1. Classification of Glaucoma
R4 이재형/Ap.홍승우

2. Introduction Primary Secondary
a group of diseases share certain features
- including cupping and atrophy of the optic nerve head, which has attendant visual field loss and is frequently related to the level of intraocular pressure (IOP)
Primary
confined to the anterior chamber angle or conventional outflow pathway, with no apparent contribution from other ocular or systemic disorders
usually bilateral
probably reflect genetic predispositions
The assumption that the initial events leading to outflow obstruction and IOP elevation in those glaucomas
mechanisms underlying the causes of the glaucomas continues to expand, the primary and secondary classifications become increasingly artificial and inadequate. Furthermore, glaucomas caused by developmental anomalies of the anterior chamber angle do not fit neatly into either category.
Secondary
associated with ocular or systemic abnormalities responsible for elevated IOP
unilateral and acquired

3. Introduction Etiology(cause) Mechanism underlying disorder
leads to an alteration in aqueous humor dynamics or retinal ganglion cell loss
alterations in the anterior chamber angle
open-angle
angle-closure
developmental anomalies
that leads through a multistage pathway to alterations in aqueous humor dynamics or optic neuropathy with subsequent visual field loss
incorrectly suggest that elevated IOP is the primary risk factor
genetic architecture that contributes to the majority of glaucoma

4. Staging System for Glaucoma
stage 1. In neovascular glaucoma, for example, an initiating event (stage 1) may be a central retinal vein occlusion, which can lead to release of vascular endothelial growth factor and other cytokines that may lead to a structural alteration (stage 2) in the form of a fibrovascular membrane over the anterior chamber angle, which may eventually cause a functional alteration (stage 3) by obstructing aqueous outflow with a rise in IOP, which usually leads to optic nerve damage (stage 4) and eventual loss of visual field (stage 5). An understanding of this sequence provides a rational basis for early intervention with panretinal photocoagulation at stage 1 in selected pati

5. Classification Based on Initial Events
A. Open-angle glaucomas without other known ocular or systemic disorders B. Angle-closure glaucomas C. Developmental glaucomas D. Glaucomas associated with other ocular and systemic disorders

6. Classification Based on Initial Events
Open-angle glaucomas
without other known ocular or systemic disorders
Chronic open-angle glaucoma
Normal-tension glaucoma
B. Angle-closure glaucomas
Pupillary block glaucomas
- acute, subacute, chronic
2. Combined mechanism glaucoma
including primary open-angle glaucoma, chronic open-angle glaucoma, and chronic simple glaucomaTo de-emphasize use of the “primary” and “secondary” terminology in glaucoma, the term chronic open-angle glaucoma is used in this text. A more appropriate term, however, might be idiopathic open-angle glaucoma, because our failure to provide more precise terminology stems from our lack of knowledge regarding the related mech
Among the so-called primary angle-closure glaucomas, the most common variation is pupillary block gla
Combined mechanism glaucoma, IOP elevation persists after peripheral iridotomy for the angle-closure component, despite an open, normal-appearing anterior chamber angle

7. Classification Based on Initial Events
C. Developmental glaucomas
1. Congenital glaucoma
2. Juvenile open-angle glaucoma (overlap with chronic open-angle glaucoma)
3. Axenfeld-Rieger syndrome
4. Peters anomaly
5. Aniridia
6. Other developmental anomalies
D. Glaucomas associated with other ocular and systemic disorders
1. Glaucomas associated with disorders of the corneal endothelium
a. Iridocorneal endothelial syndrome
b. Posterior polymorphous dystrophy
c. Fuchs endothelial corneal dystrophy
2. Glaucomas associated with disorders of the iris and ciliary body
a. Pigmentary glaucoma
b. Iridoschisis
c. Plateau iris
d. Iris and ciliary body cysts
3. Glaucoma associated with disorders of the lens
a. Exfoliation syndrome
b. Glaucomas associated with cataracts
c. Glaucomas associated with lens dislocation
incomplete development of the meshwork or Schlemm canal,
Iridocorneal adesion
a high insertion of the anterior uvea in the trabecular meshwork
Some classification schemes have included the plateau iris syndrome with primary angle-closure glaucomas, although recent studies of the mechanism suggest that it might more appropriately be included with glaucomas associated with disorders of the iris and ciliary body (1).

8. Classification Based on Initial Events
D. Glaucomas associated with other ocular and systemic disorders
4. Glaucomas associated with disorders of the retina, choroid, and vitreous
a. Neovascular glaucoma
b. Glaucomas associated with retinal detachment and vitreoretinal abnormalities
5. Glaucomas associated with intraocular tumors
a. Malignant melanoma
b. Retinoblastoma
c. Metastatic carcinoma
d. Leukemias and lymphomas
e. Benign tumors
6. Glaucomas associated with elevated episcleral venous pressure
7. Glaucomas associated with inflammation
a. Glaucomas associated with uveitis
b. Glaucomas associated with keratitis, episcleritis, and scleritis
8. Steroid-induced glaucoma
9. Glaucomas associated with ocular trauma
10. Glaucomas associated with hemorrhage
11. Glaucomas after intraocular surgery
a. Ciliary block (malignant) glaucoma
b. Glaucomas in pseudophakia and aphakia
c. Epithelial, fibrous, and endothelial proliferation
d. Glaucomas associated with corneal & vitreoretinal surgery

