Ophthalmoscopy - the ophthalmoscope

introduction

The fundus examination, including an ophthalmoscope, Ophthalmoscopy or Fundoscopy called, is a special examination of the eye that enables the examining doctor to take a look at the fundus in order to be able to assess it medically. The fundus implies both the retina (the retina), the choroid, the exit point of the optic nerve and all blood vessels located in the back of the eye. All these parts of the eye are normally not visible to the other person from the outside. In principle, one could say that the fundus is made visible with the help of special mirrors and lighting techniques.

You don't necessarily have to “change” something on the eye itself. The fundus is then illuminated so that the ophthalmologist can assess the various structures such as the retina, the choroid, the nervus oprticus in its exit, the yellow spot and the surrounding blood vessels and recognize any pathological changes and processes. In order to be able to look through the entire eye down to the fundus of the eye, it is of course necessary that the eye, including its vitreous humor, cornea and lens, are free of any cloudiness, deposits or other material that could obstruct the view.

If the ophthalmologist wants to examine the fundus, there are basically two different examination techniques available. The "Indirect ophthalmoscopy" and the "Direct ophthalmoscopy".

Indirect ophthalmoscopy

In the Indirect ophthalmoscopy the ophthalmologist beams the patient with a little lights from a distance of about 60 centimeters into the eye to be examined. The doctor usually uses a so-called head ophthalmoscope. This is a device with an integrated lamp that the doctor can attach to the head, so that he has both hands free for the examination and at the same time can vary the position of the light source. In order to enlarge the fundus, the doctor holds one hand with one Converging lens in front of the patient's eye, about 5 centimeters away from it. The light beam now comes out of the head lamp and falls through the converging lens into the patient's eye and onto the back of the eye. At the same time, the converging lens approximately enlarges the view of the fundus for the ophthalmologist 4.5 times magnification.

If it is necessary for a patient to be able to have a very good overview of the fundus as well as a look at the details, both examination techniques can easily be used combine with each other to give the patient the best possible examination of the fundus.

Direct ophthalmoscopy

In the Direct ophthalmoscopy the principle is basically the same as with the indirect fundus, only with the difference that the ophthalmologist does one electric ophthalmoscope used instead of a head ophthalmoscope. The electric ophthalmoscope is an ophthalmic instrument that looks like a short rod and at one end a mirror with a built-in magnifying glass is attached. The ophthalmologist now sits in front of the patient for the examination and holds the electric ophthalmoscope between the patient's eye to be examined and his own. Like a keyhole the doctor can now look into the patient's eye through the pupil and thus observe and assess the fundus. This is possible because the light that comes from the small integrated lamp in the electric ophthalmoscope parallel to the doctor's line of sight shines into the patient's eye and illuminates it so brightly. Through the ophthalmoscope itself, the image of the retina and other structures on the fundus is around the Enlarged 16 times and the doctor is able to notice and diagnose even the smallest, possibly pathological changes.

The disadvantage of direct ophthalmoscopy is the small size of the illuminated area of ​​the fundus, which, however, is much larger than with indirect ophthalmoscopy. Another difference, which actually has no meaning for the result of the investigation, is the fact that the Image of the fundusthat the doctor can see in the direct ophthalmoscope, stands upright (This means that what is below in the patient's eye is also seen below for the doctor and that which is above can also be seen above for the doctor). In the case of indirect ophthalmoscopy, however, this is the case image of the fundus for the ophthalmologist upside down (So ​​what is below is shown above for the doctor and vice versa).

If it is necessary for a patient to be able to have a very good overview of the fundus of the eye as well as a look at the details, the both examination techniques are readily available combine with each other to give the patient the best possible examination of the fundus.

Drive

Ophthalmoscopy itself is an extreme low risk and easy to perform type of examination and beyond for the patient completely painless. It is important to mention, however, that patients are encouraged to drive to the examination site either from a relative or acquaintance drive and have it picked up again, or with the public transport to arrive. Because in order to have the best possible insight into the eye, the Pupil dilated with medication (like when you are in the dark and the pupils become very large, to be able to capture as much light as possible). The eye dropwith which this in and of itself quite natural movement in the eye can be brought about, last a few hours even after the fundus has been examined, usually around five to six hours after the drop in the eye. During this period of time, absolutely pinpoint and precise vision is not guaranteed and so is the patient not allowed to actively participate in road traffic!

