title: Unilateral herpes zoster ophthalmicus results in bilateral corneal nerve alteration: an in vivo confocal microscopy study.
abstract: OBJECTIVE
  Herpes zoster ophthalmicus (HZO), thought to be a unilateral disease, results in loss of corneal sensation, leading to neurotrophic keratopathy. This study aimed to analyze bilateral corneal nerve changes in patients with HZO by in vivo confocal microscopy (IVCM) and their correlation with corneal sensation as a measure of nerve function.
  
  
  METHODS
  Prospective, cross-sectional, controlled, single-center study.
  
  
  METHODS
  Twenty-seven eyes with the diagnosis of HZO and their contralateral clinically unaffected eyes were studied and compared with normal controls (n = 15).
  
  
  METHODS
  In vivo confocal microscopy (Confoscan 4; Nidek Technologies, Gamagori, Japan) and corneal esthesiometry (Cochet-Bonnet; Luneau Ophthalmologie, Chartres, France) of the central cornea were performed bilaterally in all patients and controls. Patients were grouped into normal (>5.5 cm), mild (>2.5-5.5 cm), and severe (<2.5 cm) loss of sensation.
  
  
  METHODS
  Changes in corneal nerve density, total nerve number, main nerve trunks, branching, and tortuosity were evaluated after IVCM and were correlated to corneal sensation, disease duration, and number of recurrences.
  
  
  RESULTS
  Eyes with herpes zoster ophthalmicus had a significant (P<0.001) decrease in total nerve length (595.8±358.1 vs. 2258.4±989.0 μm/frame), total number of nerves (5.4±2.8 vs. 13.1±3.8), number of main nerve trunks (2.3±1.1 vs. 4.7±1.2), and number of nerve branches (3.2±2.3 vs. 8.4±3.7) as compared with controls. In the contralateral clinically unaffected eyes, total nerve length (1053.1±441.4 μm/frame), total number of nerves (8.3±2.9), and main nerve trunks (3.1±1.0) also were decreased significantly as compared with controls (P<0.01). Reduced nerve density, total nerve count, main trunks, and tortuosity was correlated significantly with corneal sensation across all subgroups (P<0.001).
  
  
  CONCLUSIONS
  Patients with unilateral HZO demonstrated a profound and significant bilateral loss of the corneal nerve plexus as compared with controls, demonstrating bilateral changes in a clinically unilateral disease. Loss of corneal sensation strongly correlated with subbasal nerve plexus alterations as shown by IVCM.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Ocular Surface Imaging Center and Cornea & Refractive Surgery Service, Massachusetts Eye & Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA. pedram_hamrah@meei.harvard.edu
authors.forename: Pedram
authors.initials: P
authors.lastname: Hamrah
authors.forename: Andrea
authors.initials: A
authors.lastname: Cruzat
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Dastjerdi
authors.forename: Harald
authors.initials: H
authors.lastname: Prüss
authors.forename: Lixin
authors.initials: L
authors.lastname: Zheng
authors.forename: Bashar M
authors.initials: BM
authors.lastname: Shahatit
authors.forename: Hasan A
authors.initials: HA
authors.lastname: Bayhan
authors.forename: Reza
authors.initials: R
authors.lastname: Dana
authors.forename: Deborah
authors.initials: D
authors.lastname: Pavan-Langston
mesh_terms: D003315:Cornea / Q000294:innervation* / Q000502:physiology; D003389:Cranial Nerve Diseases / Q000175:diagnosis / Q000209:etiology*; D003430:Cross-Sectional Studies; D005260:Female; D006563:Herpes Zoster Ophthalmicus / Q000150:complications*; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D011446:Prospective Studies; D016037:Single-Blind Method; D012668:Trigeminal Ganglion / Q000473:pathology*