Scleral Lens Fitting Research Articles

Characterization of the geometric properties of the sclero-conjunctival structure: a review.

To revise the peer-reviewed literature on geometric properties of the scleral-conjunctival structure in order to define their clinical relevance and the potential relationship between their changes and myopia development or progression. A bibliographic search focused on the study of the geometry of conjunctiva and/or sclera as well as those studies evaluating the relationship between geometric changes in the scleral-conjunctival structure and myopia was carried out. Several studies have been performed with different diagnostic technologies, including optical coherence tomography, profilometry and Scheimpflug imaging, to detect geometric changes of the scleral-conjunctival tissue in different physiological conditions of the eye, after use of contact lenses and in different ocular pathologies. Likewise, these technologies have been shown to be a valuable clinical tool to optimize scleral contact lens fitting. Future studies should investigate new potential clinical applications of such technologies, including the evaluation of anterior scleral changes related to myopia, as well as to define standardized clinical standard operating procedures for obtaining accurate and reproducible clinical measurement of the scleral-conjunctival morphology.

Corneoscleral Topography Measured with Fourier-based Profilometry and Scheimpflug Imaging.

Precise measurement of corneoscleral topography makes a valuable contribution to the understanding of anterior eye anatomy and supports the fitting process of contact lenses. Sagittal height data, determined by newer noninvasive techniques, are particularly useful for initial scleral lens selection. The purpose of this study was to investigate the agreement and repeatability of Fourier-based profilometry and Scheimpflug imaging, in the measurement of sagittal height and toricity of the corneoscleral region. Minimal (Minsag), maximal (Maxsag) sagittal height, toricity (Maxsag - Minsag), and the maximum possible measurement zone diameter of 38 subjects were compared using the Eye Surface Profiler (ESP; Eagle Eye, Houten, the Netherlands) and the corneoscleral profile module of the Pentacam (Oculus, Wetzlar, Germany) at two different sessions. Correlations between the instruments were analyzed using the Pearson coefficient. Differences between sessions and instruments were analyzed using Bland-Altman and paired t tests. For an equal chord length, the measurement with Pentacam was significantly greater for Minsag (344 μm; 95% confidence interval [CI], 322 to 364 μm; P < .001) and significantly greater for Maxsag (280 μm; 95% CI, 256 to 305 μm; P < .001), but significantly smaller for toricity (-63 μm; 95% CI, -95 to -31 μm; P < .001). Maximum possible measurement zone diameter with ESP (16.4 ± 1.3 mm) was significantly greater than with Pentacam (14.8 ± 1.1 mm) (P < .001). Repeated measurements from session 1 and session 2 were not significantly different for Pentacam and ESP (P = .74 and P = .64, respectively). The 95% CIs around differences indicate good repeatability for Pentacam (mean difference, -0.9 μm; 95% CI, -6.7 to 4.8 μm) and ESP (4.6 μm; -22.4 to 31.6). Although both instruments deliver useful data especially for the fitting of scleral and soft contact lenses, the sagittal height and the toricity measurements cannot be considered as interchangeable.

Are eye‐care practitioners fitting scleral contact lenses?

BackgroundTo determine the extent of scleral lens fitting worldwide and to characterise the associated patient demographics.MethodsSurvey forms were sent to contact lens fitters around the world, every year for 20 consecutive years (2000 to 2019). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey. Data were analysed for those countries reporting ≥ 1,000 contact lens fits during this period.ResultsA total of 369,209 contact lens fits were recorded from 40 eligible countries, comprising 2,309 scleral lens fits and 366,900 other (non‐scleral) lens fits. Overall scleral lenses represented 0.76 per cent of all contact lens fits with significant differences between countries (p < 0.0001), ranging from no fits in six countries: Hungary, Indonesia, Iran, Korea, Malaysia and Singapore, to 5.9 per cent in Switzerland. There has been an increase in scleral lens fitting over the survey period (p < 0.0001), with the rate of fits increasing from negligible (< 0.50 per cent) before 2006 and then increasing from 2011 onward (p < 0.0001). Scleral lenses were fit to older patients (38.5 ± 15.0-years) compared to other lenses (31.4 ± 13.7-years) (p < 0.0001), this age disparity increasing over the survey period (p < 0.0001) and were more likely to be males (scleral lens fits 53 per cent, non‐scleral lenses 33 per cent, p < 0.0001). The increase in scleral lens fits is commensurate with the increase in related publications in the peer‐reviewed literature over the same period (p < 0.05, r2 = 0.82).ConclusionScleral lens use has increased since 2011 with these specialised lenses more likely to be fitted to males and older patients than non‐scleral lenses.

