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Peer-reviewed articles


Fadel,D., Macedo-de-Araújo,R. J., Barnett,M. The Patient-Physician Relationship and Role of Empathic Communication in Contact Lens Practice Journal of Contact Lens Research and Science 2024;8(1):20-36

Wolffsohn,J. S., Berkow,D., Chan,K. Y., Chaurasiya,S. K., Fadel,D., Haddad,M., Imane, T., Jones,L., Sheppard,A. L., Vianya-Estopa,M., Walsh,K., Woods,J., Zeri,F., Morgan,P. B. BCLA CLEAR Presbyopia: Evaluation and diagnosis Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

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.


Abdi,B., Mofidfar,M., Hassanpout,F., Cilingir,E. K., Kalajahi,S., Milani,P. K., Ghanbarzadeh,M., Fadel,D., Barnett,M., Ta,C. N., Leblanc,R. M., Chauhan,A., Abbasi,F. Therapeutic contact lenses for the treatment of corneal and ocular surface diseases: Advances in extended and targeted drug delivery International Journal of Pharmaceutics 2023;638(May):122740 [ Show Abstract ]

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.

Fadel,D. Medmont Meridia™: Much More Than a Corneal Topographer Clinical Optometry 2023;15 283-301 [ Show Abstract ]

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.

Fadel,D., Gildea,C. Case Report: Remote Scleral Lens Fitting for High Toric Scleras in a Keratoconus Patient Optometry and Vision Science 2023;100(12):876-881 [ Show Abstract ]

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.

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.

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.

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.

Schulze,M., Fadel,D., Luensmann,D., Ng,A. Y., Guthrie,S., Woods,J., Jones,L. Evaluating the Performance of verofilcon A Daily Disposable Contact Lenses in a Group of Heavy Digital Device Users Clinical Ophthalmology 2023;173165-3175 [ Show Abstract ]

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.

Woods,C., Naroo,S., Zeri,F., Bakkar,M., Barodawala,F., Evans,V., Fadel,D., Kalikivayi,L., Lira,M., Maseedupally,V., Trave Huarte,S., Eperjesi,F. Evidence for commonly used teaching, learning and assessment methods in contact lens clinical skills education Contact Lens Anterior Eye 2023;46(2):101821 [ Show Abstract ]

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.

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.

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.

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.


Vincent,S. J., Cho,P., Yin Chan,K., Fadel,D., Ghorbani-Mojarrad,N., González-Méijome,J. M., Johnson,L., Michaud,L., Simard,P., Jones,L. CLEAR - Orthokeratology Contact Lens Anterior Eye 2021;44(2):240-269 [ Show Abstract ]

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.

Scientific Presentations


Fadel D, Wong S, Luensmann D, Guthrie S, Seo J, Woods J, Voltz K, Vega J. The use of Scleral Lenses to Manage Dry Eye Symptoms in Habitual Soft Lens Wearers Global Specialty Lens Symposium, Las Vegas, Jan 20, 2024 [ Show Abstract ]

PURPOSE: To determine if scleral lenses (SLs) with and without Hydra-PEG coating can improve ocular comfort and reduce dryness in symptomatic soft lens wearers.

METHODS: This prospective, randomized, double masked, 1-month bilateral cross over, daily wear study recruited symptomatic soft lens wearers who presented with healthy eyes and a CLDEQ-8 score ≥12 with their habitual contact lens (hab-CL). Eligible participants were fit with SLs (Onefit MED, CooperVision, Inc.) and wore these with and without HydraPEG coating (coated (C-SL) / uncoated (U-SL)) in a randomized order for 1 month per pair. Participants completed a CLDEQ-8 and rated comfort, vision clarity, dryness and handling after each 1-month wear period using a 0-10 scale (10=best) and these data were compared between study SLs and to their hab-CL.

RESULTS: Twenty participants (16F:4M), mean age 29.3±12.4 years [18-64 years] completed the study. The mean refraction of the right eye was Sph -4.69±3.42DS [-15.25 to -0.50DS] and Cyl -0.84±0.79DC [0.00 to -2.75DC]. At 1 month, the CLDEQ-8 score improved with both study SLs in comparison to hab-CL (p0.05) and both were rated better compared to hab-CL (p0.05). At study exit, 9 of the 20 participants requested the SL details to be shared with their eye care professional because they wanted to continue wearing these SLs in future.

