Therapeutic uses of scleral contact lenses for ocular surface disease: patient selection and special considerations

Rehabilitation Following Penetrating Ocular Trauma From Hand Grenade Fragments

This case study describes the rehabilitation efforts of a 25-year-old male reserve officer who sustained a penetrating intraocular metallic foreign body (IOFB) injury to his right eye during a military conflict. Penetrating ocular trauma can lead to severe tissue deformities, scarring, permanent visual impairment, and long-term complications like intraocular infection and ocular hypotension. The patient's initial presentation revealed vision loss, pain, irritation, a foreign body sensation, and discomfort in the right eye. Diagnostic imaging confirmed a severe globe rupture, including the presence of metallic IOFB in the retina, retinal incarceration, and detachment with severe macular damage, necessitating surgical intervention, including repair of globe rupture, lensectomy, pars plana vitrectomy, IOFB removal, and filling of the vitreous cavity with silicone oil. Despite these surgical measures, visual acuity in the right eye remained hand motion at 15 cm with maintained peripheral vision and traumatic ptosis. A specialized scleral contact lens was fitted. This improved acuity to 6/60 additionally provided a magnifying effect, clinically improving near vision acuity to 6/30. The scleral lens improved the patient's dry eye indices, evidenced by decreased corneal staining and increased margin-to-reflex distance, improving esthetics. This case highlights the potential benefits of a scleral contact lens after severe penetrating eye injuries where even advanced surgical interventions may not fully restore vision. It significantly improved visual function and comfort by alleviating dry eye symptoms and simultaneously provided psychosocial benefits by masking cosmetic imperfections.

Overview of Dry Eye Disease for Primary Care Physicians

Dry eye disease (DED), also known as keratoconjunctivitis sicca, is a multifactorial ocular disease characterized by tear film insufficiency due to diverse etiologies including aging, incomplete and infrequent blinking, hormonal changes, medications, and systemic diseases. Classified into aqueous-deficient dry eye (ADDE), evaporative dry eye (EDE), and mixed subtypes, DED presents with symptoms such as irritation, stinging, redness, foreign body sensation, sensitivity to light, and blurred or fluctuating vision. While rare, severe cases may lead to vision loss. With its rising global prevalence across age groups, DED poses a significant public health challenge. Primary care physicians (PCPs), often the first point of contact for DED patients, require timely screening and management strategies. This review explores the epidemiology, pathophysiology, clinical manifestations, diagnosis, and management of DED, emphasizing practical approaches for PCPs. This narrative review was conducted by searching MEDLINE, PubMed, and Google Scholar databases for relevant articles. Diagnostic approaches, including detailed history taking, patient-reported questionnaires, differential diagnosis, and assessments are discussed alongside management strategies, including symptomatic ophthalmic treatment, risk factor mitigation (e.g., reduced digital device screen time), prevention, and nutrition. By providing a synopsis of early symptoms that PCPs are often the first to encounter, practical approaches to screening and managing DED in the primary care setting, and guidelines on when to refer to specialty care, this comprehensive review aims to equip PCPs with the knowledge to improve DED screening and optimize patient outcomes.

Variation of Bruch's membrane opening in response to intraocular pressure change during scleral lens wear, in a population with keratoconus

PURPOSE

The present study aimed to determine the potential impact of scleral lenses on intraocular pressure (IOP) by analysing the Bruch's membrane opening-minimum rim width (BMO-MRW) while the lenses are worn, in a population with keratoconus.

METHODS

Participants were required to have keratoconus and be successfully fitted with scleral lenses for at least 3 months. A new pair of optimised scleral lenses was provided before the study. During the first session, corneal biomechanics was assessed using an air tonometer, coupling Scheimpflug technology. Then, a scan of the optic nerve was carried out using optical coherence tomography (OCT) at 2 h intervals for 6 h. Particular attention was paid to identifying the BMO-MRW, which represents the smallest distance between the BMO and the internal limiting membrane. These tests were repeated, respecting the time at which the initial measurements were taken, while the scleral lens was worn. Results from only one eye were analysed.

RESULTS

A statistically significant change of 10.5 ± 3.6 μm (95% CI [241.3-473.1]; p = 0.02) in BMO-MRW was observed after 6 h of scleral lens wear, compared to measurements without lenses (4.8 ± 3.4 μm; 95% CI [285.1-439.7]; p = 0.18). The fluctuation was greater in participants with keratoconus than found in a previous study of regular corneas.

