Differences in Practitioner Experience, Practice Type, and Profession in Attitudes Toward Growing Contact Lens Practice.

OBJECTIVE: To investigate eye care practitioners' attitudes and perceptions toward potential interventions that can enhance contact lens (CL) practice across the world, and how this is influenced by their practice setting. METHODS: A self-administered, anonymized survey was constructed in English and then forward and backward translated into six more languages. The survey was distributed online via social media platforms and mailing lists involving reputed international professional bodies. RESULTS: In total, 2,222 responses from 27 countries with sufficient responses were analyzed (53% females, median age- 37 years). Most of the respondents were optometrists (81.9%) and 47.6% were from stand-alone/independent practices. Median working experience in CL prescribing was 11.0 years (IQR: 18.0, 4-22 years). Over two-third of them declared themselves to be very hopeful (22.9%) or hopeful (45.1%) about the future of their CL practice. Among the potential interventions proposed, continuous update of knowledge and skills and competently managing CL-related complications were rated the most important (median score: 9/10 for each). Practitioners working in national/regional retail chains expressed higher proactivity in recommending CLs (9/10) than those in local chains, hospitals, and universities (for all 8/10, P <0.05). National differences were also identified in eye care practitioner attitudes and perceptions ( P <0.05). CONCLUSIONS: The study provided important information to delineate a variety of elements characterizing CL practice across the world. These insights can serve as a basis to design strategies at national and international levels.

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.

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.

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.

Daily disposable soft lens sagittal depth and other lens parameter changes measured at room temperature (20 °C) and on-eye temperature (34 °C).

PURPOSE: To investigate the differences in contact lens sagittal depth (CL-SAG), base curve (BC), and overall lens diameter (OAD) of daily disposable (DD) SCLs at room temperature (20 °C) and on-eye (34 °C) temperature. METHODS: Twelve different spherical daily SCLs were analyzed (labeled power -3.00 D) at 20 °C and 34 °C. The posterior CL-SAG, BC, and OAD were measured directly using a spectral domain OCT-based instrument (Optimec is830). RESULTS: The CL-SAG range for the daily disposable lenses measured at 20 °C was 3468-4016 µm. At 34 °C, the DD CL-SAG of all lenses individually decreased compared to 20 °C (t = 7.78, p < 0.001), ranging from 3385 to 3913 µm. On average at the higher temperature, the measured overall lens diameter was smaller (t = 8.18, p < 0.001) and the BC was marginally steeper (t = 2.11, p = 0.058). CONCLUSIONS: Soft lens parameters change when equilibrated from room temperature (20 °C) to on-eye temperature (34 °C). All lenses shrink when going to on-eye temperature (both lens diameter and CL-SAG decreases), compared to lenses measured at room temperature by ISO standards. Higher water content materials tend to have greater changes to the lens parameters compared to lower water content material lenses.

Variation in sag values in daily disposable, reusable and toric soft contact lenses.

PURPOSE: While knowledge of the ocular surface sagittal height (OC-SAG) is increasing with newer instrumentation, understanding of soft lens sag values (CL-SAG) in daily clinical practice is limited. This study aimed to report the differences in CL-SAG of a large collection of daily disposable (DD), reusable (2-week and 4-week replacement) and toric lens designs. METHODS: 12 different spherical DD and 15 reusable lens types were analysed (labelled power -3.00D); 17 different toric lens types analysed (6 DD and 11 reusable) in -3.00D =C 0.75 × 180. Posterior CL-SAG was measured directly using a spectral domain OCT-based instrument (Optimec is830). RESULTS: The range in CL-SAG for DDs was 3,398-3,912 microns, for reusable lenses 3,372-4,004 microns and for toric lenses 3,536-4,157 microns. Lens diameter and BC together influence CL-SAG values. For lenses with the same labelled base curve (BC), the maximum difference in the DD group was 264 microns, in the reusable group 418 microns and in the toric group 345 microns. Three lens designs within the DD group and five in the reusable group offer two BCs, with an average variation (±SD) in CL-SAG of 276 ± 39 microns; one toric lens with two BCs showed a 377-micron difference. CONCLUSIONS: Marked differences in CL-SAG values were found in this study, also between lenses of the same BC. While ECPs should be aware that diameter and BC together influence CL-SAG, this also indicates that lens substitution based on BC alone could result in substantial differences in CL-SAG, with a potential impact on lens fit. Lens designs offering two BCs showed a somewhat narrow band in absolute terms in CL-SAG, and switching from a spherical to a toric lens of the same lens manufacturer could result in a significant change in CL-SAG.

