Fluorescein dye is used to detect defects of the cornea as well as tear quality. It is also used to evaluate the flow of the tears through the nasolacrimal duct to the nostrils.
A hand-held microscope (slit lamp) allows precise localization of lesions within the eyelids, cornea, anterior chamber, lens, anterior vitreous and using an interposed biconvex lens, the posterior segment including the retina. The magnification permits the ophthalmologist to find small foreign bodies, misplaced eyelashes and microscopic signs of ocular disease.
The direct ophthalmoscope gives a largely magnified view of the ocular features. Performing distant direct ophthalmoscopy it is an excellent tool to evaluate even the slightest differences in pupil size.
Using a headset and hand lens allows the ophthalmologist to examine the structures in the back of the eye including the vitreous humor, retina, and optic nerve. Magnification and field of view can be altered by selection of lenses of different strength – typically between 14 dioptres and 30 diopters.
After instillation of an anesthetic drop, a digital tonometer (TonoPen) is gently touched to the patient’s cornea to determine the intraocular pressure. High pressure is indicative of glaucoma while low pressure may be the result of inflammation in the eye.
Schirmer Tear Test
Paper tear test strips are placed inside the patients eyelids for 1 minute. The tears produced by the patient can be measured and evaluated. Detection of low tear production allows early diagnosis of dry eye.