Eye conditions: Inflammation, infections and trauma: Pathology review


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Eye conditions: Inflammation, infections and trauma: Pathology review

Eyes, ears, nose and throat

Eye disorders

Color blindness

Cortical blindness


Homonymous hemianopsia

Bitemporal hemianopsia



Retinal detachment

Age-related macular degeneration

Diabetic retinopathy

Corneal ulcer


Retinopathy of prematurity

Periorbital cellulitis



Orbital cellulitis

Hordeolum (stye)


Neonatal conjunctivitis

Ear disorders

Conductive hearing loss

Eustachian tube dysfunction

Tympanic membrane perforation

Otitis externa

Otitis media

Vestibular disorders


Meniere disease


Acoustic neuroma (schwannoma)

Nasal and nasopharyngeal disorders

Choanal atresia

Allergic rhinitis

Nasal polyps

Nasopharyngeal carcinoma

Oral cavity and oropharyngeal disorders



Ludwig angina

Aphthous ulcers

Temporomandibular joint dysfunction

Oral cancer

Warthin tumor

Sleep apnea

Gastroesophageal reflux disease (GERD)

Zenker diverticulum

Retropharyngeal and peritonsillar abscesses

Esophageal cancer

Laryngeal disorders



Bacterial epiglottitis

Thyroid and parathyroid gland disorders

Thyroglossal duct cyst

Thyroid cancer



Eyes, ears, nose and throat pathology review

Eye conditions: Refractive errors, lens disorders and glaucoma: Pathology review

Eye conditions: Retinal disorders: Pathology review

Eye conditions: Inflammation, infections and trauma: Pathology review

Vertigo: Pathology review

Nasal, oral and pharyngeal diseases: Pathology review

Thyroid nodules and thyroid cancer: Pathology review

Parathyroid disorders and calcium imbalance: Pathology review


Eye conditions: Inflammation, infections and trauma: Pathology review

USMLE® Step 1 questions

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USMLE® Step 1 style questions USMLE

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A 26-year-old man comes to the emergency department for evaluation of left eye pain and swelling for three hours. He was brought in by local police following an altercation at a bar, where he was punched in the left eye. He reports that he has double vision when looking upward. Temperature is 37°C (98.6°F), pulse is 94/min, respirations are 15/min, and blood pressure is 132/84 mmHg. On examination, the left orbit is ecchymotic with associated swelling. Pupils are equal and reactive to light, and visual acuity is 20/20 bilaterally. Neurologic evaluation demonstrates diminished sensation of the skin to fine touch at the left lower eyelid and left anterior cheek. A CT scan of the face reveals a fracture of the floor of the left orbit with entrapment of orbital contents in the left maxillary sinus. Injury to which of the following nerves is the most likely etiology of this patient’s sensory deficits?  

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Antonia Syrnioti, MD

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David G. Walker

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While doing your rounds, you meet a 4 day old newborn girl, named Caitlyn, who is brought to the emergency department due to redness and swelling of the eyes. Physical examination shows bilateral eye erythema and purulent discharge. The infant was born at home to a mother who received no prenatal care and is unable to provide any medical history. Some days later, 41-year-old Joshua comes to the ophthalmology clinic complaining of black spots and blurry vision that started about two weeks ago. He mentions that the spots go away when he closes his left eye. On examination, visual acuity is 20/100 in the right eye and 20/20 in the left. Fundus examination is pictured. His medical history includes a diagnosis of HIV infection 8 years ago.

Based on the initial presentation, both Caitlyn and Joshua have some form of inflammatory, infectious or traumatic eye condition. But first, a bit of physiology real quick. If we zoom into the wall of the eye, it is made up of three major layers. There’s a fibrous outer layer that contains the cornea and sclera. The outer surface of the sclera is covered by a mucous membrane, called conjunctiva, which also lines the inside of the eyelids. The middle vascular layer is called uvea and consists of the iris, pupil, choroid, and ciliary body. Finally, the neural layer consists of the retina which helps convert light into neural signals that travel via the optic nerve to the brain for visual processing. Okay, let’s start with stye, also known as hordeolum, which is a common bacterial infection of the sebaceous glands of the eyelids. For your exams, remember that the most common pathogen is Staphylococcus aureus. Styes present as painful, red, pus-filled lumps and are usually located at the lid margin, in which case they are known as external styes, or under the conjunctival side of the eyelid, also called internal styes. For your exams, keep in mind that for unknown reasons, styes tend to be more common in individuals with acne vulgaris and diabetes mellitus. Diagnosis is clinical and treatment usually involves warm compresses, massage and topical antibiotics, usually dicloxacillin. Now, it’s important to differentiate a stye from a chalazion. A chalazion results from the obstruction of sebaceous glands of the eyelids, without any infection. It presents as a slow-growing, painless, rubbery nodule, usually in the middle of the eyelid. Diagnosis is clinical and no treatment is necessary, since it's usually self-resolving. Next is conjunctivitis, which is inflammation of the conjunctiva. For your exams, remember that there are two main types of conjunctivitis, infectious and non-infectious. Infectious conjunctivitis can be further divided into viral and bacterial conjunctivitis. Viral conjunctivitis is the most common one and is typically caused by adenovirus but can be also due to herpes simplex virus or varicella-zoster virus. Bacterial conjunctivitis can be gonococcal, which is caused by Neisseria gonorrhoeae, or chlamydial, which is caused by Chlamydia trachomatis. For your test, remember that gonococcal conjunctivitis tends to be more severe and might be accompanied by various complications. That's because gonococci can penetrate further into the cornea, causing corneal edema, ulceration or even scarring and perforation. In some cases, gonococci could get even deeper and involve the interior of the eye, causing endophthalmitis, or make it into the systemic circulation and spread throughout the body. Now, non-infectious conjunctivitis includes allergic conjunctivitis, which is usually caused by airborne allergens, like pollen, and nonallergic conjunctivitis, caused by chemical or mechanical irritation of the conjunctiva. A high-yield fact is that in newborns, chemical conjunctivitis is most often caused by the use of ophthalmic silver nitrate for prophylaxis against ocular gonococcal infection.


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  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Conjunctivitis" JAMA (2013)
  6. "Orbital cellulitis complicated by subperiosteal abscess due to Streptococcus pyogenes infection" Boletín Médico Del Hospital Infantil de México (English Edition) (2017)
  7. "Advances in the pharmacological treatment of Graves’ orbitopathy" Expert Review of Clinical Pharmacology (2016)

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