CONCLUSIONS: Switching symptomatic soft lens wearers into scleral lenses improved comfort and reduced dryness symptoms after 1 month of wear, with little reduction in ease of lens handling. Subjective ratings were similar with uncoated and HydraPEG coated scleral lenses, with the latter providing slightly better visual clarity.

Wong S, Fadel D, Seo J, Luensmann D, Guthrie S, Woods J, Voltz K, Vega J. Dry eye management with scleral lenses in non-lens wearers NCC, Veldhoven, Netherlands, Mar 10, 2024 [ Show Abstract ]

PURPOSE: To assess the benefits of scleral lenses (SLs) with and without Hydra-PEG in non-lens wearers with dry eye symptoms.

METHODS: This prospective, randomised, double-masked, 1-month bilateral cross-over study recruited symptomatic non-wearers with healthy eyes and an OSDI score ≥13. Participants were fitted with SLs (hexafocon A, Onefit MED, CooperVision, Inc.) with and without Hydra-PEG coating (Tangible Science) (coated (C-SL)/uncoated (U-SL)) for 1-month daily wear per pair. LogMAR visual acuity was measured, and participants rated overall satisfaction with ocular comfort, dryness and vision clarity using a 0-10 scale (10=best) at baseline (BL) and after each 1-month wear period with the two SLs.

RESULTS: In total, 22 participants were eligible and 18 completed the study (18F:0M, mean age 34.9±13.4 years [20-66], OSDI score 39.8±18.0 [14-80], reason for discontinuation: n=3 handling, n=1 comfort). Mean refraction of the right eye was -3.28±1.13DS [-12.00 to +1.00] and -1.11±0.90DC [0.00 to -3.25]. At 1-month, satisfaction with ocular comfort and dryness was similar between study SLs (p>0.05), and both were rated better than BL (p0.05) (BL: 7.6±19, C-SL: 7.8±2.3, U-SL: 7.8±2.9), which was confirmed by LogMAR visual acuity with no clinically relevant differences noted (BL: -0.14±0.07, C-SL: -0.17±0.07, U-SL: -0.18±0.08). At study exit, 44% asked to share their SL details with their eye care professional to continue wear in the future.

CONCLUSIONS: Symptomatic non-lens wearers were successfully fit with SLs, which improved ocular comfort and reduced dryness after 1 month of wear. Although no difference was noted between Hydra-PEG-coated and uncoated lenses, participants with a wide range of dryness symptoms benefited from SL wear and almost every second participant indicated an interested to continue SL wear.

Continuing Education Presentations


Carrasquillo K, Fadel D, Cardenas N, Flores P . Workshop: Conquering Scleral Lens Complications (Spanish & English session) Global Specialty Lens Symposium, Las Vegas, Jan 19, 2024

Fadel D. Mastering Scleral, Corneal, and Myopia Management With Contact Lenses! Ontario Association of Optometrists, Symposium, April 12, 2024

Fadel D. Scleral Lenses Know No Bounds Ontario Association of Optometrists, Symposium, April 12, 2024

Fadel D, Barnett M. Masterclass: Scleral Lens Special Applications Global Specialty Lens Symposium, Las Vegas, Jan 18, 2024

Fadel D, Frogozo M. Aspheric Optics in Scleral Lenses for Normal and Diseased Eyes Global Specialty Lens Symposium, Las Vegas, Jan 20, 2024

Morrison S, Sorkin S, Fadel D, Severinsky B, Seira P. Rapid Fire CE Breakout: Contemporary Topics in Specialty Contact Lenses Global Specialty Lens Symposium, Las Vegas, Jan 19, 2024

Sindt C, Jedlicka J, Fadel D, Garcia C . Oculus: Specialty Contact Lens fitting solutions for every patient and every doctor Global Specialty Lens Symposium, Las Vegas, Jan 18, 2024

Wolf A, Fadel D. Presentation Provided by WAVE: Become a more Successful Scleral Fitter by Utilizing WAVE and Advanced Technologies! Global Specialty Lens Symposium, Las Vegas, Jan 18, 2024


Carrasquillo K, Fadel D. Fitting, evaluating, and troubleshooting the fit FitAcademy, Boston, USA, Sep 15, 2023

