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Ocular Disease > Iris > Flashcards

Iris Flashcards

1
Q

what sympathetic nerves innervate the iris?

A

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

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2
Q

what parasympathetic nerves innervate the iris?

A

short ciliary nerves = sphinctor muscle

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3
Q

what 3 structures make up the uveal tract?

A

iris, ciliary body and choroid

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4
Q

what causes neovascularization of the iris (NVI)?

A

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

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5
Q

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

A

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

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6
Q

where is the most common area for NVI to form?

A

pupillary frill (occurs in end arteries)

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7
Q

how can NVI affect the anterior angle?

A

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

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8
Q

what is the treatment for NVI?

A

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

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9
Q

what is an iris nevus?

A

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

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10
Q

what are the characteristics of an iris nevus?

A

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

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11
Q

how common are iris melanomas?

A

very rare - about 8% of all uveal melanomas

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12
Q

what are the characteristics of an iris melanoma?

A

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

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13
Q

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

A

lens opacities and secondary glaucoma

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14
Q

what are some differential diagnoses for an iris melanoma?

A

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

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15
Q

what is the treatment/management for an iris melanoma?

A

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

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16
Q

what is neurofibromatosis?

A

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

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17
Q

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

A

NF1 is more common (and more ocular involvement)

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18
Q

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

A

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

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19
Q

which NF type has fibroma molluscum and what is it?

A

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

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20
Q

what are the 4 ocular findings in NF1?

A

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

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21
Q

what are the 3 ocular findings in NF2?

A

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

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22
Q

what causes albinism?

A

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

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23
Q

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

A

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

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24
Q

what are 4 ocular findings in albinism?

A

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

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25
Q

what are some management/treatment options for albinism?

A

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

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26
Q

what is heterochromia?

A

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

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27
Q

what is a coloboma?

A

lack of closure in utero of the iris

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28
Q

what is the management for a coloboma?

A

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

29
Q

what is aniridia?

A

lack of iris (rare, genetic, and bilateral)

30
Q

what are some secondary conditions for aniridia?

A

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

31
Q

what is floppy iris syndrome and who does it affect?

A

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

32
Q

what happens to the iris in floppy iris syndrome?

A

during cataract surgery the pupil constricts, iris billows and prolapses

33
Q

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

A

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

34
Q

what is irdodialysis?

A

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

35
Q

what are symptoms of irdodialysis?

A

can be asymptomatic, glare, monocular diplopia

36
Q

what is the management for irdodialysis?

A

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

37
Q

what is angle recession?

A

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

38
Q

what is the management for angle recession?

A

monitor as a glaucoma patient/suspect

39
Q

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

A

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

40
Q

what is pigment dispersion?

A

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

41
Q

how can pigment dispersion cause glaucoma?

A

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

42
Q

what are symptoms of pigment dispersion?

A

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

43
Q

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

A

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

44
Q

what is ICE?

A

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

45
Q

what are the 3 types of ICE?

A

progressive iris atrophy, cogan reese, and chandler

46
Q

what is progressive iris atrophy and what is its prognosis?

A

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

47
Q

what is Cogan-reese and what is its prognosis?

A

diffuse iris nevus and pigmented nodules on iris prognosis = poor

48
Q

what is Chandler?

A

most common ICE - greater corneal changes and variable prognosis

49
Q

what are the symptoms of ICE?

A

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

50
Q

what is the management for ICE?

A

glaucoma as indicated

51
Q

what causes primary angle closure?

A

obstruction of aqueous outflow by blockage of TM by iris

52
Q

what are 3 anatomical causes for primary angle closure?

A

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

53
Q

what causes secondary angle closure glaucoma?

A

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

54
Q

what are the symptoms of angle closure?

A

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

55
Q

what is the management for angle closure?

A

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

56
Q
A

ICE

57
Q
A

Pigment Dispersion - Krunkenberg spindle

58
Q
A

Lisch Nodules

59
Q
A

Iris Melanoma

60
Q
A

Angle recession

61
Q
A

Neovascularization of Iris (NVI)

62
Q
A

Coloboma

63
Q
A

Aniridia

64
Q
A

Iridodialysis

65
Q
A

Iris Nevus

66
Q
A

Chandler - ICE

67
Q
A

Cogan-Reese ICE

68
Q
A

Progressive Iris Atrophy - ICE

Ocular Disease (10 decks)

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