches of the trigeminal nerve,always involves the first branch,ophthalmic nerve. Radiofrequency thermocoagulation is one of the most effective therapies for trigeminal neuralgia which is a micro-traumatic therapy.Corneal nerve is one of the most important substances of ocular surface,which support the normal structure and function of cornea.Most of them come from ophthalmic division leaves of trigeminal nerve.Therefore, any damage to the ocular surface nerve can cause changes in ocular surface microenvironment.Cochet&Bonnet esthesiometer,confocal microscopy and many clinical examination methods are adopted in this study, to analyze ocular surface changes after radiofrequency thermocoagulation therapy in patients with TN.Materials and MethodologyA series of case-control study was designed in this study. A total of consecutive28TN patients who were scheduled for radiofrequency thermocoagulation therapy were enrolled in this study.The patients with TN was diagnosed in my hospital from April2012to December2012.The relevant examinations were performed under the informed consent of the subjects. The contralateral eyes were regarded as the control group. The central corneal sensitivity, the function of lacrimal secretion (Schiemer I test), tear break-up time (BUT),corneal fluorescei staining and laser scanning confocal microscopic examinations were recorded before and after surgery in all patients. Then using SPSS17.0for statistical analysis.Results1. No significant differences were found between the two groups before surgery in the central corneal sensitivity, the function of lacrimal secretion, BUT,corneal fluorescei staining and densities value of corneal subepithelial nerve plexus (Z=-1.511,-1.119,-0.428,-0.378,-0.854; P=0.131,0.263,0.669,0.705,0.393)2. Comparing with the self control group the BUT result without significant changes in value at3days after radiofrequency thermocoagulation therapy.The Schirmer I test result was a little higher and the score of Ocular surface fluorescein staining was a slight increase at3day but without statistical significance (Z=-0.620,-0.315,-1.732; P=0.535,0.753,0.083). Corneal sensitivity and subbasal nerve density were decreased at3days after surgery (Z=-2.708,-2.813;.P=0.007,0.005)3.1month after operation,differences of all indexes between the two groups showed statistical significance (Z=-3.888,-2.373,-3.311,-2.535, P=0.000,0.018,0.001,0.011). The corneal subepithelial nerve were thinner and sparse compared with preoperation.Dendritic cells can be found in the corneas of some patients.ConclusionsThe secretion of tears and the stability of tear film are poorer and the corneal sensitivity and subbasal nerve density are affected in a certain extent in the eye received radiofrequency thermocoagulation therapy. Dry eye can be induced or deteriorated if it can not be treated on time.