Evaluation of the depth of the anterior chamber
Last reviewed: 23.04.2024
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Before investigating the angle configuration, the Van Chrik Schaffer method is used to estimate the depth of the anterior chamber. Evaluation is carried out when the patient is examined using a slit lamp. The cornea is perpendicularly illuminated with the smallest light beam near the limb from the temporal side (creating an optical cut) and viewed at an angle of 50-60 ° to the axis of illumination. To assess the depth of the anterior chamber, the relationship between the irido-corneal distance and the thickness of the cornea is important. If the distance is more than 50% of the thickness of the cornea, it is most likely that the anterior chamber is deep, with a wide angle configuration; if the distance is less than 50% of the thickness of the cornea, a narrow angle can be assumed.
The value of the angle can be estimated as follows:
- The degree of 0 (closed) iris adjoins the endothelium of the cornea.
- Degree I - the space between the iris and the cornea is less than 25% of the thickness of the cornea.
- Degree II - the space between the iris and the cornea is 25% of the thickness of the cornea.
- Degree III - the space between the iris and the cornea is 25-50% of the thickness of the cornea.
- The degree of IV between the iris and the cornea is more than 50% of the thickness of the cornea.
This technique does not replace gonioscopy, but it is very useful for assessing the depth of the anterior chamber, especially in patients with opaque or turbid cornea.
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