GLAUCOMA
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| Glaucoma |
Glaucoma definition - Glaucoma is a group of ocular disorders that have in common increased intraocular pressure.
Glaucoma symptoms
Glaucoma is one of the leading causes of blindness because of the ocular tissue damage produced by raised intraocular pressure. In almost all cases, glaucoma occurs due to impaired outflow of aqueous humor, though there is a theoretical possibility of increased production of aqueous by the ciliary body causing glaucoma. The obstruction to the aqueous flow may occur as a result of developmental malformations (congenital glaucoma); or due to complications of some other diseases such as uveitis, trauma, intraocular hemorrhage, and tumors (secondary glaucoma); or maybe primary glaucoma which is typically bilateral and is the most common type.
Blur Vision
Distorted Vision
Headache
Sometimes symptomless
Types of glaucoma
There are 2 types of primary glaucoma—primary open-angle
A. Open-angle (wide-angle, chronic simple) glaucoma
It is probably a genetically predisposed degenerative
a disease affecting patency of the trabecular
meshwork which is gradually lost past middle
age. The i.o.t. rises insidiously and progressively.
Ocular hypotensive drugs are used on a long term
basis and constitute the definitive treatment in
majority of cases.
B. Angle-closure (narrow-angle, acute congestive) glaucoma
It occurs in individuals with a narrow iridocorneal
angle and a shallow anterior chamber. The i.o.t
remains normal until an attack is precipitated,
usually by mydriasis. The i.o.t.
rises rapidly to very high values (40–60 mmHg).
It is an emergent condition with marked congestion
of eyes and severe headache. Failure to lower
i.o.t. quickly may result in loss of sight.
Vigorous therapy employing various measures to
reduce i.o.t. is instituted.
What is the best treatment for glaucoma? |DRUGS FOR GLAUCOMA|
Treatment for glaucoma
Laser surgery
Trabeculoplasty
Medicines for Glaucoma | Glaucoma eyedrops
A glaucoma is a group of diseases characterized by a progressive form of optic nerve damage. This is generally but not necessarily associated with raised (> 21 mmHg) intraocular tension (i.o.t), but the etiology is unknown and there are many risk factors. The chief therapeutic measure is to lower i.o.t., either by reducing the secretion of aqueous humor or by promoting its drainage. Lowering of i.o.t. retards progression of optic nerve damage even in normal/low i.o.t. glaucoma. The site of formation and pathway of drainage of aqueous humor as well as sites of action of antiglaucoma drugs. A major amount of aqueous (~90%) drains through the trabecular route, while ~10% fluid passes into the connective tissue spaces within the ciliary muscle—then via suprachoroid into episcleral vessels (uveoscleral outflow).
1. Hypertonic mannitol (20%) 1.5–2 g/kg or glycerol (10%): infused i.v. decongest the eye by osmotic action. A retention enema of 50% glycerine is also sometimes used.
2. Acetazolamide: 0.5 g i.v. followed by oral twice daily is started concurrently.
3. Miotic: Once the i.o.t. starts falling due to the above i.v. therapy, pilocarpine 1–4% is instilled every 10 min initially and then at longer intervals. Contraction of sphincter pupillae changes the direction of forces in the iris to lessen its contact with the lens and spreads the iris mass centrally → pupillary block is removed and iridocorneal angle is freed. However, when i.o.t. is very high, the iris muscle fails to respond to miotics; tension should be reduced by other measures before miotics can act.
4. Topical β blocker: Timolol 0.5% is instilled 12 hourly in addition.
5. Apraclonidine (1%)/latanoprost 0.005% instillation may be added.
Drugs are used only to terminate the attack of angle-closure glaucoma. Definitive treatment is surgical or laser iridotomy. Few cases, who have chronic narrow-angle glaucoma, may be treated with a miotic/another ocular hypotensive drug for long periods, but often surgery/laser therapy is ultimately required
Timolol
It is the prototype of ocular β blockers; is nonselective (β1 + β2) and has no local anesthetic or intrinsic sympathomimetic activity.
The ocular hypotensive action (20–35% fall in i.o.t.) becomes evident within 1 hour and lasts for ~12 hours. After chronic dosing, the action is smooth and well sustained. Some effect on i.o.t. persists for 1–2 weeks following discontinuation. This feature, in contrast to pilocarpine drops, gives a high level of clinical safety, i.e. 1 or 2 missed doses will not affect i.o.t. control. However, ~30% of cases of open-angle glaucoma fail to achieve the desired level of i.o.t. with timolol alone and may need additional medication.
GLUCOMOL, OCUPRES, IOTIM, LOPRES 0.25% and 0.5%
eye drops; start with 0.25% drops BD, change to 0.5% drops
in case of inadequate response. TIMOLAST 0.5% as
gel-forming eyedrop for OD use.
Betaxolol
It is a β1 selective blocker offering the advantage of fewer bronchopulmonary and probably less cardiac, central, and metabolic side effects. In addition, it appears to exert a protective effect on retinal neurons independent of i.o.t. lowering, by blocking some Ca2+ channels and reducing Na+/Ca2+ influx. This action is more prominent in betaxolol than in timolol. However, betaxolol is less efficacious in lowering i.o.t. than timolol, because ocular β receptors are predominantly of the β2 subtype. Transient stinging and burning in the eye are more common with it. Most ophthalmologists prefer to start with betaxolol and change over to timolol (or a similar drug) only if i.o.t. control is insufficient or there is local intolerance to betaxolol.
OPTIPRESS, IOBET, OCUBETA 0.5% eye drops; 1 drop-in
each eye BD.
Levobunolol It has been introduced as a once-daily alternative to timolol. The ocular and
systemic effects are very similar to timolol except
for a longer duration of action.
BETAGAN 0.5% ophthalmic soln., 1 drop OD.
Carteolol and Metipranolol are the other ocular β blockers.
(chronic simple glaucoma) and primary angle-closure (acute congestive glaucoma). Primary open-angle glaucoma is a more common type and is usually a genetically-determined disease. Primary angle-closure glaucoma occurs due to shallow anterior chamber and hence narrow-angle causing blockage of aqueous outflow.
In all types of glaucoma, degenerative changes appear after some duration, and eventually, damage to the optic nerve and retina occurs.
Glaucoma test | Glaucoma diagnosis
Ophthalmologists will dilate your eyes for a proper 3D view inside your eye or proper checkup of the Retina.
He/she check your optic nerve.
He/she check Vessels size,structure,color.
Tonometry - Tonometry check the Pressure of your eyeball.
What causes glaucoma?
The obstruction to the aqueous flow may occur as a result of developmental malformations (congenital glaucoma); or due to complications of some other diseases such as uveitis, trauma, intraocular hemorrhage, and tumors (secondary glaucoma); or maybe primary glaucoma which is typically bilateral and is the most common type.
Glaucoma prevention
Wear Sunglasses
Use prescribed Eye drops
Take Proper medicine
Wash your eyes with water
Frequent eye checkup
Frequently visit ophthalmologist
