Influence of pupillary diameter, ciliary muscle tone, and ambient light on nerve fiber layer measurements with scanning laser polarimetry.
OBJECTIVE
To evaluate the influence of the pupillary diameter, ciliary muscle tone, and room light on nerve fiber layer measurements with the scanning laser polarimeter (GDx).


METHODS
One randomly selected eye of ten normal volunteers was examined with the GDx in a two-day protocol under eight testing conditions (pilocarpine 1%, phenylephrine 10%, tropicamide 1%, or no drops with room lights on or off). The twelve parameters, obtained by the GDx, were compared under the eight testing conditions, using two way ANOVA for repeated measurements and Tukey HSD post hoc test.


RESULTS
Ten of the twelve parameters were statistically significantly different (P < 0.05) when measured under the three medication or no medication conditions, controlling for the ambient light status. There were no significant differences when measured with the light on or off, controlling for use of drops.


CONCLUSIONS
Nerve fiber layer measurements with the GDx were influenced by drugs affecting pupillary diameter, but not by the status of room light or ciliary muscle tone.
Paranhos
Augusto
A
Ophthalmology Department, Federal University of São Paulo, São Paulo, Brazil 04023-062. augusto.paranhos@uol.com.br
Silvestre
Ana Maria
AM
Passerotti
Carlo C
CC
Martins
Elizabeth M R
EM
de Arruda Mello
Paulo Augusto
PA
Prata
João Antônio
JA
Shields
Milton Bruce
MB
D000328:Adult; D002924:Ciliary Body / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D005260:Female; D006801:Humans; D007834:Lasers; D008027:Light; D008297:Male; D008916:Miotics / Q000008:administration & dosage; D009130:Muscle, Smooth / Q000502:physiology*; D009184:Mydriatics / Q000008:administration & dosage; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D019721:Ophthalmoscopes; D009887:Ophthalmoscopy / Q000379:methods*; D009900:Optic Nerve / Q000502:physiology*; D010656:Phenylephrine / Q000008:administration & dosage; D010862:Pilocarpine / Q000008:administration & dosage; D011680:Pupil / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D012165:Retinal Ganglion Cells / Q000502:physiology; D014331:Tropicamide / Q000008:administration & dosage
D008916:Miotics; D009184:Mydriatics; D010862:Pilocarpine; D010656:Phenylephrine; D014331:Tropicamide