Scleral lenses are a hard/rigid contact lens with a large diameter, ranging from 14-20mm. They are given the name ‘scleral’ lenses due to the fact that they vault over the cornea (the transparent layer at the front of the eye) and they rest on the sclera (the white part of the eye).
Although these lenses appear of large diameter, they offer great comfort as a result of providing less interaction between the lens edge and the eyelids. The lens also does not touch the cornea and rests on the conjunctiva, which is less sensitive. Scleral lenses do not move on the eye when blinking, and as a result provide stable vision in contrast to the fluctuating vision that can occur in the case of other lens types fitted on irregular corneas.
The space created between the back surface of the lens and the cornea allows for the formation of a liquid reservoir. This reservoir is useful as it corrects a large percentage of corneal astigmatism. Furthermore, it lubricates the surface of the eye during wearing time, which is particularly beneficial for patients with severe dry eye and other ocular surface diseases.
Many indications for scleral lenses include corneal irregularities and ocular surface diseases.
These include keratoconus, keratoglobus, pellucid marginal degeneration, severe dry eye and Sjӧgrens disease, post-penetrating keratoplasty, post-laser refractive ectasia, post-radial keratotomy, small GP and soft contact lens intolerant.
Patients who need vision correction (myopia, hyperopia, astigmatism, presbyopia) but have failed with other contact lens types, could also benefit from wearing scleral lenses.
Your initial visit will include the following:
- A comprehensive history is taken regarding your general and ocular health, as well as your visual requirements
- A full eye health examination of the anterior and posterior eye is carried out
- A detailed examination of the eyelids and ocular glands (which play a vital role in maintaining a healthy tear film)
- A dry eye evaluation will also be carried out
- Corneal topography will be performed on both eyes. This is essential for measuring the curvature of the front surface of the eye. The results of this test assist us in designing the scleral lens needed for your eye.
- An OCT scan will be carried out, which allows us to evaluate the relationship of the lens on the cornea
- To conclude the visit, a customised lens will be ordered for you based on the results of the above tests. The lenses can take 3-4 weeks to manufacture.
- You will be invited back for a follow up appointment, during which the above procedures will be repeated with your customised lens to ensure the best visual potential and comfort is achieved.
We use a range of advanced equipment to help achieve a customised lens for each individual patient. Some of these technologies include:
- Pentacam (Computerised Corneal Topography): this gives a 3D map of the entire corneal surface, providing us with an outline of the curvatures, elevation and depressions along the corneal surface.
- OCT (Optical Coherence Tomography): this is an ultrasound-like scan that allows us to view both the back of the eye and the front the eye. This allows us to image the lens on the patient’s eye and assess the fit of the lens parameters.
- Specular Microscope: this instrument allows us to record and count the number of corneal endothelial cells. This is important to ensure the eyes remain healthy when wearing a scleral lens.
- Slit Lamp Microscope: this allows us to view the lens on the patient’s eye under high magnification using a range of diagnostic dyes applied to the ocular surface. These dyes wash out with the tears naturally and have no negative effect on vision.
With good hygiene and care we expect scleral lenses to last at least one year.
The wear time of scleral lenses depends on the ocular condition present, you will be advised by your lens practitioner.
Plungers should be replaced every three months or sooner if required.
A full teach appointment will be carried out where you will be shown how to insert, remove, handle and care for you lenses, one-to-one with your practitioner.
No, under no circumstance should tap water come into contact with your lenses. Tap water can harbour dangerous pathogens including Acanthamoeba, which can cause a vision threatening and painful eye infection, which is difficult to treat. You are recommended to rinse your lenses with preservative free sterile saline.
No, sleeping in lenses reduces oxygen transmission to the eye. This can cause a swelling of the cornea and in turn results in abnormal blood vessels growing into the normally blood vessel-free cornea.
You can purchase all solutions and accessories through the clinic via email.