Difference between Glaucoma and Cataract

Glaucoma

Affected area

Vision loss

Parameter

Glaucoma

Open-angle glaucoma

1. No symptoms at first
2. Over time, patchy blind spots in peripheral vision (side vision)
3. Difficulty seeing things in central vision (during later stages)

Angle-closure glaucoma

1. Severe eye pain
2. Severe headache
3. Nausea and vomiting
4. Redness of the eye
5. Blurred vision
6. Seeing coloured rings or halos around light

1. Blurry or cloudy vision
2. Yellowing or fading of colours
3. Night blindness
4. Double vision in a single eye
5. Extra sensitivity to light
6. Seeing halos around lights
7. Frequent changes to your glasses prescription

Risk Factors

1. Age above 60
2. Family history of glaucoma
3. Black, Asian, or Hispanic heritage
4. Corneas thin at the centre
5. Previous eye injury or eye surgery 
6. Myopia or nearsightedness (for open-angle glaucoma)
7. Hyperopia or farsightedness (for angle-closure glaucoma)
8. Medical conditions like diabetes, high blood pressure, migraines, and sickle cell anaemia
9. Long-term use of corticosteroid medicines

1. Increasing age
2. Diabetes
3. Obesity
4. Smoking
5. High blood pressure
6. Excessive exposure to sunlight
7. Excessive alcohol consumption
8. Previous eye injury or eye surgery
9. Long-term use of corticosteroid medicines

1. Review of medical history
2. Physical eye examination
3. Tonometry (to measure intraocular pressure)
4. Dilated eye exam (to widen the pupils and check for optic nerve damage)
5. Visual field test (to check changes in peripheral vision)
6. Visual acuity test (to look for vision loss)
7. Pachymetry (to measure corneal thickness)
8. Gonioscopy (to examine the drainage angle)
9. Optical coherence tomography (to look for changes in the optic nerve)
10. Slit-lamp examination (to examine the structures at the front of the eye using a microscope, called a slit lamp)

1. Review of medical history and symptoms
2. Physical eye examination
3. Visual acuity test (to check the vision at different distances by using an eye chart)
4. Slit-lamp examination (to examine the structures at the front of the eye using a microscope, called a slit lamp)
5. Retinal exam (special eye drops are used to widen the pupil and examine the back of the eye, called the retina)
6. Tonometry (to measure eye pressure)

The damage due to glaucoma cannot be reversed. However, regular checkups and treatment can help slow its progression. The treatment of glaucoma involves lowering intraocular pressure. 

Eye drops

Prescription eye drops may decrease eye pressure by improving fluid drainage or decreasing the amount of fluid the eye makes. Some prescription eye drops include:

1. Prostaglandins
2. Beta-blockers
3. Carbonic anhydrase inhibitors
4. Alpha-adrenergic agonists
5. Miotic or cholinergic agents
6. Rho kinase inhibitors
7. Oral medicines

These are prescribed with eye drops to reduce eye pressure to the desired level. 

Laser therapy

Laser trabeculoplasty is recommended when medicine has not slowed the progression, and you cannot tolerate eye drops. In this procedure, the doctor uses a small laser to improve the angle of drainage in the eye. 

Surgery

While surgery can slow down the progression of vision loss, it cannot restore lost vision. 

1. Trabeculectomy: Creates a new pathway for the fluid to leave the eye
2. Drainage tubes: The surgeon inserts a small tube in the eye to drain excess fluid
3. Minimally invasive glaucoma surgery (MIGS): Several MIGS techniques are available to lower eye pressure. These procedures have less risk and require less postoperative care.

A new prescription for glasses or contacts 

When symptoms are mild, and you are uninterested in surgery.

Surgery

Most doctors suggest surgery for cataracts when it starts interfering with your daily activities, such as reading or driving at night. The two types of cataract surgery include:

1. Phacoemulsification cataract surgery: The surgeon makes a small opening in your eye to reach the clouded lens. They then use ultrasound or laser to break the lens into pieces and suction it out from the eye. A new plastic lens is inserted to replace the old one. 
2. Extracapsular cataract surgery: It is recommended for an advanced cataract. The surgeon makes a large opening in the eye and removes the clouded lens in one piece. They then insert an artificial lens to replace the old one. 

Complications

If left untreated, glaucoma will:

1. Continue to get worse
2. Cause loss of peripheral vision and central vision
3. Eventually, cause vision loss and blindness

If left untreated, cataracts will:

1. Become worse with time and interfere with vision
2. Affect quality of life by impacting daily activities like reading and driving
3. Eventually, cause total blindness