9. Classification Based on Mechanism
A. Open angle glaucoma mechanism B. Angle-closure glaucoma mechanisms C. Developmental anomalies of the anterior chamber angle
압력과 연관 없는 원인을 알 수 없음, 병의 경과에 따라 다른 mechanism 의 obstruction 발생 가능
Until the initial events in each form of glaucoma becomes available, however, most treatment strategies will continue to focus on IOP and depend on an understanding of the mechanisms of aqueous outflow obstruction

10. Classification Based on Mechanism - Open angle
A. Pretrabecular (membrane overgrowth)
1. Fibrovascular membrane (neovascular glaucoma)
2. Endothelial layer, often with Descemet-like membrane
a. Iridocorneal endothelial syndrome
b. Posterior polymorphous dystrophy
c. Penetrating and nonpenetrating trauma
3. Epithelial downgrowth
4. Fibrous ingrowth
5. Inflammatory membrane
a. Fuchs heterochromic iridocyclitis
b. Luetic interstitial keratitis
B. Trabecular (occlusion of intertrabecular spaces)
1. Idiopathic
a. Chronic open-angle glaucoma
b. Steroid-induced glaucoma
2. Obstruction of trabecular meshwork
a. Red blood cells - Hemorrhagic glaucoma, Ghost cell glaucoma
b. Macrophages – Hemolytic, Phacolytic, Melanomalytic glaucoma
c. Neoplastic cells - Malignant tumors
d. Pigment particles - Pigmentary glaucoma, Exfoliation syndrome, Uveitis, Malignant melanoma
e. Protein – Uveitis, Lens-induced glaucoma
f. Viscoelastic agents
g. α-Chymotrypsin-induced glaucoma
h. Vitreous
3. Alterations of the trabecular meshwork
a. Edema - Uveitis (trabeculitis), Scleritis and episcleritis, Alkali burns
b. Trauma (angle recession)
c. Intraocular foreign bodies (hemosiderosis, chalcosis)
C. Posttrabecular
1. Obstruction of Schlemm canal
a. Collapse of canal
b. Obstruction of Schlemm canal (e.g., sickled red blood cells)
2. Elevated episcleral venous pressure
a. Carotid-cavernous fistula
b. Cavernous sinus thrombosis
c. Retrobulbar tumors
d. Thyrotropic exophthalmos
e. Superior vena cava obstruction
f. Mediastinal tumors
g. Sturge-Weber syndrome
h. Elevated episcleral venous pressure
anterior chamber angle structures (i.e., trabecular meshwork, scleral spur, and ciliary body band) are visible by gonioscopy

11. Classification Based on Mechanism - Open angle
A. Pretrabecular (membrane overgrowth)
1. Fibrovascular membrane (neovascular glaucoma)
2. Endothelial layer, often with Descemet-like membrane
a. Iridocorneal endothelial syndrome
b. Posterior polymorphous dystrophy
c. Penetrating and nonpenetrating trauma
3. Epithelial downgrowth
4. Fibrous ingrowth
5. Inflammatory membrane
a. Fuchs heterochromic iridocyclitis
b. Luetic interstitial keratitis
B. Trabecular (occlusion of intertrabecular spaces)
1. Idiopathic
a. Chronic open-angle glaucoma
b. Steroid-induced glaucoma
2. Obstruction of trabecular meshwork
a. Red blood cells - Hemorrhagic glaucoma, Ghost cell glaucoma
b. Macrophages – Hemolytic, Phacolytic, Melanomalytic glaucoma
c. Neoplastic cells - Malignant tumors
d. Pigment particles - Pigmentary glaucoma, Exfoliation syndrome, Uveitis, Malignant melanoma
e. Protein – Uveitis, Lens-induced glaucoma
f. Viscoelastic agents
g. α-Chymotrypsin-induced glaucoma
h. Vitreous
3. Alterations of the trabecular meshwork
a. Edema - Uveitis (trabeculitis), Scleritis and episcleritis, Alkali burns
b. Trauma (angle recession)
c. Intraocular foreign bodies (hemosiderosis, chalcosis)
C. Posttrabecular
1. Obstruction of Schlemm canal
a. Collapse of canal
b. Obstruction of Schlemm canal (e.g., sickled red blood cells)
2. Elevated episcleral venous pressure
a. Carotid-cavernous fistula
b. Cavernous sinus thrombosis
c. Retrobulbar tumors
d. Thyrotropic exophthalmos
e. Superior vena cava obstruction
f. Mediastinal tumors
g. Sturge-Weber syndrome
h. Elevated episcleral venous pressure
represents distinct entities with differing mechanisms of outflow obstruction –
clogging” of the meshwork, acquired alterations of the trabecular meshwork tissue

12. Anterior (“pulling” mechanism) Posterior (“pushing” mechanism)
Classification Based on Mechanism – Angle closure
Anterior (“pulling” mechanism)
Posterior (“pushing” mechanism)

13. Anterior (“pulling” mechanism)
Classification Based on Mechanism – Angle closure
Anterior (“pulling” mechanism)
Posterior
(“pushing” mechanism)
an abnormal tissue bridges the anterior chamber angle and subsequently undergoes contraction, pulling the
peripheral iris into the iridocorneal angle
pressure behind the iris, lens, or vitreous causes the peripheral iris to be pushed into the anterior chamber angle. This may occur with or without pupillary block.

