J Glaucoma Summary
©Glaucoma: is an optic neuropathy associated with characteristic damage to the optic
nerve head (cupping) and the visual field (nerve fiber bundle defect).
The appearance of the optic nerve head and visual field are the major prognostic factors and
the extent of the damage of both of them determines the stage of the glaucoma. (VIP)
First peripheral visual field becomes constricted à then loss of central visual acuity
©Risk factors
1-Age
2-Ethnicity
3-Family history
4-IOP
-Represents the equilibrium between the rigidity of the cornea and sclera, and the outward
pressure of the ocular contents; as the vitreous humour is fixed, the amount of the aqueous
humour [normal volume is 0.25 cc] is the most important variable which varies with
respect to production and drainage.
-Normal range (10-21 mmHg à normal mean is 15.5 mmHg).
-Standard way to measure is GAT (Goldmann Applanation Tonometry).
-An elevated IOP is neither necessary nor sufficient to make the diagnosis (we can have
normal tension glaucoma and Ocular hypertension [no glaucoma]) but it is the main risk factor
and important in treatment monitoring.
§Theories for raised IOP acting on the nerve head damaging the optic nerve fibers:-
I-Raised IOP causes mechanical damage to the axons
II-Raised IOP causes Ischemia by decreasing blood flow to the nerve head
5-Trauma
6-Eye surgery
7-Drugs
8-Refractive errors
9-Systemic vascular dysregulation (Raynaud’s, Prinzmetal angina, Migraine)
10-Sleep apnea
(8+9+10) à are non-IOP dependent risk factors
©Classifications
Glaucoma is classified ,using Gonioscopy, according to the anatomy of the anterior chamber
angle as Open or Closed, and each type has primary (chronic) and secondary sub-
categories.
, © 1-Open-angle glaucoma
Primary Secondary
Definition Idiopathic increase in Trabecular meshwork
outflow resistance resulting obstruction causes
in increased in IOP. increased in IOP.
Epidemiology Most prevalent type Much rarer than the
Females = Males primary.
More in Myopes
Maybe a family history
although the mode of
inheritance is unknown yet.
Causes 1-Trabecular lamellae 1-Blood (Hyphaema) à due
thickening. to blunt trauma
2-Reduciton in the lining 2-Inflammatory cells à
trabecular cells. Uveitis
3-Increased in the 3- Pigment released from the
extracellular material of the iris à Pigment dispersion
trabecular meshwork space. syndrome
4-Material produced form the
epithelial cells of the iris, lens
and ciliary body à
Pseudoexfoliative glaucoma
5-Steriod-induced
glaucoma.
©Glaucoma: is an optic neuropathy associated with characteristic damage to the optic
nerve head (cupping) and the visual field (nerve fiber bundle defect).
The appearance of the optic nerve head and visual field are the major prognostic factors and
the extent of the damage of both of them determines the stage of the glaucoma. (VIP)
First peripheral visual field becomes constricted à then loss of central visual acuity
©Risk factors
1-Age
2-Ethnicity
3-Family history
4-IOP
-Represents the equilibrium between the rigidity of the cornea and sclera, and the outward
pressure of the ocular contents; as the vitreous humour is fixed, the amount of the aqueous
humour [normal volume is 0.25 cc] is the most important variable which varies with
respect to production and drainage.
-Normal range (10-21 mmHg à normal mean is 15.5 mmHg).
-Standard way to measure is GAT (Goldmann Applanation Tonometry).
-An elevated IOP is neither necessary nor sufficient to make the diagnosis (we can have
normal tension glaucoma and Ocular hypertension [no glaucoma]) but it is the main risk factor
and important in treatment monitoring.
§Theories for raised IOP acting on the nerve head damaging the optic nerve fibers:-
I-Raised IOP causes mechanical damage to the axons
II-Raised IOP causes Ischemia by decreasing blood flow to the nerve head
5-Trauma
6-Eye surgery
7-Drugs
8-Refractive errors
9-Systemic vascular dysregulation (Raynaud’s, Prinzmetal angina, Migraine)
10-Sleep apnea
(8+9+10) à are non-IOP dependent risk factors
©Classifications
Glaucoma is classified ,using Gonioscopy, according to the anatomy of the anterior chamber
angle as Open or Closed, and each type has primary (chronic) and secondary sub-
categories.
, © 1-Open-angle glaucoma
Primary Secondary
Definition Idiopathic increase in Trabecular meshwork
outflow resistance resulting obstruction causes
in increased in IOP. increased in IOP.
Epidemiology Most prevalent type Much rarer than the
Females = Males primary.
More in Myopes
Maybe a family history
although the mode of
inheritance is unknown yet.
Causes 1-Trabecular lamellae 1-Blood (Hyphaema) à due
thickening. to blunt trauma
2-Reduciton in the lining 2-Inflammatory cells à
trabecular cells. Uveitis
3-Increased in the 3- Pigment released from the
extracellular material of the iris à Pigment dispersion
trabecular meshwork space. syndrome
4-Material produced form the
epithelial cells of the iris, lens
and ciliary body à
Pseudoexfoliative glaucoma
5-Steriod-induced
glaucoma.
