Potential contraindications to scleral lens wear

Short-term changes in the trabecular iris angle and anterior chamber during wear of scleral lenses with different diameters

CLINICAL RELEVANCE

Scleral lens (SL) compression on the conjunctiva/episclera during wear may alter adjacent structures related to aqueous humour drainage.

BACKGROUND

The aim of this work was to assess short-term changes in the four quadrants of trabecular iris angle (TIA) and anterior chamber parameters during SL wear, using anterior segment optical coherence tomography (AS-OCT).

METHODS

Prospective study was conducted involving 16 healthy subjects with a mean age of 28 ± 5 years. Two SL of diameter 15.80 mm (L1) and 16.80 mm (L2) with the same parameters were used for 2 hours in different days. The central fluid reservoir (FR), the TIA in superior, inferior, nasal, temporal quadrants, and anterior chamber parameters; anterior chamber depth (ACD), anterior chamber width (ACW), anterior chamber area (ACAr) and anterior chamber volume (ACV) were measured with AS-OCT. These measurements were performed immediately after SL application (0 h), one hour (1 h) and two hours (2 h) of SL wear.

RESULTS

TIA decreases significantly in the superior quadrant at 2 hours of L2 wear (-5.19 ± 7.79º) (p = 0.04). In this sector, differences were also observed between the changes induced by both lenses during the 2 hours of wear (p = 0.04) and between first and second hours of wear (p = 0.04). ACD was significantly lower with L1 (-0.09 ± 0.14 mm) relative to L2 (0.00 ± 0.06 mm) between immediately after the application and 2 hours of wear (p = 0.02). A significant reduction in ACAr at 1 hour (-0.65 ± 0.75 mm2) (p = 0.01) and 2 hours of wear (-0.81 ± 1.15 mm2) (p = 0.04), as well as in ACW at 2 hours (-0.11 ± 0.14 mm) (p = 0.02) compared to immediately after application of L1 was found.

CONCLUSION

Small changes in TIA and anterior chamber occur during two hours of SL wear, but these changes are of limited clinical relevance in healthy subjects.

Visual rehabilitation with mini scleral contact lenses in scarred corneas

PURPOSE

To present a case series of patients with corneal scars who were successfully fitted with mini scleral contact lenses (mSCL).

METHODS

Case series study.

RESULTS

Six eyes of six patients with corneal scars were fitted with mSCLs. All scars were situated in the visual axis within the scotopic pupillary zone. The sizes of the scars varied, with the smallest being confined to a central corneal area (case 5) and the largest covering the entire visual axis (case 2). In addition to compromising corneal transparency, these scars also induced significant corneal irregularities, especially in cases 1, 3, and 4. The average corrected distance visual acuity (CDVA) with spectacles was 20/80, with a range of 20/200 to 20/40. With the use of mSCLs, CDVA improved to an average of 20/25, ranging from 20/40 to 20/16. The mean visual acuity improvement observed was five optotype lines, with a range of 3 to 7 lines.

CONCLUSION

Corneas with scars often exhibit increased higher-order aberrations (HOA), and affected patients not only experience reduced vision but also suffer from seriously reduced optical quality and optical phenomena such as photophobia. Utilizing mSCLs in such individuals can significantly enhance visual acuity and improve optical side effects resulting from corneal opacity and irregularity.

Scleral Lenses for Managing Dry Eye Disease in the Absence of Corneal Irregularities: What Is the Current Evidence?

Scleral lenses (SLs) are large-diameter rigid contact lenses that are a mainstay treatment for eyes with corneal irregularities. In recent years, there has been increased interest in the role of managing dry eye disease (DED) with SLs, as many patients with DED have reported symptomatic relief with SL wear. The role of SLs for DED management when there are associated corneal irregularities is supported by individual case reports and studies. This has prompted practitioners to begin advocating using SLs in DED cases, even in the absence of associated corneal irregularities and other ocular surface diseases (OSDs). There have also been discussions on potentially placing SLs earlier in the treatment hierarchy of DED, where it currently sits at a more advanced level of intervention (Step 3) in the TFOS DEWS II Report. This review will present the currently available, albeit sparse, evidence that supports and suggests this practice, as well as ancillary evidence supporting the purported benefits of SL wear in DED. The advantages of SL wear, such as corneal healing, absence of tear evaporation and contact lens dehydration, and improved visual acuity with associated increased wear comfort, and how this will benefit DED patients will be explored. Conversely, the challenges associated with fitting SLs in DED patients, including increased midday fogging, poor wettability, and subjective patient satisfaction, will also be presented, as well as a discussion on the key considerations for SL fitting in this population. Overall, while more research is needed to support the use of SLs in DED patients without associated corneal irregularities and other forms of OSD, the use of these lenses may prove to have a potentially wider role given their reported ancillary benefits in these populations.

