Herpetic keratitis with new characterisations - A unique case series highlighting punched-out ulcer margin with lamellar cleavage

Although HSV keratitis is one of the leading infectious causes of blindness world-wide, its misdiagnosis is not infrequent in clinical practise. We present here six eyes of five cases, all of which were initially misdiagnosed as bacterial / fungal ulcers. All these ulcers had some characteristics in common like, overt/ impending sloughing ulcer with punched out margin and clear-cut lamella planar separation. To the best of our knowledge these characterisations of HSV keratitis were not discussed earlier in literature. Diagnosis rested on clinical findings and response to antiviral therapy. A possible pathophysiology based on anatomical distribution of corneal nerves was discussed. Placement of this distinct group of ulcers in the classification of infective HSK, between dendritic, geographical, punctate ulcers at one end of the spectrum and neurotrophic ulcers at the other, and named as 'neuropathic ulcers' is hereby suggested.: Apart from dendritic, geographical, punctate ulcers at one end of the spectrum and neurotrophic ulcers at the other, there seemed to be another distinct group of herpetic ulcers in between. This new group was characterised by sloughing of that area of the cornea, which was innervated by the HSV infected corneal nerve. The process of sloughing might be aggressive or slow and seemed to progress in an orderly fashion. The area of cornea supplied by the affected nerve was separated from normal cornea by a punched-out border of demarcation followed by lamellar cleavage (separation) following the architecture of lamella- planar distribution of the affected corneal nerve. The lamellar separation could be demonstrated by the pooling of fluorescein dye in the cleaved inter lamellar space. Treatment with oral and local Acyclovir established healing.