CONCLUSION

BMO-MRW became significantly thinner after 6 h of scleral lens wear compared with measurements without lenses. These variations may be associated with a rise in IOP during lens wear. Close monitoring for optic head changes should be carried out for patients at risk. These results should be compared with future longer-term studies including a larger cohort of patients.

Bibliometric and Visual Analysis of the Status of Scleral Lens Research Based on the Web of Science Database and Scopus Database (2014-2024)

Objective

To examine the current status of research, identify key areas of interest, and explore emerging frontiers in the field of scleral lenses (SL) with the goal of informing and advancing further research in this field.

Methods

Bibliometric methods were utilized to retrieve SL-related literature published in the Web of Science and Scopus database from 2014 to 2024. Elements such as authors, country/region, institution, journal, and keywords were analyzed using CiteSpace information visualization and analysis software and Bibliometrix R package.

Results

A total of 506 articles were included. Among 117 countries/regions, the United States ranked first in the number of publications, followed by Spain and Australia. The distribution of research institutions showed that the Queensland University of Technology had the largest number of publications. Prof. Schornack, MM from Mayo Clinic had the highest number of articles. The research literature on SLwas published in 184 journals, of which Contact Lens & Anterior Eye and Eye & Contact Lens: Science and Clinical Practice were the most influential. Keyword clustering mainly included corneal topography, dry eye, limbal stem cell deficiency, ocular surface disease.

Conclusion

SL has emerged as a prominent area of investigation in the field of ophthalmology. In this study, the research field of SL from 2014 to 2024 was visualized and analyzed, providing a visualization of the development status of SL and revealing the trends and cutting-edge hotspots of SL-related research. SL exhibits a broad spectrum of applications and demonstrates considerable potential for enhancing both visual acuity and overall quality of life in patients afflicted with diverse ocular conditions. This study offers a comprehensive overview of current state of knowledge and understanding on SL for researchers and clinicians.

Ocular manifestations of juvenile Sjögren's disease

PURPOSE OF REVIEW

This review aims to enhance understanding of juvenile Sjögren's disease (jSjD) by exploring diagnostic criteria, ocular clinical features, ancillary ophthalmic testing, and management strategies specific to this rare pediatric condition.

RECENT FINDINGS

Unlike adults, children with jSjD often present with recurrent parotitis and extra-glandular symptoms before developing sicca symptoms. Adult SjD classification criteria do not consider pediatric-specific symptoms and physiological differences. Underutilization of diagnostic tests such as the ocular staining score (OSS) and Schirmer I may result in an incomplete understanding of the prevalence of keratoconjunctivitis sicca in jSjD.

SUMMARY

Timely referral to an ophthalmologist can address perceived feasibility issues with respect to ocular features in jSjD. Management of keratoconjunctivitis sicca in jSjD includes improving ocular surface lubrication and decreasing inflammation. Recognition of pediatric-specific clinical features and development of universally accepted jSjD classification criteria will allow for better identification of potential participants for future jSjD studies.

Settling characteristics of scleral lenses in Chinese adults with refractive error

PURPOSE

To investigate the settling characteristics of a scleral lens in Chinese adults with refractive error and to provide guidance for its clinical application.

METHODS

A total of 21 healthy Chinese adults (27.2 ± 4.1 years) with refractive error were enrolled in this study. The average spherical equivalent was -5.50 ± 2.92 D. Subjects were fitted with 15.6 mm diameter scleral lenses. The central post-lens tear thickness (PoLTT) was measured immediately after lens placement, 30, 60, 120, and 240 min after lens insertion at the dispensing visit and immediately after lens placement and 240 min after three months through optical coherence tomography. Statistical analyses were conducted using repeated measures analysis of variance and paired-t test.

RESULTS

At the dispensing visit, the amount of settling after 240 min of lens wear was 126 ± 33 μm. After three months, the amount of settling was 98 ± 55 μm after 240 min. No significant difference was detected in the PoLTT immediately after lens placement between the dispensing visit and after three months (t = -0.246, p = 0.807), while a significant difference was noted at 240 min after lens insertion (t = -6.575, p < 0.001). The amount of settling was higher at the dispensing visit than that after three months (average difference = 28 ± 63 μm, t = 2.733, p = 0.01). The prediction model of PoLTT over time was y = 26.263-0.690 × t + 0.001 × t2 + 0.926 × y30 (R2 = 0.939), where y denotes the predicted PoLTT at t min after lens insertion, y30 denotes the PoLTT at 30 min after lens insertion.

