|Year : 2021 | Volume
| Issue : 3 | Page : 391-392
Corneal ring infiltrate in fungal keratitis
Manokamna Agarwal1, Appakkudal R Anand2, Meena Lakshmipathy1
1 Department of Cornea and Refractive Surgery, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
2 Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
|Date of Submission||24-Aug-2020|
|Date of Acceptance||02-Mar-2021|
|Date of Web Publication||02-Jul-2021|
Dr. Meena Lakshmipathy
Department of Cornea and Refractive Surgery, Medical Research Foundation, Sankara Nethralaya, 18, College Road, Chennai - 600 006, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Keywords: Corneal ulcer, keratitis, ring infiltrate, Wessely ring
|How to cite this article:|
Agarwal M, Anand AR, Lakshmipathy M. Corneal ring infiltrate in fungal keratitis. Indian J Ophthalmol Case Rep 2021;1:391-2
Corneal ring infiltrate is noted in a variety of microbial keratitis. It can be infectious or sterile. Infectious rings contain a viable microorganism, whereas noninfectious rings are the result of immunologic type-3 hypersensitivity responses to confounding agents.
An apparently healthy 28-year-old man presented with left eye 2 mm x 2 mm central infiltrate with epithelial defect surrounded by 4 mm x 4 mm ring infiltrate with smooth margins [Figure 1]a. Though there was a clinical suspicion of Acanthamoeba keratitis (AK), corneal scraping from the central ulcerated area showed the presence of fungal filaments [Figure 1]b. The patient was started on ½ hourly 5% natamycin eyedrops and 2% homatropine hydrobromide twice daily. Resolution was noticed after 2 weeks of therapy.
|Figure 1: (a): Slit-lamp photograph of the left eye in diffuse illumination showing 2 mm × 2 mm central infiltrate with epithelial defect surrounded by 4 mm × 4 mm ring infiltrate with smooth margins and surrounding stromal edema. (b): KOH-Calcofluor white staining showing septate fungal filaments in the direct smear of the corneal scraping at 40 × magnification|
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| Discussion|| |
Though considered pathognomic of AK, ring infiltrates are seen in about 30% cases of AK, 5% cases of fungal keratitis, and 4% cases of bacterial keratitis. Clinical differentiation of infective from sterile ring is difficult, but sterile rings usually have smooth borders with clearing between ring and central infiltrate without overlying epithelial defect, as noted in our case.
In AK, the ring is stromal in a location containing amoebic cysts and polymorphonuclear leukocytes. Bacterial ring infiltrates form when endo/exotoxins damage the host cells attracting inflammatory cells toward immune-complexes. Noninfectious rings (Wessely ring) form due to type-3 hypersensitivity response leading to aggregation of polymorphonuclear leukocytes at area of antigen-antibody complex, leaving a clear space between the visible ring and central infiltrate. Our case had a similar presentation. Wessely ring is reported to form in fungal keratitis, Herpes simplex, Varicella zoster, Microsporidium, and Mycobacteria. Sterile rings are also reported with drug Perifosine, topical anesthetic abuse, Behcet's Disease, contact-lens overwear, recurrent corneal erosions, post-refractive surgery, and corneal-crosslinking.
Clinical suspicion of a disease with ring infiltrate should be correlated with microbiology for a definite diagnosis. Even though in our case, suspicion was of AK, the microbiology proved it to be fungal keratitis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Barash A, Chou TY. Moraxella atlantae keratitis presenting with an infectious ring ulcer. Am J Ophthalmol Case Rep 2017;7:62-5.
Mascarenhas J, Lalitha P, Prajna NV, Srinivasan M, Das M, D'Silva SS, et al
. Acanthamoeba, fungal, and bacterial keratitis: A comparison of risk factors and clinical features. Am J Ophthalmol 2014;157:56-62.
Theodore FH, Jakobiec FA, Juechter KB, Ma P, Troutman RC, Pang PM, et al
. The diagnostic value of a ring infiltrate in acanthamoebic keratitis. Ophthalmology 1985;92:1471-9.