Retinal examination: diagnostic procedure for examining the retina

Whether as a preventive measure, for unclear visual disorders or to clarify a known eye disease. The retina is the central sensory organ in the eye through which light is converted into images. Changes to the retina are often gradual – but can lead to permanent visual impairment if left untreated.

Modern methods such as OCT, fundus camera or Optomap now allow precise and contact-free analysis down to the finest structures. In this blog, you will find out when a retinal examination makes sense, how it is carried out, what methods are available – and what role it also plays in preparing for laser eye treatment.

What is a retinal examination – and why is it so important?

The retinal examination is one of the most important diagnostic procedures in ophthalmology. It makes it possible to detect changes to the retina at an early stage – often before symptoms appear. The retina is the part of the eye that processes incoming light and is crucial for vision. Diseases such as macular degeneration, diabetic retinal damage or vascular changes can begin there – and progress unnoticed.

What happens during a retinal examination by an ophthalmologist?

The exact procedure and the choice of examination method depend on whether it is a preventive measure, a follow-up check or the specific diagnosis of a retinal disease.

Retinoscopy with eye drops – the classic method

In classic retinoscopy (ophthalmoscopy), the pupil is dilated using eye drops so that the ophthalmologist can assess the entire back of the eye using a magnifying glass and light source. This allows the optic disc, macula, vessels and peripheral areas of the retina to be inspected in detail.

This method is proven, safe and frequently used for routine examinations and for the early detection of retinal diseases.

After the drops are administered, visual acuity is temporarily restricted – driving is therefore not permitted.

Retinal examination with contact lens – precise insights

For certain issues – such as suspected retinal detachment, vascular changes or tumors – a special contact lens is used. It is placed directly on the anesthetized eye and allows a three-dimensional and high-precision assessment of the retina, especially its outer areas.

This examination is particularly helpful for severe nearsightedness, changes in the peripheral area of the retina or for the follow-up of known diseases. It is not painful, but somewhat more intensive than a simple retinoscopy.

Digital retinal examination with fundus camera or Optomap

Modern devices such as the fundus camera or the Optomap system enable contact-free, high-resolution imaging of the retina – often without pupil dilation. This produces digital images that can be saved and, if necessary, compared with previous recordings.

This non-invasive examination is ideally suited for prevention, documentation and follow-up. Especially for chronic retinal diseases such as AMD or diabetic retinopathy, it is a central component of modern diagnostics.

Modern imaging techniques for retinal analysis

In addition to classic retinoscopy, numerous imaging techniques are available today that allow a detailed representation of the retinal structures – often contact-free and digital. They are particularly important for the early detection, follow-up and documentation of changes to the retina, especially in the area of the macula, the optic disc or the blood vessels.

OCT – Optical Coherence Tomography at a glance

The OCT (Optical Coherence Tomography) is a state-of-the-art, non-invasive procedure that uses light waves to generate cross-sectional images of the retina. This allows even the finest changes to the retina and macula to be detected – often at the earliest stage of a disease.

It is standard in the diagnosis of:

• AMD (age-related macular degeneration)
• Macular edema
• Glaucoma
• Diabetic retinal changes

The examination is fast, painless and possible without pupil dilation.

Fluorescence angiography for visualizing vessels in the retina

In fluorescence angiography, a dye is injected into the arm vein, which is distributed via the blood vessels of the retina. Special cameras then capture how the dye is distributed in the fine retinal vessels. In this way, vascular narrowing, leaks or occlusions can be precisely detected.

It is particularly helpful for:

• Diabetic retinopathy
• Vascular diseases
• Macular changes with fluid accumulation

The method is proven, but somewhat more complex and is used specifically when vascular changes are suspected.

Laser-based diagnostic procedures – precise and contact-free

Modern laser-based procedures, such as the scanning laser ophthalmoscope (SLO), enable contact-free and high-resolution imaging of the retina, often even in sub-optimal lighting conditions or without dilating the pupil. By using special laser light wavelengths, even deeper structures are visualized.

This technique is primarily used in specialized eye clinics or for the early diagnosis of retinal changes and offers maximum precision with minimal stress for the patient.

What role do retinal examinations play in laser eye surgery?

For planned laser eye treatment – for example to correct nearsightedness, farsightedness or astigmatism – the examination of the retina is an indispensable part of the pre-examination. Because even if the laser treatment is performed on the cornea, it must first be ensured that the retina is free of pathological changes.

Why this is so important:

• Severe nearsightedness increases the risk of retinal changes or detachment
• Fine tears, holes or degenerative zones must be identified before the procedure and, if necessary, stabilized with the laser beforehand
• Retinal diseases such as maculopathies or vascular changes can influence the expected visual acuity after laser treatment

Depending on the individual findings, the ophthalmologist will therefore perform one or more retinal examinations (e.g. OCT, fundus camera or contact lens examination) in order to be able to make a well-founded decision on suitability for laser eye surgery.