CONCLUSION

For the investigated small-diameter scleral lens (material: Boston XO, diameter: 15.6 mm, four-zone and periphery toric design), the PoLTT decreased over time after lens insertion in Chinese adults with refractive error, and the amount of settling varied among individuals (range: 71-204 μm). The amount of settling did not increase further after three months, indicating the long-term fitting stability of the scleral lens. Practitioners could estimate the PoLTT using the prediction model based on the PoLTT at 30 min after wearing lenses.

Corneal blindness in the developing world: The role of prevention strategies

Corneal blindness is an important contributor to the burden of global blindness and has a greater prevalence in low-income countries of the developing world where resources and infrastructure are limited. The causes of corneal blindness too are different from high-income countries and include infectious keratitis, ocular trauma, and xerophthalmia. Persons with these indications tend to have unfavourable outcomes after corneal transplantation, limiting their chances of benefitting from this sight-saving procedure. However, most causes of corneal blindness in the developing world are preventable. This highlights the importance of understanding the unique challenges in these regions and the need for targeted interventions. This article discusses various prevention strategies, including primordial, primary, and secondary prevention, aimed at reducing the burden of corneal blindness in low-income countries. These include capacity building, training, and awareness campaigns to reduce the risk factors of ocular trauma, infectious keratitis, and to improve access to first aid. It is also important to promote safe eye practices and tackle nutritional deficiencies through public health interventions and policy changes. Providing the required training to general ophthalmologists in the management of basic corneal surgeries and diseases and enhancing the accessibility of eye care services in rural areas will ensure early treatment and prevent sequelae. Current treatment modalities belong to the tertiary level of prevention and are largely limited to corneal transplantation. In developing nations, there is a scarcity of donor corneal tissue necessitating an urgent expansion of eye banking services. Alternative approaches to corneal transplantation such as 3D printed corneas, cultured stem cells, and biomaterials should also be explored to meet this demand. Thus, there is a need for collaborative efforts between healthcare professionals, policymakers, and communities to implement effective prevention strategies and reduce the prevalence of corneal blindness in the developing world.

Patient Experiences With Therapeutic Contact Lenses and Dry Eye Disease

OBJECTIVES

To report patient-reported experiences with dry eye disease and therapeutic contact lenses.

METHODS

A survey was distributed to patients with dry eye disease. Demographics, Ocular Surface Disease Index (OSDI), systemic disease, contact lens history, and burden of care information were collected. Descriptive statistics are presented and categorized by nonlens, soft lens, and scleral lens (SL) wearers.

RESULTS

Of 639 respondents, 15% (94/639) were currently using therapeutic soft or SLs (47 soft and 69 SL). Mid-day fogging or clouding of vision was reported by SL (75%, 50/67) and soft lens (62%, 29/47) wearers. Seventy-two percent of SL wearers spent more than 20 min daily on dry eye treatment while 43% of soft lens wearers spent more than 20 min. Median annual expenditure was higher for SL ($1,500, n=63) than nonlens ($500, n=371) or soft lens wearers ($700, n=43). Mean OSDI scores in all groups were in the severe category (51±22 years, n=401 nonlens wearers; mean age; 45±22 years, n=47 soft lens wearers; 60±24 years, n=69 SL wearers).

CONCLUSIONS

Mid-day fogging and blurring of vision was reported by most of the individuals using therapeutic lenses for dry eye disease. SL wearers allocate the most resources for dry eye care.

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).

Ocular Surface Homeostasis After Scleral Lens Usage

OBJECTIVES

The aim of this prospective study is to examine the effects of 5 hours of well-fitted, mini-scleral contact lens (mini-SL) wear on the tear film cytokine expression in healthy eyes.

METHODS

Twenty-three healthy participants were included in the study. One eye of each participant was selected at random, and a mini-SL measuring 16.5 mm in diameter was fitted by an experienced contact lens specialist. The contact lens remained in place for 5 hours. Precorneal tear fluid was collected using capillary tubes at three different time points: baseline before SL insertion (T0), after 5 hours of SL wear (T1), and 3 hours after SL removal (T2). The concentration of 40 inflammatory cytokines at the three different time points was determined using multiplex bead assay.

RESULTS

Mini-scleral lens wear did not result in significant changes in the cytokine-to-protein ratio after 5 hours of wear on a healthy eye.