14. Classification Based on Mechanism – Angle closure
A. Anterior (“pulling” mechanism)
1. Contracture of membranes
a. Neovascular glaucoma
b. Iridocorneal endothelial syndrome
c. Posterior polymorphous dystrophy
d. Penetrating and nonpenetrating trauma
2. Contracture of inflammatory precipitates
B. Posterior (“pushing” mechanism)
1. With pupillary block
a. Pupillary block glaucoma
b. Lens-induced mechanisms
(1) Intumescent lens
(2) Subluxation of lens
(3) Mobile lens syndrome
c. Posterior synechiae
(1) Iris-intraocular lens block in pseudophakia
(2) Uveitis with posterior synechiae
(3) Iris-vitreous block in aphakia
2. Without pupillary block
a. Plateau iris syndrome
b. Ciliary block (malignant) glaucoma
c. Lens-induced mechanisms
(1) Intumescent lens
(2) Subluxation of lens
(3) Mobile lens syndrome
d. After lens extraction (forward vitreous shift)
e. Secondary to scleral buckling surgery
f. Secondary to panretinal photocoagulation
g. Central retinal vein occlusion
h. Intraocular tumors
(1) Malignant melanoma
(2) Retinoblastoma
i. Cysts of the iris and ciliary body
j. Retrolenticular tissue contracture
(1) Retinopathy of prematurity (retrolental fibroplasia)
(2) Persistent hyperplastic primary vitreous

15. Classification Based on Mechanism – Angle closure
A. Anterior (“pulling” mechanism)
1. Contracture of membranes
a. Neovascular glaucoma
b. Iridocorneal endothelial syndrome
c. Posterior polymorphous dystrophy
d. Penetrating and nonpenetrating trauma
2. Contracture of inflammatory precipitates
B. Posterior (“pushing” mechanism)
1. With pupillary block
a. Pupillary block glaucoma
b. Lens-induced mechanisms
(1) Intumescent lens
(2) Subluxation of lens
(3) Mobile lens syndrome
c. Posterior synechiae
(1) Iris-intraocular lens block in pseudophakia
(2) Uveitis with posterior synechiae
(3) Iris-vitreous block in aphakia
2. Without pupillary block
a. Plateau iris syndrome
b. Ciliary block (malignant) glaucoma
c. Lens-induced mechanisms
(1) Intumescent lens
(2) Subluxation of lens
(3) Mobile lens syndrome
d. After lens extraction (forward vitreous shift)
e. Secondary to scleral buckling surgery
f. Secondary to panretinal photocoagulation
g. Central retinal vein occlusion
h. Intraocular tumors
(1) Malignant melanoma
(2) Retinoblastoma
i. Cysts of the iris and ciliary body
j. Retrolenticular tissue contracture
(1) Retinopathy of prematurity (retrolental fibroplasia)
(2) Persistent hyperplastic primary vitreous
apposition between the iris and the lens, intraocular lens, or vitreous obstructs the flow of aqueous humor into the anterior chamber, resulting in increased pressure in the posterior chamber and
forward bowing of the peripheral iris into the anterior chamber angle.

16. Classification Based on Mechanism – Angle closure
A. Anterior (“pulling” mechanism)
1. Contracture of membranes
a. Neovascular glaucoma
b. Iridocorneal endothelial syndrome
c. Posterior polymorphous dystrophy
d. Penetrating and nonpenetrating trauma
2. Contracture of inflammatory precipitates
B. Posterior (“pushing” mechanism)
1. With pupillary block
a. Pupillary block glaucoma
b. Lens-induced mechanisms
(1) Intumescent lens
(2) Subluxation of lens
(3) Mobile lens syndrome
c. Posterior synechiae
(1) Iris-intraocular lens block in pseudophakia
(2) Uveitis with posterior synechiae
(3) Iris-vitreous block in aphakia
2. Without pupillary block
a. Plateau iris syndrome
b. Ciliary block (malignant) glaucoma
c. Lens-induced mechanisms
(1) Intumescent lens
(2) Subluxation of lens
(3) Mobile lens syndrome
d. After lens extraction (forward vitreous shift)
e. Secondary to scleral buckling surgery
f. Secondary to panretinal photocoagulation
g. Central retinal vein occlusion
h. Intraocular tumors
(1) Malignant melanoma
(2) Retinoblastoma
i. Cysts of the iris and ciliary body
j. Retrolenticular tissue contracture
(1) Retinopathy of prematurity (retrolental fibroplasia)
(2) Persistent hyperplastic primary vitreous
increased pressure in the posterior portion of the eye pushes the lens-iris or
vitreous-iris diaphragm forward.