[Viscoelastic substances as a breaking factor of ocular rotations II: studies with carboxymethylcellulose].
OBJECTIVE
From a quantitative point of view, to determine if the viscous friction forces could act as possible promoters of ocular stabilization keeping the rotational movements, which would provide the necessary values to be used in the ocular system.


METHODS
A mechanical model was created to measure the necessary forces to overcome the friction of an aluminum sphere partially kept in a viscous liquid. Solutions of carboxymethylcellulose from 1.0% to 6.0% (with a variation of 0.5%) were used. Another variant to be considered was the area of contact between the sphere and the viscous liquid.


RESULTS
After appropriate corrections and discounts a meaningful force (over 5 gf) was found in the solutions of carboxymethylcellulose at 3.5% or more in the largest contact area (587.8 mm2), in the solutions of carboxymethylcellulose at 4.5% or more in the intermediate area (335.9 mm2), in the solutions of carboxymethylcellulose at 5.5% and 6.0% in the smallest area (167.9 mm2).


CONCLUSIONS
Some of the viscous liquids tested are apparently able to ensure enough friction force for ocular stabilization, specially the solutions of carboxymethylcellulose at 5.5% and 6.0% which provided good results in the smallest contact area.
Jorge
André Augusto Homsi
AA
Departamento de Oftalmologia e Otorrinolaringologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil. andrehomsi@netsite.com.br
Bicas
Harley Edison Amaral
HE
D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D004548:Elasticity; D005133:Eye Movements / Q000502:physiology*; D017276:Friction; D006801:Humans; D008954:Models, Biological; D012399:Rotation; D013499:Surface Properties; D014783:Viscosity
D002266:Carboxymethylcellulose Sodium