CONCLUSIONS

Although a well-fitted mini-SL reduces the rate at which the precorneal tear film is refreshed, 5 hours of lens wear did not appear to significantly affect the tears cytokine-to-protein ratio, suggesting that scleral lenses have minimal impact on corneal cytokine expression.

Average Scleral Lens Replacement Period at a Tertiary Care Hospital

OBJECTIVE

To evaluate the average scleral lens replacement period at a tertiary care hospital.

METHODS

Patients were identified retrospectively through electronic medical records. Inclusion criteria included scleral lens patients treated at the USC Department of Ophthalmology who had reordered a scleral lens at least once in one eye. Lens order histories were evaluated, and statistical analysis included a multivariable, mixed-methods, linear, regression model.

RESULTS

Two hundred fifty-one patients (120 men and 131 women; average age 57.1±17.4 years, range 9-93 years) and a total of 445 eyes (227 OD, 218 OS; 199 irregular corneas, 246 ocular surface disease) were included. The average replacement period for a scleral lens was 23.9±14.3 months (range 5-2,617 days). Patients with greater scleral lens experience had a statistically significant increase in their average scleral lens replacement period; for every one year of additional experience wearing scleral lenses, average replacement period increased by 30.7 days ( P =0.001). There was no statistically significant correlation between average scleral lens replacement period and sex, diagnosis, prior outside scleral lens treatment, lens brand, or lens diameter.

CONCLUSION

The average scleral lens replacement period in this patient cohort at a tertiary care hospital was 23.9±14.3 months (1.99±1.19 years). Further studies are needed to better understand the impact of scleral lens age on ocular health and vision. Certainly, proper scleral lens training and education are essential to ensure optimal lens condition and treatment outcomes.

Treatment and Management of Ectrodactyly-Ectodermal Dysplasia-Clefting Syndrome With Scleral Prosthetic Devices

ABSTRACT

This case report highlights the unique application and long-term benefits of customized scleral devices in a patient with ocular complications from ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome over the span of 10 years. A 13-year-old girl with a history of EEC syndrome and ocular manifestations, including severe bilateral dry eye disease, corneal neovascularization and scarring, progressive fibrous pannus, and limbal stem cell deficiency, was examined and fitted with scleral devices. The goal of treatment was to stabilize the ocular surface, enhance vision, and improve ocular comfort. Throughout the course of treatment, there was minimal progression in ocular signs, despite interruptions in scleral device wear from application and removal challenges secondary to ectrodactyly. Customized scleral devices provided an optimal environment to support the ocular surface, improve comfort, and improve visual acuity. Further studies are required to demonstrate the benefits of scleral devices in larger populations of patients with EEC syndrome.

Prescription Habits of Scleral Lenses for the Management of Corneal Irregularity and Ocular Surface Disease Among Scleral Lens Practitioners

OBJECTIVES

To describe prescribing patterns of therapeutic scleral lenses (SLs) in the management of corneal irregularity and ocular surface disease among practitioners who prescribe SLs.

METHODS

Participants ranked treatment options for corneal irregularity and ocular surface disease in the order they would generally consider using them in an electronic survey. Median rank score for each option is reported, along with the percentage of participants assigning first place ranking to each option. The percentage of participants assigning first, second, or third place ranking to each option is also reported.

RESULTS

Seven hundred and seventy-eight practitioners participated. Scleral lenses are most frequently considered as the first choice for the management of corneal irregularity based on overall median rank, followed by corneal rigid lenses (rigid gas-permeable [RGPs]). Scleral lenses were the first choice of 42% of participants, followed by RGPs (20%). For ocular surface disease, lubricant drops are most frequently used first, followed by meibomian gland expression, topical cyclosporine or lifitegrast, topical steroids, punctal plugs, and SLs, respectively. Lubricant drops were the first therapeutic option considered for ocular surface disease by 63% of participants and 45% ranked SLs as their sixth, seventh or eighth treatment based on median overall rank.

CONCLUSIONS

Scleral lenses were identified as the first option for management of corneal irregularity more frequently than RGPs. Scleral lenses are considered for management of ocular surface disease before surgical intervention but after meibomian gland expression, punctal occlusion, and topical medical therapy are attempted.

Investigating the role of inflammation in keratoconus: A retrospective analysis of 551 eyes

PURPOSE

Keratoconus (KCN), classically defined as a noninflammatory corneal ectasia, was recently associated with chronic inflammation. This study aimed to further evaluate the association between inflammation and KCN severity by assessing patient tear films.