Influence of midday removal and re-application of a scleral lens on fluid reservoir thickness, pre-lens tear film quality and visual acuity

PURPOSE

To investigate whether the midday removal and re-application of scleral lenses (SL) influences fluid reservoir (FR) thickness, pre-lens tear film quality and visual acuity.

METHODS

Two clinical experiments were conducted. A total of 49 keratoconic eyes were evaluated for Part1(tear film and visual acuity analysis) and 12 keratoconic eyes for Part2 (FR thickness analysis). All subjects were wearing 16.4 mm SL for more than 12-months. Tear Film Surface Quality (TFSQ) was evaluated with Medmont E300 at more than 120 min of SL wear, 10 min after SL removal (pre-corneal TFSQ) and 5 min after re-apply the same SL. High and Low Contrast Visual Acuity (HCVA and LCVA) were also assessed with the SL on eye (before and after re-application). For Part2, Anterior OCT (MOptim MOcean4000, China) measurements were taken with and without the SL (at the same time points of Part1) and three outcomes were evaluated: FR thickness, SL thickness (control measurement) and corneal thickness.

RESULTS

Removing and re-applying a SL had a statistically significant positive impact on TFSQ, with an improvement from 0.26 ± 011 to 0.16 ± 0.08 (p = 0.001). This was accompanied by a statistically significant improvement in LogMAR HCVA (from 0.10 ± 0.09 to 0.08 ± 0.08, p < 0.001) and LCVA (from 0.39 ± 0.13 to 0.36 ± 0.13, p < 0.001). Regarding Part2 of the study, a statistically significant increase in FR thickness was observed after SL re-application (from 223.64 ± 48.08 µm to 267.81 ± 80.03 µm, p = 0.007). No changes in corneal thickness were observed.

CONCLUSIONS

Midday removal and re-application of a scleral lens positively impacted pre-lens tear film surface quality, although the observed improvement in visual acuity does not constitute a clinically significant change. Clinicians should consider that removing and reapplying a scleral lens may result in an overestimation of the fluid reservoir thickness, which could affect clinical assessments and treatment decisions.

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).

Clinical features, evaluation, and management of ophthalmic complications of facial paralysis: A review

The purpose of this review was to study the evaluation, diagnosis, and management of ophthalmic complications associated with facial nerve palsy and to discuss the current and future interventions. The ophthalmic complications of facial paralysis include lagophthalmos, ectropion, exposure keratopathy, ocular synkinesis, and crocodile tears. Evaluation by an ophthalmologist skilled in recognizing and managing complications of facial paralysis shortly after its initial diagnosis can help identify and prevent long-term complications. Several types of grading scales are used to evaluate, measure the severity, and track surgical and patient-reported treatment outcomes. Lagophthalmos or ectropion are managed using temporary measures aimed at lubricating and covering the eye, including scleral lenses; however, these measures can be expensive and challenging to acquire and maintain. Temporary surgical interventions include lateral tarsorrhaphy, weighted eyelid implants, lateral canthoplasty, and other procedures that tighten or lift the eyelid or surrounding tissues. Management of flaccid facial paralysis due to iatrogenic injury or neoplasm requires neurorrhaphy or graft repair. The most common techniques for dynamic reconstruction in chronic facial paralysis are regional and free muscle flap transfer. Future directions for the management of ophthalmic complications aim to induce blinking and eye closure by developing systems that can detect blinking in the normal eye and transmit the signal to the paralyzed eye using mechanisms that would stimulate the muscles to induce eyelid closure. Blink detection technology has been developed, and a study demonstrated that blinking can be stimulated using electrodes on the zygomatic branch of the facial nerve. Further studies are needed to develop a system that will automate blinking and synchronize it with that of the normal eye.

