Morphological characteristics of Meibomian Glands and their Influence on Dry Eye disease in contact lens wearers.

PURPOSE: Meibomian glands (MG) are now easily imaged via clinical meibography machines. The purpose of this work was to explore the utility of the known MG morphology metrics for predicting dry eye disease (DED) in contact lens (CL) wearers. METHODS: Successful and previous CL wearers were recruited. DED was diagnosed if the participant's worst eye had a reduced tear meniscus height (TMH) of <0.2 mm or non-invasive tear break-up time (NITBUT) of <10 s and a Standardized Patient Evaluation of Eye Dryness (SPEED) score >5.0. Meibography was performed and images were subjectively graded by two examiners for the following MG characteristics: distorted, tortuous, hooked, abnormal gap, overlapping, fluffy areas, tadpoling, thinned, thickened, ghost, no extension to lid margin, shortened and dropout (atrophy). DED diagnostic ability of each metric was determined with receiver operating characteristic (ROC) analysis. RESULTS: A total of 112 participants were recruited, with 18.8% having DED and 60.7% being female. The only MG morphology metrics that were marginally predictive of DED were thickened upper eyelid MGs (p = 0.046), thickened mean upper plus lower eyelid MGs (p = 0.007), and atrophy of upper eyelid MGs (p = 0.043); however, none of these metrics reached a meaningful area under the curve in ROC analysis (all <0.70). CONCLUSION: While abnormal MG morphology is likely suggestive of DED in CL wearers, none of the MG morphology metrics evaluated alone in this study had clinically meaningful predictive value for detecting DED in this group of current and previous CL wearers.

Ultraviolet and Visible Transmittance of Soft Contact Lenses with and without Ultraviolet Blockers.

SIGNIFICANCE: Ultraviolet (UV) and visible light transmittance of soft contact lenses (SCLs) was measured. A significant difference in UV transmittance has been found between SCLs with a positive and negative back vertex power (BVP). It can be shown that thicker SCLs absorb more UV radiation. PURPOSE: This study aimed to determine UV and visible light transmittance of different SCLs with and without UV protection filters. METHODS: Twenty-one lens brands were investigated in the BVP range of -12.00 to +6.00 D. Three SCLs were measured per BVP 25 times. Three hundred thirty-nine SCLs with UV filter (stenfilcon A, somofilcon A, narafilcon A, senofilcon A, senofilcon C, etafilcon A, nesofilcon A) and 489 SCLs without UV filter (delefilcon A, lotrafilcon A, lotrafilcon B, comfilcon A, balafilcon A, samfilcon A, asmofilcon A, nelfilcon A, omafilcon A, hilafilcon B, ocufilcon D, hioxifilcon A, omafilcon B) have been examined. The measurement setup was created according to ISO 18369-3. RESULTS: All UV-absorbing labeled test SCLs meet UV protection class 2. senofilcon A, senofilcon C, and narafilcon A meet the higher UV protection class 1 level. A statistically significant difference in UV transmittance (280 to 380 nm) has been found between SCLs with a positive BVP (+1.00 to +6.00 D) and SCLs with a negative BVP (-1.00 to -12.00 D), both without (P = .04) and with UV filters (P = .02). CONCLUSIONS: With the ISO-conforming, diopter-independent measurement setup, the UV-absorbing test contact lenses that meet the current international standards, regardless of their BVP, were identified. Lenses with increased center thickness absorb more UV radiation. Further studies may use a modified measurement setup with a larger aperture than 10 mm. It would also be worthwhile to examine the UV absorption of the contact lens over the complete corneal area and limbal area because UV radiation may damage inner ocular tissues like the crystalline lens as well as limbal stem cells.