Optimising subjective grading of corneal staining in Sjögren's syndrome dry eye disease.

AIM: To assess whether smaller increment and regionalised subjective grading improves the repeatability of corneal fluorescein staining assessment, and to determine the neurological approach adopted for subjective grading by practitioners. METHODS: Experienced eye-care practitioners (n = 28, aged 45 ± 12 years), graded 20 full corneal staining images of patients with mild to severe Sjögren's syndrome with the Oxford grading scheme (both in 0.5 and 1.0 increments, globally and in 5 regions), expanded National Eye Institute (NEI) and SICCA Ocular Staining Score (OSS) grading scales in randomised order. This was repeated after 7-10 days. The digital images were also analysed objectively to determine staining dots, area, intensity and location (using ImageJ) for comparison. RESULTS: The Oxford grading scheme was similar with whole and half unit grading (2.77vs2.81,p = 0.145), but the variability was reduced (0.14vs0.12,p < 0.001). Regional grade was lower (p < 0.001) and more variable (p < 0.001) than global image grading (1.86 ± 0.44 for whole increment grading and 1.90 ± 0.39 for half unit increments). The correlation with global grading was high for both whole (r = 0.928,p < 0.001) and half increment (r = 0.934,p < 0.001) grading. Average grading across participants was associated with particle number and vertical position, with 74.4-80.4% of the linear variance accounted for by the digital image analysis. CONCLUSIONS: Using half unit increments with the Oxford grading scheme improve its sensitivity and repeatability in recording corneal staining. Regional grading doesn't give a comparable score and increased variability. The key neurally extracted features in assigning a subjective staining grade by clinicians were identified as the number of discrete staining locations (particles) and how close to the vertical centre was their spread, across all three scales.

Best technique for upper lid eversion.

AIM: Lid eversion is an essential component of contact lens aftercare. Hence, this study determined the best method of lid eversion based on three criteria: comfort, speed of administration and the area of the palpebral conjunctiva exposed. METHOD: Twenty-five participants (aged 20-34) had 6 different techniques applied in random order by the same clinician on two separate occasions: three involving a cotton bud placed on the extended upper eyelid either centrally, at the top of the tarsal plate or off-centre; one using the wooden end of the bud placed at the top of the tarsal plate; one using the clinician's index finger to evert the lid; and one using a silicone rubber, finger-shaped substitute. The participants judged the degree of discomfort of each technique on a visual analogue scale. The time to complete the task was timed with a stop-watch and the area of exposed palpebral conjunctiva was captured with a digital slit lamp and assessed using image analysis. RESULTS: There was no difference between the initial lid eversion or subsequent repeat in terms of comfort (F = 0.304, p = 0.586), time to complete (F = 3.075, p = 0.092) or area exposed (F = 2.311, p = 0.142). Lid eversion using fingers alone or the silicone substitute everter were similar in comfort (p = 0.312), being the most comfortable methods, with off-centre cotton bud eversion or the wooden end of the cotton bud the least comfortable techniques (F = 17.480, p < 0.001). The quickest method to perform was the wooden end of the cotton bud, followed by the silicone everter (F = 17.522, p < 0.001). The area of exposed palpebral conjunctiva was greatest using the silicone everter (F = 28.199, p < 0.001). CONCLUSIONS: Lid eversion had repeatable results, with the silicone everter placed at the top of the tarsal plate the most comfortable for the patient, quick to perform and exposed a greater area of tarsal plate than other techniques and therefore is recommended to clinicians.

Crossover Evaluation of Silicone Hydrogel Daily Disposable Contact Lenses.

PURPOSE: To assess the surface tear breakup time and clinical performance of three daily disposable silicone hydrogel contact lenses over 16 hours of wear. METHODS: Thirty-nine patients (mean [± SD] age, 22.1 [± 3.5] years) bilaterally wore (narafilcon A, filcon II-3, and delefilcon A) contact lenses in a prospective, randomized, masked, 1-week crossover clinical trial. Tear film was assessed by the tear meniscus height (TMH), ocular/contact lens surface temperature dynamics, and lens surface noninvasive breakup time at 8, 12, and 16 hours of wear. Clinical performance and ocular physiology were assessed by subjective questionnaire, by high-/low-contrast logMAR (logarithm of the minimum angle of resolution) acuity, and through bulbar and limbal hyperemia grading. Corneal and conjunctival staining were assessed after lens removal. RESULTS: Delefilcon A demonstrated a longer noninvasive breakup time (13.4 [± 4.4] seconds) than filcon II-3 (11.6 [± 3.7] seconds; p < 0.001) and narafilcon A (12.3 [± 3.7] seconds; p < 0.001). A greater TMH (0.35 [± 0.11] mm) was shown by delefilcon A than filcon II-3 (0.32 [± 0.10] seconds; p = 0.016). Delefilcon A showed less corneal staining after 16 hours of lens wear (0.7 [± 0.6] Efron grade) than filcon II-3 (1.1 [± 0.7]; p < 0.001) and narafilcon A (0.9 [± 0.7]; p = 0.031). Time was not a significant factor for prelens tear film stability (F = 0.594, p = 0.555) or TMH (F = 0.632, p = 0.534). Lens brand did not affect temperature (F = 1.220, p = 0.308), but it decreased toward the end of the day (F = 19.497, p < 0.001). Comfort, quality of vision, visual acuity and contrast acuity, and limbal grading were similar between the lens brands but decreased with time during the day (p < 0.05). CONCLUSIONS: The tear breakup time over the contact lens surface differed between lens types and may have a role in protecting the ocular surface.

The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability.

