title: Measurement of peripapillary retinal nerve fiber layer thickness and macular thickness in anisometropia using spectral domain optical coherence tomography: a prospective study.
abstract: OBJECTIVE
  To study whether there is a difference in central macular thickness (CMT) and peripapillary retinal nerve fiber layer (RNFL) thickness between the two eyes of individuals having anisometropia >1 diopter (D) using spectral domain optical coherence tomography (OCT).
  
  
  METHODS
  One hundred and one subjects, 31 with myopic anisometropia, 28 with astigmatic anisometropia, and 42 with hypermetropic anisometropia, were enrolled in the study. After informed consent, detailed ophthalmological examination was performed for every patient including cycloplegic refraction, best corrected visual acuity, slit lamp, and fundus examination. After routine ophthalmic examination peripapillary RNFL and CMT were measured using spectral domain OCT and the values of the two eyes were compared in the three types of anisometropia. Axial length was measured using an A Scan ultrasound biometer (Appa Scan-2000).
  
  
  RESULTS
  The average age of subjects was 21.7±9.3 years. The mean anisometropia was 3.11±1.7 D in myopia; 2±0.99 D in astigmatism; and 3.68±1.85 D in hypermetropia. There was a statistically significant difference in axial length of the worse and better eye in both myopic and hypermetropic anisometropia (P=0.00). There was no significant difference between CMT of better and worse eyes in anisomyopia (P=0.79), anisohypermetropia (P=0.09), or anisoastigmatism (P=0.16). In anisohypermetropia only inferior quadrant RNFL was found to be significantly thicker (P=0.011) in eyes with greater refractive error.
  
  
  CONCLUSIONS
  There does not appear to be a significant difference in CMT and peripapillary RNFL thickness in anisomyopia and anisoastigmatism. However, in anisohypermetropia inferior quadrant RNFL was found to be significantly thicker.
authors.affiliation: Department of Ophthalmology, University College of Medical Sciences, Delhi, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Singh
authors.affiliation: Department of Ophthalmology, University College of Medical Sciences, Delhi, India.
authors.forename: Jolly
authors.initials: J
authors.lastname: Rohatgi
authors.affiliation: Department of Ophthalmology, University College of Medical Sciences, Delhi, India.
authors.forename: Ved Prakash
authors.initials: VP
authors.lastname: Gupta
authors.affiliation: Department of Ophthalmology, University College of Medical Sciences, Delhi, India.
authors.forename: Vinod
authors.initials: V
authors.lastname: Kumar
keywords: CMT; RNFL; amblyopia; anisometropia