Key Concepts Cytomegalovirus (CMV) corneal endotheliitis presents with corneal edema, keratic precipitates, and mild anterior chamber inflammation. Epstein-Barr virus can cause a monocular follicular conjunctivitis, conjunctival nodules, and a multifocal stromal keratitis. Acute hemorrhagic conjunctivitis can be caused by enterovirus…
Key Concepts Herpes zoster ophthalmicus (HZO) involves reactivation of latent varicella-zoster virus from the trigeminal sensory ganglia along the V1 distribution of the trigeminal nerve with ocular manifestations. Severe corneal complications from HZO may include a secondary infectious keratitis, ulceration…
Key Concepts Herpes simplex virus (HSV) keratitis is one of the most common infectious causes of corneal blindness. HSV keratitis has multiple presentations that can be challenging for clinicians. The main corneal manifestations include infectious epithelial keratitis, neurotrophic keratopathy, necrotizing…
Key Concepts Nontuberculous mycobacterial (NTM) keratitis commonly occurs after trauma or refractive surgery, and can masquerade as fungal, herpetic, or amoebic keratitis, often delaying the diagnosis. NTM keratitis has been most commonly reported following laser in situ keratomileusis (LASIK). Mycobacterium…
Key Concepts Bacterial keratitis is a common and potentially sight-threatening corneal infection. Ocular trauma and contact lens use are the most common risk factors. The most frequent causative organisms are gram-positive cocci, whereas gram-negative bacilli are more commonly associated with…
Key Concepts Degenerations represent a deterioration resulting in impaired function and structure of the affected tissue. Degenerations are either related to aging or secondary to a wide variety of adverse internal or external influences. Characteristics of a degenerative process: later…
Key Concepts Iridocorneal endothelial syndrome (ICE) is a disorder of the corneal endothelium manifested by abnormal endothelial cell formation and a proliferating membrane that may overlie the endothelium, chamber angle, and iris. The etiology of ICE syndrome is unknown, although…
Key Concepts Keratoconus should be suspected in a young person whose eyes cannot be refracted to 20/20 or requires multiple changes of glasses. Atopy, Ehlers-Danlos syndrome, Down syndrome, Leber congenital amaurosis, and eye rubbing are associated with keratoconus. Thinning at…
Key Concepts Posterior polymorphous corneal dystrophy (PPCD), characterized by endothelial vesicles, is often asymptomatic. Fuchs endothelial corneal dystrophy (FECD) with family history is typically associated with progressive endothelial cell loss, corneal edema, and visual loss. Late-onset FECD manifesting in the…
Key Concepts The distinctive morphologic features of the stromal opacities associated with each of the corneal stromal dystrophies typically allow accurate diagnosis. The genetic basis of the majority of the stromal dystrophies has been identified, indicating that molecular genetic analysis…