Scleral Topography-Guided Scleral Lens Fitting

Keratoconus is a progressive corneal ectatic disease that leads to corneal shape irregularity and subsequent blur, visual distortion, and glare. One of the best non-surgical treatments for those suffering from keratoconus are scleral lenses. The ability of scleral lenses to compensate for irregular astigmatism allows patients to see clearer, more comfortably, and with visual stability. Technological advances such as Map3D scleral topography allow for a more precise first lens, which enhances initial comfort and vision, all while reducing chair time. Despite technological guidance, considerations must still be made to conjunctival settling, corneal edema, and corneal hypoxia. CE Notification: This article is available as a COPE accredited CE course. You may take this course for 1-hour credit. Read the article and take the qualifying test to earn your credit. Click here to Enroll (https://www.crojournal.com/scleral-topography-guided-scleral-lens-fitting) Please check COPE course expiry date prior to enrollment. The COPE course test must be taken before the course expiry date.

Scleral lens fitting in a Sjogren's syndrome Patient with post LASIK cornea and surgical induced scleral irregularity: A case report

Scleral lens fitting in a Sjogren's syndrome Patient with post LASIK cornea and surgical induced scleral irregularity: A case report

Profilometry. Using Corneo-scleral topography for scleral lens fitting

The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.

Ways to use image analysis software to evaluate the peripheral fitting of scleral contact lenses

Ways to use image analysis software to evaluate the peripheral fitting of scleral contact lenses

Scleral lenses reduce the need for corneal transplants after hydrops

Purpose To investigate the success and failure of scleral lens fitting for keratoconus with resolved hydrops.

The official guide to scleral lens terminology

PurposeIn absence of scleral lens standards, this article aims to provide an official definition of terms related to scleral lens fitting and manufacturing, in order to make more uniform the use of appropriate terms when describing, writing or lecturing about scelral lenses. Adoption of a common terminology may also favor more fruitful exchanges between eyecare practitioners and manufacturers. MethodsA committee of 12 advances scleral lens clinicians met and develop a list of terms related to scleral lens fit and manufacturing. Litterature review was made using PubMed database with the keywords “scleral lenses” and “terminology”. Other related publications such as textbooks were also considered valid references. Validation of the terms selected and their suggested definition was made by consultation of other experts in the field, over 2 years. A final version was adopted by the Scleral Lens Education Society late in 2018. ResultsThis article contains three main sections. Section I provides the definition of a scleral lens. Section II addresses the general terminology habitually applied to contact lens field but in the context of scleral lens usage. Finally, Section III suggests a decription of terms specifically used when fitting or manufacturing scleral lenses. At the end, recommendations are made to manufacturers about the essential elements to provide to eyecare practitioners in order to help them understanding the lens design and to customize their fit. ConclusionA common language is key to advancing the science and clinical practice of scleral lens fitting. The current terminology will help standardize this field, helping eyecare practitioners, educators, speakers and manufacturers to talk with the same language.

OKVision® Onefit™ Mini-Scleral Lenses Fitting Guide

Corneal topography has been widely used in medical practice over recent years and it has helped to detect keratectasias of various genesis more often and in the earlier stages. The emergence of the new polymer materials with high oxygen permeability made it possible to wear scleral contact lenses safely, that also resulted in their popularization. Scleral gas permeable lenses are an effective method of vision correction not only for various ectasias, but also for ametropia, presbyopia and other refractive pathologies. Scleral contact lenses do not directly touch the cornea and the limbus area, whereas tear firm under the lens physically smoothes out all of the existing defects and irregularities of the corneal surface, thus creating a ”cornea-tear-lens“ unified optical system. As a result, visual acuity increases significantly. In addition, scleral lenses ensure excellent comfort starting from the first minutes of wearing due to a larger diameter, no direct contact with the cornea and relatively low mobility. Scleral lenses ensure high visual functions and comfort owing to their specific self-supporting design, which is rested on the sclera. Selection and fitting of scleral contact lenses is simple and can be mastered by any ophthalmologist

The Outcome of Scleral Lens Fitting for Keratoconus With Resolved Corneal Hydrops.

To investigate the success and failure of scleral lens fitting in patients with keratoconus with resolved hydrops. Retrospective case series of patients with keratoconus who attended the Ophthalmology Department at Antwerp University Hospital, Belgium, and developed acute hydrops between January 1, 2015, and June 30, 2018. The exclusion criteria included amblyopia, mental retardation, and insufficient follow-up. Of the 25 patients with keratoconus with acute hydrops, 14 patients (16 eyes) were included in this study. Median age was 31 years (range 19-52 years). Before hydrops, the median maximum keratometry value of affected eyes was 81.3 D (range 66.3-108.3 D). Acute hydrops was managed medically in 5 eyes (31.3%), by observation in 5 eyes (31.3%), by application of bandage contact lens in 1 eye (6.3%), and compression corneal sutures in 5 eyes (31.3%). Contact lens fitting after hydrops was not necessary for 2 patients (2 eyes; 12.5%) because of excellent vision in the fellow eye. Of the remaining patients, 11 (68.8%) were successfully fitted with mini-scleral lenses, with a median visual acuity of 0.7 (0.5-0.9; decimal Snellen). Three patients (3 eyes; 18.8%) proceeded to graft surgery because of limited visual acuity with scleral lenses (n = 2) or persistent edema (n = 1). Scleral lenses are effective for providing satisfactory visual acuity after corneal hydrops in keratoconus. A scleral lens trial is advised before listing patients for graft surgery.

