The Humphrey visual field is a **diagnostic test to measure visual fields, or perimetry**. The Humphrey visual field test measures the entire area of peripheral vision that can be seen while the eye is focused on a central point.
Central corneal thickness (CCT) has emerged as an important predictive factor for the development of glaucomatous damage. Although a child's cornea reaches adult thickness by the age of 3, little has been reported about normal CCT measurements in eyes of children.
The "air puff test" is a slang term for **non-contact tonometry** (NCT), a test used during an eye exam to measure the pressure inside your eye. The air puff test gives your eye doctor an eye pressure reading known as intraocular pressure (IOP), which helps detect glaucoma.
Optical coherence tomography (OCT) provides noncontact and noninvasive retinal nerve fiber layer (RNFL) thickness measurements and has become an essential clinical measure for objective glaucoma assessment.
Colour fundus photography (CFP) and fluorescein fundus angiography (FFA) showing different features of diabetic retinopathy (DR). (A) An eye with mild non-proliferative diabetic retinopathy (NPDR) presented with microaneurysms (short arrows), haemorrhages (long arrows), as well as hard and soft exudates (arrowhead).
Fundus fluorescein angiography (FFA) is an invasive diagnostic procedure. It helps to assess the anatomy, physiology, and pathology of retinal and choroidal circulation. It aids in the diagnosis of various ocular pathologies. It contributes to decision-making when planning the management of ocular pathology.
B-scan ultrasonography (USG) is a simple, noninvasive tool for diagnosing lesions of the posterior segment of the eyeball. Common conditions such as cataract, vitreous degeneration, retinal detachment, ocular trauma, choroidal melanoma, and retinoblastoma can be accurately evaluated with this modality.
Ocular biometry refers to the measurement of anatomical dimensions of the eye, which include corneal curvature (keratometry, axial length, and anterior chamber depth. These measurements are primarily used to calculate the appropriate power of the intraocular lens (IOL) to be implanted during cataract surgery.
Optical coherence tomography (OCT) provides cross-sectional images of the retina, the light-sensitive layer at the back of the eye that communicates with the brain and enables people to see. The macula is the part of the retina that allows central vision so people can see objects or text directly in front of them.
