Dry Eye Syndrome / Irregular Cornea

(e.g., Keratoconus) Rehabilitation  - Scleral Lens

Scleral lenses are a type of specialty rigid contact lens that has been around for over a century. Unlike standard contact lenses, scleral lenses are specialty contact lenses which have a larger diameter and are made from highly breathable materials. They are designed to rest on the less sensitive sclera (the white part of the eye) while completely avoiding contact with the sensitive cornea. This design not only provides vision correction but also protects the eyes.

Scleral lenses are suitable for patients recovering from various corneal issues, including dry eye disease and Sjögren’s syndrome, irregular corneas such as keratoconus and corneal scarring. They are also beneficial for individuals who cannot tolerate traditional rigid gas permeable (RGP) lenses or those with high prescriptions and astigmatism who struggle with disposable contact lenses. Additionally, patients dissatisfied with the visual outcomes of refractive surgery may find relief and clearer vision with scleral lenses.

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Principles of Scleral Lenses

Scleral lenses are crafted from rigid materials with high oxygen transmission and have a larger diameter than standard contact lenses. When worn, they act as a protective shield for the cornea, blocking external environmental irritants. The space between the lens and the cornea is filled with saline solution or artificial tears, creating a rich tear reservoir that keeps the cornea hydrated and promotes healing.

This tear reservoir also smooths out irregularities on the corneal surface, reshaping it into a uniform optical surface that corrects irregular astigmatism not manageable by regular glasses or contact lenses. This significantly enhances visual quality for patients whose corneas have become distorted due to disease, trauma, or surgery. Furthermore, because scleral lenses sit on the less sensitive sclera, they remain stable during blinking or physical activity. The enhanced comfort during scleral lens wear is better than you thought!

‍Benefits of Scleral Lenses

1. Corrects Irregular Astigmatism: Reshapes the optical surface for patients with corneal conditions like keratoconus, corneal scars, corneal transplant and has potential benefits for post-refractive surgeries with undesirable visual outcomes. 

2. Alleviates Dry Eye Symptoms of Moderate to Severe Dry Eye Disease and Sjogren Syndrome: Maintains hydration of the cornea through a stable liquid layer.

3. Protects the Corneal Surface: Shields against external irritants and aids in recovery from conditions such as neuropathic corneal pain, exposure keratitis and Stevens-Johnson Syndrome.

4. Provides Stable Vision Correction: Suitable for individuals with high prescriptions, high astigmatisms or those who cannot wear traditional RGP lenses.

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Fitting Process for Scleral Lenses

Our expert team customizes scleral lenses tailored to the shape and size of your eyes, as well as your specific needs.

✅ Understanding the patient’s visual needs

✅ Comprehensive eye examination, including refraction and biometry measurements

✅ Feasibility assessment for scleral lenses

✅ Trial fitting with scleral lens trial lenses

✅ Evaluation of lens comfort and clarity

✅ Determining parameters and arranging for custom lens production

✅ Lens pickup and inspection

✅ Tutorial on lens application and removal

⏲The initial fitting process typically takes about 1 to 2 hours.

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Suitable Candidates for Scleral Lenses:

1. Individuals with keratoconus or irregular corneas, corneal scars, or those who have undergone corneal transplant surgery, and individuals dissatisfied with visual outcomes after refractive surgery.
2. Patients suffering from moderate to severe dry eye disease and Sjögren's syndrome, seeking relief from dry eye symptoms.
3. Those with high astigmatism, high myopia, high hyperopia, or who do not adapt well to traditional RGP (rigid gas permeable) contact lenses.
4. Patients with corneal neuralgia, exposure keratitis, Stevens-Johnson syndrome (SJS), and similar conditions.

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Technological Advancements in the Next-Generation Scleral Lenses:

‍The next-generation scleral lenses incorporate significant technological innovations compared to traditional scleral lenses, enhancing stability and comfort. These lenses are often referred to as "mini-scleral lenses," measuring between 15-18mm in diameter, while traditional scleral lenses are larger than 18mm. The smaller size allows them to completely bypass the cornea while avoiding irregular areas at the periphery of the eye white, reducing lens weight and minimizing displacement caused by gravity.

The next-generation scleral lenses employ a toric haptic design that closely conforms to the true shape of the sclera, further improving lens stability. They also support quadrant-specific modification for precise adjustments based on the topography of the cornea and sclera. The development of ultra-high oxygen-permeable materials ensures that these lenses can be worn comfortably throughout the day and may include coatings to enhance hydration and overall performance.

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Full-Eye Topography-Guided Custom Scleral Lenses

In the past, scleral lens fitting relied heavily on trial lenses. Patients had to wear trial lenses and wait for the lens settlement before practitioners could start designing the product lenses. The process often required back-and-forth modifications on the lens height, curvature, or diameter, as well as frequent switching of trial lenses. Lens performance was further limited by design restrictions and observation errors. Studies have also shown that over 60% of people have asymmetric scleral shapes, which makes traditional scleral lens fitting even more challenging and highlights the limitations of the conventional trial-and-error method.

