Assessment of meibomian gland drop-out and visibility through a new quantitative method in scleral lens wearers: A one-year follow-up study.

OBJECTIVES: To validate a previously developed algorithm based on the visibility of meibomian gland images obtained with Cobra fundus camera and to assess the changes in meibomian glands in scleral lens wearers over one year of lens wear. METHODS: Infrared meibography was obtained from the upper eyelid using the Cobra fundus camera in forty-three volunteers (34.2 ± 10.1 years). Meibographies were classified into 3 groups: Group 1 = good subjective gland visibility and gland drop-out < 1/3 of the total area; Group 2 = low visibility and gland drop-out < 1/3; and Group 3 = low visibility and gland drop-out > 1/3. Meibomian gland visibility metrics were then calculated using the developed algorithm from the pixel intensity values of meibographies. Repeatability of new metrics and their correlations with gland drop-out were assessed. Meibographies and ocular symptoms were also assessed after 1 year of scleral lens wear in 29 subjects. RESULTS: Gland drop-out percentage was not statistically different between groups 1 and 2 (p = 0.464). Nevertheless, group 1 showed higher grey pixel intensity values than the other groups. Statistically significant correlations were found between gland visibility metrics and gland drop-out percentage. Repeatability was acceptable for all metrics, coefficient of variation achieving values between 0.52 and 3.18. While ocular symptoms decreased with scleral lens wear (p < 0.001), no statistically significant differences were found in gland drop-out percentage (p = 0.157) and gland visibility metrics (p > 0.217). CONCLUSIONS: The proposed method can assess meibomian gland visibility in an objective and repeatable way. Scleral lens wear appears to not adversely affect meibomian gland drop-out and visibility while might improve dry eye symptoms after one year of lens wear. These preliminary results should be confirmed with a control group.

Short-term tear film stability, optical quality and visual performance in two dual-focus contact lenses for myopia control with different optical designs.

PURPOSE: To assess and compare short-term visual and optical quality and tear film stability between two dual-focus (DF) prototype myopia control contact lenses (CLs) having different inner zone diameters. METHODS: Twenty-eight myopic subjects were included in this randomised, double-masked crossover study. Refraction, best-corrected visual acuity (VA) and tear film stability were measured at baseline (i.e., when uncorrected). Subjects were then binocularly fitted with the DF CLs, with only the sensorial dominant eye being assessed. Lenses were of the same material and had inner zone diameters of either 2.1 mm (S design) or 4.0 mm (M design). Visual and physical short-term lens comfort, over-refraction, best-corrected VA, stereopsis at 40 cm, best-corrected photopic and mesopic contrast sensitivity (CS), size and shape of light disturbance (LD), wavefront aberrations, subjective quality of vision (QoV Questionnaire) and tear film stability were measured for each lens. RESULTS: Both CL designs decreased tear film stability compared with baseline (p < 0.05). VA and photopic CS were within normal values for the subjects' age with each CL. When comparing lenses, the M design promoted better photopic CS for the 18 cycles per degree spatial frequency (p < 0.001) and better LD (p < 0.02). However, higher-order aberrations were improved with the S design (p = 0.02). No significant difference between the two CLs was found for QoV scores and tear film stability. CONCLUSIONS: Both DF CLs provided acceptable visual performance under photopic conditions. The 4.0 mm inner zone gave better contrast sensitivity at high frequencies and lower light disturbance, while the 2.1 mm central diameter induced fewer higher-order aberrations for a 5 mm pupil diameter. Both CLs produced the same subjective visual short-term lens comfort.

Comparison of short-term light disturbance, optical and visual performance outcomes between a myopia control contact lens and a single-vision contact lens.

PURPOSE: To compare the optical and visual performance of a dual-focus (DF) contact lens used for myopia control with a single-vision (SV) contact lens of the same material. METHODS: A randomised, double-masked crossover study. Twenty-eight healthy, myopic volunteers between 18 and 32 years of age (23.49 ± 4.07 years) participated in this study. The sensory dominant eye for distance vision was determined. Refraction, best-corrected visual acuity (VA) and aberrations for 3 mm and 5 mm pupil diameters were quantified without a contact lens in situ. Subjects were fitted with two contact lens designs: DF and SV, both made of omafilcon A material. The Quality of Vision (QoV) questionnaire, over-refraction, best-corrected VA, stereopsis at 40 cm, best-corrected photopic and mesopic contrast sensitivity, light disturbance and aberrations were assessed 25 min after contact lens insertion. RESULTS: There were no statistically significant differences in best-corrected VA and stereopsis between the baseline, DF and SV conditions. Photopic and mesopic contrast sensitivity were lower for the DF contact lens at all frequencies, with the exception of the mesopic contrast sensitivity at 18 cycles per degree (p = 0.23). Higher order aberrations and light disturbance size and irregularity were higher for the DF contact lens (p < 0.001). No differences were found in higher order aberrations between baseline and the SV contact lens condition for each pupil diameter. QoV scores also revealed lower frequency, severity and bothersome scores with the SV contact lens than with the DF contact lens (p < 0.001). CONCLUSIONS: The DF contact lens design decreased the psychophysical and psychometric visual quality scores in the short-term under dim-light conditions when compared with a single-vision contact lens design of the same material. VA and stereopsis were unaffected by the lens design.

