Reply: Microanatomy of Sensory Nerves in the Upper Eyelid: A Cadaveric Anatomical Study.

Abstract

Sir: We appreciate Dr. Hwang’s thoughtful comments about our article, “Microanatomy of Sensory Nerves in the Upper Eyelid: A Cadaveric Anatomical Study.”1 In his comments, Dr. Hwang claims that the supratrochlear nerve supplies the medial extremity of the upper eyelid rather than being widely distributed in the upper eyelid. A previous study by Dr. Hwang’s group2 considered the frontal nerve, the supraorbital nerve, the supratrochlear nerve, the infratrochlear nerve, and the lacrimal nerve to all be terminal branches in the upper eyelid. In describing the anatomy of nerves in the upper eyelid, Gray’s Anatomy indicates that the frontal nerve splits into the supraorbital and supratrochlear nerves in the orbit.3 The supraorbital nerve exits the orbit through the supraorbital notch or foramen. The supratrochlear nerve runs medially above the trochlea for the tendon of the superior oblique muscle. Our study1 considered the supraorbital nerve, supratrochlear nerve, infratrochlear nerve, and lacrimal nerve to be terminal branches in the upper eyelid; the frontal nerve was not considered a terminal branch of the upper eyelid. Hwang et al. state that the supratrochlear nerve enters the upper eyelid at the orbital margin −6.7 ± 3.1 mm medial to the medial canthus and 11.9 ± 4.3 mm from the eyelid margin.2 Shin et al. reported that the vertical distance from the apex of the lacrimal caruncle to the superolateral tip of the trochlea was 15.8 mm.4 Given the report by Shin et al. and our own study, we wonder whether the point at which the supratrochlear nerve enters the upper eyelid according to Hwang et al. might be below the trochlea (i.e., they may be considering a supratrochlear nerve to be the frontal nerve). Figures 2 and 6 in our report show the distribution of the supratrochlear nerve in the upper eyelid.1 We hope that these images help address the concerns about our findings. Lastly, we agree with Dr. Hwang that upper eyelid sensory nerve anatomy has not been described in sufficient detail and that further investigation is merited. DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication. Takuya Higashino, M.D., Ph.D.Department of Plastic and Reconstructive SurgeryTokyo Medical and Dental UniversityTokyo, JapanDepartment of Plastic and Reconstructive SurgeryNational Cancer Center Hospital EastKashiwa, Japan Mutsumi Okazaki, M.D., Ph.D.Department of Plastic and Reconstructive SurgeryGraduate School of MedicineUniversity of TokyoTokyo, Japan Hiroki Mori, M.D., Ph.D.Department of Plastic and Reconstructive SurgeryTokyo Medical and Dental UniversityTokyo, Japan Kumiko Yamaguchi, M.D., Ph.D.Institute of EducationTokyo Medical and Dental UniversityTokyo, Japan Keiichi Akita, M.D., Ph.D.Department of Clinical AnatomyTokyo Medical and Dental UniversityTokyo, Japan