HEINE Direct Ophthalmoscopy — How to perform Ophthalmoscopy

Summary

This video tutorial on ophthalmoscopy covers the essential steps for performing a thorough eye examination using a direct ophthalmoscope. The process is divided into three stages: understanding the instrument’s components, preparing both the patient and the ophthalmoscope, and performing the examination. Key topics include recognizing the red reflex, assessing the optic disc, and exploring the ocular fundus for common eye pathologies. The video also highlights the limitations of the technique, including the monocular view and limited field of focus. Regular practice is emphasized to master this critical skill, especially for diagnosing eye and systemic conditions.

Takeaways

• 😀 Ophthalmoscopy allows examination of the back of the eye through the pupil and is crucial for diagnosing both eye and systemic diseases.
• 😀 The direct ophthalmoscope, introduced over 150 years ago, remains a key instrument for eye examination, with some design refinements over time.
• 😀 The ophthalmoscope has three basic controls: an on/off switch that adjusts brightness, a lens wheel to focus, and a light aperture to change the shape and size of the light source.
• 😀 To prepare for ophthalmoscopy, ensure the instrument is on, set to zero focus, and choose a large round aperture for illumination.
• 😀 Ideally, the patient’s pupils should be dilated for a clearer view, and glasses should be removed unless they are very high-powered.
• 😀 Position yourself approximately 15 degrees temporal to the patient’s visual axis to align with the optic disc for examination.
• 😀 The red reflex, seen as the light reflected from the back of the eye, helps assess the clarity of ocular media and detect opacities like cataracts or corneal scars.
• 😀 The optic disc is the reference point for examining the fundus, and it's important to look at its margin, color, and central cup.
• 😀 Blood vessels radiating from the optic disc are used to assess the four vascular arcades, and the patient can help by looking in the direction of the quadrant to be examined.
• 😀 The macular region and fovea are examined last, and the patient should be asked to look directly at the light to bring the fovea into view.
• 😀 Limitations of direct ophthalmoscopy include its high magnification and small field of view, making it difficult to view the entire fundus at once, and its monocular nature, which limits depth perception.

Q & A

What is ophthalmoscopy, and why is it important?

Ophthalmoscopy is the examination of the internal surface at the back of the eye through the pupil. It is important because it helps diagnose not only intrinsic eye pathologies but also systemic diseases through their ocular manifestations.

Who invented the direct ophthalmoscope and when?

The direct ophthalmoscope was invented by Hermann von Helmholtz in 1850, and although there have been optical refinements, the basic principles of its operation remain unchanged.

What are the three basic controls common to all modern ophthalmoscopes?

The three basic controls are: 1) the on/off switch which also adjusts brightness, 2) the lens wheel which adjusts focus, and 3) the light aperture control, allowing different shapes and sizes of apertures.

How does the lens wheel on the ophthalmoscope function?

The lens wheel allows you to adjust the focus by rotating it. Turning it clockwise increases the lens power, bringing the focal point closer, while rotating it anti-clockwise decreases the lens power, moving the focal point further away.

Why is it recommended to remove the patient's glasses during ophthalmoscopy?

It is generally recommended to remove the patient's glasses because they can cause reflections and artifacts that hinder the examination. However, for patients with high refractive errors, leaving glasses on may be helpful.

What is the purpose of the red reflex during ophthalmoscopy?

The red reflex is the reflection of the ophthalmoscope light off the back of the eye, primarily from the choroidal vessels. It is useful for assessing the clarity of the ocular media, as opacities like cataracts or corneal scars may obscure or alter the reflex.

What is the primary goal when examining the ocular fundus?

The primary goal when examining the ocular fundus is to identify and focus on the optic disc, which serves as a reference point for exploring the rest of the fundus.

What are the characteristics of a healthy optic nerve head?

A healthy optic nerve head appears orange-pink in color, with a clear disc margin and a central cup from which the blood vessels emerge.

Why is it difficult to assess the height and depth of structures in the eye during ophthalmoscopy?

The direct ophthalmoscope is a monocular instrument, which means it provides a flat, two-dimensional image. This limits the ability to assess depth and height accurately, as stereoscopic vision is necessary for this.

What are some common pathologies that can be identified through ophthalmoscopy?

Some common pathologies include pale atrophic discs (seen in multiple sclerosis or optic nerve trauma), swollen discs (indicating raised intracranial pressure), enlarged cups (indicating glaucoma), new disc vessels (in proliferative diabetic retinopathy), and pigment aggregation (seen in retinitis pigmentosa).

What is the significance of the macular region during ophthalmoscopy?

The macular region, located within the central retina, is crucial for detailed vision. It contains the fovea, which is the area responsible for sharp central vision. Examining this area can reveal conditions like age-related macular degeneration.