Objective Analysis of Pre-Lens Tear Film Stability of Daily Disposable Contact Lenses Using Ring Mire Projection

Figures & data

Figure 1 Graphic of theoretical Placido ring distortions appearing after last blink (left: ideal ring reflection, middle: area with gaps in the projected ring structure, right: wave-like distortions). The red rings highlight areas where distortions (dewetting) has occurred.

Table 1 Specifications of Nelfilcon A and Stenfilcon A Daily Disposable Silicone Hydrogel Soft Contact Lenses

Lens Brand Name	Material (Manufacturer)	Wettability Component	H2O Content [%]	Rx Power Range [D]	Base Curve [mm]	Diameter [mm]
DAILIES^® AquaComfort Plus^®	nelfilcon A (ALCON Vision Care Ltd.)	PVA (31%), Blister: PEG, HPMC	69	+0.50 to +6.00 (0.25D steps) -0.50 to −6.00 (0.25D steps) -6.50 to −10.00 (0.50 steps)	8.7	14.0
MyDay™	stenfilcon A (Cooper Vision)	-	54	+0.50 to +5.00 (0.25D steps) +5.00 to +6.00 (0.50 D steps) -0.50 to −6.00 (0.25D steps) -6.50 to −10.00 (0.50 steps)	8.4	14.2

Figure 2 Overlay grid used by the Oculus NIK-BUT software.

Figure 3 Screenshot of the analyzing software (LEFT: purple segments = objectively detected, blue segments = added by investigator, RIGHT wettability map and function segments over time).

Figure 4 Kaplan–Meier analysis of time post-blink required to reach 15% distortion after 12 hours of lens wear.

Table 2 Time Post-Blink to Reach 15% Distortion of the Projected Rings After 12 Hours in Subjects Who Reached 15% Distortion

Seconds	Nelfilcon A	Stenfilcon A
N	11	12
Mean (SD)	19.25 (3.20)	20.24 (3.02)
Median	19.50	20.46
Min – Max	12.2 −23.3	15.9 −24.1

Table 3 Mean Break-Up Speed at 15 Sec Post-Blink (% Distortion/Sec) After 12 Hours of Wear of Nelfilcon A and Stenfilcon A Contact Lenses

%/Second	Nelfilcon A	Stenfilcon A
N	31	30
Mean (SD)	0.3 (0.38)	0.2 (0.23)
95% CI	[0.138, 0.365]	[0.048, 0.279]