Ophthalmology - the study of diseases of the eye.
The eye is a complex and exciting organ which, in the event of illness, often requires personnel with extra expertise in just the eye as well as advanced equipment. The eye is made up of several layers; an outer protective layer (cornea and tendon), a middle layer which is responsible for the supply of nutrients and the removal of waste substances and finally the innermost layer with the optic nerve. Using different techniques and instruments, all these layers must be assessed from the outside and by looking in through the pupil.
Table of contents
WHEN DO YOU EXAMINE THE EYE?
Often a visit to an eye specialist or an ophthalmologist is made because the owner has registered signs of illness. Typical symptoms the owner notices are: damage to the cornea, pinching, tearing and color change. Apart from illness, eye examinations are also done routinely throughout the animal's life and in connection with breeding. For some breeds there is a requirement for an "eye examination certificate", the vet then excludes symptoms of various hereditary diseases. If you want a routine check-up, we recommend an eye examination at ophthalmologists at 1,3, 7 and XNUMX years.
Below is an overview and description of typical investigations that are carried out. In addition to the specific eye examinations mentioned below, ultrasound, MRI and other diagnostic imaging can be used if necessary. An eye examination is not painful unless the eye is damaged. Then it can be painful to get light in the eye.
Conversation with owner and visual inspection
Initially, the vet talks to the owner about what the visit is about. What is the main problem, when did it start, has the animal had the same or a similar problem in the past, has there been an incident etc. At the same time as talking to the owner, the animal is observed from a distance. Mental status, orientation ability, winking, pinching and more are important information. Then you may do some tests to check reflexes, these are not described in this text.
Schirmer's tear test
Schirmer's tear test is used to assess tear fluid production. It is a simple test where a strip of paper with a millimeter scale is placed between the conjunctiva and the eyelid. The strip is impregnated with a blue color at the bottom, this creeps up the strip together with the tear fluid and makes it easier to read the result. The Schirmer test is usually one of the first examinations carried out during an eye examination and must be carried out before applying eye drops or the like.
Results
Tonometry
Tonometry is a method used to measure the pressure inside the eye using a tonometer. Eye pressure is an important indicator of eye health, especially in connection with glaucoma, where elevated pressure can damage the optic nerve. A pressure that is too high or too low can also be a symptom of other eye disorders. When performing tonometry, positioning and handling of the instrument is critical to obtaining accurate measurements. Some tonometers require touching the surface of the eye, while others measure the pressure without direct contact.
Fluorescein
Fluorescein test is a diagnostic method that uses a special dye to detect wounds or damage to the cornea. When fluorescein is applied to the eye, it attaches to damaged tissue and lights up when illuminated with blue light. This makes it easier to identify wounds, tears or foreign bodies on the cornea, which is particularly useful in the case of injuries or infections. The method is quick and painless, and is often used when damage to the surface of the eye is suspected.
Slit lamp
A slit lamp is an advanced optical instrument that functions as a mobile microscope for detailed examinations of the outer and inner parts of the eye. With the slit lamp, the eyelid, cornea and parts of the eye's internal structures, such as the iris and lens, can be seen in detail. The strong light source combined with the microscope makes it possible to assess small structures and detect any damage or disease. The use of the slit lamp requires special training, and a lot of practice is necessary to master the technique.
Ophthalmoscope
The ophthalmoscope is an instrument designed to examine the retina and other structures at the back of the eye. There are different types of ophthalmoscopes, including direct and indirect varieties. Often, the veterinarian will use a lamp on the head along with a magnifying glass in front of the eye being examined, which provides a detailed image of the retina. This examination can reveal signs of diseases such as retinal detachment, tumours, or diabetes-related changes.