Which of the following is not a feature of fungal corneal ulcer?
Ans. c. Symptoms are more pronounced than signs (Ref: Khurana 5/e p101; 4/e p100; Parson 21st/e p199-200 ; Kanski 7/e p180-82)Symptoms are much milder than the clinical signs in fungal corneal ulcer hut not the vice-versa.Fungal (Mycotic) Corneal Ulcer:Symptoms are much milder than the clinical signsQ.Ulcer is dry looking, grayish white with elevated rolled out marginsQ and feathery finger like extensions into surrounding stromaQ under intact epithelium.A big hypopyonQ is present even if the ulcer is very small.Unlike bacterial ulcer, the hypopyon may not be sterile (pseudohypopyon)Q as fungi can penetrate into anterior chamber without perforation.Diagnosis: Examination of wet KOH mountQ, calcoflour white for fungal hyphae and culture on sabouraud's medium.Fungal (Mycotic) Corneal Ulcer / KeratomycosisAspergillus fumigates (MC), Candida and fusariumQ are common agents.Injury by vegetative materials or animal tailQ is common modes of infection.Etiology:Filamentous septate hyphae (tubular projections) producing multicellular fungi, most notably, Fusarium and Aspergillus (fumigatus) are the most common causative organism in tropics (or hot climate) and around the wordUnicellular budding yeast e.g. Candida is most common cause of fungal keratitis in temperate (cold) regions.Predisposing Factors* Injury by vegetative materials or animal tail is common modes of infectionQ.* Excessive use of antibiotics* Corneal trauma involving plant matter or gardening / agricultural tool (in tropics)* Comeal disease* Local immunosuppression* Long term use of topical steroid* Prior comeal transplantation* Contact lens wear* Diabetes mellitusClinical Features:Symptoms are much milder than the clinical signsQMarked ciliary and conjunctival congestion but symptoms of pain, watering and photophobia are disproportionately less.Ulcer is dry looking, grayish white with elevated rolled out marginsQ and feathery finger like extensions into surrounding stromaQ under intact epithelium.A sterile immune ring (yellow line of Wesseley)Q present where fungal antigen and host antibody meet.Multiple small satellite lesionsQ may be present around the ulcer.A big hypopyonQ is present even if the ulcer is very small.Unlike bacterial ulcer, the hypopyon may not be sterile (pseudohypopyon)Q as fungi can penetrate into anterior chamber without perforation.Perforation is rare and corneal vascularization is conspicuously absentQ.Diagnosis:Examination of wet KOH mountQ, calcoflour white for fungal hyphae and culture on sabouraud's medium.TreatmentAntifungal TreatmentAdjuvant Therapy* Natamycin and amphotericin B are used in filamentous infectionsQ topically.* Imidazole and flucytosine are used in Candida infection.* Systemic antifungal is required for severe keratitis and endopthalmitis.* CycloplegicsQ as atropine or scopolamine are used to reduce ciliary spasm, uveal inflammation and prevent posterior synechiae formation.* Anti-inflammatory and analgesics* Carbonic anhydrase inhibitors for complications as secondary glaucomaQ
Fixed hypopyon
Ulcer with sloughing margins
Symptoms are more pronounced than signs
Fungal hyphae are seen on KOH mount
Inflammations of the Cornea