title: Delineating the extent of anterior capsulorhexis with gentian violet using capsulorhexis marker: a preliminary study of efficacy and toxicity in an animal model.
abstract: BACKGROUND
  The purpose of this study was to evaluate the efficacy and safety of a new instrument to optimize the size, shape, and centration of anterior capsulorhexis.
  
  
  METHODS
  The study was divided into two parts. The first part was done in 10 goats' eyes. A specially designed capsulorhexis marker was used. The lower edge of the instrument was stained by gentian violet and then applied to the anterior capsule to produce a circular mark of 5.5 mm. In five eyes, the gentian violet was applied to the marker using a corneal marking pen; in the remaining five eyes, the gentian violet was applied using a corneal marking pad. In the second part, the toxicity of gentian violet was tested as follows: ten albino rabbits received a gentian violet injection into the anterior chamber in one eye (experimental group) and an equal volume of balanced salt solution in the fellow eye (control group). Five rabbits were sacrificed one day after surgery and the remaining five rabbits after one week.
  
  
  RESULTS
  In the first part, there was no difficulty in the introduction or removal of the instrument from all eyes. In the first two eyes, the circular mark was diffuse due to sliding of the marker on the surface of the anterior capsule. In the remaining eight eyes, there was a well-centered, rounded mark which was adequately stained. In the second part, there was no histopathological evidence of corneal toxicity in either group. There was loss of ganglion cells from the neurosensory retina one day after surgery in one eye from the experimental group. At one week, there was no evidence of retinal toxicity in any of the rabbits.
  
  
  CONCLUSIONS
  This capsulorhexis marker can guide the surgeon to a better centration and proper sizing of anterior capsulorhexis using gentian violet staining. More refinement of the instrument is needed to be able to use it in human eyes.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, Egypt.
authors.forename: Mohamed Abdel Moneim
authors.initials: MA
authors.lastname: Hassaballa
authors.forename: Amr Abd El-Latif
authors.initials: AA
authors.lastname: Osman