Enhancement of the Inner Foveal Response of Young Adults with Extended-Depth-of-Focus Contact Lens for Myopia Management.

BACKGROUND: Myopia management contact lenses have been shown to successfully decrease the rate of eye elongation in children by changing the peripheral refractive profile of the retina. Despite the efforts of the scientific community, the retinal response mechanism to defocus is still unknown. The purpose of this study was to evaluate the local electrophysiological response of the retina with a myopia control contact lens (CL) compared to a single-vision CL of the same material. METHODS: The retinal electrical activity and peripheral refraction of 16 eyes (16 subjects, 27.5 ± 5.7 years, 13 females and 3 males) with myopia between -0.75 D and -6.00 D (astigmatism < 1.00 D) were assessed with two CLs (Filcon 5B): a single-vision (SV) CL and an extended-depth-of-focus (EDOF) CL used for myopia management. The peripheral refraction was assessed with an open-field WAM-5500 auto-refractometer/keratometer in four meridians separated by 45° at 2.50 m distance. The global-flash multifocal electroretinogram (gf-mfERG) was recorded with the Reti-port/scan21 (Roland Consult) using a stimulus of 61 hexagons. The implicit time (in milliseconds) and response density (RD, in nV/deg2) of the direct (DC) and induced (IC) components were used for comparison between lenses in physiological pupil conditions. RESULTS: Although the EDOF decreased both the HCVA and the LCVA (one and two lines, respectively; p < 0.003), it still allowed a good VA. The EDOF lens induced a myopic shift in most retinal areas, with a higher and statistically significant effect on the nasal retina. No differences in the implicit times of the DC and IC components were observed between SV and EDOF. Compared with the SV, the EDOF lens showed a higher RD in the IC component in the foveal region (p = 0.032). In the remaining retinal areas, the EDOF evoked lower, non-statistically significant RD in both the DC and IC components. CONCLUSIONS: The EDOF myopia control CL enhanced the response of the inner layers of the fovea. This might suggest that, besides other mechanisms potentially involved, the central foveal retinal activity might be involved in the mechanism of myopia control with these lenses.

Daytime Changes in Tear Film Parameters and Visual Acuity with New-Generation Daily Disposable Silicone Hydrogel Contact Lenses-A Double-Masked Study in Symptomatic Subjects.

This prospective, double-masked, contralateral study aimed to analyze and compare daytime changes in pre-lens tear film (PLTF) stability and optical quality in symptomatic subjects wearing two contact lenses (CL). A secondary goal was to assess the performance of the PLTF by using dynamic topography techniques and analyzing surface asymmetry and irregularity indexes (SAI and SRI, respectively). Measurements were conducted on 20 symptomatic subjects (OSDI score > 13). Participants were fitted contralaterally and randomly with spherical Delefilcon A and Stenfilcon A CLs and underwent a series of measurements over 3 consecutive days: three in the morning (after 1-2 h of CL wear) and three in the afternoon (after 7-9 h of CL wear). High- and low-contrast visual acuity (HCVA and LCVA, respectively), pre-lens NIBUT, and dynamic topography were assessed. The contralateral fit of the two lenses allowed a direct and better comparison between them since they were exposed to the same conditions during the day. Consequently, both lenses demonstrated similar performance in HCVA, LCVA, and PLTF stability, with no statistically significant differences between them, although some fluctuations were observed throughout the day. Dynamic topography proved sensitive in evaluating temporal changes in the PLTF. The SRI index showed greater sensitivity to topographic changes due to lacrimal destabilization, making it potentially valuable for evaluating dry eye patients.

Prospective assessment of corneal biomechanical properties and intraocular pressure after scleral lens wear: A 12-month follow-up study.