At Berlin Optical, we are the first scleral lens fitting centre in East Asia to introduce the ESP scleral topographer. By scanning both the cornea and scleral surface, the ESP system generates a highly precise 3D map of the eye and transmits the data to the overseas experts to design fully customized scleral lenses. These lenses are created with freeform technology, allowing the lenses to reproduce complex ocular contours with exceptional accuracy. They can effectively vault over conjunctival irregularities such as pingueculae, eliminating the needs of multiple modifications. Full-Eye Topography-Guided Custom Scleral Lenses conform perfectly to each individual’s unique eye shape, significantly enhancing comfort, accuracy, and overall visual performance.

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Wavefront-Guided Custom Scleral Lenses

While scleral lenses with standard optics can correct optical imperfections and irregular astigmatism on the corneal surface, they are unable to neutralize optical flaws originating from deeper corneal layers and the internal structures of the eye. These uncorrected optical imperfections are scientifically known as Higher-Order Aberrations (HOA). The visual symptoms they produce include glare, halos, starbursts, and ghosting—commonly described as light or light sources appearing scattered, unfocused, and lacking clarity. The impact of higher-order aberrations is particularly pronounced at night when the pupil is dilated, which is why many people notice that light appears more scattered and distorted in low-light conditions compared to daytime. Individuals with conditions such as keratoconus or those who have undergone refractive surgery like LASIK or SMILE—where the corneal shape has been altered—are more likely to experience visual disturbance. After wearing scleral lenses, some people may achieve visual acuity of 1.0 (20/20) or better, yet the visual quality may still remain suboptimal. This is because scleral lenses with standard optics may not effectively correct all higher-order aberrations to an ideal level.

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However, with continuous innovation in scleral lens technology, lenses that offer pre-designed higher-order aberration correction—and even fully customized wavefront-guided scleral lenses—have now been developed! Their basic principles and differences are as follows:

1. Pre-Designed HOA-Correcting Scleral Lenses: These lenses are designed with two pre-set correction versions targeting several higher-order aberrations that most significantly impact visual quality, such as spherical aberration, coma, and trefoil. During the scleral lens trial fit, these trial lenses are applied to evaluate their corrective effect. If the results are satisfactory, the same optical design is incorporated into the final lenses.

2. HOA Customized Scleral Lenses: Also known as wavefront-guided scleral lenses, these are customized based on a detailed wavefront analysis of the entire eye taken while the patient is wearing scleral lenses. This process uses a precise aberrometer to capture optical imperfections that remain uncorrected by the scleral lenses with standard optics . The unique optics is then engraved onto the final lenses to counteract the patient's higher-order aberrations.

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Wavefront-guided custom scleral lenses represent the most advanced scleral lens category available today. This is an important breakthrough for scleral lens wearers who suffer from optical imperfections such as glare, halos, and starbursts. This technology enables patients with keratoconus and other conditions causing higher-order aberrations to achieve high-definition vision. At Berlin Optical, we are proud to be the first and currently the only scleral lens fitting center in Asia to introduce wavefront-guided scleral lenses. We are also one of the very few advanced fitting centres in the world that is equipped with the ESP scleral topographer and capable of fitting full-eye topography-guided scleral lenses. By combining these two world-class custom scleral lens technologies, we can truly tailor scleral lenses to each individual's unique optics and ocular surface anatomy. The stable and well-fitted lens design achieved through the ESP, combined with the wavefront-guided optics, maximizes both comfort and visual quality. This brings more patients to the world of high-definition vision and allows them to rediscover the beauty of life.

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Suitable Candidates for Wavefront-Guided Scleral Lenses:

• Patients with keratoconus or corneal irregularities who, after wearing standard scleral lenses, still desire further improvement in their vision.
• Patients who are dissatisfied with the outcomes of refractive surgery and continue to experience poor night vision, scattered light, or unfocused light sources even after being fitted with scleral lenses.
• Individuals without corneal disease or a history of refractive surgery but who are particularly sensitive to visual imperfections such as glare, halos, starbursts, or ghosting, and still perceive their vision as "blurry" despite wearing scleral lenses.

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Fitting Process for Wavefront-Guided Scleral Lenses:

1. Scleral Lens Trial Fit: After fitting a trial lens, a full-eye wavefront analysis is performed to assess residual higher-order aberrations and determine whether HOA-customization technology is necessary.
2. Confirm the Scleral Lens Design: Using the ESP Scleral Topographer, topography-guided scleral lenses are crafted to match the eye's contour. After the lens alignment and comfort are optimized at the follow-up visits, specific trial lenses with identical lens design and parameters are ordered for the total HOA measurement. Even if there is uncorrected refractive error or astigmatism at this stage, it does not affect the customization of the wavefront-guided trial lenses.
3. Measure the Total HOA Distribution: The patient wears the wavefront-guided trial lenses, and the total higher-order aberration values are carefully captured. These specialized trial lenses contain specific markers that allow the aberrometer to accurately record the lens's rotation and displacement on the eye.
4. Start Using the Wavefront-Guided Scleral Lens: The patient receives the HOA- customized scleral lenses, and their performance and visual quality are evaluated. Correcting total HOA may vary the required lens power and astigmatism correction. Therefore, some wearers may need lens adjustments to adjust the lens power to refine the vision.