Assessment by Optical Coherence Tomography of Short-Term Changes in IOP-Related Structures Caused by Wearing Scleral Lenses

BACKGROUND

The mechanism that could increase intraocular pressure (IOP) during scleral lens (SL) wear is not fully understood, although it may be related to compression of the landing zone on structures involved in aqueous humor drainage.

METHODS

Thirty healthy subjects were fitted with two SLs of different sizes (L1 = 15.8 mm, L2 = 16.8 mm) for 2 h in the right eye and left eye as a control. Central corneal thickness (CCT), parameters of iridocorneal angle (ICA), Schlemm's canal (SC), and optic nerve head were measured before and after wearing both SLs. IOP was measured with a Perkins applanation tonometer before and after lens removal and with a transpalpebral tonometer before, during (0 h, 1 h, and 2 h), and after lens wear.

RESULTS

CCT increased after wearing L1 (8.10 ± 4.21 µm; p < 0.01) and L2 (9.17 ± 4.41 µm; p < 0.01). After L1 removal, the ICA parameters decreased significantly (p < 0.05). With L2 removal, nasal and temporal SC area and length were reduced (p < 0.05). An increased IOP with transpalpebral tonometry was observed at 2 h of wearing L1 (2.55 ± 2.04 mmHg; p < 0.01) and L2 (2.53 ± 2.22 mmHg; p < 0.01), as well as an increased IOP with Perkins applanation tonometry after wearing L1 (0.43 ± 1.07 mmHg; p = 0.02).

CONCLUSIONS

In the short term, SL resulted in a slight increase in IOP in addition to small changes in ICA and SC parameters, although it did not seem to be clinically relevant in healthy subjects.

Anatomical and physiological considerations in scleral lens wear: Intraocular pressure

Intraocular pressure (IOP) is maintained through complex and interrelated systems which control aqueous production and drainage, and it has been suggested that scleral lens (SL) wear may disrupt these vital homeostatic processes. This review provides an overview of anatomical and physiological processes that control IOP, identifies potential effects of SLs on these regulatory mechanisms, and examines studies that have attempted to quantify the effect of SLs on IOP. Lack of access to the cornea during SL wear makes accurate assessment of IOP challenging; therefore, a range of different assessment techniques and instruments have been employed to quantify IOP during and following SL wear. Some studies have evaluated IOP using standard techniques prior to lens application and following lens removal, or through a large central fenestration. Other studies have utilised instruments that facilitate assessment of IOP on the peripheral cornea or conjunctiva overlying the sclera (e.g. Schiotz, transpalpebral, and pneumatonometry). Two studies have recently evaluated changes in optic nerve structure during SL wear. Conflicting results have been reported on this topic, much of which examines changes in IOP in healthy subjects over limited periods of time. Currently, only a few studies have reported on long-term effects of SL wear on IOP in habitual SL wearers (after lens removal). Future research in this area must not only consider the fact that ocular conditions treated with SLs may potentially alter corneal biomechanical properties which can influence IOP, but also that these properties may be further altered by SL wear. Monitoring other risk factors for glaucoma (permanent alterations in optic nerve physiology, visual field defects) could provide a more comprehensive assessment of potentially increased risk of glaucomatous optic neuropathy due to SL wear. Ongoing clinical assessment of optic nerve structure and function is advisable in patients at risk for glaucoma who require SLs.

What we know about the scleral profile and its impact on contact lens fitting

Scleral contact lens fitting has provided practitioners with one of the earliest pieces of evidence that the sclera was more often asymmetric than symmetric. Some preliminary observations such as different haptic alignment patterns over the sclera in 360 degrees, the appearance of fogging in the fluid chamber and excessive tear out-in flow through specific meridians, quadrants, or areas of the haptic provide evidence of some scleral asymmetry. The advent of technologies that allowed measurement of the scleral profile led to formal research confirming that only about 6% of scleras are symmetric, while the rest are toric, quad-specific, or irregular. This has an evident impact on how to focus scleral lens fitting. Measuring the scleral profile also provided us with true ocular sagittal height data for cord diameters beyond the cornea. Although high variability was expected in pathological eyes, healthy eyes also showed a wide range of ocular sagittal heights. Due to this variability among healthy eyes, a discussion has emerged on whether the one-size-fits-all approach to soft lens fitting is a proper strategy to fit the whole spectrum of sagittal heights. The traditional mode of selecting the parameters for custom soft lenses through corneal parameters is also questioned.

