Corneal sensation in acute angle closure glaucoma

Abstract

Corneal sensation was found to be decreased in eyes affected by acute angle closure glaucoma. In those patients with a short history (less than four days) the difference in sensation between the two eyes was only detectable using the Cochet-Bonnet aesthesiometer and not by using cotton wool. Patients with a longer history had a more marked decrease in corneal sensation that was detectable by both methods. Corneal sensation in both groups tended to recover partially on normalization of the intraocular pressure.

Relationship between corneal sensitivity, corneal thickness, corneal diameter, and intraocular pressure in normal cats and cats with congenital glaucoma

“…Similar findings were reported in prior studies involving human PCG patients . Prior studies in human patients have shown that buphthalmos at an early age may be associated with significant reduction in corneal sensitivity, although in these patients, increased CD is also associated with increased CT and corneal edema . In 1988, Patel and others noted that persistent corneal edema led to decreased corneal sensitivity, even after normalization of IOP, in patients that had prolonged elevation of IOP .…”

“…Prior studies in human patients have shown that buphthalmos at an early age may be associated with significant reduction in corneal sensitivity, although in these patients, increased CD is also associated with increased CT and corneal edema . In 1988, Patel and others noted that persistent corneal edema led to decreased corneal sensitivity, even after normalization of IOP, in patients that had prolonged elevation of IOP . In the veterinary literature, one prospective clinical study evaluating canine eyes with buphthalmos and/or chronically elevated intraocular pressure prior to evisceration with intraocular prosthesis placement determined that corneal sensitivity in these eyes was significantly reduced relative to contralateral control eyes .…”

“…In particular, corneal enlargement can be very pronounced in patients that are affected by glaucoma at a very young age . Chronic glaucoma has been associated with reduced corneal sensitivity in human PCG patients . In their study involving patients aged 8 to 16 years old with PCG, Gatzioufas et al identified significant reduction in mean corneal sub‐basal nerve density and total number of nerve fibers in the central cornea.…”

Corneal sensitivity and aqueous tear production in dogs undergoing evisceration with intraocular prosthesis placement

“…Diurnal fluctuations in corneal sensitivity also occur 24 . Numerous pathologic conditions of the eye have been shown to increase the corneal touch threshold in humans including scleritis, 25 keratoconjunctivitis sicca, 26 herpes viral keratitis, 27 corneal edema, 28,29 and glaucoma 30,31 . Additionally, systemic diseases that can affect the peripheral nerves, such as diabetes mellitus, myasthenia gravis, and leprosy, can also lead to an increase in corneal touch threshold 14,32–36 …”

“…In a study of five human patients with prolonged rise in IOP, no patients reverted to normal corneal sensitivity even after normalization of IOP 30 . Those authors proposed a lasting damage to corneal nerves due to corneal edema 30 . Corneal edema has been shown to decrease corneal sensitivity in humans 28,29 .…”