METHODS

Retrospective chart review of consecutive patients (July 2016-February 2020) referred to a tertiary KCN centre. Using tomography Kmax values, the worst-eyes of patients with a diagnosis of KCN and tear film test results were included. Eyes were stratified as matrix metalloproteinase-9 (MMP9) positive or negative and analyzed using independent t and Pearson chi-squared tests. A p-value ≤ 0.05 was considered significant.

RESULTS

551 (51.40%) unilateral eyes were included. Mean age was 30.1 years and 70.1% were male. 55.5% of the eyes were MMP9 positive. Mean corrected distance visual acuity was 20/30<συπ>-3 Snellen and Kmax was 60.1 Diopters. MMP9 positive eyes had a higher Kmax (p = 0.048), and were more likely from patients who were male (p < 0.001), had a paediatric history of asthma (p = 0.042), and used glasses (p = 0.041). MMP9 negative eyes more likely corresponded to soft contact lens users (p = 0.012). No other significant differences were found in risk factors, topography, tomography, and tear film osmolarity.

CONCLUSION

MMP9 positive keratoconic eyes had significantly higher Kmax readings which may correlate with increased disease severity, supporting an association between keratoconus and inflammation. Further research is warranted to evaluate the role of targeted therapy and contact lens use on MMP9 levels in keratoconic eyes and whether disease progression is affected.

Limbal-Rigid Contact Lens Wear for the Treatment of Ocular Surface Disorders: A Review

ABSTRACT

Recently, the prescription of large-diameter rigid gas-permeable contact lenses (CLs), also known as "scleral lenses," "corneoscleral lenses," and "limbal-rigid CLs," is on the rise for the treatment of both moderate and severe ocular surface disorders (OSDs). Compared with scleral lenses, the diameter of limbal-rigid CLs is generally smaller, that is, a diameter ranging from 13.0 to 14.0 mm, and they are designed so that the peripheral edge bears on the limbus. The Suncon Kyoto-CS (Sun Contact Lens Co., Ltd.) is a novel limbal-rigid CL design with multistep curves on the peripheral edge for easy tear exchange during blinking that removes debris and prevents lens clouding or fogging, thus allowing patients to enjoy a longer daily duration of CL wear. In severe OSD cases, limbal-rigid CL wear after surgery is a noninvasive therapeutic approach that can neutralize corneal irregularities, decrease dry eye symptoms, prevent the progression or recurrence of symblepharon, and improve the patient's visual acuity and overall quality of life. Thus, surgeries such as amniotic membrane transplantation and cultivated oral mucosal epithelial transplantation, as well as limbal-rigid CL wear, which is noninvasive, are valuable and effective treatment strategies that can now be applied for the management of patients afflicted with severe OSDs.

A Review of the Diagnosis and Treatment of Limbal Stem Cell Deficiency

Limbal stem cell deficiency (LSCD) can cause significant corneal vascularization and scarring and often results in serious visual morbidity. An early and accurate diagnosis can help prevent the same with a timely and appropriate intervention. This review aims to provide an understanding of the different diagnostic tools and presents an algorithmic approach to the management based on a comprehensive clinical examination. Although the diagnosis of LSCD usually relies on the clinical findings, they can be subjective and non-specific. In such cases, using an investigative modality offers an objective method of confirming the diagnosis. Several diagnostic tools have been described in literature, each having its own advantages and limitations. Impression cytology and in vivo confocal microscopy (IVCM) aid in the diagnosis of LSCD by detecting the presence of goblet cells. With immunohistochemistry, impression cytology can help in confirming the corneal or conjunctival source of epithelium. Both IVCM and anterior segment optical coherence tomography can help supplement the diagnosis of LSCD by characterizing the corneal and limbal epithelial changes. Once the diagnosis is established, one of various surgical techniques can be adopted for the treatment of LSCD. These surgeries aim to provide a new source of corneal epithelial stem cells and help in restoring the stability of the ocular surface. The choice of procedure depends on several factors including the involvement of the ocular adnexa, presence of systemic co-morbidities, status of the fellow eye and the comfort level of the surgeon. In LSCD with wet ocular surfaces, autologous and allogeneic limbal stem cell transplantation is preferred in unilateral and bilateral cases, respectively. Another approach in bilateral LSCD with wet ocular surfaces is the use of an autologous stem cell source of a different epithelial lineage, like oral or nasal mucosa. In eyes with bilateral LSCD with significant adnexal issues, a keratoprosthesis is the only viable option. This review provides an overview on the diagnosis and treatment of LSCD, which will help the clinician choose the best option amongst all the therapeutic modalities currently available and gives a clinical perspective on customizing the treatment for each individual case.

