scleral lens Flashcards
how many scleral lens categories. and which are they
4- corneo-scleral 12.9-13.5mm semi-scleral 13.6-14.9mm mini-scleral 15.0-18.0mm full-scleral 18.1-24+mm
when would u use a scleral lens
irregular cornea- keratoconos severe scarred/pathological cornea high astigmatism SEVERE dry eyes
whats a semi scleral lens
rest on sclera
contour the cornea
limbal clearance needed
scleral alignment
how do u evaluate the fit of a scleral lens
-examine the entire corneal chamber
-diffuse cobalt blue with full illumination
-lens should cover entire cornea and align to bulbar conjuctiva
-then loo at the corneal fit with an optic section with white light
-outermost dark black band is lens- in-between to hairline reflections which is front and back of lens
-middle green band is tears
-inner band is cornea
compare lens and tear layer
-look at peripheral fit
-peripheral should align with bulbar conjuctiva
_look for excessive movement, bubble formation and blanching
how long does it take for a scleral lens to settle and wot might happen
30-40 mins
after settling u may see some bearing
if it touches cornea- may disrupt corneal epithelium
over-topography after lens has settled- to see if any lens flexure- more than 0.50D u should increase central thickness of lens
whats the basic design of the scleral lens
peripheral curve |
scleral curve |
limbal curve |
central optic zone|
whats the blanchard Mini Scleral design
15.8 mm
fit based on sag value
sag varies between 3.7-4.8
why is sag values altered
for highest point of cornea-
so more curved is a higher sag value
how would u insert a scleral lens
cover px lap with paper towels, and position px face parallel to ground
clean lens with conditioning sol note not hair conditioner- that would be well silly
position the lens on large scleral cup- or form a tripod shape with ur fingers
now fill the lens with preserved tears
add fl from a strip
get px to hold upper lid
u hold lower
then close lid then take out plunger
push on inferior periphery part of lens- for several seconds- have px look in diff directions
have good control of superior lid and use inferior lid to push lens from eye
why would there be a bubble in a scleral lens
lens wasn’t inserted in one continuous motion
lens wasn’t filled completely with sol?
remove and reinsert this lens pls
how would u remove a scleral lens
use a DMV suction cup
apply this to inferior lens periphery and pull down and out
use the other hand to apply pressure on the top of the lens through the lid
how would u care for a scleral lens
clean and disinfect sold
filing liquid- nevr use cl saline, tap water, soft cl sol
rewetting frops
what does a scleral lens push back on
sclera and conjunctiva
how do u make first scleral lens
make impressions 1.5mins glass model on eye squirt material on eye take out after a min now make it as a sfot cl- and put on eye if flutes around edges then accurate impression can copy this positive mould and make a scleral lens from it
what are the positives
allow tear exchange
allows lens to sit back
same adv of cl
longer wt and comfort
