The first thing to understand is that fitting a contact lens to a Keratoconic eye is more of an art than a science. It does not compare to being fitted with spectacles. Obviously, refraction (measuring the focusing characteristics of the eye), is an essential part of the process but there are so many other factors to be taken into account and compromises to be made.
The eye does not curve at a uniform rate and it is often the curve at the edges that causes discomfort as it rubs against the lid or sometimescorneal contact in the middle causes the problem.
The patient needs to have confidence in the optometrist’s judgement. The fit can change from day to day and even hour to hour and there can never be a definitive solution.
There are so many other factors to take into account and the optometrist does not have unlimited time to assess the patient’s physiological and practical needs.
Patients have different levels of tolerance and perseverance. They may need to see clearly for short periods to work or maybe they can accept poorer vision for longer periods. So try to be as helpful as you can.
If it is your first hospital optometrist appointment it will be a lot longer than a typical high-street optician appointment for spectacles. As well as normal refraction tests, the front and back of the eye will be examined with a slit-lamp, this may involve using fluorescein drops too. Sometimes a scan of the surface of the eye (corneal topography) is done, which is a painless procedure using a red light that passes progressively across the eye. This helps to assess the degree of keratoconus and understand the irregularity to assist with fitting a lens.
It is important that as a patient you have a clear idea of what you want and how much discomfort you can tolerate. So, when you sit down with the optometrist bear in mind that they are trying to assess many things:
- the best materials and type of lens
- Your lifestyle
- Your needs Work/Leisure
- Some lenses will give sharper vision for short periods others will be more comfortable for longer periods.
Be clear about what your needs are:
- Is it distance vision
- Is it reading vision
- Is it driving
It is not unusual to wear spectacles for driving or reading over your contact lenses.
When your lens is prescribed do make sure that you understand and are competent with the procedure for inserting and removing your lens.
Once you have your lenses and start wearing them, stick to the recommended wearing time and rest intervals your optometrist has recommended. You should do this even if the lens is feeling OK. It does take time for the eye to adjust to having a lens on the cornea.
It is helpful to keep a diary recording such things as how long you can wear them, the levels of discomfort and practical issues you have faced such as:
- Reduced/changing vision
- Ghosting/diplopia (double vision)
- Flare, especially at night
- Light Sensitivity
- Allergic sensitivity to types of pollen/times of the year
This way you can give the optometrist a history of your symptoms, such as:
- What the main problems are
- Occupational related issues
- How do you manage when the lenses are out
- Is there pain associated with contact lens wear (what type of pain – put lens in early so that the Optometrist can see what the discomfort is like)
You will then be in a much better position to relate to the optometrist and they, in turn, will be more motivated to work with you to find the best solution.
It is very important that you rigidly stick to the cleaning and storage instructions you are given to avoid unnecessary infections:
- Ensure appropriate contact lens cleaning solutions are used
- Do not mix solutions
- Rinse cleaning products thoroughly
- Dispose of out of date bottles
- Change solutions daily
- Change the case weekly if possible
- Try lubricating the eye to reduce intolerance
When you attend the clinic:
- Be aware of your contact lens specification (Take a photo on your phone)
- Keep a diary
- Bring your solution and cases
- Bring a sample of print you would like to read
- Keep broken lenses
You should be given a follow-up appointment, but if you have serious concerns, contact your hospital for advice.
Please remember that with Keratoconus symptoms vary; not only day to day but moment to moment and fitting lenses can be very challenging. The perfect lens does not exist and the best lens may become unsuitable/harmful. Your lifestyle will influence the outcome.
Communication is important so give feedback. Because of the uniqueness of the condition, the optometrist will likely get to know you and develop a personal interest in your progress. They will be very interested in any feedback you can provide.
The points raised here were taken from a talk given by Dr Waheeda Illani which can be viewed here: https://www.youtube.com/watch?v=Iral-MOxJ5M