BCLA CLEAR Presbyopia: Evaluation and diagnosis.

It is important to be able to measure the range of clear focus in clinical practice to advise on presbyopia correction techniques and to optimise the correction power. Both subjective and objective techniques are necessary: subjective techniques (such as patient reported outcome questionnaires and defocus curves) assess the impact of presbyopia on a patient and how the combination of residual objective accommodation and their natural DoF work for them; objective techniques (such as autorefraction, corneal topography and lens imaging) allow the clinician to understand how well a technique is working optically and whether it is the right choice or how adjustments can be made to optimise performance. Techniques to assess visual performance and adverse effects must be carefully conducted to gain a reliable end-point, considering the target size, contrast and illumination. Objective techniques are generally more reliable, can help to explain unexpected subjective results and imaging can be a powerful communication tool with patients. A clear diagnosis, excluding factors such as binocular vision issues or digital eye strain that can also cause similar symptoms, is critical for the patient to understand and adapt to presbyopia. Some corrective options are more permanent, such as implanted inlays / intraocular lenses or laser refractive surgery, so the optics can be trialled with contact lenses in advance (including differences between the eyes) to better communicate with the patient how the optics will work for them so they can make an informed choice.

Medmont Meridia™: Much More Than a Corneal Topographer.

In recent years, advanced diagnostic instruments have become widely available in optometric practices, offering various functions that optimize clinical information gathering. This article focuses on the Medmont Meridia™, a state-of-the-art multipurpose diagnostic device with corneal topography and cutting-edge features. Corneal topography is pivotal in the early diagnosis of corneal disorders, determining baseline ocular surface assessment, helping in contact lens fitting, and monitoring ocular health over time. The Medmont Meridia boasts Placido-disc-based imaging with extensive corneal coverage. Furthermore, the Meridia accurately measures the horizontal visible iris diameter, pupil diameter, and palpebral fissure width, which assists in making contact lens parameter decisions. Additionally, it offers sagittal height data for scleral lens design and first lens selection, streamlining the fitting process. Beyond its topography capabilities, the Meridia excels as a comprehensive dry eye assessment tool. With features like tear meniscus height, tear film surface quality, and meibography capabilities, it aids in diagnosing dry eye and monitoring its progression. The device also provides customizable dry eye reports with integrated grading scales and questionnaires, making dry eye management, patient education, and compliance more accessible. In conclusion, the Medmont Meridia consolidates a multitude of examination tools in a single instrument, enhancing practice efficiency and elevating patient care and communication. Its versatility and accuracy make it an invaluable asset in optometric practices worldwide.

Case Report: Remote Scleral Lens Fitting for High Toric Scleras in a Keratoconus Patient.

SIGNIFICANCE: Technology plays a crucial role in customizing scleral lenses and improving lens alignment, especially in challenging scleral shapes. In addition, remote fitting technology allows optometrists to extend their expertise globally, empowering patients to access to customized lenses without travel expenses. PURPOSE: The objective of this study was to document the difficulties encountered in fitting a scleral lens in a patient with keratoconus and pronounced scleral toricity. In addition, the study aimed to present the successful remote fitting achieved by using advanced technology. CASE REPORT: An Irish male patient diagnosed with keratoconus exhibited high scleral toricity. Generally, keratoconus eyes often exhibit significant scleral asymmetry associated with cone decentration and disease severity. Improperly aligned scleral lenses can lead to regional changes in scleral shape, lens decentration, discomfort, and visual disturbances. Indeed, previous scleral lens fits were unsuccessful because of these issues. Corneoscleral profilometry was acquired in Ireland and then used in Italy to design customized lenses, which were then delivered to the patient's optometrist in Ireland. The first lenses designed and delivered demonstrated excellent overall performance without requiring adjustments. CONCLUSIONS: This report highlights the importance of corneoscleral profilometry to increase efficiency and reduce lens reorders and chair time, and the remote fitting in overcoming barriers to accessing specialized lens fitting.

Evaluating the Performance of Verofilcon A Daily Disposable Contact Lenses in a Group of Heavy Digital Device Users.

