Diagnosis of Dieffenbachia induced corneal injury by confocal microscopy
- Auguste G-Y Chiou, MD, Edward S Harkness Eye Institute, Columbia Presbyterian Medical Center, 635 W 165th Street, Suite 303, New York, NY 10032, USA.
- Accepted 14 October 1996
Editor,—Dieffenbachia, a tropical house plant, belongs to the family Araceae. Throughout the plant, specialised cells release needle-like crystals of calcium oxalate (raphides) in an explosive manner upon breaking the stem or the branches.1 These may penetrate skin and mucous membranes, and also involve the cornea. We present the first follow up ofDieffenbachia induced corneal lesions using a real time confocal in vivo slit scanning microscope.2 3
CASE REPORT
A 26-year-old woman presented herself at the emergency room with pain, photophobia, and foreign body sensation in her right eye. These symptoms appeared immediately after breaking a leaf of the house plantDieffenbachia 1 day earlier. She was otherwise healthy, except for an adenovirus keratoconjunctivitis 4 years earlier in her left eye. The patient’s ocular examination on presentation showed a best corrected visual acuity of 20/25 in the right eye and 20/20 in the left eye. Slit-lamp biomicroscopy of the right eye showed fine punctate opacities throughout the corneal stroma. The remainder of the ocular examination was normal, except for subepithelial opacities in the left cornea related to the previous adenovirus infection.
The patient underwent confocal in vivo slit scanning video microscopy, which offers real time non-invasive and non-contact serial imaging of corneal segments with resolution and imaging contrast.2 A 25/0.60 water immersion objective was used. For higher optical resolution, we used a 50/1.00 water immersion objective. Confocal microscopy, performed at 1, 4, and 8 weeks after the trauma, demonstrated highly reflective elongated structures (Fig 1) in all layers of the cornea. The cornea’s architecture remained globally undisturbed. There was no inflammatory cell infiltration. We observed diminution and fragmentation of the raphides (Fig 2) at 2 months, probably as a consequence of resorption.
Confocal microscopy 1 month after the injury. Numerous raphides could still be found in the corneal stroma. The keratocytes demonstrated normal reflectivity. There was no inflammatory cell infiltration.
Two months after the injury, confocal microscopy demonstrated fragmentation of the raphides (arrow).
COMMENT
Dieffenbachia induced corneal lesions represent a benign affection of the anterior segment of the eye. Treatment should be aimed at relieving pain using mild steroids and cycloplegics. Confocal microscopy highly improved visualisation of the raphides. Usually there is a good history of trauma such as this so that establishing the diagnosis should not be problematic. However, in cases of ocular irritation with unknown aetiology, particularly with a history of contact with plant, confocal microscopy can establish the diagnosis ofDieffenbachia induced injury by demonstrating the crystals of calcium oxalate.