CLEAR - Scleral lenses.

Scleral lenses were the first type of contact lens, developed in the late nineteenth century to restore vision and protect the ocular surface. With the advent of rigid corneal lenses in the middle of the twentieth century and soft lenses in the 1970's, the use of scleral lenses diminished; in recent times there has been a resurgence in their use driven by advances in manufacturing and ocular imaging technology. Scleral lenses are often the only viable form of contact lens wear across a range of clinical indications and can potentially delay the need for corneal surgery. This report provides a brief historical review of scleral lenses and a detailed account of contemporary scleral lens practice including common indications and recommended terminology. Recent research on ocular surface shape is presented, in addition to a comprehensive account of modern scleral lens fitting and on-eye evaluation. A range of optical and physiological challenges associated with scleral lenses are presented, including options for the clinical management of a range of ocular conditions. Future applications which take advantage of the stability of scleral lenses are also discussed. In summary, this report presents evidence-based recommendations to optimise patient outcomes in modern scleral lens practice.

Opportunities and threats to contact lens practice: A global survey perspective.

AIM: To understand the views of contact lens (CL) practitioners across the globe regarding what they perceive as opportunities and threats in CL practice. METHODS: A self-administered anonymised questionnaire, constructed in English and translated in six more languages, was distributed through reputed international professional bodies and academic institutions worldwide. The questionnaire included items on demographic characteristics, type of practice, and questions designed to explore practitioners' perspective on the future of their CL practice over the next five years. RESULTS: A total of 2408 valid responses were analysed. Multifocal CLs for presbyopia, CLs for myopia control, use of daily disposable (DD) CLs for occasional wear, and biocompatible materials to improve comfort were identified as promising areas of opportunities by practitioners (all 8/10). Respondents from North America, and Europe valued DDCLs for occasional wear moderately more favourable (Median: 9/10 for all) as compared to colleagues in Asia (Median: 8/10, p < 0.001), South America (Median: 8/10, p < 0.01), and Africa (Median: 8/10p < 0.01). Multifocal CLs for presbyopia was perceived as a better opportunity by practitioners in North America and Europe (Median: 9/10 for both), as well as in Australasia (Median: 8/10), in comparison to Asia, Africa, and Middle East (for all Median: 6/10, p < 0.001). Practitioners expressed concerns about the availability of CLs and CL prescriptions online without direct professional involvement (both 9/10). CONCLUSIONS: Overall, the most appealing opportunities for CL practice growth were identified in occasional use of DD CLs, biocompatible materials to reduce CL discomfort, multifocal CLs for presbyopia correction and management of myopia control with CLs. Lack of regulation in CL sales, especially online, seemed to be a constant threat. The insights from this study can be used to design targeted strategies to enhance CL practice across the globe and in specific geographical areas.

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.

Global trends in myopia management attitudes and strategies in clinical practice - 2019 Update.

PURPOSE: A survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later. METHODS: A self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies. RESULTS: Of the 1336 respondents, concern was highest (9.0 ±â€¯1.6; p < 0.001) in Asia and lowest (7.6 ±â€¯2.2; p < 0.001) in Australasia. Practitioners from Asia also considered their clinical practice of myopia control to be the most active (7.7 ±â€¯2.3; p < 0.001), the North American practitioners being the least active (6.3 ±â€¯2.9; p < 0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by pharmaceutical approaches and approved myopia control soft contact lenses (p < 0.001). Although significant intra-regional differences existed, overall, most practitioners did not consider single-vision distance under-correction to be an effective strategy for attenuating myopia progression (79.6 %), but prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients (63.6 ±â€¯21.8 %). The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (20.6 %) and inadequate information (17.6 %). CONCLUSIONS: While practitioner concern about myopia and the reported level of activity have increased over the last 4 years, the vast majority of eye care clinicians still prescribe single vision interventions to young myopes. With recent global consensus evidence-based guidelines having been published, it is hoped that this will inform the practice of myopia management in future.