In vivo assessment of the anterior scleral contour assisted by automatic profilometry and changes in conjunctival shape after miniscleral contact lens fitting / Valoración in vivo del contorno de la esclera anterior asistida por perfilometría automática, y de los cambios en la forma conjuntival tras el uso de lentillas mini-esclerales

Purpose: To compare the shape of the anterior sclera of candidates to scleral lens (ScCL) fitting with regular and irregular corneas and analyze the changes induced in the shape of the sclero-conjunctiva after ScCL wear. Methods: Thirty-five eyes of 18 subjects (19 eyes with irregular corneas and 16 with regular corneas) were consecutively recruited. Three measures of sclero-conjunctival shape were taken with Eye Surface Profiler (ESP, Eaglet Eye, Houten, The Netherlands). Tangent angles and ocular sagittal heights (OC-SAG) were analyzed at different chords from 13 to 17 mm in the nasal, temporal, superior and inferior regions. The 19 eyes with irregular cornea were selected to wear ScCL and the changes in their sclero-conjunctival surface parameters were compared before and after 3 h of lens wear. Results: Irregular corneas showed higher OC-SAG values than regular corneas in all the chords analyzed, with statistical significant differences in the temporal region. Regarding tangent angles, regular corneas showed lower values (flatter surface), with statistical significant differences at 8 and 8.50 mm on the nasal and 8.50 mm on the temporal region. Some changes were seen in sclero-conjuctival shape after short-term ScCL wear. There was an augment in OC-SAG after 3h of scleral lens wear and a reduction on tangent angles, namely on the nasal region at 7.5 mm and 8.00 mm chord lengths, which is coincidental with the landing zone of ScCL. Conclusions: ESP shows mild differences in scleral shape between eyes with regular and irregular corneas. ESP might be valuable in quantifying the mechanical impact of the ScCL on the anterior eye surface

Objetivo: Comparar la forma de la esclerótica anterior de los candidatos a utilizar lentes de apoyo escleral (ScCL) con córneas regulares e irregulares, y analizar los cambios inducidos en la forma de la superfície esclero-conjuntival tras el uso de dichas lentes. Métodos: Se incluyeron consecutivamente treinta y cinco ojos de 18 sujetos (19 ojos con córneas irregulares y 16 con córneas regulares). Se realizaron tres mediciones de la forma esclero-conjuntival con el dispositivo Eye Surface Profiler (ESP, Eaglet Eye, Houten, The Netherlands). Se analizaron los ángulos tangenciales y las alturas sagitales oculares (OC-SAG) a diferentes cuerdas, de 13 a 17 mm en las regiones nasal, temporal, superior e inferior. Se seleccionó a los 19 ojos con córnea irregular para utilizar ScCL, comparándose los cambios de los parámetros de su superficie esclero-conjuntival antes y después del uso de lentillas durante 3 horas. Resultados: Las córneas regulares reflejaron valores OC-SAG superiores a las córneas regulares en todas las cuerdas analizadas, con diferencias estadísticamente significativas en la región temporal. En cuanto a los ángulos tangenciales, las córneas regulares reflejaron unos valores inferiores (superficie más plana), con diferencias estadísticamente significativas a 8 y 8,5 mm en la región nasal, y 8,5 mm en la región temporal. También se apreciaron algunos cambios en la forma esclero-conjutival tras el uso a corto plazo de ScCL. Se produjo un aumento de los valores OC-SAG tras 3 h de uso de lentillas esclerales, y una reducción de los ángulos tangenciales, es decir, en las distancais correspondientes a las cuerdas de la región nasal a 7,5 mm y 8 mm, lo cual es coincidente con la zona de apoyo de las ScCL. Conclusiones: El dispositivo ESP muestra leves diferencias en la forma escleral entre los ojos con córneas regulares e irregulares, y ha es capaz de por lo que podría resultar de utilidad para cuantificar el impacto mecánico de las lentes ScCL en la superficie anterior del ojo

In vivo assessment of the anterior scleral contour assisted by automatic profilometry and changes in conjunctival shape after miniscleral contact lens fitting.

PURPOSE: To compare the shape of the anterior sclera of candidates to scleral lens (ScCL) fitting with regular and irregular corneas and analyze the changes induced in the shape of the sclero-conjunctiva after ScCL wear. METHODS: Thirty-five eyes of 18 subjects (19 eyes with irregular corneas and 16 with regular corneas) were consecutively recruited. Three measures of sclero-conjunctival shape were taken with Eye Surface Profiler (ESP, Eaglet Eye, Houten, The Netherlands). Tangent angles and ocular sagittal heights (OC-SAG) were analyzed at different chords from 13 to 17mm in the nasal, temporal, superior and inferior regions. The 19 eyes with irregular cornea were selected to wear ScCL and the changes in their sclero-conjunctival surface parameters were compared before and after 3h of lens wear. RESULTS: Irregular corneas showed higher OC-SAG values than regular corneas in all the chords analyzed, with statistical significant differences in the temporal region. Regarding tangent angles, regular corneas showed lower values (flatter surface), with statistical significant differences at 8 and 8.50mm on the nasal and 8.50mm on the temporal region. Some changes were seen in sclero-conjuctival shape after short-term ScCL wear. There was an augment in OC-SAG after 3h of scleral lens wear and a reduction on tangent angles, namely on the nasal region at 7.5mm and 8.00mm chord lengths, which is coincidental with the landing zone of ScCL. CONCLUSIONS: ESP shows mild differences in scleral shape between eyes with regular and irregular corneas. ESP might be valuable in quantifying the mechanical impact of the ScCL on the anterior eye surface.