Purpose: The purpose of this study was to evaluate the performance of verofilcon A daily disposable contact lenses (CL) in CL wearers who identified themselves as heavy digital device users. Patients and Methods: This prospective, non-masked, open-label study enrolled CL wearers who reported ≥6 hours digital device use per day. Participants were dispensed with the verofilcon A study lenses for 14±2 days, to be worn for at least 5 days a week and 10 hours per day, while continuing their normal routine of digital device use. Participants rated the lens performance at the Day 14 visit using a 0-100 (with 100 being best) scale. Ratings were completed at lens insertion, after 6 hours of digital device use, just before CL removal and for overall experience. Participants also completed a 4-point (strongly agree/disagree, slightly agree/disagree) Likert scale-based questionnaire. Results: Thirty-two participants were eligible and completed the study (27 females; age 25.8 ± 6.0 years, ranging from 19 to 40). Overall lens performance ratings at the Day 14 visit (mean ± standard deviation) for comfort, dryness, and clarity of vision were 91 ± 11, 88 ± 11, and 92 ± 9, respectively. Subjective ratings were stable throughout the day with no significant differences after insertion, after 6 hours of digital device use and before CL removal (all p>0.05). The majority of participants agreed that the study lenses performed well, provided good all-day comfort (28/32; p<0.01) and good all-day vision (29/32; p<0.01). Participants also agreed that after ≥6 hours of digital device use they were satisfied with CL comfort (27/32; p<0.01), vision (29/32; p<0.01) and that the lenses provided good performance (26/32; p<0.01). Conclusion: Verofilcon A lenses were found to perform well, with high ratings for comfort, dryness and vision that remained high throughout the day, during extensive digital device use.

Therapeutic contact lenses for the treatment of corneal and ocular surface diseases: Advances in extended and targeted drug delivery.

The eye is one of the most important organs in the human body providing critical information on the environment. Many corneal diseases can lead to vision loss affecting the lives of people around the world. Ophthalmic drug delivery has always been a major challenge in the medical sciences. Since traditional methods are less efficient (∼5%) at delivering drugs to ocular tissues, contact lenses have generated growing interest in ocular drug delivery due to their potential to enhance drug bioavailability in ocular tissues. The main techniques used to achieve sustained release are discussed in this review, including soaking in drug solutions, incorporating drug into multilayered contact lenses, use of vitamin E barriers, molecular imprinting, nanoparticles, micelles and liposomes. The most clinically relevant results on different eye pathologies are presented. In addition, this review summarizes the benefits of contact lenses over eye drops, strategies for incorporating drugs into lenses to achieve sustained release, results of in vitro and in vivo studies, and recent advances in the commercialization of therapeutic contact lenses for allergic conjunctivitis.

Evidence for commonly used teaching, learning and assessment methods in contact lens clinical skills education.

INTRODUCTION: Evidence based practice is now an important part of healthcare education. The aim of this narrative literature review was to determine what evidence exists on the efficacy of commonly used teaching and learning and assessment methods in the realm of contact lens skills education (CLE) in order to provide insights into best practice. A summary of the global regulation and provision of postgraduate learning and continuing professional development in CLE is included. METHOD: An expert panel of educators was recruited and completed a literature review of current evidence of teaching and learning and assessment methods in healthcare training, with an emphasis on health care, general optometry and CLE. RESULTS: No direct evidence of benefit of teaching and learning and assessment methods in CLE were found. There was evidence for the benefit of some teaching and learning and assessment methods in other disciplines that could be transferable to CLE and could help students meet the intended learning outcomes. There was evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; clinical teaching and learning, flipped classrooms, clinical skills videos and clerkships. For assessment these methods were; essays, case presentations, objective structured clinical examinations, self-assessment and formative assessment. There was no evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; journal clubs and case discussions. Nor was any evidence found for the following assessment methods; multiple-choice questions, oral examinations, objective structured practical examinations, holistic assessment, and summative assessment. CONCLUSION: Investigation into the efficacy of common teaching and learning and assessment methods in CLE are required and would be beneficial for the entire community of contact lens educators, and other disciplines that wish to adapt this approach of evidence-based teaching.

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.

CLEAR - Orthokeratology.

Orthokeratology (ortho-k) is the process of deliberately reshaping the anterior cornea by utilising specialty contact lenses to temporarily and reversibly reduce refractive error after lens removal. Modern ortho-k utilises reverse geometry lens designs, made with highly oxygen permeable rigid materials, worn overnight to reshape the anterior cornea and provide temporary correction of refractive error. More recently, ortho-k has been extensively used to slow the progression of myopia in children. This report reviews the practice of ortho-k, including its history, mechanisms of refractive and ocular changes, current use in the correction of myopia, astigmatism, hyperopia, and presbyopia, and standard of care. Suitable candidates for ortho-k are described, along with the fitting process, factors impacting success, and the potential options for using newer lens designs. Ocular changes associated with ortho-k, such as alterations in corneal thickness, development of microcysts, pigmented arcs, and fibrillary lines are reviewed. The safety of ortho-k is extensively reviewed, along with an overview of non-compliant behaviours and appropriate disinfection regimens. Finally, the role of ortho-k in myopia management for children is discussed in terms of efficacy, safety, and potential mechanisms of myopia control, including the impact of factors such as initial fitting age, baseline refractive error, the role of peripheral defocus, higher order aberrations, pupil size, and treatment zone size.

