Anterior Segment Evaluation

Cornea and anterior eye assessment with slit lamp biomicroscopy, specular microscopy, confocal microscopy, and ultrasound biomicroscopy

“…Second, SLB has an independent illumination arm centered on the focal plane of the microscope, which allows one to modify the illumination angle with the observation arm, tilt of the light beam, thickness of the beam, the level of illumination, and also to introduce different filters, usually red-free (green), useful to increase contrast in blood vessel or hemorrhages or to view Fleischer ring in keratoconus- and cobalt blue and others (neutral density – useful to decrease brightness, for example, in photosensitive patients, polarizing – reduce patient discomfort). [ 3 4 ]…”

“…Slight side-to-side movements of the joystick to compare the appearance of an area in direct and indirect illumination are recommended for the detection and study of structural details that may be “washed out” under direct illumination. [ 3 ]…”

“…Sclerotic scatter (when the beam is focused on the corneal limbus and produced by a fiber-optic effect of the cornea) is generally used to visualize central corneal edema, haze, scarring, infiltrates, and foreign bodies. [ 3 ]…”

“…The eye care practitioner should conduct a standard examination routine with an anterior-to-posterior approach which should be completed and repeated on each patient, to guarantee that nothing is overlooked and all structures examined for abnormality. [ 3 7 ]…”

“…With this approach, the lashes, eyelids, and their margins are examined first (direct and diffuse illumination with low [less than, ×10] or medium magnification [between ×10 to ×25] is recommended in this step), followed by the assessment of the tear film, conjunctiva (bulbar and fornix), and cornea (parallelepiped and/or optic section with high illumination and medium-to-high magnification is recommended). [ 3 4 ] Two or three scans across the cornea, with the beam directed from both the nasal and temporal sides, superior, inferior, and center, are recommended to guarantee a complete examination. High magnification (more than ×25) is recommended for the detailed assessment of corneal findings.…”