61. Anterior Segment Disease

Question 1

What is the Anterior Segment?

Answer 1

All structures in front of lens (including lengs)

Question 2

Glaucoma: type of blindness, what it is, types

Answer 2

one of leading causes of blindness - dim image, loss of peripheral vision

Damage to OPTIC NERVE causing cupping and visual field DEFECTS

1. Open Angle Glaucoma
2. Acute Angle Closure Glaucoma
3. Chronic Angle Closure Glaucoma
4. Secondary Glaucoma

Question 3

Open Angle Glaucoma

• signs
• risk factors
• tx

Answer 3

Open outflow angle - trouble regulating outflow
Sign: cupping - chronic process physically affecting optic nerve - progressive irreversible damage causing visual field defects
RF: high IOP, +FHx, African-American race, Age
Tx: Medical (Timolol, Latanoprostin [PG Agonist], Bromonadine [A2 Agonist], CA-i)
surgical (laser trabeculoplasty, trabeculectomy, glaucoma drainage device)

Question 4

Acute Angle Glaucoma

• mechanism
• sx
• signs
• tx

Answer 4

EMERGENCY - sudden rise in IOP
M: inflow of aqueous pushes iris forward, blocks outflow angle
sx: pain, HA, N/V, redness, photophobia, blurred vision, haloes
signs: redness, corneal edema (fuzzy), mid-dilated pupil (less reactive), shallow ant chamber (iris pushed forward)
tx: acutely lower IOP (topical hypotensives - NO dilators/pilocarpine, systemic acetazolamide (CA-i), IV Mannitol)
definitive tx: laser iridotomy - alt drainage path

Question 5

Chronic Angle Closure Glaucoma

• mechanism
• cause/tx

Answer 5

Slow, progressive, asx chronic scarring of ant chamber angle (anatomic/diabetes)

• eventually causes high IOP and optic nerve damage
• tx: medical/surgical

Question 6

Secondary Glaucoma (etiology)

Answer 6

Steroid Induced (dysfx of outflow = high IOP)
Neovascular (DM)
Uveitic (inflammatory/infectious)
Hemorrhage/Trauma
Masses

Question 7

Uveitis: what it is, sx, etiologies

Leukocoria: what it is, etiologies

Answer 7

Uveitis: eye inflammation
sx: RED EYE, photophobia, blurred vision
E: immune-mediated (HLA-B27 spondyloarthropathy, sarcoid), infectious (HSV, VZV, CMV, TB, Toxo, Syphilis)

Leukocoria: white reflex
E: TUMOR (RETINOBLASTOMA), inflammation, congenital cataract, retinal detachment

Question 8

Cataract

• what happens
• causes
• subtypes
• tx

Answer 8

Lens fibers lose transparency, opacify = blurry vision
cause: age-related, uveitis, steroids, trauma, congenital
subtypes
1. Nuclear Cataract: center of lens opacifies, myopic shift (more near sighted), blurred vision
2. Cortical Cataract: webbing opacification outside lens nucleus - more visually significant - causes GLARE
3. Posterior Subcapsular Cataract - MOST visually significant - causes GLARE, decreased reading (due to steroids, inflammation, diabetes)

Tx: cataract surgery (remove lens and insert new intraocular lens [IOL])

Question 9

Conjunctivitis: what is it, sx

Subconjuctival Hemorrhage: what is it, sx

Answer 9

C: inflammation of conjunctiva, common cause of red eye (Adenoviral = Pink eye)

SCH: blood b/w sclera and conjunctiva - idiopathic, trauma, blood thinners - self-resolving

Question 10

Episcleritis vs. Anterior Scleritis

Answer 10

Episcleritis: irritation/discomfort of outermost layer of sclera - contains vascular plexus

Ant Scleritis: inflammation of structural white wall of eye - pain and RED EYE!!

Question 11

DDx of Red Eye

Answer 11

1. Acute Angle Closure Glaucoma
2. Conjunctivitis
3. Subconjunctival Hemorrhage
4. Scleritis/Episcleritis
5. Uveitis
6. Blepharitis (dry eyes)
7. Corneal Abrasion
8. Chemical Injury
9. Corneal Ulcer
10. Foreign Body/Trauma

Question 12

Anterior Segment Trauma:
Hyphema (what it is, assoc, tx)

Open Globe Trauma (what it is, warning signs, tx)

Answer 12

H: layered RBCs in ant chamber - can cause high IOP - check for sickle cell anemia
Tx: steroids, pressure drops

OG: full thickness laceration/rupture of cornea and sclera - aqueous/vitreous leakage
signs: distorted pupil, subconjunctival hemorrhage, hyphema
NEEDS IMMEDIATE SURGICAL REPAIR, shield eye, IV ABx/Pain meds/Anti-emetics