Comparison of white and blue light assessment of the upper and lower palpebral conjunctiva.

PURPOSE: To compare upper and lower eyelids in terms of palpebral redness, and roughness under two lighting conditions, and assess the extent of association between redness and roughness. METHODS: This was a cross-sectional study conducted at The Netherlands Contact Lens Congress (2016). The palpebral conjunctivae of the right, upper and lower eyelids of 250 subjects were assessed using a slit-lamp biomicroscope. White light was used to assess palpebral redness and roughness. Roughness was also assessed using cobalt blue light and fluorescein. A 5-point grading scale was used to grade the conditions. The average and maximum grades of 5 zones for the upper, and 3 zones for the lower eyelid were used in the non-parametric analysis. RESULTS: A significantly higher grading in palpebral roughness was found using fluorescein with blue light, compared to using white light, for both upper and lower eyelids (p < 0.001). Upper eyelids appeared significantly rougher than lower eyelids with white and blue light (p < 0.001). Correlations between redness and roughness for upper and lower eyelids were low to moderate (p = <0.001). CONCLUSION: Palpebral roughness was scored more highly with blue, than white light, therefore these methods should not be used interchangeably. Also, roughness was more apparent in the upper eyelid, therefore eyelids should be assessed separately. Palpebral redness and roughness should be considered independent variables due to the low to moderate correlation between them. It is therefore recommended to first assess both eyelids first for redness using white light, followed by examination with fluorescein and blue light to assess roughness.

Sagittal height differences of frequent replacement silicone hydrogel contact lenses.

PURPOSE: This study aims to evaluate the sagittal height differences among a selection of commercially available monthly or two weekly replacement silicone hydrogel soft lenses. METHODS: The sagittal height (CL-SAG) of four frequent replacement silicone hydrogel lenses (lotrafilcon B, balafilcon A, comfilcon A and senofilcon A) was measured for all base curve radius manufactured in spherical (-3.00D and +3.00D) and toric (=C-0.75×180°) designs (11 spherical and 8 toric lenses in total). Two different lenses of each lens type were evaluated (the intra CL-SAG) using the SHSOphthalmic omniSpect by Optocraft. RESULTS: The intra CL-SAG difference (the difference between two identical lenses from the same batch) was 11±SD 2µm. The CL-SAG of all minus lenses ranged from 3454 to 3765µm (an inter CL-SAG difference of 311µm), while the plus spherical lenses ranged from 3493 to 3757µm (inter CL-SAG difference 264µm). In the toric lens group, the range in toric minus lenses was 3495-3953µm (inter CL-SAG difference 458µm) and 3493-3980µm in the plus group (inter CL-SAG difference 487µm). The inter CL-SAG difference between the spherical and the toric lenses was statistically significant (p=0.03). CONCLUSION: Marked differences in sagittal height among different commercially available frequent replacement silicone hydrogel lenses exist. Different lenses with the same package base curve value had marked differences in CL-SAG, with potential clinical significance on-eye in terms of lens behavior. The inter CL-SAG variance in the spherical lens group was smaller than in the toric lens group.