Principles of Gonioscopy | 合法醫療器材資訊網

2017年11月8日—Inmoderngonioscopy,contactlensesareusedtoovercometheproblemoftotalinternalreflection.Twobasictypesoflensareused:thedirect ...

The links to each individual chapter of the Color Atlas of Gonioscopy are available at the Chapters link, below.

Viewing the anterior chamber of a normal eye directly (3‑1) is not possible. Light from the junction of the iris and cornea strikes the tear–air interface at a shallow angle, and it is totally reflected back into the eye (3‑2). This is the principle of total internal reflection. If light from the interior of the eye strikes the cornea at an angle steeper than 46° (the critical angle), the light will exit the eye and the trabecular meshwork will be visible (Shields, 1992). Rarely, this may occur in eyes with keratoconus, keratoglobus, or severe myopia (3‑3). The angle of approach to the trabecular meshwork can be altered if the limbus is indented, as shown by Trantas in his initial description of gonioscopy (3‑4) (Trantas, 1907).

In modern gonioscopy, contact lenses are used t...