Purpose:
To investigate and characterize symptoms, signs and morphology of corneal innervation in corneal neuropathy, with comparison to non-Sjögren Syndrom dry eye patients.
Methods:
21 patients, 25 age and gender-matched non-Sjögren Syndrom dry eye subjects and 16 normal controls were involved. Subjects underwent slit-lamp examination and intraocular pressure (IOP) initially, then a series of dry eye investigations were conducted, including Ocular Surface Index (OSDI), Schirmer’s test, tear breakup time (TBUT), corneal staining with fluorescein (FL) and laser in vivo confocal microscopy. Corneal sensitivity was assessed with Cochet-Bonnet aesthesiometer. Hospital Anxiety and Depression Scale (HAD) and Visual Analogue Scale (VAS) were recorded for psychal and severity of pain evaluation respectively.
Results:
The proportion of female patients was 2/3 (14/21). Results of FL, Shirmer’s test and TBUT were found normal among the study group, compared to dry eye (p<0.001) and control (p>0.05) groups. High OSDI and VAS scores revealed as significant symptoms as that of the dry eyes (p>0.05), with contrast to the controls (p<0.001). All the subjects had normal IOP and similar HAD scores (p>0.05), which indicated there were no signs of glaucoma or psycho-induced pain. Decreased mechanical thresholds were detected among neuropathy subjects (p<0.001). Corneal nerve densities, degrees of tortuosity and inflammatory cells were found increased under in vivo confocal microscopy among the neuropathy patients (p<0.05; fig.).
Conclusions:
Corneal neuropathy could be identified and diagnosed through dry eye investigations. Though the causes and risk factors were unclear yet, patients with dry eye-like symptoms, increased corneal sensitivity and changes of corneal nerve morphology, but no signs of dryness should be suspected of the morbidity.
Keywords: cornea: tears/tear film/dry eye • cornea: clinical science • neuro-ophthalmology: diagnosis