Oculoplastics and Orbit
This domain tests eyelid anatomy, ptosis, eyelid tumors, orbital cellulitis, thyroid eye disease, lacrimal disorders, and orbital fractures. The exam favors safe distinction of preseptal from orbital disease.
Core oculoplastics
- Ptosis: aponeurotic is most common and age-related; myogenic includes CPEO; neurogenic includes Horner and CN III palsy; mechanical causes include tumor. Levator function determines surgery.
- Eyelid tumors: basal cell carcinoma is most common; squamous cell carcinoma; sebaceous carcinoma has pagetoid spread and poor prognosis; melanoma.
- Orbital cellulitis: fever, proptosis, restricted eye movement, and pain; CT and IV antibiotics. Children often have sinusitis. Preseptal cellulitis spares eye movement.
- Thyroid eye disease: proptosis, lid retraction, diplopia, and optic neuropathy; smoking worsens it; treat with steroids, teprotumumab, or decompression.
- Lacrimal: epiphora, dacryocystitis, and DCR.
- Blowout fracture: inferior rectus entrapment, diplopia, and restricted upgaze.
Worked example
A 6-year-old has eyelid swelling, fever, and pain on eye movement. Reasoning: orbital cellulitis, not preseptal. Obtain CT and start IV antibiotics; monitor vision.
Traps
Preseptal cellulitis does not limit eye movement. BCC is more common than SCC, but SCC metastasizes more often.