Differential Diagnosis for Hazy Central Opacity on Fluorescein Staining
Single Most Likely Diagnosis
- Corneal Abrasion or Corneal Epithelial Defect: This is the most common cause of a hazy central opacity seen on fluorescein staining only in a red, painful eye with normal pressure. The fluorescein staining pattern is characteristic of epithelial defects, and the symptoms of pain and redness are consistent with corneal abrasion.
Other Likely Diagnoses
- Corneal Ulcer: A corneal ulcer could present with similar symptoms, including pain, redness, and a positive fluorescein stain. However, ulcers often have other distinguishing features such as a more defined edge or purulent discharge.
- Conjunctivitis or Keratoconjunctivitis: Inflammatory conditions of the conjunctiva and cornea can cause pain, redness, and fluorescein staining due to epithelial disruption. These conditions might not always present with a distinct "hazy central opacity" but could be considered in the differential.
Do Not Miss Diagnoses
- Acute Angle-Closure Glaucoma with Normal Pressure: Although the question specifies normal pressure, it's crucial to consider acute angle-closure glaucoma, as it can sometimes present with normal or only slightly elevated intraocular pressure, especially in the early stages or in cases of intermittent closure. The pain and redness could be misleading, and missing this diagnosis could lead to severe vision loss.
- Corneal Infiltrate or Marginal Keratitis: These conditions can present with pain, redness, and fluorescein staining. They are less common but important to consider due to their potential for complications and the need for specific treatments.
Rare Diagnoses
- Fuchs Endothelial Dystrophy: While primarily a condition affecting the corneal endothelium and leading to edema, in rare cases, it could present with epithelial changes visible on fluorescein staining. However, it's less likely to cause acute pain and redness.
- Posterior Polymorphous Corneal Dystrophy: A rare condition that can affect the cornea and potentially cause changes visible on fluorescein staining, though it's not typically associated with acute pain and redness.
- Cogan’s Dystrophy (Map-Dot-Fingerprint Dystrophy): A rare condition affecting the corneal epithelium and basement membrane, which could potentially cause symptoms and signs similar to those described, including positive fluorescein staining.