Zenlens scleral lenses for visual rehabilitation of patients with irregular cornea: a usage experience

Scleral lenses improve visual acuity in patients with irregular corneal astigmatism, which is especially important when other methods of correction are ineffective.Purpose: to assess the efficiency of Zenlens scleral lenses in patients with irregular cornea.Material and methods. A total of 120 patients (164 eyes) were examined, including 86 males and 34 females, aged from 13 to 63 years (mean age 35 ± 12 years). The patients were divided into 4 groups. Group 1 consisted of patients with keratoconus, group 2 — postpenetrating keratoplasty, group 3 — keratoconus after cross-linking and/or corneal ring segment implantation, while group 4 consisted of patients with other diseases. The efficiency criteria included visual acuity before and after scleral lens fitting and wearing time (hours per day). To determine social significance of scleral lens wearing, we selected 30 patients (46 eyes) with average best-corrected visual acuity (BCVA) before fitting 0.21 ± 0.08 (0.1–0.3).Results. Average uncorrected visual acuity before fitting did not exceed 0.2 and average visual acuity after fitting was 0.8 ± 0.15. Average improvement in visual acuity after fitting compared to uncorrected visual acuity was at least six lines in all groups and average improvement of visual acuity was approximately three lines compared to BCVA before fitting. 74.4 % and 19.5 % of patients demonstrated long-term (&gt; 10 hours per day) and partial (8–10 hours per day) wear, respectively. Short-term wear (&lt; 8 hours per day) was noted in 6.1 % of patients. Visual acuity of patients with low BCVA (mean 0.21 ± 0.08) increased by 0.57 (271.4 %).Conclusion. Scleral lenses can be successfully used for visual acuity improvement and social rehabilitation of patients with irregular cornea when other methods of correction are ineffective.

Assessment of a practitioner's perception of scleral contact lens complications.

The purpose of this survey was to better understand scleral lens (SL) practitioners' fitting preferences and minor SL complications and their subsequent treatments. Practitioners who attended the 2017 Global Specialty Lens Symposium were asked to complete an electronic questionnaire that was created by the investigators, a survey that asked practitioners about their SL fitting experience and preferences, their patients' experience with poor SL wetting, SL fogging, ocular symptoms (redness, pain/discomfort, dryness), and blurred central and side vision, and how the practitioners treated these conditions. This study analyzed data from 164 SL practitioners. The practitioners had been in practice for 16.3 ± 13.4 years, had been fitting SL for 5.5 ± 5.0 years, and fit 7.4 ± 7.1 SL/month. Practitioners preferred a SL with a final central corneal clearance of ∼200 μm and an overall diameter between 15.1 mm to 16.5 mm. Poor SL wetting (90.8% of practitioners documented condition), SL fogging (84.8%), blurred central vision (40.2%), ocular redness (34.8%), ocular dryness (24.4%), ocular pain/discomfort (20.7%), and blurred side vision (12.8%) were encountered by the practitioners. Practitioners preferred treating poor wetting and fogging with lens removal, cleaning, and reapplication, blurred central vision with a lens power change, blurred side (peripheral) vision, ocular redness, and ocular pain with a lens parameter change, and dryness with artificial tears. Most SL practitioners preferred a SL central corneal clearance of ∼200 μm, and they occasionally encountered SL-related complications in their practice, which they treated similarly to corneal gas permeable CLs.

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

PurposeTo 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. MethodsThirty-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. ResultsIrregular 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. ConclusionsESP 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.

Scleral lens fitting and assessment strategies.

