Venom ophthalmia (keratoconjunctivitis) caused by nuchal gland secretion of Rhabdophis tigrinus: case report

Rhabdophis tigrinus (R. tigrinus) is a common colubrid snake that possesses a series of paired sac-like nuchal glands behind the head. When pressure is applied to the nuchal area, the thin skin over the nuchal glands can rupture and release secretions. In Japan, 19 cases of ophthalmia caused by the nuchal gland secretion of R. tigrinus have been reported. However, only one case has been documented in an English report. A 72-year old woman was sprayed by the nuchal gland fluid of R. tigrinus in her right eye. She presented with symptoms of eye pain and blurred vision. A slit-lamp examination revealed diffuse superficial keratitis, corneal stromal edema with Descemet membrane folds, and conjunctival injection. The best-corrected visual acuity (BCVA) of her right eye was 0.6. She was prescribed 0.5% moxifloxacin and 0.1% fluorometholone eye drops four times a day, and the symptoms resolved without sequelae within 5 days. The BCVA in the right eye improved to 1.0. In previous reports, ophthalmic examinations revealed conjunctivitis, keratitis, and corneal edema with Descemet membrane folds. Topical antibiotics and corticosteroid were prescribed in most cases, and eyes healed within 5-7 days without any sequelae. While corneal edema may resolve spontaneously in a few days when inhibition of the toxin has ceased, the use of topical steroids is recommended, as it can increase the activity of Na/K pumps that remained functional, thereby accelerating recovery. In fact, our patient used a topical steroid and recovered without sequelae.