Fadel D. Expert Panel Discussion FitAcademy, Boston, USA, Sep 16, 2023

Fadel D. Therapeutic Contact lenses. How to manage each individual case? IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Meet the experts: Which lens to apply in irregular corneas? IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Scleral lens design and calculation of parameters based on corneal topography. Workshop. IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Scleral lens complications and management. IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Take Control of Your Scleral Fitting International Congress of Scleral Contact (ICSC), Florida USA, Jul 28, 2023

Fadel D. Scleral Lenses Using WAVE Design Software: Once You Start, There’s no Going Back Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023

Fadel D, Dutta D. Specialist Lens Cases British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 10, 2023

Fadel D, Frogozo M. Optical Challenges When Fitting Scleral Lenses Global Specialty Lens Symposium, Las Vegas, Jan 21, 2023

Fadel D, jedlicka J, Gelles J, Sindt C. The Future of Contact Lens Fitting Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023

Fadel D, Weshefsky T. Advanced Specialty Lens Designs Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023


Barnett M, Fadel D, Gelles J, Sclafani L. Panel Discussion: International Keratoconus Academy (IKA) Session: New thoughts on keratoconus prevalence and its impact on clinical management The Summit of Specialty Contacts, Sorrento, Italy, Oct 14, 2022

Eiden B, Gelles J, Fadel D, Morgenstern A, Sclafani L, Sindt C. Workshop: Adapting to the new normal with scleral lens empirical design using advanced technology American Academy of Optometry, San Diego, 2022

Fadel D. “I did it my way”… How to fit without advanced technology The Summit of Specialty Contacts, Sorrento, Italy, Oct 16, 2022

Fadel D. Scleral lens fitting with Boston® materials CLASS Symposium 2022, Cartagena, Colombia, Nov 4, 2022

Fadel D. Scleral lenses: Procedure for correct fitting CLASS Symposium 2022, Cartagena, Colombia, Nov 3, 2022

Fadel D, Howard N. Panelist: British Contact Lens Association (BCLA): Pandemic Positives The Summit of Specialty Contacts, Sorrento, Italy, Oct 14, 2022

Fadel D, van der Worp E, Norvik Jervel A, Morgan P. Panel Discussion: Keratconus detection and its management with specialty contact lenses Specsavers Clinical Conference (Virtual), Copenhagen, Denmark, Oct 6, 2022

Professional Publications


Fadel D. Preventing and Managing Edema with Scleral Lenses Review of Cornea and Contact Lenses 2023, March/April: 18-21

Fadel D. Fast Forward to the Future: Envisaging the Future of Scleral Lenses Contact Lens Spectrum 2023;38, October: 46

Fadel D.. Three of a kind: Examples of challenges presented with scleral lens patients and how to overcome them. Contact Lens Spectrum 2023;38, July: 32-36, 38-40, 51

Walker M, Bergmanson J, Schornack M, Fadel D. IFSLR 2023 RECAP Contact Lens Spectrum 2023;38, September: 37-41


Walker M, Bergmanson J, Fadel D, Johns L. Evidence-based Research and Clinical Practice Contact Lens Spectrum 2022;37, October: 38-43


Fadel D, Walsh K.. COVID-19, quando l'uso delle lenti è sicurio B2Eyes 2020;March. [ Show Abstract ]

Recentemente alcuni articoli di giornali sul possibile contagio da coronavirus tramite lenti a contatto e alcune organizzazioni sanitarie che consigliano il passaggio in questa fase agli occhiali anziché l’uso delle lenti a contatto sollevano facilmente la preoccupazione che l'utilizzo delle lac potrebbe non essere sicuro durante la pandemia da Covid-19. Questa inondazione di informazioni fuorvianti ha portato ricercatori di spicco nel panorama internazionale, da Canada, Regno Unito e Stati Uniti, a rispondere. Lyndon Jones, direttore del Center for Ocular Research & Education (CORE) presso l'Università di Waterloo (Canada), Philip Morgan, direttore di Eurolens Research presso l'Università di Manchester (Regno Unito), e Jason Nichols, vicepresidente associato di ricerca e docente all'Università dell'Alabama presso la Birmingham School of Optometry (Stati Uniti) e direttore editoriale di Contact Lens Spectrum, hanno fornito le seguenti informazioni sulla sicurezza dell'uso delle lenti a contatto.