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.

Fenestrated Scleral Lenses: Back to the Origins? Review of Their Benefits and Fitting Techniques.

SIGNIFICANCE: This review illustrates the history of fenestrated scleral lenses, reporting personal communication from one of the present authors; describes their peculiarities and disadvantages; explains the fitting methods so far used; and recommends future fitting methods.Indications and benefits of scleral lenses are widely described in the literature. The introduction of more advanced gas-permeable materials allowed scleral lenses to spread and be available to patients worldwide. Despite the improvement of the gas-permeable scleral lens' clinical performance, complications associated with corneal hypoxia persist, especially in patients with corneal endothelial abnormalities. Fenestrated scleral lenses may solve different complications caused by hypoxia. Also, fenestrated scleral lenses may be beneficial for several issues such as handling difficulties, midday fogging, lens suction, lens instability, conjunctival compression, and alteration of IOP. There is a need and a benefit to directly comparing fenestrated scleral lenses to sealed gas-permeable scleral lenses. This topical review allows practitioners to understand the fenestration philosophy in scleral lenses, practice better, and obtain information on their indications and fitting process. Industry and patients will benefit from future advances in scleral lens designs.

Effect of Scleral Lenses on Corneal Topography in Keratoconus: A Case Series of Cross-Linked Versus Non-Cross-Linked Eyes.

PURPOSE: To evaluate the changes in anterior corneal topography induced by short-time wear of scleral contact lenses (SLs) in keratoconic subjects with and without a history of corneal cross-linking (CXL). METHODS: Nine keratoconic patients (14 eyes) were fitted with 18.5 mm SLs for optical rehabilitation. Subjects were divided into 2 groups: 7 eyes without a history of CXL (Non-CXL group) and 7 with a history of CXL (CXL group). Corneal topography was performed at baseline and after 2 and 5 hours of lens wear. The differences for simulated flat (Kflat), steep (Ksteep) and maximal (Kmax) corneal curvatures, central corneal astigmatism (CCA), and central cornea thickness were evaluated. RESULTS: No statistically significant difference was detected between Non-CXL and CXL groups in any of these measures. Statistically significant flattening was detected in Ksteep Repeated measures analysis of variance ([RM-ANOVA), F (2,24) = 11.32, P < 0.0001], CCA [RM-ANOVA, F (2,24) = 15.34, P < 0.0001], and Kmax [RM-ANOVA, F (2,24) = 19.10, P < 0.0001). From baseline to 5 hours of SL wear, Ksteep decreased on average from 53.1 to 52.4 D, Kmax decreased from 56.7 to 55.8 D, and CCA decreased from 7.2 to 6.3 D. Kmax showed a trend toward more flattening in the Non-CXL group. Central cornea thickness showed significant thickening over time from baseline (451 µm) to 5 hours (458 µm) of SL wear [RM-ANOVA, F (1,12) = 319.3, P < 0.0001]. CONCLUSIONS: Short-term scleral lens wear in keratoconic patients may cause flattening of the anterior cornea. A history of CXL treatment does not guarantee corneal shape stability after scleral lens wear. Practitioners should be aware of these changes because scleral lens wear may mask the signs of keratoconus progression.

Optical considerations for scleral contact lenses: A review.

Scleral contact lenses have a range of therapeutic and optical applications. In recent years, scleral lens prescribing has increased due to significant advances in ocular imaging technology, lens manufacturing processes, and the widespread availability of scleral lenses globally. While the optical principles of scleral lenses are identical to those of corneal rigid lenses (i.e. the post-lens tear layer neutralises the majority of anterior corneal astigmatism and higher order aberrations), the nature of scleral lenses and their typical fitting characteristics means that many of the assumptions of 'thin lens' paraxial optics traditionally used for corneal rigid lens calculations may be inappropriate in certain clinical scenarios. This review provides a comprehensive overview of a variety of lens and fitting characteristics that are unique to scleral lenses, or not typically encountered with corneal rigid lenses, and how these factors may potentially influence optical performance based on theoretical modelling, in particular; scleral lens parameters, the post-lens tear layer, and dynamic changes during lens wear. Current front and back surface lens designs and future scleral lens applications are also discussed, along with lens modifications to improve visual outcomes and transient changes in corneal optics induced by appropriately fitted modern scleral lenses.

Scleral Lens Issues and Complications Related to a Non-optimal Fitting Relationship Between the Lens and Ocular Surface.