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.

IOP and Optic Nerve Head Morphology during Scleral Lens Wear

SIGNIFICANCE

Scleral lenses (SLs) are increasing in scope, and understanding their ocular health impact is imperative. The unique fit of an SL raises concern that the landing zone causes compression of conjunctival tissue that can lead to resistance of aqueous humor outflow and increased intraocular pressure (IOP).

PURPOSE

This study aimed to assess changes in optic nerve head morphology as an indirect assessment of IOP and evaluate other IOP assessment methods during SL wear.

METHODS

Twenty-six healthy adults wore SL on one randomly selected eye for 6 hours, whereas the fellow eye served as a control. Global minimum rim width (optical coherence tomography) and IOP (Icare, Diaton) were measured at baseline, 2 and 6 hours after SL application, and again after SL removal. Central corneal thickness, anterior chamber depth, and fluid reservoir depth were monitored.

RESULTS

Minimum rim width thinning was observed in the test (-8 μm; 95% confidence interval [CI], -11 to -6 μm) and control (-6 μm; 95% CI, -9 to -3 μm) eyes after 6 hours of SL wear (P < .01), although the magnitude of thinning was not significantly greater in the lens-wearing eyes (P = .09). Mean IOP (Icare) significantly increased +2 mmHg (95% CI, +1 to +3 mmHg) in the test eyes (P = .002), with no change in the control eyes. Mean IOP changes with Diaton were +0.3 mmHg (95% CI, -0.9 to +3.2 mmHg) in the test eyes and +0.4 mmHg (95% CI, -0.8 to +1.7 mmHg) in the control eyes. However, Diaton tonometry showed poor within-subject variation and poor correlation with Icare. No clinically significant changes were observed in central corneal thickness or anterior chamber depth.

CONCLUSIONS

This study suggests that SLs have a minimal effect on IOP homeostasis in the normal eye during SL wear and an insignificant impact on the optic nerve head morphology in healthy adult eyes.

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.

Microbiological Evaluation of Opened Saline Bottles for Scleral Lens Use and Hygiene Habits of Scleral Lens Patients

SIGNIFICANCE

Scleral lenses have become a widely used treatment option for patients with irregular corneas and ocular surface disease. Successful wear entails use of a nonpreserved saline solution to fill the lens before application on the eye.

PURPOSE

The purposes of this study were to evaluate solution from opened bottles of multidose preservative-free saline for microbiological growth and to better understand study participant hygiene habits while handling these bottles for scleral lens wear.

METHODS

Eligible study participants in this single-center prospective study were patients who routinely used multidose preservative-free saline solution for scleral lens rinsing and filling. Study participants completed a 12-question survey regarding their scleral lens hygiene habits and donated their opened multidose preservative-free saline bottle (PuriLens Plus; The Lifestyle Company, Inc., Freehold, NJ), which was processed for bacterial and fungal cultures.

RESULTS

Thirty-five participants (19 males, 16 females) with ages ranging from 6 to 81 years (mean, 47.9 years) were included. Indications for scleral lens wear included those with irregular corneas and ocular surface disease. The overall rate of microbial contamination among saline samples was 62.9% (n = 22). Twenty-one different microorganisms were identified. The survey responses did not differ significantly (P > .05) for any of the questions with regard to likelihood of positive culture. There were no significant age or sex differences between participants with positive or negative culture results. No significant differences were found between isolation of specific microorganisms and any of the survey responses.

CONCLUSIONS

This study suggests that off-label multidose preservative-free saline commonly used to rinse and fill scleral lenses before application on the eye may become contaminated with microorganisms once the bottle has been opened. Eye care practitioners and scleral lens patients should be aware of these potential contaminations and prioritize lens, hand, and environmental hygiene to minimize the risk of ocular complications.

