It is done for objective evaluation of retinal nerve flore layer, and optic disc which are affected (damaged) in glaucoma. RNFL thickness decreases & cupping of optic disc increase with progression of disease.
Central Corneal Thickness :
Its determined to know the true effective IOP from the measured value of IOP.
It helps to determine changes in the size of cup of optic disc occuring over a period of time.
Tonometry is method to measure the intraocular.
IOP is the measure of the fluid pressure inside the eye. It is routine test in middle & elderly aged patients.
There are various methods of determining intraocular pressure (IOP), of which applanation tomometoy is most accurate & gold standard.
It is most useful in patient having glaucoma or suspected to have glaucoma. It is also important test whenever increase in IOP is expected due to some reason.
It is the procedure to measure the curvature of anterior corneal surface.
It is important for:
Calculating power of intraocular lens to be implanted
Fitting of contact lens
For refractive surgeries lite lasik, ICL/IPCL
TO Check corneal astigmatism
It is test to measure the thickness of cornea.
Useful in glaucoma/glaucoma suspects patient for lasik, patients having keratoconus, corneal edema Biometry is done to measure the axial length and depth of anterior chamber.
why is it important:
Axial length is used for calculation of the power of lens to be implanted in the eye after cataract surgery or refractie lens exchange.
Anterior chamber depth is importent for ICL/IPCL implantation. Lesser anterior chamber depth makes patient unfit for ICL/IPCL.
Contact Biometry: In this method, cornea is touched by ultrasound porbe so it is lesser accurate.
Immersion Biometry: Ultrasound poobe does not come in contact with cornea, so it is more accurate.
Optical Biometry: This also is very accurate.
Fundus fluorescein Angiography:
In this test, fluorescein dye is injected intravenously and instantly photographs of the retina are taken by special equipment called fundus cemera.
It is useful for seeing the status of blood vessels of retina for thereby helps in making diagnosis of retinal diseases and optic nerve disorders. It is also useful to check the benefits of prior retinal treatment like laser or intravitreal injection.