Corneal Nerve Abnormalities in Painful Dry Eye Disease Patients

Abstract

This study aimed to compare the corneal nerve structural abnormalities detected using in vivo confocal microscopy (IVCM) in patients with neuropathic corneal pain (NCP) secondary to primary meibomian gland dysfunction (MGD) or autoimmune dry eye (AIDE). Methods: A two-stage retrospective nested case–control study was conducted. First, data from patients with either MGD or AIDE were assessed, selecting only cases with no corneal pain (VAS = 0) or severe pain (VAS ≥ 8). Ocular signs and symptoms of the 238 selected patients were compared between painful and painless cases. Next, painful patients with no corneal damage (Oxford score ≤ 1) were selected within each study group, defining the cases with NCP (i.e., “pain without stain”). IVCM images from all groups were compared with prospectively-recruited healthy controls, focusing on dendritiform cell density and nerve abnormalities (density, tortuosity, microneuromas). Results: AIDE patients had more ocular signs/symptoms than MGD patients. Compared with healthy controls, AIDE-related NCP patients showed increased nerve tortuosity and number of neuromas, whereas MGD-related NCP patients had reduced nerve density and increased number, perimeter, and area of microneuromas. Microneuromas were also observed in healthy controls. Furthermore, a higher number of microneuromas was found in MGD-related NCP compared to AIDE-related NCP or painless MGD. Conclusions: MGD-related NCP was associated with significantly more corneal nerve abnormalities than AIDE-related NCP or healthy controls. Although IVCM can be useful to detect NCP-related corneal nerve changes in such patients, the diagnosis of dry eye disease-related NCP will require an association of several IVCM-based criteria without relying solely on the presence of microneuromas.

Differences of Anxiety and Depression in Dry Eye Disease Patients According to Age Groups

“…First, although the OSDI and SPEED questionnaires are validated and widely used instruments to evaluate dry eye, they may not accurately identify the DED symptoms of patients with corneal sensation disorders (which might be caused by older age, neurological problems, etc.) (30,(59)(60)(61). Therefore, it is advisable to evaluate a patient's corneal nerve condition using confocal microscopy before assessing the symptoms of DED.…”

Topical Omega-3 Fatty Acids Eyedrops in the Treatment of Dry Eye and Ocular Surface Disease: A Systematic Review

“…Topical ω-3 (in particular, DHA) might also promote regeneration of the corneal nerve plexus, which is damaged in DED, as demonstrated in Cagini’s study in our review and is borne out elsewhere [ 61 , 62 ]. One explanation is that human corneal epithelial cells express 15-LOX, which converts topical DHA into neuroprotectin D1 (NPD1) [ 63 ], which is understood to be a pro-resolving mediator [ 64 , 65 ].…”

Characterisation and clustering of corneal stromal‐epithelial nerve penetration sites in healthy adults: A laser‐scanning in vivo confocal microscopy study

“…3 A recent study revealed that relying solely on the presence or density of CSENPS is not sufficient to diagnose neuropathic corneal pain, and additional morphological features, including area and perimeter, could be indicative of dry eye-related neuropathic pain. 5 Findings from the present study provide a basis for subsequent investigations into how the density and morphology of CSENPS may be altered in disease, and the potential utility of such features as biomarkers of corneal pathology.…”