Frequently Asked Questions about Scleral Lenses

1. What is the difference between scleral lenses and other contact lenses?

Scleral lenses differ from other contact lenses in several key aspects:

a. Shape and Size: The next-generation scleral lenses typically fall into the category of mini-scleral lenses, which measure between 15-18mm in diameter, slightly larger than soft contact lenses. These lenses are designed to completely cover and bypass the cornea, resting on the less sensitive sclera (the white part of the eye), with the space between the lens and cornea filled with preservative-free saline or artificial tears. In contrast, traditional contact lenses (both soft and rigid) do not bypass the cornea, making their stability highly dependent on the shape and condition of the cornea.

b. Contact Points: The design of scleral lenses allows them to land on the sclera rather than directly contacting the cornea. This design avoids pressure and friction on the cornea, potentially enhancing comfort for wearers.

c. Visual Effects: Scleral lenses create a tear reservoir that fills in irregularities on the corneal surface, improving vision. This is particularly beneficial for individuals with irregular corneas or high astigmatisms.

d. Corneal Rehabilitation: Scleral lenses act as a protective shield for the cornea, blocking external environmental disturbances while keeping the cornea hydrated with saline or artificial tears, thus promoting corneal healing. Traditional contact lenses do not provide the same rehabilitative effects.

2. Are Scleral Lenses Safe?

Scleral lenses have a history of over 100 years, and recent technological advancements have made them the fastest-growing type of rigid contact lens in the United States. The FDA has cleared scleral lenses for use as a non-surgical option to treat certain eye conditions, such as dry eye disease.

At Berlin Optical, our professional optometrists conduct comprehensive eye examinations for each scleral lens patient to assess the feasibility of wearing these lenses, ensuring that each individual is suitable for the treatment. After fitting, our optometrists provide detailed instructions on how to wear and remove the lenses, along with follow-up appointments to ensure safe use.

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3. Why are Scleral Lenses an Effective Treatment Option for Irregular Corneas (e.g., Keratoconus)?

Scleral lenses can correct irregular corneas and restore vision. An irregular cornea, such as in keratoconus, is one in which the shape of the cornea is no longer optically perfect but becomes conical or distorted. This condition causes light to disperse when entering the eye, affecting vision.

Scleral lenses utilize a tear reservoir to smooth out optical imperfections caused by the irregular cornea and the lenses also completely bypass the cornea. This design alleviates concerns about lens instability due to corneal deformation, ensuring effective wear without compromising comfort or vision quality.

4. How are Scleral Lenses Priced?

Scleral lenses need to be replaced approximately every two years. The pricing includes a pair of scleral lenses as well as all follow-up consultation fees. The cost will be decreased at the lens replacement and onwards.

‍Our Optometrists at Berlin Optical

Jeff graduated with First Class Honors from the University of Melbourne with a Master of Clinical Optometry and a Bachelor of Science in Optometry (Honors) from the Hong Kong Polytechnic University. He is currently in private practice at Berlin Optical Vision Center and also serves as a visiting clinical associate at the School of Optometry at Polytechnic University. Additionally, he has been a visiting lectuer and an expert blogger for the Oh! Parent-Child Platform. Jeff is also often invited to participate in academic conferences around the world, committed to addressing the eye care needs of different types of clients.

Jeff also continuously advances his expertise in various areas of optometry, including obtaining a certificate in orthokeratology from the Polytechnic University, which involves vision correction through orthokeratology lenses (OK lenses) particularly suitable for those who love sports and prefer not to wear glasses; and completing a certificate from the Optometric Extension Program Foundation Clinical Curriculum in the United States. This program involves a series of examinations and visual training to improve problems with binocular coordination in children and visual-related learning issues in children with Special Educational Needs (SEN).

Moreover, Jeff has successfully attained the qualification of Fellow of The American Academy of Optometry. The American Academy of Optometry, established in 1922, is an organization dedicated to advancing the optometric profession. To achieve fellowship status, optometrists must have certain educational qualifications and professional experience, demonstrate their professional knowledge and competence by writing various case reports and passing an interview to meet internationally recognized standards.

According to the website of the American Academy of Optometry, there are currently only around 30 optometrists in Hong Kong who hold this qualification.

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Jeff is one of the pioneers of personalized scleral lens fitting in Asia and the first clinical eye care professional in the region to introduce advanced topography-based and wavefront-guided scleral lenses. He has managed a wide range of vision rehabilitation needs using scleral lenses, including various irregular corneal conditions, different types of dry eye, and other ocular surface diseases, all to enhance patients' visual quality and quality of life. Every month, there are patients visiting Hong Kong for scleral lens consultations and assessments with Jeff.