PURPOSE: To investigate the long-term influence of scleral lens (SL) wear on corneal biomechanical properties and intraocular pressure (IOP) in irregular and regular corneas. Secondary goal comprised evaluate the fluid reservoir (FR) thickness overtime and correlate it with the changes in corneal biomechanical parameters and IOP. METHODS: Seventy (70) eyes with irregular corneas (IC Group) and 21 eyes with regular corneas (RC Group) were fitted with 16.4 mm SL and wore the lenses for 12 months. Corrected IOP (IOPcc), Goldmann equivalent IOP (IOPg) and corneal biomechanical parameters (Corneal Hysteresis (CH) and Corneal Resistance Factor (CRF)) were measured with Ocular Response Analyzer. Slit lamp images were analyzed with ImageJ software to assess FR thickness overtime. Measurements were taken at lens dispensing visit prior lens wear (LDV1) and after 60 min of lens wear (LDV2) and at 1, 6 and 12-month follow-up visits. Measurements were done immediately after lens removal. RESULTS: There were no statistically significant differences on IOPcc, IOPg, CRF and CH over the follow-up visits in both groups. Mean IOPcc and IOPg fluctuations overtime were clinically insignificant and below 1 mmHg in both groups. IOPg, CH and CRF were significantly lower on IC Group (p < 0.001), although no statistically significant differences were found between groups for IOPcc. Regarding FR thickness, statistically significant differences were found over the follow-up on both groups, with a mean decrease of 186.29 µm on IC Group and 175.32 µm on RC Group (p < 0.001). Statistically significant moderate to high negative correlations between FR and IOPg, CRF and CH were found only in the RC Group. CONCLUSIONS: Long-term SL wear was not associated to changes in corneal biomechanical parameters neither on IOP as measured after lens removal. Besides IOP measurement without SL removal, more studies are needed to investigate the potential relationship with SL fitting characteristics (namely FR thickness).

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.

How Can We Best Measure the Performance of Scleral Lenses? Current Insights.

Scleral lenses (SLs) present several unique advantageous characteristics for patients. As these lenses are mainly fitted in severely diseased eyes, a thorough evaluation of the ocular surface before and after SL fitting and the on-eye SL fitting evaluation are essential and help minimize potential physiological complications. This review will explore the current and emerging techniques and instrumentation to best measure SL performance ensuring optimal lens fitting, visual quality, comfort and physiological responses, highlighting some potential complications and follow-up recommendations. A single physician could perform the great majority of evaluations. Still, the authors consider that the assessment of SL fitting should be a collaborative and multidisciplinary job, involving contact lens practitioners, ophthalmologists and the industry. This publication has reviewed the most up-to-date work and listed the most used techniques; however, the authors encourage the development of more evidence-based recommendations for SL clinical practice.

Tear film stability over a myopia control contact lens compared to a monofocal design.

Clinical relevance: Tear film assessment is essential in contact lens wearers and it can improve the success rates of the fitting.Background: To compare the short-term effect of two contact lenses on pre-lens tear film stability and comfort: dual-focus contact lens (MiSight) and a monofocal contact lens (Proclear 1-day).Methods: This randomised, double-masked, crossover study was performed in twenty-eight healthy, myopic volunteers aged between 18 and 32 years (23.5 ± 4.1 years). Only one randomly chosen eye was assessed. Distance vision and refraction were evaluated at baseline. Each contact lens type (monofocal and dual-focus) was randomly fitted, always in both eyes. A visual analogue scale between 0 and 10 was used to assess general comfort, physical comfort, and visual comfort. Tear Film Surface Quality (TFSQ) index, TFSQ_area and auto Tear Break-Up Time were obtained using Medmont E-300 at baseline (naked eye condition) and 25 minutes after each contact lens insertion.Results: Refractive sphere and cylinder were, respectively, -1.36 ± 1.04 D (ranging from -6.00 to -0.25 D) and -0.23 ± 0.30 D (ranging from -0.75 to 0.00 D). TFSQ and TFSQ area were lower (meaning more stable tear film) at baseline when compared with both contact lens types (p < 0.025). Higher pre-lens tear instability (larger TFSQ and_TFSQ area values) was found with the dual-focus than the monofocal lens. Auto Tear Break-Up Time was higher at baseline than with each of the contact lenses, without statistically significant differences between both contact lens types. Visual analogue scales revealed statistically significant better scores in the monofocal contact lens than in dual-focus contact lens for general (0.77 ± 1.14 vs 3.12 ± 2.79), physical (0.96 ± 1.46 vs 2.19 ± 2.45) and visual comfort (1.27 ± 1.66 vs 3.92 ± 2.04).Conclusion: A slight reduction in short-term pre-lens tear film stability was found in the dual-focus design in comparison with the monofocal lens, potentially contributing to the deterioration of visual performance and comfort during dual-focus contact lens wear.