Large diameter scleral lens benefits for Asians with intractable ocular surface diseases: a prospective, single-arm clinical trial

To report the efficacy and safety of large diameter scleral lenses and determine their suitability in Asian subjects with intractable ocular surface diseases. This prospective study enrolled intractable ocular surface diseases subjects with uncorrected visual acuity > counting finger but ≥ 0.3 logMAR and best-corrected visual acuity (BCVA) ≥ 0.3 logMAR, to fit large diameter scleral lenses for 12 weeks. 21 eyes (13 subjects) consisting ten eyes (47.6%) with persistent epithelial defects, 6 (28.6%) with graft-versus-host disease, 4 (19.0%) with Stevens-Johnson syndrome and one (4.8%) with severe dry eye were ultimately enrolled. Primary outcome measures were the visual acuity, corneal and conjunctival fluorescein staining, Ocular Surface Disease Index (OSDI), and National Eye Institute 25-Item Visual Function Questionnaire (NEI-VFQ-25). At week 12 with large diameter scleral lenses, BCVA improved from 0.77 logMAR to 0.27 logMAR (P < 0.001). High-grade corneal and conjunctival fluorescein staining proportion decreased from 61.90 to 14.29% and 52.38 to 9.52%, respectively (P = 0.0036 and 0.0063, respectively). OSDI and NEI-VFQ-25 improved from 67.89 to 34.69 and 51.40 to 64.48, respectively (P < 0.001). No adverse effects were observed. In Asians with intractable ocular surface diseases, large diameter scleral lens improves visual acuity and alleviates signs and symptoms of ocular surface diseases without any significant complications.Trial registration Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (Project No. HI12C0015 (A120018)). Clinical Trials.gov, NCT04535388. Registered 18 August 2020-Retrospectively registered, http://clinicaltrials.gov/ct2/show/NCT04535388 .

[Intraocular pressure with miniscleral contact lenses]

According to literature data, some experts do not exclude the possibility that scleral lens wear could influence intraocular pressure.

PURPOSE

To evaluate the influence of rigid gas permeable miniscleral contact lenses on intraocular pressure (IOP), keratometry readings and corneal thickness, and to study the correlation between scleral (IOPs) and corneal (IOPc) intraocular pressure using the Icare ic100 tonometer (model TAO11, Icare Finland Oy).

MATERIAL AND METHODS

The study included 99 volunteers without history of ocular diseases. The first group consisted of 66 participants (122 eyes) aged 22.3±2.2 years - IOPc and IOPs were measured by the Icare ic100 tonometer in order to determine the correlation. The second group (33 participants, aged 22.7±1.7 years) - day 1, diurnal IOPc and IOPs fluctuations were measured; on day 2, a miniscleral lens (diameter 14.9 mm) was placed on the study eye and was worn for 6 hours, the paired eye served as control. IOP was measured before, after lens placement, after 2 hours of lens wear, and before and after lens removal. Corneal topography was evaluated before and after lens removal.

RESULTS

In the first group, there was a weak but significant correlation between IOPc and IOPs (Spearman correlation coefficient 0.285, p=0.001). In the second group, IOPc in the study eye before lens placement (14.8±3.8 mm Hg) and IOPc after its removal (13.6±3.9 mm Hg) were not different from those in the control eye. There were also no statistically significant changes in IOPs before, during lens wear, and after lens removal. The central corneal thickness increased by 2.9% (p<0.001) after 6 hours of lens wear.

CONCLUSION

In young individuals without history of ocular diseases, wearing the miniscleral lens for 6 hours does not have significant influence on IOP and does not cause clinically significant corneal edema.

Case Report: Use of Prosthetic Replacement of the Ocular Surface Ecosystem Treatment of Traumatic Lid Ptosis in a Pediatric Patient

SIGNIFICANCE

This report shares the long-term outcomes of an uncommon use of prosthetic replacement of the ocular surface ecosystem (PROSE) treatment and scleral lenses in the treatment for patients with ptosis who are not surgical candidates.

PURPOSE

This study aimed to describe a case of pediatric traumatic lid ptosis and follow-up during an 8-year period with PROSE treatment.