Scleral Lens Thickness and Corneal Edema Under Closed Eye Conditions

OBJECTIVES

To examine the relationship between central lens thickness and central corneal edema during short-term closed eye scleral lens wear.

METHODS

Nine participants (mean age 30 years) with normal corneas wore scleral lenses (Dk 141) under closed eye conditions on separate days with nominal center thicknesses of 150, 300, 600, and 1,200 μm. Epithelial, stromal, and total corneal edema were measured using high-resolution optical coherence tomography immediately after lens application and after 90 min of wear, before lens removal. Data were corrected for variations in initial fluid reservoir thickness and compared with predictions from theoretical modeling of overnight scleral lens wear.

RESULTS

Scleral lens-induced central corneal edema was primarily stromal in nature. The mean±standard error of corrected total corneal edema was 4.31%±0.32%, 4.55%±0.42%, 4.92%±0.50%, and 4.83%±0.22% for the 150-, 300-, 600-, and 1,200-μm lenses, respectively. No significant differences in the corrected total corneal edema were observed across all thickness groups (P=0.20). Theoretical modeling of overnight scleral lens wear seemed to overestimate the relative increase in central corneal edema as a function of decreasing lens Dk/t for values lower than 25.

CONCLUSION

The magnitude of scleral lens-induced central corneal edema during short-term closed eye lens wear did not vary significantly with increasing central lens thickness. Theoretical modeling of overnight closed eye scleral lens wear seems to overestimate the effect of increasing lens thickness.

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.

Update on indications, complications, and outcomes of scleral contact lenses

Background

The role of scleral contact lenses (SCLs) has increasingly expanded since the first lens was fitted more than a century ago. While it was initially prescribed for the management of severely compromised corneas, the indications for modern SCL use have expanded to include less severe diseases. In this review, we aimed to provide an up-to-date overview of the current indications, complications, and outcomes for the various types of SCLs.

Methods

In this narrative review, we thoroughly searched the PubMed/MEDLINE database for literature published from January 1980 to November 2021. Only relevant up-to-date English references were included. Furthermore, the figures in this manuscript were derived from our unit's patient documentation.

Results

Currently, SCLs can successfully be used to manage ocular surface diseases, visually rehabilitate irregular corneas, and correct irregular refractive errors. Although newer materials have yielded the same visual outcomes with fewer complications, these consequences still occur in approximately one-third of contact lens wearers, including difficulties in insertion and/or removal, discomfort or pain, and developing either halos, blurriness, or haze. Even though most of these complications are minor and can be easily treated, a good practice is essential to avoid sight-threatening complications such as microbial keratitis.

Conclusions

SCLs are indispensable in ophthalmic clinics. The development of better-quality SCLs has increased the number of indications and improved the achievable visual rehabilitation. The future of developing improvements in SCL design, materials, and fit, and the expansion of their indication range is promising.

Genetic Modification of Limbal Stem Cells to Decrease Allogeneic Immune Responses

Limbal stem cell (LSC) transplantation is the only efficient treatment for patients affected by LSC deficiency (LSCD). Allogeneic LSC transplantation is one of the most successful alternative for patients with bilateral LSCD. Nevertheless, the high variability of the human leukocyte antigens (HLA) remains a relevant obstacle to long-term allogeneic graft survival. This study characterized the immunologic properties of LSCs and proposed a genetic engineering strategy to reduce the immunogenicity of LSCs and of their derivatives. Hence, LSC HLA expression was silenced using lentiviral vectors encoding for short hairpin (sh) RNAs targeting β2-microglobulin (β2M) or class II major histocompatibility complex transactivator (CIITA) to silence HLA class I and II respectively. Beside the constitutive expression of HLA class I, LSCs showed the capability to upregulate HLA class II expression under inflammatory conditions. Furthermore, LSCs demonstrated the capability to induce T-cell mediated immune responses. LSCs phenotypical and functional characteristics are not disturbed after genetic modification. However, HLA silenced LSC showed to prevent T cell activation, proliferation and cytotoxicity in comparison to fully HLA-expressing LSCs. Additionally; HLA-silenced LSCs were protected against antibody-mediated cellular-dependent cytotoxicity. Our data is a proof-of-concept of the feasibility to generate low immunogenic human LSCs without affecting their typical features. The use of low immunogenic LSCs may support for long-term survival of LSCs and their derivatives after allogeneic transplantation.

