The Extended Eye Exam
The tests available in an Extended Eye Examination are:
Threshold Visual Fields (Humphrey Gold Standard)
and
Peripheral Retinal Laser Powered Photograph (Optos)
We are pleased to announce that as of 2010 Ocular Coherence Tomography (OCT) which is Deep Tissue Layer Screening of the Retina especially the Macula Area is now included as part of a standard eye examination
Why The Extra Tests?
The standard tests sometimes reveal issues that need further investigating. There are ocular problems associated with high blood pressure, diabetes, smoking and your environment. There are all sorts of obscure conditions that we can detect, such as eye tumours, retinal detachments and degenerations. With ageing come well known eye problems such as glaucoma, cataracts and Macula Degeneration. The extended tests aid us in the detection, monitoring and management of these various potential eye problems.
We will always recommend an extended test if it is needed to further investigate specific signs or symptoms found during the normal eye examination, such as flashing lights or floaters, high intraocular pressures, or abnormal lesions shown on the retinal photographs. Often the tests are useful for screening purposes when there is a family history of potentially hereditary diseases such as glaucoma, age-related macular degeneration, or loss of vision in elderly family members.
Many people like to have these extended tests done as part of their routine eye examinations, for complete peace of mind.
We obviously recommend regular screening for the most thorough examination (at least every two years). However, as it takes more time and is more expensive we give you the choice. The regular Eye Examination is essential, the Extended Eye Examination might be essential but can also be considered an optional extra - it's up to you. We will insist on the extra tests when they are clinically called for, especially if we are preparing a report for the specialists.
What Exactly Are The Extra Tests?
Threshold Visual Fields
This test records your 'field of vision', or the extent of your visual area when you are looking straight ahead. It is your visual field that allows you to see an object out of the corner of your eye, even when you are not looking directly at it. If there are any abnormal 'blind spots', this test will pick them up.
We use this test primarily to help diagnose if a person has glaucoma and to monitor progression of the disease in a diagnosed patient. Our field machine, a 'Humphrey Field Analyser' is the same test as used in Hospitals and eye departments, and our trained technicians can ensure a very accurate record of your field of vision. Another important application of recording a patients' visual field is in the detection of brain and optic nerve lesions caused by strokes or trauma for example, or very occasionally from pituitary tumours.
The test works by shining a tiny spot of light in various positions in your peripheral vision, whilst you are staring straight ahead. The patient is asked to indicate when they have seen the spot of light by clicking a button. The intensity of the light is varied, so that the analyser can work out the exact amount of light needed for you to see it in every point in your visual field. This is called the Light Threshold. The test is quite tiring so we only do it when necessary.
Once the test is completed the computer compares your results against 10,000 'normal' patients in the same age group. This is to see how much variance you have from the norm.
A patient having their field of vision measured
An example of an abnormal field plot, showing a glaucomatous defect
'OPTOS' Peripheral Retina Photographs
Part of a normal eye examination is to examine your retinas, the light sensitive area at the back of the eyes. The current Retinal cameras photograph 45 degrees of the retina and take close ups of the nerve and macula. If we dilate the pupil we can go out further to perhaps 100 degrees. Using an ophthalmoscope or a Volk lens and a slit lamp we can get to 150 degrees but there are no photographic recordings. The Optos does not need dilation but uses lasers to see around 200 degrees of your retina. It allows us to see almost to the very edges of the retina. Therefore there is a much greater chance of picking up peripheral lesions such as retinal holes, detachments and melanomas. It also gives us a permanent record of what the back of your eye looks like for future comparison and monitoring of disease progression.
A patient having their fundus scanned with Optos.
An example of a fundus picture taken with Optos, which has picked up a melanoma (bottom right of picture)
Optical Coherence Tomography (OCT)
When we take a photograph of the retina, we are essentially looking at the topmost of 9 layers that make up the full retinal thickness. Most of these layers are almost transparent, allowing us some view of the underlying layers, but OCT scans through each of these layers, creating a 'profile' view of each layer, like a cross-section. The most useful application of this is to better examine the central and most important area in the retina, the macula.
It can sometimes be difficult to assess the macula simply by looking at the top layer, as very small changes beneath the surface of the retina can cause significant visual problems. By employing the OCT we get a detailed view of exactly what is going on beneath the macula, and can detect the early stages of both wet and dry age-related macular degeneration , as well as pathology such as central serous retinopathy, macular holes, macular oedema and diabetic maculopathy.
An example of a healthy macula, imaged with OCT.
Procedure
Wherever possible the Extended Examination will be done straight after the normal examination. This can add up to 45 minutes to the time but usually about 20 minutes is sufficient. It can also be booked as a stand-alone appointment. Usually the tests are reviewed later in the day and we will contact you with the results
The tests will be done by the practice technicians, Jason Huque, Richard Cox or Matthew Carter
Referrals and Reports
You may request a full report of your examination results for your own records, or we may need to prepare a report for referral to an Ophthalmologist. These reports are quite extensive and require a large amount of time to prepare, as there are always lots of pictures to be printed or transferred onto CDs. Some of the Retinal Specialists have software provided by us to see the results on their own computers.
If we decide that you need to be referred, we will always try to recommend an Ophthalmologist who specialises in your particular problem. We have several choices in many specialist areas and the choice may be made on practical considerations like area, availability and cost. A full report will be prepared and passed on to the specialist or it can be sent to you to take to your GP for a referral through the NHS. In our experience the NHS does a good job but you do need to be patient if you take this route.
So What Does It Cost?
The fees are split as follows: -
1) 30 minute Eye Examination and regular tests ........................ £ 130.00
2) Threshold Fields (Humphrey Gold Standard) ......................... £ 73.00
3) Optos Peripheral Photography .......................................... £ 45.00
4) Full Eye and Extended Examinaton and Report ..................... £ 240.00
5) DVLA Estermann Test (For Drivers License) .......................... £ 40.00
If tests have to be repeated within 6 months then a 10% discount will be applied.