Evaluation of signs and symptoms in 3- and 9-o'clock staining.

PURPOSE: This study evaluates the relationship between bulbar hyperemia, conjunctival staining, lens comfort and 3- and 9-o'clock corneal staining in rigid gas permeable (GP) contact lens wear. METHODS: The study involved 55 GP contact lens wearers (with and without 3- and 9-o'clock staining) and 26 non-lens wearers. Corneal staining was graded based on a specially designed image grading scale developed at the University of Maastricht. The Efron grading scale was used to grade bulbar hyperemia and conjunctival staining. Ocular comfort and lens comfort were analyzed using a visual analogue scale (VAS) and a questionnaire to differentiate symptomatic from asymptomatic subjects. RESULTS: Bulbar hyperemia showed a significant but low correlation with corneal staining, and eyes with conjunctival staining showed more corneal staining than eyes without conjunctival staining. No correlation was found between staining in the nasal and temporal regions of the cornea in subjects with substantial 3- and 9-o'clock staining. No correlation was found between VAS comfort scores and corneal staining. In those subjects with substantial 3- and 9-o'clock staining, symptomatic subjects showed more corneal staining than asymptomatic subjects. CONCLUSIONS: Practitioners are advised to evaluate both the nasal and temporal regions of the cornea when assessing 3- and 9-o'clock staining, and they should be hesitant to rely on the amount of bulbar hyperemia for the prediction of the severity of 3- and 9-o'clock staining. Assessment of conjunctival staining could potentially be a useful tool in clinical practice to identify patients at risk of developing 3- and 9-o'clock staining. The lack of correlation between corneal staining and lens comfort stresses the need for regular contact lens check-ups in GP lens wearers. It appears that the simple registration of the presence or absence of ocular symptoms is a better predictor of 3- and 9-o'clock staining than using VAS comfort scores.

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.

Determination of central corneal clearance in scleral lenses with an optical biometer and agreement with subjective evaluation.

PURPOSE: To compare three methods to measure central corneal clearance (CCC) during scleral lens wear: subjective (slit lamp), image processed (ImageJ) and with an optic biometer. The optic biometer technique was validated in comparison to an OCT in the first part of the study. METHODS: Twenty-two eyes (11 subjects) with healthy corneas were recruited. Three measures of OCT with scleral lens and ten measurements of axial length (AL) with IOLMaster with and without lens were performed. For the second part, 61 eyes (35 subjects) enrolled in a clinical study were selected. Measurements of CCC were done with IOLMaster, SlitLamp and ImageJ. RESULTS: The measurements of CCC indirectly obtained with IOLMaster had a strong correlation with AS-OCT measurements (r = 0.981), showing a mean difference of 122.18 ± 46.05 µm (higher with IOLMaster). Regarding the second part, measurements of CCC were 238.66 ± 95.94 µm, 250.16 ± 124.31 µm and 263.15 ± 90.60 µm, for the IOLMaster, SlitLamp and ImageJ, respectively. The correlations were higher for ImageJ vs Subjective measure (r = 0.891) than for IOL vs Subjective (r = 0.748) and IOL vs ImageJ (r = 0.745). Analysis of differences and correlations between SlitLamp and ImageJ through time showed a mean difference of -32.28 ± 89.95 µm (r = 0.683) at V1month, 12.53 ± 59.46 µm (r = 0.850) at V6months and 11.57 ± 32.95 µm (r = 0.940) at V12months. CONCLUSIONS: It is possible to measure CCC with IOLMaster, considering AL measured with and without lens and lens thickness. The three methods tested have good correspondence, showing that IOLMaster and ImageJ could be objective techniques to measure CCC. Also, it is possible to improve the agreement of subjective measures when compared to objective measures trough time.

Eyeblink frequency and type in relation to 3- and 9-o'clock staining and gas permeable contact lens variables.