CASE REPORT

A 7-year-old Honduran girl presented with a history of severe cranial, facial, and ocular trauma as a result of a motor vehicle accident. Significant ptosis with left-sided facial paralysis and irregular astigmatism significantly reduced the patient's visual function in the left eye. She was evaluated and treated with a scleral prosthetic device in the left eye to improve vision, the ocular surface, and overall function for activities of daily living. After 8 years of PROSE treatment, acuity in the left eye remained stable at 20/25. The corneal health remained stable throughout this period, without complications of corneal neovascularization or corneal edema.

CONCLUSIONS

Prosthetic replacement of the ocular surface ecosystem treatment provided support of the ocular surface and mechanical left upper eyelid lift in a traumatic eyelid ptosis, ultimately providing improved visual function during an extensive 8-year period in a pediatric patient. Further studies are needed to evaluate the applicability of this approach in broader ptosis cases.

Indications for Wear, Visual Outcomes, and Complications of Custom Imprint 3D Scanned Scleral Contact Lens Use

PURPOSE

To report indications for wear, visual outcomes, and complications of EyePrintPRO (EPP) scleral contact lens (SCL) use.

METHODS

A retrospective review identified all patients fitted with this device between December 2013 and March 2018. Baseline demographics, wear indication, and contact lens history were determined. Habitual-corrected visual acuity was measured at baseline and follow-up. Adverse wear symptoms and signs, reprinting, and device cessation were tracked.

RESULTS

Ninety-five eyes from 69 patients were followed for a median of 12.1 months (interquartile range 4.4-19.6). Indications for wear included vision improvement and/or ocular surface stabilization in the setting of irregular corneal shape (n = 68 eyes, 72%), ocular surface disease (n = 17, 18%), exposure keratopathy (n = 7, 7%), neurotrophic keratitis (n = 5, 5%), and extracorneal topographical abnormalities preventing noncustom lens fitting such as glaucoma drainage devices (n = 8, 8%). Median habitual-corrected visual acuity improved from 0.67 to 0.08 (P = 0.0003). One-third of eyes (33.1%) developed adverse wear symptoms. Fifteen of 95 eyes (16%) developed adverse wear signs. Device cessation occurred in 10 eyes (10.5%) and reprinting occurred in 14 eyes (14.7%) unrelated to prior lens wear or indication (P = 0.67 and 0.15, respectively). In eyes that previously failed SCLs (n = 56), 12 eyes required reprinting and 49 eyes continued use.

CONCLUSIONS

Indications for EPP wear include irregular corneal shape, ocular surface disease, and extracorneal topographic abnormalities. Visual acuity improves with the use of EPP. Clinicians and patients should be aware of potential adverse wear symptoms/signs and device cessation that may occur with EPP use. EPP is a viable salvage therapy in eyes that previously failed SCLs.

[Modern options for non-surgical correction of keratoconus]

The article reviews data on the so called non-surgical methods of keratoconus (KC) correction. The combined approach to KC treatment entails three main tasks: prevention of progression, optical correction of induced refractive disorders, and structural repair. Measures taken to accomplish the first two tasks should be regarded as symptomatic treatment, while addressing the last task requires pathogenetically oriented solutions. Corneal cross-linking and optical correction of refractive disorders with rigid gas permeable (RGP) scleral contact lenses should be regarded as the first choice for symptomatic non-surgical correction of keratoconus.

Safety and Efficacy of Scleral Lenses for Keratoconus

SIGNIFICANCE

This study affirms the long-term safety and efficacy of scleral contact lens use in patients with keratoconus.

PURPOSE

This study aimed to evaluate the safety and efficacy of contemporary scleral contact lenses in the visual rehabilitation of the keratoconic population.

METHODS

A retrospective study of keratoconic subjects examined between 2013 and 2018 was conducted. Subjects were included regardless of age, sex, pre-existing morbidity, or scleral lens design. Only eyes fit successfully with scleral contact lenses for ≥1 year were included. Exclusion criteria were prior corneal surgery, dystrophy, degeneration, and trauma.

