LASIK既往のある中枢性神経麻痺性角膜症に対し角膜知覚再建術を施行した1例

A case of corneal neurotization for central paralytic keratopathy with a history of LASIK

要約　目的：Laser in situ keratomileusis（LASIK）施行歴のある眼において，聴神経腫瘍摘出後に生じた三叉神経不全麻痺に対し，角膜知覚再建術を施行して知覚回復が得られたため，これを報告する。

症例：49歳，女性。40歳時に両眼のLASIK施行歴あり。聴神経腫瘍摘出手術を2回施行後，放射線治療を受けたのち1年8か月が経過し，三叉神経麻痺による中枢性角膜知覚低下が生じた。角膜知覚再建術目的で当院に紹介となった。初診時の視力は右0.5（1.2），左0.06（0.1）で，Cochet-Bonnet角膜知覚計では右眼が全部位で60mmと正常であるのに対し，左眼は角膜中心部15mm，上部35mm，耳側25mm，鼻側25mmと低下を認めた。左眼瞼は顔面神経麻痺動的再建術後で軽度兎眼を認め，左眼の眼球結膜充血，角膜上皮障害を認めた。

　全身麻酔下に，形成外科と合同にて手術を行った。形成外科が右腓腹神経を採取し，右眉毛下内側で右滑車上神経を同定した。同定した部位から皮下トンネルを作成し，右腓腹神経を通したのち，当科にて経Tenon囊下に右腓腹神経と左角膜輪部縫合を行った。その後，形成外科によって右滑車上神経と右腓腹神経縫合を行った。術後2年のフォローアップ時には，左眼の角膜知覚は角膜中心部60mm，上部60mm，耳側60mm，鼻側60mmと改善を認め，視力は（0.5）に改善し，角膜上皮障害は減少した。

考察：LASIK手術により角膜神経線維が減少するといわれているが，中枢性三叉神経麻痺に対する角膜知覚再建術は，LASIK施行歴があっても有用である可能性がある。

Abstract　Purpose：We report a case where corneal neurotization was performed for the treatment of trigeminal nerve paresis following acoustic neuroma removal in an eye with a history of laser in situ keratomileusis（LASIK）, resulting in successful sensory recovery.

Case：A 49-year-old female, who had undergone LASIK for both eyes when she was 40 years old. After two surgeries to remove an acoustic neuroma and radiotherapy, at 1 year and 8 months later, the patient was referred for corneal sensory reconstruction due to decreased central corneal sensitivity based on trigeminal nerve palsy. At the time of consultation, RV＝0.5（1.2）, LV＝0.06（0.1）, and Cochet-Bonnet corneal esthesiometer indicated that the right eye was normal at 60 mm in all areas, whereas the cornea in the left eye was 15 mm in the center and 15 mm in the upper portion. A decrease of 35 mm was observed, with 25 mm on the temporal side and 25 mm on the nasal side. Mild lagophthalmia was observed in the left eyelid after dynamic reconstruction of the facial nerve paralysis, bulbar conjunctival hyperemia, and corneal epithelial disorder in the left eye. Surgery was performed under general anesthesia in collaboration with a plastic surgeon. The plastic surgeon harvested the right sural nerve and identified the right supratrochlear nerve below the right eyebrow. A subcutaneous tunnel was created from the identified site, and the right sural nerve was passed through it. The right sural nerve and left limbal limbus were sutured transtenonally in our department. The plastic surgeon sutures the right supratrochlear and right sural nerves. At two-year follow-up after surgery, corneal sensitivity improved to 60 mm in the central cornea, 60 mm in the upper part, 60 mm in the temporal part, and 60 mm in the nasal part, and the corneal epithelial disorder improved to LV＝（0.5）.

Discussion：Corneal nerve fibers decreased after LASIK surgery, but corneal sensory reconstruction surgery for central trigeminal nerve palsy may be useful, even with a history of LASIK surgery.