A Guide to Understanding Glaucoma – Dr Vertika Kulshrestha

An eye disease that gradually steals your vision is Glaucoma. Glaucoma has no symptoms in its early stages usually. In the absence of proper treatment, Glaucoma can lead to blindness. In this condition, usually, there is too much pressure in your eye that can damage your optic nerve. The optic nerve performs an essential job of sending signals from your eye to your brain, which turns them into an image you can see. You will get problems with your vision when the optic nerve is not working right. You can even lose your sight. But the good news is that with regular eye exams, early detection, and treatment, you can easily preserve your eyesight. You will get a complete introduction to the facts about Glaucoma with this guide.

The main types of glaucoma are open-angle and angle-closure. These are marked by pressure inside the eye or by an increase of intraocular pressure (IOP).

Open-Angle Glaucoma

It is the most common type of glaucoma, accounting for at least 90% of all glaucoma cases:

Slow clogging of the drainage canals, which results in increased eye pressure, causes it.
It has the presence of a wide and open angle between the iris and cornea
This develops slowly and is a lifelong condition
The symptoms and damage are not noticeable.

Angle-Closure Glaucoma

This form of Glaucoma is less common:

It results in a sudden rise in intraocular pressure caused by blocked drainage canals.
It has the presence of a closed or narrow-angle between the iris and cornea
It develops very quickly
The symptoms and damage are usually very much noticeable
It demands immediate medical attention.

Normal-Tension Glaucoma (NTG)

Even though the eye pressure is not very high, still the optic nerve gets damaged in it.

Congenital Glaucoma

This type of Glaucoma can be found in babies when there is incomplete or incorrect development of the eye’s drainage canals during the prenatal period.

Risk Factors

Substantial risk factors for open-angle glaucoma include:

High pressure in the eyes
The presence of the family history of Glaucoma
Thin Cornea
The suspicious appearance of the optic nerve with increased cupping (size of the cup, the space at the center of the optic nerve, is larger than usual)

Potential risk factors for open-angle glaucoma include:

High myopia (very severe nearsightedness)
Diabetes
Eye surgery or injury
High blood pressure
The use of corticosteroids (for example, eye drops, inhalers, pills, and creams)

Risk Factors for Angle-Closure Glaucoma

Age of 40 and above
Presence of the family history of Glaucoma
Low short-distance vision (farsightedness)
Some eye injury or surgery

Risk Factors for Normal-Tension Glaucoma

Cardiovascular disease
Family history of Glaucoma
Low pressure in the eyes

Signs and Symptoms

The signs and symptoms vary according to the type and stage of the condition of Glaucoma. For example in:

Open-angle glaucoma

There is patchy blind spots in your side (peripheral) or central vision, frequently in both eyes
Presence of tunneled vision in the advanced stages.

Acute angle-closure glaucoma

Blurred vision
Halos around lights
Eye redness
Severe headache
Eye pain
Nausea and vomiting

Glaucoma will eventually cause blindness if left untreated. About 15 percent of people with Glaucoma become blind in at least one eye within 20 years, even with treatment

Five Common Glaucoma Tests

Early detection is the key to protecting your vision from damage caused by Glaucoma through regular and complete eye exams. A comprehensive eye exam includes five standard tests to detect Glaucoma.

A Comprehensive Glaucoma Exam

Five factors should be checked to be safe and accurate before making a glaucoma diagnosis:

Examining…	Name of Test
The inner eye pressure	Tonometry
The shape and color of the optic nerve	Ophthalmoscopy (dilated eye exam)
The complete field of vision	Perimetry (visual field test)
The angle in the eye where the iris meets the cornea	Gonioscopy
Thickness of the cornea	Pachymetry

Two routine eye tests: tonometry and ophthalmoscopy will be included in regular check-ups of Glaucoma.

Tonometry

Tonometry measures the pressure within your eye. Eye drops are used to numb the eye during tonometry.

Eye drops are used to dilate the pupil so that the doctor can see through your eye to examine the optic nerve’s shape and color.

Your doctor may ask you to have one or two more glaucoma exams: perimetry and gonioscopy if your intraocular pressure (IOP) is not within the normal range or if the optic nerve looks unusual.

Perimetry

Perimetry is a visual field test that produces a map of your entire field of vision. This test will help a doctor in determining whether your vision has been affected by Glaucoma or not. One to two times a year, visual field tests are done to check for any changes in your vision after Glaucoma has been diagnosed.

Gonioscopy

This diagnostic exam helps in determining whether the angle where the iris meets the cornea is open and expansive, or is it narrow and closed.

Pachymetry

It is a simple, painless test to measure the thickness of the cornea, which is the transparent window at the front of the eye. Since corneal thickness has the potential to influence eye the pressure readings so pachymetry can help your diagnosis. Your doctor can develop a treatment plan that is right for you by understanding your IOP reading with this measurement.

Effective Strategies To Manage Glaucoma

Glaucoma treatment aims to prevent further vision loss by controlling the eye’s pressure – like regulating blood pressure to prevent a stroke. Glaucoma can be treated successfully by:

Medications: In the form of eye drops or pills, lower pressure by reducing the amount of fluid produced in the eye, and increasing drainage. There can be the usage of one or more medicines at the same time.
Laser therapy: Laser therapy is used to reduce pressure in the eye and is performed on an outpatient basis. Fluid drainage is improved in patients by a procedure called laser trabeculoplasty with open-angle Glaucoma. A technique called laser iridotomy should be used to treat people with closed-angle glaucoma which creates a tiny opening in the iris.
Surgery: To create a second drainage channel in the eye in order to support the natural one, surgery might be needed. The surgery is usually performed on an outpatient basis by using local anesthesia. It may allow the patient to reduce or eliminate glaucoma medications.
Implant: An artificial glaucoma drainage implant may help to decrease pressure for more advanced cases. The excess fluid, which then gets absorbed into the body, the implant helps in draining that.

Dr Vertika Kulshrestha