Effect of hinge width on corneal sensation and dry eye after laser in situ keratomileusis

Abstract

Corneal sensation and dry-eye signs and symptoms improved at all intervals between 1 week and 6 months. The loss of corneal sensation and presence of dry-eye syndrome were greater in eyes with a narrow hinge flap than in eyes with a wider hinge flap.

Dry eyes and corneal sensation after laser in situ keratomileusis with femtosecond laser flap creation

“…Results in studies using a microkeratome 26 indicate that creating flaps with narrower hinge angles decreases corneal sensation and aggravates dry eye because more corneal nerves are severed. However, using a single femtosecond laser keratome, we found that varying the hinge angle had no significant effect on corneal sensation or other dry-eye parameters.…”

Comparison of dry-eye disease severity after laser in situ keratomileusis and laser-assisted subepithelial keratectomy

“…These include higher refractive correction, 12 deeper ablation depth, 13 a thicker flap, 14 a superior flap hinge, 15 and a narrow flap hinge. 16 This study compared the 1-year postoperative changes in dry-eye metrics between thin-flap LASIK (120 mm) and LASEK.…”

Safety and efficacy of cyclosporine 0.05% drops versus unpreserved artificial tears in dry-eye patients having laser in situ keratomileusis

“…31 It is believed that severing corneal nerves during surgery may interrupt a neural feedback loop to the lacrimal glands. 3,35,[39][40][41][42] In a normal eye, the tear film supports and maintains the ocular surface. When tear production is needed, sensation from the ocular surface stimulates the brain, which sends secretomotor nerve impulses to the lacrimal gland to produce tears.…”

“…Use of a wide hinge, a nasal rather than a superior hinge, preserves more corneal innervation and lessens the incidence or exacerbation of dry eye resulting from the procedure. 41,42 Because LASIK can exacerbate or cause dry-eye disease, it may be important to treat the disease in susceptible LASIK candidates before and after surgery. This study was undertaken to evaluate the effect of 2 treatments, unpreserved artificial tears and cyclosporine 0.05%, on the signs and symptoms of dry-eye disease and on refractive outcomes for dry-eye patients having LASIK.…”