Progression From Soft Lens to Piggyback Soft-Scleral Contact Lens System to Facilitate Scleral Lens Use in a Pediatric Patient

ABSTRACT

Traumatic injury in the pediatric population often results in significant refractive errors that if left untreated can lead to amblyopia. Scleral contact lenses (ScCLs) have recently gained popularity in this population for efficacy in treatment of significant refractive errors, including irregularity astigmatism and corneal abnormalities. Scleral contact lens intolerance may limit the ability of practitioners to use this modality. Although a soft contact lens (SCL) is generally well tolerated, it cannot treat refractive error as effectively as an ScCL. We recently used an SCL followed by an SCL-ScCL combination ("piggyback" system) sequence in a pediatric patient to facilitate use of an ScCL alone. We hope that our results may provide practitioners with an additional option when treating this challenging patient population.

Miniscleral Contact Lens in Pediatric Age Group: Indications, Safety, and Efficacy

OBJECTIVE

To report indications, fitting feasibility, and safety of miniscleral design (MSD) lenses in children.

METHODS

Medical records of patients aged <18 years at the time of referral to Contact Lens Clinic of Farabi Eye Hospital, because of inadequate spectacle-corrected visual acuity, rigid gas-permeable or soft contact lens intolerance, and ocular surface disease were reviewed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), best-corrected vision with the lens (CCVA), lens parameters, and comfortable daily wearing time (CDWT) were documented.

RESULTS

Seventy-two eyes of 52 pediatric patients were fitted with MSD lens over a 9-year period. The indications for MSD lens fitting were keratoconus (29 eyes), corneal scarring from ocular trauma (16 eyes), ocular surface diseases (25 eyes), and postkeratitis corneal scar (2 eyes). The average UCVA and the mean difference between CCVA and BSCVA were 1.20 and 0.55 logarithm of the minimal angle of resolution, respectively, which shows statistically significant improvement. This significant increase in vision was even seen in those who were referred for the management of ocular surface diseases. The mean CDWT for most patients was 10 hr/day.

CONCLUSION

Miniscleral design lens can be used as a safe and helpful modality to provide good vision and comfort in children experiencing ectatic disorders, traumatic corneal scars, and ocular surface diseases.

Bacteriostatic Effect of Multidose Preservative-free Buffered Saline Used in Scleral Lens Wear

SIGNIFICANCE

Scleral lenses have become an increasingly common treatment for ocular surface disease and irregular corneas. Multidose, preservative-free saline solutions are frequently used off-label to fill scleral lenses. Because the fluid resides over the ocular surface during lens wear, contaminated solutions may increase the risk of infectious complications.

PURPOSE

We sought to assess the viability of skin microorganisms and pathogens associated with keratitis once introduced into a multidose preservative-free saline (MDPFS) solution containing the bacteriostatic agent boric acid (PuriLens Plus; The Lifestyle Co., Inc., Freehold, NJ).

METHODS

Eleven bacterial and one yeast isolate were each inoculated to three lots of MDPFS as well as to sterile normal saline for comparison. Microorganism concentrations were enumerated at baseline and days 1, 3, 7, 14, 21, and 28. Persistence of microorganism viability was compared between MDPFS lots and between MDPFS and normal saline for each organism.

RESULTS

Duration of microorganism viability was ≥24 hours in MDPFS with no significant difference in the distribution of survival duration of microorganisms in MDPFS versus normal saline (P = .15). Candida albicans concentrations declined 14 days earlier in MDPFS, whereas concentrations of viable organisms in MDPFS remained within 1 log of baseline for the longest durations for Pseudomonas aeruginosa (7 days), Escherichia coli (14 days), and Achromobacter xylosoxidans (≥28 days). Gram-positive organism concentrations remained within 1 log of baseline for no more than 3 days. Mild lot-to-lot variation in organism concentrations was noted near the end points of viability. Bacteriostasis was demonstrated in that concentrations of all organisms remained at or below baseline levels throughout the 28-day period.

CONCLUSIONS

After microbial contamination, persistence of organism viability was similar in PuriLens and normal saline. Environmental gram-negative organisms, many of which can contribute to infectious keratitis, can persist for weeks once introduced into saline solutions.

