This course will review anterior segment pathologies and the role of anterior segment OCT in the fitting of scleral lenses to manage these conditions. Selected cases are included at the end of the course, as is a quiz.
The anterior segment includes structures in the front one-third of the eye, starting from the cornea to the crystalline lens. The cornea and ocular surface are especially complex, and, when functioning correctly, allow for clear and comfortable vision. However, significant visual impairment can result from abnormalities at the front of the eye, namely corneal ectasias and dry eye disease.
Anterior segment OCT can also be useful in managing glaucoma specifically when examining the angle, blebs, tubes and laser iridotomy assessments. Additionally it can help with managing ocular surface disorders such as dry eye disease, pterygia, pinguecula and scleromalacia. It can be helpful for surgical analysis for cornea, lens/cataract, biometry and LASIK. Anterior segment OCT provides a pivotal role in managing patients with corneal dystrophies and degenerations including keratoconus in addition to anterior segment tumors.
Keratoconus is a chronic, non-inflammatory ectasia of the cornea. It usually involves both eyes, but the severity per eye can be asymmetric. It is characterized by corneal steepening, visual distortion, corneal thinning, and central corneal scarring. Associated clinical findings that can be seen on slit lamp biomicroscopy are Fleischer ring, which are iron deposits around the cone’s base; Vogt’s striae, which are vertical stress marks in the areas of thinning; and apical scarring.
In Image 1, Fleischer ring is represented.
Image 1: Fleischer ring
In Image 2, we see an example of Vogt’s striae
Image 2: Vogt's striae
In Image 3, Apical Scarring is shown.