To describe prescriber reported scleral lens fitting and assessment strategies. The SCOPE (Scleral Lenses in Current Ophthalmic Practice Evaluation) study group designed and administered an IRB approved, electronic survey (REDCap) regarding current scleral lens fitting and assessment methods. The survey was distributed to attendees of the 2017 Global Specialty Lens Symposium. 95 practitioners responded to the survey. Over half of the respondents, 58% (55/95) reported fitting scleral lenses for less than five years (new prescribers), and 42% (40/95) reported fitting scleral lenses for more than five years (experienced prescribers). There was a statistically significant difference between their initial use of technology (χ2 = 21.117, p < 0.0005) in selection of a diagnostic lens. New prescribers consider base curve first (60%, 33/55), while experienced prescribers considered sagittal depth first (63%, 25/40) in their initial scleral lens selection. All of the experienced lens prescribers (100%, 39/39) reported estimating central clearance by comparing thickness of the post-lens tear reservoir to scleral lens thickness using a slit lamp beam at least some of the time, and 62% of new scleral lens prescribers (34/55; χ2 = 19.175, p < 0.0005) reported doing so. All (100%, 40/40) experienced prescribers schedule scleral lens follow-ups at a specific time and assess conjunctival compression (100%, 40/40), conjunctival staining (100%, 39/39), and corneal staining (100%,40/40) after lens removal. Practitioners with varying backgrounds and experience have added sclerals to their lens inventories. However, definite guidelines for fitting have not been developed. The results of a survey are provided; demonstrating that among practitioners with greater than 5 years of scleral lens experience, a consensus has emerged for best practices. Strategies for lens evaluation, which may inform future efforts at generating scleral fitting standards are described.

Anterior segment optical coherence tomography angiography to evaluate the peripheral fitting of scleral contact lenses.

PurposeThe aim of this study was to show the potential applicability of optical coherence tomography angiography (OCTA) for the evaluation of the peripheral fitting of fully scleral contact lenses.MethodsA pilot study was proposed fitting three different scleral contact lenses (Irregular Corneal Design [ICD]) with different sagittal heights (4200, 4800, and 5600 mm) in a healthy volunteer of 27 years old. We evaluated by means of optical coherence tomography (OCT, DRI Triton) the apical clearance achieved with each of the three lenses fitted. The impact over scleral flow was assessed with the OCTA module of the same device.ResultsThe apical clearance was 310, 901, and 1680 µm with the scleral lenses of sagittal heights 4200, 4800, and 5600 µm, respectively. With OCTA, we evaluated the impact of the lens bearing on the conjunctival vascular flow, observing an area of vascular interruption of 0, 25, and 75% with the lenses of 4200, 4800, and 5600 µm of sagittal heights, respectively. The vascular interruption was induced in the perilimbar area, suggesting the need of readjusting the limbal clearance zone of the lens.ConclusionFully scleral contact lens fitting may be optimized with the use of OCTA, allowing the practitioner to perform the fitting with better control of the peripheral bearing of the lens on the conjunctival tissue, assessing the impact on vascular structures. This potential use of OCTA must be investigated further in future studies including large samples of eyes.

SMap3D Corneo-Scleral Topographer Repeatability in Scleral Lens Patients.

To determine repeatability of measurements using the sMap3D Corneo-Scleral Topographer in patients presenting for scleral lens fitting. As part of our standard clinical evaluation, 25 eyes of 23 patients who presented for scleral lens fitting were examined twice in the same day with the sMap3D in this retrospective study. Sagittal height (SAG), sMap3D principal toricity magnitude (as calculated by the instrument software), and steep axis location were measured at a 16-mm chord diameter. Up gaze, primary, and down gaze positions of each eye were imaged and "stitched" by the instrument software into a single corneoscleral topography map from which the measurements were derived. The mean difference in SAG between the 2 examinations was 14 μm with an SD of 55 μm. Sixty-eight percent of cases had a difference of ≤50 μm, and 95% of cases had a difference of ≤100 μm. The mean difference in sMap3D principal toricity magnitude between examinations was 0.15 diopter (D) with an SD of 0.38 D. Eighty-four percent of cases had a difference of ≤0.5 D, and all cases had a difference of <1 D. Mean toric axis difference between examinations was 2.5° with an SD of 18.4°. Sixty-four percent of cases had an axis difference of ≤10°, and 84% had an axis difference of ≤15°. The sMap3D measurements are repeatable with regard to scleral toricity and SAG values at a 16-mm diameter and thus would be suitable to use for scleral lens fitting.

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

To analyze the relationship between corneal sagittal height and asymmetry parameters derived from Placido-videokeratoscopy with the parameters of fitted scleral lenses (ScCLs). 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. 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. 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.

From corneal to scleral – Scleral lens fitting in monocular keratoconus patients: A case series

From corneal to scleral – Scleral lens fitting in monocular keratoconus patients: A case series

Difference in corneal sagittal heights from 10 to 15 mm of keratoconic eyes measured with Pentacam, Visante OCT and a calculated method

Purpose: Sagittal height is important during scleral lens fitting. This study compares: Pentacam's internal measurement program, optical coherence tomography (Visante OCT) and sagittal height calculation using K's and e-values at 10 and 15 mm chords. The sagittal height difference between these chords was calculated to determine a constant that could be added for measures taken only at 10 mm.