Purpose: We investigated the relationship between tear menisci and corneal subbasal nerve density (SND) in long-term soft contact lens (CL) wearers.
Methods: Three groups were enrolled for this study: asymptomatic non-CL controls (N-CL group), asymptomatic soft CL wearers (A-CL group), and symptomatic soft CL wearers with self-reported moderate to severe dryness (S-CL group). Upper and lower tear menisci height (UTMH, LTMH) and area (UTMA, LTMA) were measured by optical coherence tomography. This was followed by measurements of fluorescein tear breakup time, fluorescein staining, and the Schirmer I test. In vivo confocal microscopy measured the SND in the nasal, central, and temporal regions of the cornea.
Results: The UTMH, UTMA, LTMH, and LTMA were significantly lower in the S-CL group compared with the N-CL group (P<0.05). The combined corneal SND of the temporal and nasal regions of the S-CL group was lower than for the N-CL group (P<0.05). The LTMH was correlated with the SND of the temporal (r=0.410), nasal (r=0.423), combined temporal and nasal (r=0.516), and combined temporal, nasal, and central regions (r=0.430, all P<0.01). The LTMA was also correlated with the SND of the temporal (r=0.379), nasal (r=0.292), combined temporal and nasal (r=0.422), and combined temporal, nasal, and central regions (r=0.367, all P<0.05). The temporal and nasal corneal SNDs were more strongly correlated with the LTMH and LTMA than with the UTMH and UTMA.
Conclusions: Soft CL wearers with dry eye symptoms have reduced tear menisci. The alteration of midperipheral corneal SND may contribute to dry eye symptoms.