Overview of Neurotrophic Keratopathy and a Stage-Based Approach to Its Management

ABSTRACT

Neurotrophic keratopathy (NK) occurs because of disruption of corneal sensory innervation. There are many etiologies that can lead to NK, such as infection, trauma, topical medication use, cornea surgery, and intracranial tumors among others. We review the current available treatment options and provide a stage-based approach to its management.

Scleral Lens Use in Neurotrophic Keratopathy: A Review of Current Concepts and Practice

OBJECTIVE

Neurotrophic keratopathy (NK) is a rare corneal condition characterized by epitheliopathy, which is associated with reduced or absent corneal sensation. The main goal of treatment of this condition is the preservation of ocular surface integrity. Contact lenses provide a nonsurgical and reversible option to provide the necessary corneal protection. The purpose of this review was to summarize the available literature regarding the use of contact lenses in the management of NK, with particular emphasis on the use of scleral lenses.

METHODS

Literature related to both soft and scleral contact lens use as treatment options for NK was reviewed.

RESULTS

As of yet, randomized clinical trials have compared neither the efficacy of contact lens therapy for NK to other therapeutic alternatives nor outcomes of therapy with different contact lens modalities. However, clinical case reports and limited case series have suggested that scleral lenses may be a safe and effective treatment option for NK at any stage of the disease, preserving epithelial integrity and even improving visual function in patients with this condition.

CONCLUSIONS

Scleral lenses may be effective in reducing the need for surgical intervention and improving the quality of life in patients with NK.

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 .

Limbus misrepresentation in parametric eye models

Purpose

To assess the axial, radial and tangential limbus position misrepresentation when parametric models are used to represent the cornea and the sclera.

Methods

This retrospective study included 135 subjects aged 22 to 65 years (36.5 mean ±9.8 STD), 71 females and 64 males. Topography measurements were taken using an Eye Surface Profiler topographer and processed by a custom-built MATLAB code. Eye surfaces were freed from edge-effect artefacts and fitted to spherical, conic and biconic models.

Results

When comparing the radial position of the limbus, average errors of -0.83±0.19mm, -0.76±0.20mm and -0.69±0.20mm were observed within the right eye population for the spherical, conic and biconic models fitted up to 5mm. For the same fitting radius, the average fitting errors were -0.86±0.23mm, -0.78±0.23mm and -0.73±0.23mm for the spherical, conic and biconic models respectively within the left eye population. For the whole cornea fit, the average errors were -0.27±0.12mm and -0.28±0.13mm for the spherical models, -0.02±0.29mm and -0.05±0.27mm for the conic models, and -0.22±0.16mm and 0.24±0.17mm for the biconic models in the right and left eye populations respectively.

Conclusions

Through the use of spherical, conic and biconic parametric modelling methods, the eye’s limbus is being mislocated. Additionally, it is evident that the magnitude of fitting error associated with the sclera may be propagating through the other components of the eye. This suggests that a corneal nonparametric model may be necessary to improve the representation of the limbus.

Treatment of Severe Infectious Keratitis With Scleral Contact Lenses as a Reservoir of Moxifloxacin 0.5

PURPOSE

To report the outcomes of using scleral contact lenses as antibiotic reservoirs as a therapeutic approach in a case series of severe infectious keratitis and to discuss the clinical potential.

METHODS

This was a prospective consecutive case series study of 12 eyes treated for infectious keratitis at the "Conde de Valenciana" Institute of Ophthalmology. A scleral lens (SL) filled with 0.5% moxifloxacin was used as a reservoir and replaced every 24 hours until epithelization was complete or the culture report and/or antibiogram demonstrated either a microorganism not susceptible to or resistant to moxifloxacin.

RESULTS

The study included 12 eyes of 12 patients (7 women; 58.33%; average age of 63 ± 20.11 years). All patients completed at least 1 month of follow-up. Patients had a diagnosis of infectious keratitis, and the SL was fitted on initial consultation. Of the 12 eyes, 7 had culture-positive bacterial infection, 2 eyes were mycotic, and 3 eyes had no culture growth. In 3 eyes, SL was discontinued because of the lack of response (one eye) and to the presence of mycotic infection (2 eyes). All infections resolved favorably at the final follow-up.

CONCLUSIONS

The use of SLs could be an alternative for antibiotic impregnation and treatment of infectious keratitis. No complications or side effects were observed related to the use of the scleral contact lens as a reservoir for the antibiotic. This treatment modality could offer a comfortable treatment for the patient, ensuring good impregnation and maintenance of antibiotic concentrations during the 24-hour wear periods.