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OP4.1-10 | Cornea, Keratitis and Eye Donation — PBL Case

CLINICAL SETTING

Rajan Pillai, a 52-year-old paddy farmer from a village 80 km from the district hospital, presents to the ophthalmology outpatient department escorted by his son. He is unable to open his right eye due to severe pain and photophobia. His son explains that the problem started eight days ago when a dry paddy leaf struck Rajan's right eye while he was harvesting. He initially went to the local pharmacy, where he was given an antibiotic-steroid combination eye drop. Over the next four days his pain worsened, and the pharmacist added a second antibiotic. Today his son noticed a white spot in the eye and brought him to hospital. Rajan has no systemic illness, does not wear contact lenses, and has had no previous eye problems. On examination: Visual acuity right eye: counting fingers at 1 metre. Left eye: 6/6. Right eye slit-lamp examination: conjunctival congestion +++, a 7 mm x 5 mm dirty grey-white stromal infiltrate with feathery irregular margins, satellite lesions at the periphery of the infiltrate, an immune (Wessely) ring, and a 2 mm hypopyon. The infiltrate is located centrally over the pupillary axis. Corneal sensation is intact. No fluorescein pooling suggestive of perforation. Left eye: normal.

Trigger 1: First Encounter — Diagnosis and Immediate Management

The registrar examines Rajan and reviews the history: agricultural vegetative trauma, eight days of worsening despite antibiotics and a steroid combination drop. She notes the feathery infiltrate margins, satellite lesions, Wessely immune ring, and hypopyon on slit-lamp examination. The microbiologist is contacted to arrange corneal scraping and culture. The registrar must now make an empirical treatment decision.

DISCUSSION POINTS

  • What is the most likely diagnosis based on the history and slit-lamp findings? Justify each feature that supports your diagnosis.
  • Why did the antibiotic-steroid combination drops likely worsen rather than improve this patient's condition? What specific harm do corticosteroids cause in this clinical context?
  • What organisms should be targeted in your empirical treatment regimen? Name the specific drugs, their concentrations, and the initial dosing frequency.
  • Describe the procedure for corneal scraping: which instruments are used, where on the ulcer do you scrape, and how is the sample processed for microscopy and culture?
  • What additional systemic investigation would you order if you suspected deep fungal extension, and what imaging modality helps assess posterior segment involvement?
Click to reveal Trigger 2: Day 5 — Treatment Response and Emerging Complications (discuss previous trigger first!)

Trigger 2: Day 5 — Treatment Response and Emerging Complications

On day 5 of antifungal treatment, Rajan's pain is slightly better but the infiltrate has not significantly reduced. Repeat slit-lamp shows the infiltrate is now 8 mm x 6 mm — slightly larger. There is no evidence of perforation. His visual acuity remains counting fingers. The culture report returns: Fusarium solani isolated, sensitive to natamycin and voriconazole. The treating ophthalmologist considers adding oral voriconazole and discusses with Rajan the possibility that he may need surgical intervention if the ulcer does not respond over the next 7 days. Rajan's son asks: 'Doctor, if his eye is not responding, will he need a transplant? And can his eyes be donated after he dies?'

DISCUSSION POINTS

  • The culture confirms Fusarium solani. Is your current empirical regimen appropriate, or should the treatment be modified? What is the role of oral voriconazole in fungal keratitis?
  • What are the criteria for declaring treatment failure in infective keratitis, and what surgical options exist at this stage (therapeutic penetrating keratoplasty versus evisceration)?
  • Rajan's family asks about keratoplasty. Using the lamellar versus penetrating classification, explain which type of keratoplasty applies to Rajan's situation if surgical intervention becomes necessary, and why.
  • Answer the family's question about eye donation: Is Rajan eligible to donate his eyes after death? What are the absolute contraindications to eye donation, and does his current fungal infection affect his eligibility?
  • Discuss the corneal blindness burden in India. What proportion of corneal blindness in rural India is attributable to infective keratitis, and how does the NPCBVI address this?
Click to reveal Trigger 3: Six Months Later — Healed Ulcer, Corneal Opacity and Rehabilitation (discuss previous trigger first!)

Trigger 3: Six Months Later — Healed Ulcer, Corneal Opacity and Rehabilitation

Rajan's fungal keratitis eventually responded to combined natamycin and oral voriconazole after 6 weeks of intensive treatment. The ulcer healed but left a central dense corneal opacity. On review at 6 months: Visual acuity right eye: hand movements only. Slit-lamp shows a dense central leukoma 8 mm in diameter through which the iris is not visible. The opacity involves the full corneal thickness. Projection of light test is positive in all four quadrants. Specular microscopy of the unaffected peripheral cornea shows an endothelial count of 1,200 cells/mm2. He is devastated about his vision and asks whether anything can restore his sight. The ophthalmologist refers him to the corneal transplant clinic. A family member of another patient overhears the conversation and asks whether Rajan could receive a cornea from a recently deceased relative.

DISCUSSION POINTS

  • Grade this corneal opacity using the standard classification system (nebula, macula, leukoma, adherent leukoma). Justify your answer.
  • Based on the clinical findings (positive projection of light, endothelial count of 1,200 cells/mm2, full-thickness opacity), which keratoplasty procedure is indicated? Which layers will the surgeon replace, and what is the most dreaded post-operative complication that Rajan must be taught to recognise?
  • Counsel Rajan's family (in role-play or written format) on eye donation: who can donate, the time window for retrieval after death, the immediate preservation steps the family must take at home before the eye bank team arrives, and which conditions in the potential donor would absolutely prevent donation.
  • Describe the complete eye banking pathway from donor death to surgical recipient. Name two preservation media used in India and the maximum storage duration each allows.
  • Rajan asks whether the transplanted graft will last forever. Explain graft rejection to him in simple language: what it is, the warning signs (use the RSVP mnemonic), and what he must do if he notices those signs.

Learning Issues

Research these questions and bring your findings to the discussion.

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