Improvement of Vision and Ocular Surface Symptoms With a Scleral Lens After Microbial Keratitis.

ABSTRACT: A 38-year-old woman, previous daily disposable soft contact lens wearer, reported an episode of microbial keratitis positive for Pseudomonas aeruginosa 11 months before contacting the investigators. After acute treatment, she was left with a degree of opacity in the pupillary area, corneal scar, and an irregular corneal profile, with a best spectacle visual acuity of +0.48 logarithm of the minimum angle of resolution. A scleral lens was able to mask those corneal sequelae and, even considering the corneal opacity, the visual acuity recovered to +0.06 logarithm of the minimum angle of resolution. The patient was fitted with a 16.4-mm scleral lens and attended several appointments over a 12-month follow-up period. After 12 months of scleral lens wear, the improvement of both high-contrast and low-contrast visual acuities remained stable and a clearing of the corneal opacity was observed. The comfort was assessed with the Ocular Surface Disease Index questionnaire, which depicted a comfort enhancement from 75.0 to 47.9 over the short term. The Quality of Vision questionnaire was also administrated and showed an improvement on frequency, severity, and bothersome of the vision-related symptoms over time. Scleral lens may be a good option to improve vision, comfort, and restore the ocular surface function in patients with corneal scars and opacities secondary to microbial keratitis.

Multifocal Electroretinogram in Keratoconus Patients without and with Scleral Lenses.

Purpose: To investigate changes in the multifocal electroretinogram (mfERG) response in eyes with keratoconus when corrected with scleral lenses (SL) compared with the best correction in glasses.Methods: The mfERG responses in 10 eyes with keratoconus were recorded with the best correction using both a trial frame (baseline) and a hexafocon A SL using an electrophysiological diagnostic system. Electrophysiologic measurements were performed with the pupils fully dilated with instillation of 1% phenylephrine. The implicit time (milliseconds), amplitude (nV), and response density (nV/deg2) of the peaks (N1, P1, and N2) were analyzed for the total mfERG response, six rings and four quadrants of the retina, and compared between the two conditions.Results: All eyes had a significant improvement in visual quality with the SL compared with baseline (mean differences, 0.26 ± 0.17 and 0.22 ± 0.13 logarithm of the minimum angle of resolution for high- and low-contrast visual acuity, respectively). The peaks implicit times of the mfERG responses did not show significant differences (p > .05). The P1 amplitude decreased in all the retinal areas with the SL. Only the total retinal response and the nasal quadrants reached significance (p ≤ 0.044). The P1 response density in ring 1 was on average higher with the SL, but not significantly so. The decline in P1 response density from the center to the periphery was more abrupt with the SL, and was more similar to the response density distribution of a typical subject, without a corneal pathology.Conclusions: mfERG did not show any change associated with retinal disease in young patients with keratoconus. Although the improved visual performance was not associated with changes in the mfERG response, the correction of irregular astigmatism with the SL helps exclude the optical effect induced by keratoconus.

Differences between Inferior and Superior Bulbar Conjunctiva Goblet Cells in Scleral Lens Wearers: A Pilot Study.

SIGNIFICANCE: Scleral lenses (SLs) rest on the scleroconjunctival region, which could result in a mechanical impact in the bulbar conjunctiva that can hypothetically modify some properties of conjunctival cells. PURPOSE: The purpose of this study was to evaluate the differences in goblet cell density (GCD) and mucin cloud amplitude (MCA) between superior and inferior bulbar conjunctiva in SL wearers. METHODS: A total of 26 eyes wearing SL were randomly selected from 26 subjects (11 females) with different grades of keratoconus enrolled in a prospective clinical series. Superior and inferior conjunctival impression cytologies were performed and therefore analyzed with scanning laser confocal microscopy to evaluate GCD and MCA. All subjects filled out the Ocular Surface Disease Index (OSDI) questionnaire. RESULTS: The mean ± standard deviation OSDI score was 23.62 ± 15.12. Although a higher density of goblet cells was observed in the samples taken in the superior conjunctiva (74.70 ± 57.55 cells/mm) than on the inferior conjunctiva (55.91 ± 34.80 cells/mm), there were no statistically significant differences between them (P = .14, Wilcoxon). Regarding MCA, no differences were found between superior (21.81 ± 3.30 µm) and inferior (20.72 ± 2.95 µm) samples (P = .201, Wilcoxon). No statistically significant differences were found in GCD and MCA regarding the time of SL wear. CONCLUSIONS: There were no differences in GCD and MCA in the samples taken in the superior and inferior conjunctival areas. Also, it seems that the SL wearing time does not affect the density and secretion of goblet cells. Prospective studies need to be conducted in larger samples to confirm those outcomes.