PURPOSE: The primary goal of this study was to evaluate if there is a difference in frequency and in completeness of eyeblinks (type of eyeblink) in rigid gas permeable (GP) lens wearers experiencing 3- and 9-o'clock staining compared with GP lens wearers without substantial staining and nonlens wearers. METHODS: The study involved 26 nonlens wearers and 55 GP contact lens wearers, with and without 3- and 9-o'clock staining. Every eyeblink over a 5-min period was categorized as a complete eyeblink, incomplete eyeblink, or an eyeblink attempt. In addition, type of lens fit (interpalpebral vs. lid attachment), lens-to-cornea fit (flat vs. steep), spherical equivalent of the refraction, and corneal coverage (on-eye lens diameter) were analyzed. RESULTS: No difference in overall eyeblink frequency was found between nonlens wearers (group I, n = 26), GP lens wearers with less than grade 1 corneal staining (group II, n = 25) and GP lens wearers with grade 1 or more corneal staining (group III, n = 30). Fewer complete eyeblinks, more incomplete eyeblinks and more eyeblink attempts were seen in group III than in group I or II (p < 0.01, p = 0.03, p < 0.01, respectively). Fewer complete eyeblinks and more eyeblink attempts (p < 0.01 for both) were found in interpalpebral lens fits than in lid attachment fits. Fewer complete eyeblinks (p = 0.02) and more incomplete eyeblinks (p = 0.03) were found with lenses rated as large or optimal in size than with lenses rated as small. CONCLUSIONS: GP lens wearers experiencing 3- and 9-o'clock staining showed a different eyeblink frequency for individual types of eyeblinks, but not for overall eyeblinks. Fewer complete eyeblinks, more incomplete eyeblinks, and more eyeblink attempts were observed in GP wearers with 3- and 9-o'clock staining compared with wearers with minimal staining and nonwearers. In addition, some individual contact lens variables were associated with more incomplete eyeblinks.

On-eye breakage and recovery of mini-scleral contact lens without compromise for the ocular surface.

PURPOSE: To report the on-eye breakage of a mini-scleral contact lens in a healthy cornea after being hit by a speeding object, without causing any severe corneal damage. CASE REPORT: A 24-year-old Caucasian male involved in a clinical study reported the in situ breakage of a mini-scleral contact lens during motorbike maintenance. The patient reported eye redness and irritation that significantly decreased after all the pieces of the lens were recovered from the eye. Ocular examinations within 48 h showed absence of corneal damage other than superficial punctate keratitis inferiorly and no fragments of the lens were found in the conjunctival sac. The patient was wearing a 15.2 mm mini-scleral lens in a high Dk material. The evolution of rigid materials towards higher Dk values has resulted in a decreased hardness and modulus values, so these materials are more elastic when subjected to mechanical stress, which could be a beneficial aspect in absorbing the energy of an impact before breaking in pieces. CONCLUSION: This case report shows that ScCL could have a protective effect to the corneal surface from the direct impact of a high-speed object. Mechanical material properties, wide supporting area and post-lens tear volume acted as protective factors helping to absorb and distribute the kinetic energy of the impacting object.

Global trends in myopia management attitudes and strategies in clinical practice.

PURPOSE: Myopia is a global public health issue; however, no information exists as to how potential myopia retardation strategies are being adopted globally. METHODS: A self-administrated, internet-based questionnaire was distributed in six languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy and adoption of available strategies, and reasons for not adopting specific strategies. RESULTS: Of the 971 respondents, concern was higher (median 9/10) in Asia than in any other continent (7/10, p<0.001) and they considered themselves more active in implementing myopia control strategies (8/10) than Australasia and Europe (7/10), with North (4/10) and South America (5/10) being least proactive (p<0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by increased time outdoors and pharmaceutical approaches, with under-correction and single vision spectacles felt to be the least effective (p<0.05). Although significant intra-regional differences existed, overall most practitioners 67.5 (±37.8)% prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients. The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (35.6%), inadequate information (33.3%) and the unpredictability of outcomes (28.2%). CONCLUSIONS: Regardless of practitioners' awareness of the efficacy of myopia control techniques, the vast majority still prescribe single vision interventions to young myopes. In view of the increasing prevalence of myopia and existing evidence for interventions to slow myopia progression, clear guidelines for myopia management need to be established.

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.