INTRODUCTION: The advent of high oxygen permeability (Dk) of rigid contact lens materials has reduced complications related to hypoxia when using scleral contact lenses (ScCLs). However, new issues and complications have emerged. Some of these issues and complications are caused by the nonoptimal fitting relationship with the underlying ocular surface, which may pose a challenge in their management. METHOD: PubMed searches using different keywords and an investigation into the issues and complications etiology were conducted. Detailed guidelines for their management are provided. RESULTS: The literature provides a few reports of severe adverse reactions to ScCLs. The most common issues, unique to ScCL wear, have been described. Likewise, other anomalies in ScCL fitting may affect patient satisfaction and lead to drop out, promoting eye surgery or dramatic psychological effects. The management of these issues and complications may be also frustrating for clinicians who will, in turn, rarely, or not at all, prescribe them. CONCLUSION: Scleral contact lenses intimidate practitioners because of their large diameter and the lack of knowledge in regard to the fitting process but especially because of the challenging management of issues and complications that may occur relating to the lens fitting relationship with the underlying ocular surface. A detailed description of the etiology and management of these anomalies will allow practitioners to gain more confidence in fitting ScCLs and prescribe them more often. Patients are the primary beneficiaries from wearing these large rigid lenses; ScCLs represent a life-changing event for many patients.

Potential contraindications to scleral lens wear.

Research and reviews have resulted in clear indications for scleral lens (SL) wear. Those indications include visual rehabilitation; therapeutic use in managing ocular surface diseases, lid and orbit disorders; and refractive correction to enhance visual quality, comfort and quality of life. In some cases, the use of SLs may be contraindicated: the presence of low endothelial cell density; Fuchs' endothelial corneal dystrophy; glaucoma (because of the risk of an increase in intraocular pressure and the existence and location of draining devices and blebs); or overnight wear. While the literature provides an extensive description of the indications for scleral lens wear, the authors recognize that there is no paper reporting the contraindications to their use. The aim of this review is to illustrate the conditions for which SL wear is potentially contraindicated or requires caution. Improved knowledge of SL limits should reduce the risk of adverse events and increase the likelihood of fitting success.

The influence of limbal and scleral shape on scleral lens design.

PURPOSE: To summarize the research findings on the ocular surface profile, to provide a definition and a classification of the corneoscleral shape, and to offer guidelines in selecting scleral lens design. METHODS: The definition of rotational symmetry and rotational asymmetry was inquired and PubMed searches were conducted. RESULTS: The better understanding of the scleral contact lens comportment on the eye and the introduction of new diagnostic instruments to measure the anterior ocular surface have led to improve comprehension of corneoscleral contour formulating new scleral lens designs. The scleral lens landing zone is influenced by corneoscleral profile which may be rotationally symmetric and rotationally asymmetric. Corneal sagittal height, limbal shape, corneoscleral junction profile, corneal, limbal, and conjunctival angles, and scleral shape should be taken in consideration to prevent and manage fitting problems, such as air bubble formation, midday fogging, localized blanching, impingement, conjunctival prolapse, lens decentration, lens flexure, and to increase comfort, wearing time, overall satisfaction, and visual quality. CONCLUSION: Corneoscleral shape may be considered rotationally symmetric including spherical, aspherical and toric profiles, and rotationally asymmetric including regular and irregular quadrants profiles. Each ocular surface contour requires a different landing zone design for an optimal fitting, vaulting properly over the cornea and limbus, and ideal alignment on the sclera. Further studies are still necessary to clarify many aspects of scleral lenses which are little known yet.

Modern scleral lenses: Mini versus large.

The evolution of scleral lenses has led to new formulations of scleral fitting concepts and designs. The diameters of modern scleral lenses have been overhauled too and they are smaller comparing to the original ones. Nowadays, prescription of mini-sclerals supposedly seems in major extension and it appears indeed the necessity of some practitioner to differentiate the smaller mini-scleral lenses from larger mini-scleral lenses empathizing that they are the "smaller" ones. Therefore, it is maybe, necessary a definition of mini-scleral lenses referring to the landing zone width in relation to the horizontal visible iris diameter (HVID) and the limbus extension. The choice of the total diameter is crucial for a successful fitting and it depends majorly on patient's topographic patterns and anatomic factors. However, there are other important criteria for the selection of the scleral lens diameter based on oxygen supply, bubbles formation, mechanical stress on a toric sclera, ocular surface disease protection, entity of the vault over the cornea and distribution of the lens weight on the sclera. The advantages of mini-scleral lenses are various nonetheless in some cases large lenses are necessary. This paper presents a review of the benefits and disadvantages of both mini and large scleral lenses analyzing the conditions in which it may be better to prefer one diameter to another. A suggestion may be that to start fitting the smallest lens as possible, depending on the dimension of HVID and limbus width and consider larger lenses only when issues occur.