Optical Quality and Visual Performance for One Year in a Sample of Scleral Lens Wearers.

SIGNIFICANCE: This study shows the optical and visual quality behavior of modern scleral lenses (SLs) in the medium and long term in patients with irregular cornea (IC) and regular cornea (RC). PURPOSE: The purpose of this study was to evaluate the 12-month optical quality outcomes with SL in patients with IC and RC. METHODS: Sixty-nine patients completed the 12 months of follow-up (99 eyes with IC and 27 with RC). LogMAR high- and low-contrast visual acuity, whole eye aberrometry, and the size (Light Disturbance Index, %) and shape (BFCIrregSD, mm) of night vision disturbances were measured at baseline with habitual correction (HC), best spectacle correction (BSC), and SL at all the follow-up visits (1, 3, 6, and 12 months). Subjective visual quality was measured with the Quality of Vision (QoV) questionnaire. RESULTS: After SL fitting, high-contrast visual acuity improved significantly compared with HC and BSC in the IC group (average improvement of +0.35 ± 0.32 and +0.29 ± 0.26 to +0.08 ± 0.14, P < .001) and RC group (+0.17 ± 0.23 and +0.12 ± 0.23 to +0.10 ± 0.23, P < .05). Light Disturbance Index decreased significantly with SL compared with HC and BSC from 13.85 ± 13.99% and 15.89 ± 13.38% to 5.75 ± 4.51% in the IC group (P < .001) and 6.16 ± 5.38 and 5.98 ± 5.39 to 3.99 ± 3.05 in the RC group (P < .05). BFCIrregSD also decreased significantly, namely, in the IC group (-51%). All subscales of the QoV questionnaire had a statistically significant decrease (improvement) with SL (P < .05). CONCLUSIONS: Scleral lenses promote a better subjective and objective visual quality, mainly in patients with IC. Additional measurements such as night vision disturbances, aberrometry, and subjective perceptions should be considered to characterize the visual enhancement promoted by SL in RC and IC patients.

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.

Bifocal and Multifocal Contact Lenses for Presbyopia and Myopia Control.

Bifocal and multifocal optical devices are intended to get images into focus from objects placed at different distances from the observer. Spectacles, contact lenses, and intraocular lenses can meet the requirements to provide such a solution. Contact lenses provide unique characteristics as a platform for implementing bifocality and multifocality. Compared to spectacles, they are closer to the eye, providing a wider field of view, less distortion, and their use is more consistent as they are not so easily removed along the day. In addition, contact lenses are also minimally invasive, can be easily exchangeable, and, therefore, suitable for conditions in which surgical procedures are not indicated. Contact lenses can remain centered with the eye despite eye movements, providing the possibility for simultaneous imaging from different object distances. The main current indications for bifocal and multifocal contact lenses include presbyopia correction in adult population and myopia control in children. Considering the large numbers of potential candidates for optical correction of presbyopia and the demographic trends in myopia, the potential impact of contact lenses for presbyopia and myopia applications is undoubtedly tremendous. However, the ocular characteristics and expectations vary significantly between young and older candidates and impose different challenges in fitting bifocal and multifocal contact lenses for the correction of presbyopia and myopia control. This review presents the recent developments in material platforms, optical designs, simulated visual performance, and the clinical performance assessment of bifocal and multifocal contact lenses for presbyopia correction and/or myopia progression control.

Impact of contact lens materials on the mfERG response of the human retina.

