Fungal corneal ulcer detection in a slit-lamp-based intraocular lens microscopy clinical setup

Dear Editor, Microbial keratitis is a major health concern predominantly affecting the lower socioeconomic strata and hence requires attention from ophthalmologists and public health specialists.[1] Corneal blindness due to keratitis is a serious cause of ocular morbidity in India only second to cataracts.[2] Fungal keratitis is an ocular emergency with early recognition, prompt diagnosis, and rapid institution of appropriate therapy that can rapidly improve visual prognosis.[3] There is an existing challenge of poor sample collection and improper diagnosis in rural, peripheral, and small clinic setups due to a lack of microbiological setup.[3] Chandrakanth et al.[4] described the use of a slit-lamp-based intraocular lens microscope (SLIM) as a stable platform for viewing the microbiological specimen.[5] We use SLIM as an office-based rapid diagnosis of a suspected corneal ulcer, where the entire examination from the anterior segment examination to microbiological detection is done just with the help of slit-lamp bio-microscopy. After examination of a patient with microbial keratitis, a corneal scraping is performed taking aseptic precautions on the slit-lamp. The specimen is mounted on a slide which was kept on top of a light source and viewed using the SLIM. The specimen was focused to get the required microscopic image or video using the joystick of the slit-lamp. The microscopic image and video of the fungal hyphae obtained were easily detected and were of good quality [Fig. 1].Figure 1: Smartphone with intraocular lens attached to the mobile end of a smartphone adaptor (a); superior view of the slit-lamp-based intraocular lens microscope (SLIM) assembly along with the torchlight in a hollow PVC/sanitizer bottle tube to keep the sample slide (b); SLIM setup with the examination of a patient with suspected corneal ulcer (c); slit-lamp-assisted sterile corneal scraping under topical anesthesia (d); collected sample/material spread on a glass slide (e); KOH mount being prepared (f); microscopic examination of the sample slide using SLIM (g); fungal hyphae seen on microscopic examination using SLIM (h)This is a preliminary step in screening fungal ulcer cases and enabling quick diagnosis and appropriate management in clinics previously devoid of microbiological setups. It is a do-it-yourself, easy-to-build, cost-effective setup which can be adapted by any ophthalmologist. It can be especially useful in vision centers, peripheral rural centers, and small setup clinics with the availability of slit-lamp. Although this technique serves the purpose of screening, it does not replace the gold-standard microbiological setup. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.