RESULTS

A total of 157 eyes of 86 subjects met the study criteria. The mean Keratoconus Severity Score at initial fitting was 3.6 ± 1.0. Lenses were gas-permeable and nonfenestrated, with a mean overall diameter of 15.8 ± 0.6 mm and 70.1% toric scleral periphery. Physiological adverse events occurred in 9.6% of eyes, including microbial keratitis (0.6%), phlyctenulosis (0.6%), corneal abrasion (1.3%), contact lens–induced acute red eye (1.3%), corneal infiltrative events (1.3%), pingueculitis (1.3%), and hydrops (3.2%). Lens-related adverse events were documented in 55.4% of eyes. Adverse events related to surface issues included poor wetting in 1.9%, handling in 3.8%, reservoir fogging in 7.0%, lens intolerance in 7.6%, deposit in 8.9%, and broken lenses in 26.1% of eyes. The most common management strategies involved refits (54.0% of interventions), patient reeducation (29.5%), medical treatment (5.5%), surgical referral (6.8%), adjustment to wear time (2.5%), surface treatment (1.2%), and lens replacement (0.6%). Best-corrected distance logMAR visual acuity improved significantly from a mean of 0.50 in spectacles to a mean of 0.08 in scleral lenses (P < .0001). During the study period, 14.6% of eyes lost best-corrected scleral lens visual acuity, all from keratoconus progression.

CONCLUSIONS

Consistent with other groups, our study demonstrates excellent safety and efficacy of scleral contact lenses in subjects with keratoconus.

Anatomical and physiological considerations in scleral lens wear: Conjunctiva and sclera

While scleral lenses have been fitted using diagnostic lenses or impression moulding techniques for over a century, recent advances in anterior segment imaging such as optical coherence tomography and corneo-scleral profilometry have significantly improved the current understanding of the anatomy of the anterior eye including the morphometry of the conjunctiva, sclera, and corneo-scleral junction, as well as the ocular surface shape and elevation. These technological advances in ocular imaging along with continual improvements and innovations in scleral lens design and manufacturing have led to a global increase in scleral lens prescribing. This review provides a comprehensive overview of the conjunctiva and sclera in the context of modern scleral lens practice, including anatomical variations in healthy and diseased eyes, the physiological impact of scleral lens wear, potential fitting challenges, and current approaches to lens modifications in order to minimise lens-induced complications and adverse ocular effects. Specific topics requiring further research are also discussed.

Scleral lens wear: Measuring inflammation in the fluid reservoir

PURPOSE

To measure inflammatory mediators in the scleral lens fluid reservoir (FR) in healthy eyes and to compare them to basal tear samples after 8-hs (8h) and 4-days (4d) of scleral lens (SL) wear.

METHODS

Fifteen normal, habitual soft contact lens wearers were fitted with 14.8- or 15.4-mm SLs (Zenlens, Alden Optical, USA). Basal ocular surface tears and FR samples were collected after 8h and 4d of daily SL wear. Levels of interleukin (IL) -4 and -8, matrix metalloproteinase (MMP)-7, -9, and -10, and tissue inhibitor of MMPs (TIMPs) 1-4 were measured in all samples using Luminex assays. Visual acuity, corneal and conjunctival staining, and comfort assessments were completed at the baseline, 8h and 4d time points.

RESULTS

MMP-9 and MMP-10 were greater in FR than basal ocular surface tears. After 8h of SL wear, the median concentration of MMP-9 in the FR and basal tears were 62.7 and 15.2 ng/mL, respectively (p = 0.047). Likewise, MMP-10 was significantly greater in FR compared to basal tears, after 8h (25.8 ng/mL vs 2.8 ng/mL, p < 0.001) and 4d (2.1 ng/mL vs17.2 ng/mL, p = 0.047). IL-4 and IL-8 levels were greater in FR but not significantly at 8h (2.2 vs 3.1 ng/mL; and 0.1 vs 0.4 ng/mL, respectively) or 4d (0.9 vs 3.5 ng/mL; 0.0 vs 0.2 ng/mL). MMP-7 was not affected by SL wear after 8h (46.0 basal vs 54.4 ng/mL FR) or 4d (34.2 vs 87.5 ng/mL). Visual acuity, corneal and conjunctival staining did not change; comfort was reduced in SL compared to soft contact lens wear.

CONCLUSIONS

This is the first study to compare the FR with the basal ocular surface tears. MMP-9 and MMP-10 were elevated in the FR after several hours of SL wear, suggesting potential clinical implications of SL wear and deserves further investigation.