PURPOSE: To investigate the effect of different hydrophilic and rigid gas-permeable contact lens (CL) materials on multifocal electroretinography (mfERG). METHODS: The mfERG was recorded in 18 healthy subjects with RETI-port/scan21™: 11 subjects underwent mfERG recording wearing two different hydrophilic CLs with different water contents in a randomized order (1 silicone hydrogel-Comfilcon A, 48%EWC, and 1 hydrogel-Omafilcon A, 62% EWC) and 7 other subjects wore a hydrophobic rigid gas-permeable scleral lens (SL)-Hexafocon A. Control measures were recorded without CL in both groups. mfERG recordings were performed with a stimulus array pattern of 103-scaled hexagons displayed on a 19-inch RGB monitor at 28 cm distance at a frame rate of 60 Hz. The amplitude (nV), implicit time and response density (nV/deg2) of the first-order kernel components N1, P1 and N2 were evaluated for the total mfERG response and for the response averages of 4 quadrants and of 6 successive concentric rings. Subjects were optically corrected for the working distance of ERG display. RESULTS: Hydrophobic material significantly decreased the P1 amplitude of the total mfERG response, at Rings 3, 4 and 6 and Quadrant 4 (> 53.77 ± 43.2 nV; P ≤ 0.050), as well as the total (- 71.59 ± 50.68 nV) and Ring 6 (- 104.76 ± 79.88 nV) N2 amplitude (P ≤ 0.043). N1, P1 and N2 peak times suffered significant changes with both hydrophilic CL (P ≤ 0.050). Omafilcon A significantly increased P1 amplitude of Ring 5 and N2 amplitude of Ring 4, when compared to baseline (52.40 ± 71.87 nV; P = 0.036) and to Comfilcon A (39.51 ± 48.63 nV; P = 0.023), respectively. CONCLUSIONS: Hydrophobic CL slightly attenuated the strength of the mfERG signal, especially at the middle to peripheral retinal areas, while hydrophilic CL slightly changed the implicit time of the response. Different hydrophilic CL materials might affect the mfERG response differently. When considering the measurement of mfERG obtained with a CL in place, researchers should bear in mind that some changes can be related to CL material.

Clinical Findings and Ocular Symptoms Over 1 Year in a Sample of Scleral Lens Wearers.

PURPOSE: To report the fitting aspects, clinical findings, and symptoms over 12 months of scleral lens (SL) wear. METHODS: Sixty-nine patients with irregular cornea due to ectasia or surgical procedures (IC group) or regular corneas with high ametropia (RC group) completed the 12-month prospective follow-up period. Patients were evaluated at baseline, lens dispensing visit, 1 month, 3 months, 6 months, and 12 months for assessment of comfort, fitting aspects, and slitlamp findings. Comfort was assessed with the Ocular Surface Disease Index (OSDI) questionnaire and Dry Eye Questionnaire. Slitlamp evaluations comprised on-eye lens fitting (lens alignment and tear reservoir thickness) and anterior ocular surface health after removing the lens (edema, hyperemia, staining, and adverse events). RESULTS: OSDI Scores were significantly reduced after 1 month of SL wear comparing to baseline (from 47.0±22.7-23.9±14.7 in IC group, P<0.001 and 27.0±16.1-17.0±13.7, P=0.029 in RC group, P<0.05), without statistical significant differences from 1 to 12 months. Tear reservoir thickness showed a significant reduction at V1m (122 µm on IC group and 126 µm in RC group, P<0.05), that continued over time until V12m (195 and 184 µm lower compared with Baseline (P<0.05, Wilcoxon). Hyperemia and staining were significantly higher after SL removal when compared with baseline (P<0.05), and maintained the same behavior over the 12 months. There were no severe adverse events during the entire follow-up period. CONCLUSIONS: Comfort enhancement promoted by SL remained over the entire follow-up. Despite no severe adverse events recorded over the 12 months of follow-up, higher hyperemia and staining grades were found after SL removal when compared with no-lens condition.

A one-year prospective study on scleral lens wear success.

