6 th international congress of 6 international congress of - - PowerPoint PPT Presentation

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 ti i “Astigm atism is very 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 b h dit d i I t can be hereditary and is 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 h i i need them . > Most have astigm atism 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 di ti I t is an indication

• f the
• f 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

id d d Did m y doctors and then m y glasses then m y glasses cause increased astigm atism ?

Astigmatism is generally

• ne 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 ld w ould ever develop astigm atism in develop astigm atism in the absence of t t l d structural dam age.

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 ffi i i d inefficient processing and 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 P ti l A li d O t t ) (from Practical Applied Optometry)

“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

di t t d I d ’t f h it distorted so I don’t focus so much on 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

• n?

> 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?