6 th international congress of 6 international congress of behavioral optom etry april 8 -1 1 , 2 0 1 0 april 8 1 1 , 2 0 1 0 Steve Gallop, O.D., FCOVD
“A ti “Astigm atism is very ti i difficult to define.” difficult to define. “Astigm atism is difficult to understand ” to understand. A.M. Skeffington (from Practical Applied Optometry)
> Almost everyone has some > Almost everyone has some amount of astigmatism. > Astigmatism is easy to measure and prescribe. > Practically no one knows what it is what it is.
“ The specific cause of The specific cause of astigm atism is unknow n. I t I t can be hereditary and is b h dit d i usually present from y p birth. I t can change as a child grow s and m ay child grow s and m ay decrease or w orsen over tim e.” ( according to the AOA website ) ( according to the AOA website )
> Som e people seem to > Som e people seem to need com pensation. > Many have com pensating lenses but seem not to need them need them . > Most have astigm atism h i i and are asym ptom atic. and are asym ptom atic.
I once m et a I once m et a w om an w ho had w om an w ho had no cylinder in her y lenses.
I ’m not convinced that decreased acuity that decreased acuity is a prerequisite for is a prerequisite for prescribing cylinder.
-3.25–0.25 x 74? + 4 75 0 50 x 23? + 4.75–0.50 x 23? W hat is the expected W hat is the expected benefit of this cylinder?
Low Acuity Low Acuity
Astigm atism is not the Astigm atism is not the problem . p I t i I t is an indication i di ti of the of the person’s attem pt to solve problem s.
Astigm atism is Astigm atism is m easured MONOCULARLY I t is rarely investigated BI NOCULARLY b f BI NOCULARLY before being prescribed. being prescribed.
Form Form Form Form follows follows Function Function Function Function
Did m y doctors and id d d then m y glasses then m y glasses cause increased astigm atism ?
Astigmatism is generally one of three things: > a normal variant that requires > a normal variant that requires no attention whatsoever > a refractive issue that requires compensation of requires compensation of some sort > a sign of visual stress that may well be amenable to may well be amenable to therapeutic intervention
There m ust be som e benefit or nobody w ould ever ld develop astigm atism in develop astigm atism in the absence of structural dam age. t t l d
I n the sam e w ay that m uch nearsightedness results from nearsightedness results from inefficient processing and perform ance at near m ost perform ance at near, m ost astigm atism results from i inefficient processing and ffi i i d perform ance at any or all distances.
Your glasses have Your glasses have astigmatism astigmatism.
The single m ost The single m ost effective first step in visual training is often changing the is often changing the habitual Rx. habitual Rx.
“I f the em bedded visual behavior is to be superseded by im proved superseded by im proved perform ance, through the process of training the process of training, the cylinders m ay w ell be a deterrent.” A.M. Skeffington (f (from Practical Applied Optometry) P ti l A li d O t t )
“I t is not w hat lenses do to a person, it’s w hat a person it s w hat a person does w ith a lens.” Robert A Kraskin O D Robert A. Kraskin, O.D.
Com pensating lenses can cause m ore problem s than they problem s than they solve.
“ It actually affected my driving quite a bit. Now I ’ m watching where I ’ m going g g g instead of feeling where I ’ m going and now I have my visor scratched up and now I have my visor scratched up and dirty. I try to keep my vision a little bit distorted so I don ’ t focus so much on it di t t d I d ’ t f h it and I actually get back to the feel of the sled. ” Steve Holcomb
Alex C Jan 7 , 2 0 1 0 OD + 2.50 –1.25 x 180 20/ 25+ OD 2.50 1.25 x 180 20/ 25 OS + 4.00 –2.00 x175 20/ 20- Jan 2 0 , 2 0 1 0 OD/ OS + 2.50/ + 1.50 O / OS 50/ 50 OD 20/ 60+ OS 20/ 70 Feb 2 5 , 2 0 1 0 OD/ OS + 2.00 OD/ OS + 2.00 OD 20/ 30 OS 20/ 40 OU 20/ 25-
Mar 2 5 , 2 0 1 0 + 0.50 OD/ OS PL OD 20/ 20 OS 20/ 50 OU 20/ 20+ PL OD 20/ 20 OS 20/ 50 OU 20/ 20+ (OS PL –1.50 x 180 20/ 20+ ) Apr 5 2 0 1 0 Apr 5 , 2 0 1 0 PL OD 20/ 25+ OS 20/ 40 OU 20/ 20
How do you y feel feel w ith these lenses w ith these lenses on?
> Cylinder is greatly over- > Cylinder is greatly over- prescribed. > I t never hurts to try som ething new . > Any change can be reversed or m odified reversed or m odified as needed.
Hopefully the next time Hopefully the next time you are confronted with astigmatism, instead of simply asking yourself simply asking yourself… “How m uch?” How m uch? You’ll start asking… You ll start asking… “How com e?” How com e?
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