PURPOSE: To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability. METHODS: Thirty-nine subjects (22.1±3.5 years) were randomised to wear each of 3 silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for one week. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16h after lens insertion. Hyperaemia, non-invasive tear break-up time, tear meniscus height and comfort were also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal. RESULTS: Lens fit assessments were not different between brands (P>0.05), with the exception of the movement at blink where narafilcon A was more mobile. Overall, lag reduced but push-up speed increased from 8 to 12h (P<0.05), but remained stable from 12 to 16h (P>0.05). Movement-on-blink was unaffected by wear-time (F=0.403, P=0.670). A more mobile lens fit with one brand did not indicate that person would have a more mobile fit with another brand (r=-0.06 to 0.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (P>0.01). CONCLUSIONS: Among the lenses tested, objective lens fit changed between 8h and 12h of lens wear. The weak correlation in individual lens fit between brands indicates that fit is dependent on more than ocular shape. Consequently, substitution of a different lens brand with similar parameters will not necessarily provide comparable lens fit.

Objective clinical performance of 'comfort-enhanced' daily disposable soft contact lenses.

PURPOSE: To examine the objective clinical performance of 'comfort-enhanced' daily disposable contact lenses over a 16-h day. METHODS: Four contact lenses (Hilafilcon B, Etafilcon A Plus, Nelfilcon A and Nelfilcon A Plus) were evaluated in an investigator masked, open label trial at the end of a week's bilateral wear. Pre-lens non-invasive tear break-up time (PL-NITBUT), tear prism height, bulbar hyperaemia and ocular surface temperature (OST) were measured with the lens in situ at 8, 12 and 16h of wear. RESULTS: There was no difference between how many hours the lenses types were worn each day (F=0.90, p=0.44). The PL-NITBUT decreased with the duration of daily lens wear (F=32.0, p<0.001) and was more stable with Nelfilcon A Plus (F=6.00, p=0.002) than with the other lenses evaluated. Bulbar blood vessels increased in coverage (F=11.5, p<0.001) but not overall redness (F=0.0, p=0.99) with the duration of daily lens wear, but there was no difference between the lenses (p>0.05). The tear prism height decreased with the duration of daily wear (F=27.0, p<0.001) and differed between lenses (F=2.9, p=0.04). The OST decreased with the duration of lens wear (F=119.7, p<0.001) and was reduced by daily disposable lens wear (F=7.88, p<0.001), but did not differ between lenses (F=0.88, p=0.45). CONCLUSIONS: Objective measures of tear film indicated a difference between the lenses evaluated for PL-NITBUT and tear prism height, but not for wearing time or bulbar conjunctival hyperaemia. Therefore clinical benefits of daily disposable 'comfort enhancing' contact lenses can be measured, but challenges remain in producing contact lenses that do not compromise anterior eye physiology over the whole day.

Simplified recording of soft contact lens fit.

PURPOSE: To determine the critical fitting characteristics of modern soft contact lens fits and from this to devise a simplified recording scheme. METHODS: Ten subjects (aged 28.1+/-7.4 years) wore eight different modern soft contact lenses. Video was captured and analysed of blink (central and up-gaze), excursion lag (up, down, right and left gaze) and push-up movement, centration and coverage. RESULTS: Lens centration was on average close to the corneal centre. Movement on blink was significantly smaller in up-gaze than in primary-gaze (p<0.001). Lag was greatest in down-gaze and least in up-gaze (p<0.001). Push-up test recovery speed was 1.32+/-0.73 mm/s. Overall lens movement was determined best by assessing horizontal lag, movement on blink in up-gaze and push-up recovery speed. Steeper lens base-curves did not have a significant effect on lens fit characteristics. Contact lens material did influence lens fit characteristics, particularly silicone-hydrogels which generally had lower centration and a faster push-up speed of recovery than HEMA lenses (p<0.05). CONCLUSION: Lag on vertical gaze, and movement on blink in primary gaze generally provide little extra information on overall lens movement compared to horizontal lag, movement on blink in up-gaze and push-up recovery speed. They can therefore be excluded from a simplified recording scheme. A simplified and comprehensive soft contact lens fit recording system could consist of a cross-hairs indicating the centre of the cornea; a circle to indicate the lens centration; a mark on the relevant position of the circle to indicate any limbal incursion; a grade (B) below for movement with blink in up-gaze, a grade (L) to the side for horizontal lag and a grade above (P) for the assessed push-up recovery speed.

Ocular motor triad with single vision contact lenses compared to spectacle lenses.

AIM: Theoretically myopes are required to exert more accommodation and vergence when wearing single vision contact lenses compared to glasses and hypermetropes less. This study aims to quantify the effects clinically. METHOD: Thirty subjects (21 female, nine male, average age 21.0+/-2.2 years) with a range of refractive errors (-7.87 D to +3.50 D) viewed in a random order, static targets at 0.1, 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 D accommodative demand that were matched for angular subtense. The subjects were fully corrected with spectacles and daily disposable contact lenses to their full prescription. Accommodation was monitored objectively with the PowerRefractor and Shin-Nippon SRW5000 and vergence and pupil size with the PowerRefractor. RESULTS: Myopes exerted greater accommodative effort for viewing near targets with contact lenses than glasses and hypermetropes less (r(2)=0.35, p=0.001 PowerRefractor). Myopes also exerted greater vergence effort for viewing near targets with contact lenses than glasses and hypermetropes less (r(2)=0.22, p<0.01). CONCLUSION: Theoretical calculation of the accommodative and vergence requirements with glasses compared to contact lenses reflect clinical findings, although there is reasonable variability between individuals.