However, this is no cause for alarm: the patients themselves usually do not notice very much of the slight blurring. Only reading the newspaper and recognizing distant objects no longer works 100% and so that nothing can happen, it is mandatory to wait until the effects of the eye-widening drops have worn off. These drops are given to the patient in the eye to be examined shortly before the ophthalmoscopy.

How often?

Because the ophthalmoscopy quick and easy to implement it is part of the routine ophthalmological examination of every patient. Not just the diseases that directly affect the eye itself, such as one Retinal detachment (in technical language also as ablatio retinae or amotio retinae) and the widespread macular degeneration in older patients are a reason to have an examination of the fundus.

Numerous other diseases also have effects on the fundus and can lead to pathologically altered processes there. Here are among others the diabetes mellitus that hypertension (High blood pressure) and arteriosclerosis (hardening of the arteries) as the most common representatives. People who suffer from any of these diseases or other diseases that affect the eye should visit their ophthalmologist regularly and have the fundus examined. How often a patient should go for a check-up, depends entirely on the indication. If the eye is healthy and there are no other complaints, it is enough if once a year the fundus of the eye is also assessed as part of a routine ophthalmological check. However, if the eye or both eyes are diseased or if there is a disease that affects the patient's eyes and could also lead to short-term or long-term damage, the patient is encouraged to visit an ophthalmologist more often, in some special cases In some cases, it may even be necessary to check the fundus daily for new complications or changes.

diabetes

Diabetics are a particularly susceptible risk group for a certain disease or consequential damage to the eye. The disease here is called "Diabetic Retinopathy". Because diabetes mellitus is not an acute disease, but rather a slow, creeping process that ultimately affects almost all areas of our body. Of course, it also affects the eyes.

The real problem with diabetics is the permanently high blood sugar levels, which over the years cause damage and pathological changes to the blood vessels all over the body. In terms of the eye, this means that the small blood vessels of the retina (the retina) close over time and the retina can no longer be adequately supplied with blood and nutrients and the extremely sensitive ones Visual receptors die off. In addition, the The walls of the blood vessels themselves are porous and leaky, they leak and the blood can leak into the vitreous humor at these points, which causes additional damage to the sensitive eye. The dangerous thing about diabetic retinopathy is that those affected tend to suffer creeping processes usually remain hidden and even if entire parts of the field of vision should fail, the human brain is still able to cover up these blind spots and fill them in with the information from the second eye.

In the early stages of diabetic retinopathy you can Fluctuations in eyesight and eyesight give an initial indication of the pathological processes. If the disease is more advanced and the damage caused to the photoreceptor cells is greater, the eyesight deteriorates and the image becomes cloudy and distorted (this is called Metamorphopsia). If the bleeding in the retina is very heavy, vision can sometimes be completely lost. Hence, it is extremely important for diabetics to be regular, that is at least once a year to visit the ophthalmologist for an ophthalmoscopy. If the onset of diabetic retinopathy has already been identified, the controls are tied more closely, usually every six months or even once a quarter. Even if the patient has not yet noticed any symptoms, these check-ups should definitely be attended to.

Baby / with children

Another high risk group for pathological changes in the blood vessels of the retina are Premature babiesespecially if they were ventilated with oxygen after birth. Since the baby's retina and its vessels do not fully develop until the last third of pregnancy, it can easily happen in premature babies that this development was not yet fully completed at the time of birth. Of course, this does not necessarily mean that the child will have damage to the eye and retina as a result. But it happens that one slight developmental disturbance in the formation of vessels in the retina occurs. Then the growth of the vessels and the new formation can overshoot, so to speak, as a reaction to the early birth and the associated contact with oxygen and too many form Veins in Fundus. In serious and untreated cases, this can lead to the child's retina peeling off and the eyesight rapidly deteriorating (all too tragic, since the problem usually affects both eyes of the baby). Will the However, fundus is assessed well and regularly by ophthalmoscopy, one can see blood vessel growth assess and control well and intervene therapeuticallyin case problems arise.