Iris

Question 1

what sympathetic nerves innervate the iris?

Answer 1

long ciliary nerves = branches of trigeminal (CN5) - dilator muscle

Question 2

what parasympathetic nerves innervate the iris?

Answer 2

short ciliary nerves = sphinctor muscle

Question 3

what 3 structures make up the uveal tract?

Answer 3

iris, ciliary body and choroid

Question 4

what causes neovascularization of the iris (NVI)?

Answer 4

retinal ischemia or any condition that affects retinal vasculature (diabetes, CRVO, BRVO, CRAO, intraocular tumors, RD)

Question 5

how does retinal ischemia cause new blood vessel growth in the iris (NVI)?

Answer 5

hypoxia in the retina causes a release of angiogenesis factors, they diffuse into aqueous humor and interact with anterior segment blood vessels (iris vasculature)

Question 6

where is the most common area for NVI to form?

Answer 6

pupillary frill (occurs in end arteries)

Question 7

how can NVI affect the anterior angle?

Answer 7

new blood vessels growing in the iris can lead to neovascularization of the angle (NVA) and can cause neovascular glaucoma

Question 8

what is the treatment for NVI?

Answer 8

refer to pan-retinal photocoagulation (PRP) to kill retinal cells and decrease hypoxia

Question 9

what is an iris nevus?

Answer 9

pigmented lesion (uveal tissue), benign and composed of melanocytes

Question 10

what are the characteristics of an iris nevus?

Answer 10

pigmented, flat, usually less than 3mm and doesn’t grow

Question 11

how common are iris melanomas?

Answer 11

very rare - about 8% of all uveal melanomas

Question 12

what are the characteristics of an iris melanoma?

Answer 12

slow growing, low malignancy, at least 3mm diameter and 1mm thick, composed of spindle cells and 3x more common in blue/light iris than brown

Question 13

what are 2 complications that can occur with an iris melanoma?

Answer 13

lens opacities and secondary glaucoma

Question 14

what are some differential diagnoses for an iris melanoma?

Answer 14

iris nevus, metastasis (rare), iris cyst, iris heterochromia, hemosiderosis and other rare tumors

Question 15

what is the treatment/management for an iris melanoma?

Answer 15

observe until diagnosis is confirmed and refer for surgical evaluation (iridectomy and/or enucleation)

Question 16

what is neurofibromatosis?

Answer 16

a hereditary disorder that affects cell growth of neural tissues (autosomal dominant)

Question 17

which type of NF is more common - 1 or 2?

Answer 17

NF1 is more common (and more ocular involvement)

Question 18

which NF type has cafe au lait spots and what are they?

Answer 18

NF1 - flat, light brown patches on skin (need at least 6 for diagnosis criteria)

Question 19

which NF type has fibroma molluscum and what is it?

Answer 19

NF1 - pigmented nodules of the skin (raised - like skin tags)

Question 20

what are the 4 ocular findings in NF1?

Answer 20

lisch nodules on iris (need at least 2), glaucoma, choroidal nevus or retinal astrocytoma, and optic nerve glioma

Question 21

what are the 3 ocular findings in NF2?

Answer 21

cataracts (2/3 of patients before age 30), fundus lesions and EOM defects

Question 22

what causes albinism?

Answer 22

its a congenital hypopigmentary disease = deficit in enzyme tyrosine (mediates conversion of tyrosine to melanin)

Question 23

what are the 2 types of albinism and how are they different?

Answer 23

oculocutaneous albinism (OCA) = light skin and hair, very little pigment ocular = signs are only in eyes

Question 24

what are 4 ocular findings in albinism?

Answer 24

nystagmus, blue/red iris with no visible pigment, pale fundus, and optic nerve hypoplasia

Question 25

what are some management/treatment options for albinism?

Answer 25

appropriate refractive correction, binocular work-up and low vision if necessary

Question 26

what is heterochromia?

Answer 26

difference in coloration of iris between both eyes - result of excess/lack of melanin

Question 27

what is a coloboma?

Answer 27

lack of closure in utero of the iris

Question 28

what is the management for a coloboma?

Answer 28

colored CL (cosmetic or to reduce glare) and low vision if needed

Question 29

what is aniridia?

Answer 29

lack of iris (rare, genetic, and bilateral)

Question 30

what are some secondary conditions for aniridia?