PURPOSE: To report the success rate of scleral lens wear and the lens handling learning curve from the wearers perspective. METHODS: Ninety-five participants were consecutively screened for enrollment in a prospective study. Participants were divided into two groups: ICGroup (71 participants with irregular corneas) and RCGroup (24 participants with regular corneas). Participants attended several visits: Baseline, Lens Dispense Visit (LDV), 1-month, 3-month, 6-month and 12-month follow-ups. The number and causes of scleral lens discontinuation and the time to correctly apply the lens for the first time at the LDV were evaluated. During follow-ups, participants answered a questionnaire regarding scleral lens wear (mean number of hours/day and days/week of lens wear, methods used for handling, number of attempts to correctly apply and remove the lenses). RESULTS: Sixty-nine participants (73 %) successfully completed the 12-month period. Twenty-six participants (27 %) discontinued scleral lens wear. None of the discontinuations were due to adverse events. The success rate (number of participants that wore the lenses for the 12 months) was 77 % in ICGroup and 58 % in RCGroup. The main reasons for scleral lens discontinuation were handling issues (35 %) and discomfort (19 %). 36 % of participants required <15 min to correctly apply the lens at the LDV, however 13 % required >60 min (participants that wore spectacles, soft lenses or had no correction method at Baseline). The mean wearing time (hours/day and days/week) increased significantly from 1-month to 12-month appointments: from 9.8-11.1 h and 5.1-5.6 days in new scleral lens wearers, while the number of attempts to correctly apply and remove the lenses decreased significantly. CONCLUSIONS: The success rate was 73 % during this prospective 12-month follow-up study. The main reasons for drop-out were handling issues and discomfort. Participants who continued scleral lens demonstrated increased handling skills.

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

Practitioner Learning Curve in Fitting Scleral Lenses in Irregular and Regular Corneas Using a Fitting Trial.

PURPOSE: To assess the learning curve of a novel practitioner with minor previous experience with scleral lenses (SL) fitting in the initial 156 consecutive fittings in irregular and regular corneas using a fitting trial. METHODS: Prospective dispensing case series involving a total of 85 subjects (156 eyes), 122 eyes with irregular corneas (IC Group) and 34 eyes with regular corneas (RC Group). All lenses were fitted by the same practitioner with minimal previous knowledge and practice on SL fitting. The first 156 consecutive fits were studied to estimate the number of trial lenses required to achieve the optimal fit and the number of reorders required. The results were divided into 8 chronological groups of 20 fittings (eyes) each. RESULTS: There was a decrease in the number of trial lenses required to achieve the optimal fit from 2.35±0.18 lenses in the first 20 fittings to 1.56±0.13 in the last fittings (p<0.05, Wilcoxon). There were no statistically significant differences between IC and RC groups. Regarding the number of reorders, there was also a decrease from 0.95±0.17 in the first fittings to 0.25±0.11 in the last fittings (p<0.05, Wilcoxon). Thought not statistically significant, there was an increase in the use of toric designs with increasing experience. CONCLUSIONS: Practitioner fitting experience reduced both the number of trial lenses required to achieve the best fit and the number of reorders with time. After the first 60 cases, there was a significant reduction in the trial lenses and reorders necessity.

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.

Relationship of placido corneal topography data with scleral lens fitting parameters.

PURPOSE: To analyze the relationship between corneal sagittal height and asymmetry parameters derived from Placido-videokeratoscopy with the parameters of fitted scleral lenses (ScCLs). METHODS: Corneal topographies were measured with MedmontE300 in a total of 126 eyes with irregular and regular corneas before ScCL fitting were analyzed. Measurements of sagittal height (OC-SAG) at steep and flat corneal meridians were obtained for 10 mm and 12 mm chords. Estimated Height (EHChord) parameters were taken for a chord equal to the diameter of the lens that each subject was wearing at different semi-meridians. Corneal asymmetry (difference in OC-SAG between steep and flat corneal meridians) was also assessed. These outcomes were correlated to ScCL parameters that subjects were wearing after 1 month. RESULTS: The mean ScCL-SAG was 4696 ± 240 µm, and the mean OC-SAG ranged from 1891 µm (10 mm), 2914 µm (12 mm), and between 4162 µm and 4251 µm for EH0-180º and EH30-210º. Stronger correlations (p < 0.001) between OC-SAG and ScCL-SAG were determined for EH0-180º (r = 0.595) and EH30-210º (r = 0.618). The mean differences between OC-SAG and ScCL-SAG were between 447 ± 290 µm (EH0-180º) and 389 ± 360 µm (EH30-210º). There was no relationship between corneal asymmetry and the need to fit a ScCL with toric haptic design in irregular corneas. Orientation of flat corneal and scleral meridians were similar only in corneas with high regular astigmatism. CONCLUSIONS: EHChord attributes were the parameters that best correlated with the ScCL-SAG. The corneal asymmetry was shown to be a poor predictor for the need to fit a ScCL with toricity at landing zone in irregular corneas, but could have some predictive power in regular corneas.