Answer 30

nystagmus, corneal opacities, microcornea, sclerocornea, lens opacities, subluxation of lens, glaucoma (75%), forveal hypoplasia, disc hypoplasia and choroidal coloboma

Question 31

what is floppy iris syndrome and who does it affect?

Answer 31

older men - being treated with alpha1 blockers and the iris cannot maintain structure during cataract surgery

Question 32

what happens to the iris in floppy iris syndrome?

Answer 32

during cataract surgery the pupil constricts, iris billows and prolapses

Question 33

what are 4 conditions that can result from trauma to the iris?

Answer 33

hyphema, synechia (iritis), irdodialysis, and angle recession

Question 34

what is irdodialysis?

Answer 34

dis-insertion of the iris from the scleral spur (iris is pulling away from point of attachment on ciliary body)

Question 35

what are symptoms of irdodialysis?

Answer 35

can be asymptomatic, glare, monocular diplopia

Question 36

what is the management for irdodialysis?

Answer 36

monitor for glaucoma and can give a colored CL to reduce glare

Question 37

what is angle recession?

Answer 37

due to blunt ocular trauma = incomplete dialysis of iris (iris is pushed back and pulls at the angle)

Question 38

what is the management for angle recession?

Answer 38

monitor as a glaucoma patient/suspect

Question 39

what are some things that can cause secondary open angle glaucoma?

Answer 39

traumatic (hyphema, angle recession), synechia, neovascular, pigment dispersion and ICE

Question 40

what is pigment dispersion?

Answer 40

bilateral liberation of pigment from iris pigment epithelium (posterior surface) from iris rubbing against lens zonules

Question 41

how can pigment dispersion cause glaucoma?

Answer 41

pigment can collect in TM and block the outflow of aqueous humor

Question 42

what are symptoms of pigment dispersion?

Answer 42

can be none, blur, eye pain, halos and/or eye pain following exercise (due to increased IOP)

Question 43

what are 2 possible ocular findings associated with pigment dispersion syndrome?

Answer 43

Krunenburg spindles (vertical collection of pigment on corneal endothelium) and iris transillumination

Question 44

what is ICE?

Answer 44

iridocorneal endothelial syndrome = abnormal corneal endothelial cells that can migrate to the surface of the iris

Question 45

what are the 3 types of ICE?

Answer 45

progressive iris atrophy, cogan reese, and chandler

Question 46

what is progressive iris atrophy and what is its prognosis?

Answer 46

(ICE) hole formation, corectopia and peripheral anterior synechia - the pupil is pulled in direction of synechia good prognosis

Question 47

what is Cogan-reese and what is its prognosis?

Answer 47

diffuse iris nevus and pigmented nodules on iris prognosis = poor

Question 48

what is Chandler?

Answer 48

most common ICE - greater corneal changes and variable prognosis

Question 49

what are the symptoms of ICE?

Answer 49

asymptomatic, irregular pupil, blur, pain (corneal edema and increased IOP)

Question 50

what is the management for ICE?

Answer 50

glaucoma as indicated

Question 51

what causes primary angle closure?

Answer 51

obstruction of aqueous outflow by blockage of TM by iris

Question 52

what are 3 anatomical causes for primary angle closure?

Answer 52

anterior placement of peripheral iris (plateau iris), shallow anterior chamber and attachment of iris to lens "pupillary block"

Question 53

what causes secondary angle closure glaucoma?

Answer 53

obstruction of aqueous outflow by blockage to the TM by other structures (neovascular network, peripheral anterior synechiae, ICE)

Question 54

what are the symptoms of angle closure?

Answer 54

pain, blurred vision, halos, headaches, nausea, vomiting

Question 55

what is the management for angle closure?

Answer 55

stabilize (get pressure down with topical or oral anti-glaucoma) and refer to ophthalmologist for peripheral iridotomy (PI)

Question 56

Answer 56

ICE

Question 57

Answer 57

Pigment Dispersion - Krunkenberg spindle

Question 58

Answer 58

Lisch Nodules

Question 59

Answer 59

Iris Melanoma

Question 60

Answer 60

Angle recession

Question 61

Answer 61

Neovascularization of Iris (NVI)

Question 62

Answer 62

Coloboma

Question 63

Answer 63

Aniridia

Question 64

Answer 64

Iridodialysis

Question 65

Answer 65

Iris Nevus

Question 66

Answer 66

Chandler - ICE

Question 67

Answer 67

Cogan-Reese ICE

Question 68

Answer 68

Progressive Iris Atrophy - ICE