PRELIM Flashcards
In Egypt, what eye were placed on the deceased?
Bronze and precious stone eyes
In the ancient world, the Romans decorated their statues with artificial eyes made of
Silver
A famous French surgeon who first described the use of artificial eyes to fit on eye socket
Ambrose Paré
What kind of prostheses were attractive but were expensive and not very durable
Enamel
Since World War II, what has become the preferred material for the artificial eyes in US
Plastic
The US military developed a technique of fabricating prostheses using
Oil pigments and plastics
______ could be worn at bedtime
Molded prosthesis
_______ had to be removed nightly to give the socket tissues a rest
Glass eye
A ________ were sold to those who could not afford a custom fitted glass eye
Stock glass eyes
Type of ocular devices
Prosthetic eye
Prosthetic shell
Prostheses may be required as a result of
Trauma
Malignancy
Developmental anomalies
Degenerative conditions
Providers of ocular prosthetic services
Optometrist
Ophthalmologist
Ocularist
Prostheses used when the natural eye remains
Thin prosthetic eye
Cosmetic shell
Removal of the global contents with retention of scleral wall, muscles, and cornea
Evisceration
This procedure involves removal of the entire globe
Enucleation
This procedure involves the removal of the entire orbital contents and usually occurs following severe trauma or malignancy
Exentration
Types of implants
Polyethylene Beren’s spheres
Bio-eyeTM hydroxyapatite ocular implant
Purpose of conformers
Aid in healing
Help enlarge the eye socket
Variety of sizes available
Fitting methods of prosthetic eye
Custom fitting
Stock fitting
Variation of standards sets
Advantage of custom fitting prostheses
Well-fitted prosthesis
Uses impression molding
More precise copy of the normal eye is possible
Stock prosthetic eye/shells
AO Monoplex prosthetic eye
Fitting set
Order specifications based on coding system
Variation of standard sets
Use of dental wax during refitting and trial
Routine build-up to improve fit
Globe anomalies
Scarring
Coloboma
Albinism
What are the basic fitting goals?
Optimum pupil diameter
Orthophoric appearance
Stability of fit
Fitting considerations of prosthetic eye
Overall size
Smooth edges
2 types of evisceration procedures
With insertion of an intra-scleral implant
Without implant insertion
Enucleation is indicated for the ff conditions:
Intraocular malignancy
Painful, blind eye
Disfigured, painless, blind eye
A clear, non-water- absorbent spheres of 12 to 20mm diameter, used for implantation after evisceration or enucleation
Polyethylene Beren’s spheres
An implant made of bone-like porous material derived from ocean coral
BioeyeTMhydroxyapatite ocular implant
A clear, plastic, oval-shaped concave discs placed in the socket over the implant during the post op
Conformers
Aspects of care and maintenance of prosthetic devices that require attention:
Insertion and removal
Frequency of removal
Cleaning the prosthetic eye/shell
After-care evaluation of prosthetic eye
Scratches, deposits
Refitting
Replacement
Indications for modification of prosthetic eye
Children who have outgrown their prosthesis
Socket shrinkage
Orbital or lid changes
Changes in the normal eye
Modifications performed
Enlarging the prosthesis
Size reduction of prosthesis
Prosthesis alignment
Modifications to be made when changing the iris/scleral colour
Use of color codes
More yellow and brown for the aging sclera
Ocular features to be added to match the developed eye
Pterygium
Arcus senilis
Iris freckles
Ptosis crutch
Artificial skin or cheek
Management of the patient with an ocular prosthesis
History
Test functional eye
Inspection of orbit
Cleaning and polishing of prosthesis
Supplies and equipment used for modification of prosthetic eye
CL modification unit
Motorized spindle
Dental wax
Alcohol lamp
Dental burrs
Sandpaper
Dental tools
Patient education
Protection
Vision mobility
Driving
After care
In the 1880’s, blown glass shells were used by?
Eugene Kalt
August Muller
Eugen Fick
Scleral lens is also known as?
Haptic lens
According to recorded history, what contact lenses were the first contact lenses created?
Scleral contact lenses
He attempted to reduce the ectasia of a keratoconic cornea by using the shell to compress the cone
Eugene Kalt
He investigated the correction of high myopia with a corrective lens applied directly to the cornea
August Muller
He corrected irregular astigmatism by replacing deformed cornea with another regularly curved surface
A. Eugen Fick
A term used to define a mistiness of vision accompanied by appearance of rainbow-coloured haloes
Sattler’s veil
Attempts to increase wearing time of prosthesis
Use of buffer solutions
Changes in lens parameters
Channels, fenestrations, slot and ducts were trialled
from the greek word meaning “to fasten” or “attach”
Haptic
A contact lens with a haptic portion. The main bearing portion of the lens is over the sclera. Also known as a scleral lens.
Haptic lens
A haptic contact lens
Scleral lens
Part of the lens which overlays the sclera/conjunctiva.
Haptic (scleral) portion
the central part of the lens which covers the cornea and limbus.
Optic (corneal) portion
the area of change in curvature/section of the lens between the central optic and the peripheral haptic.
Transition
a hole in the lens to assist fluid exchange.
Fenestration
A furrow on the back surface of the lens to enhance tear exchange.
Channel
a semi-finished stock lens, a lens constructed with a predetermined standardized back surface form/shape.
Performed lens
A lens molded from a cast of the anterior surface of the eye for which it is intended.
Impression lens
contact lens shape without optics.
Contact shell
Indications for scleral lenses
Patients involved in active water sports
Decentred pupils
Poorly centred lenses
Advanced keratoconus
Pathological and disfigured eyes
Types of scleral lenses
Performed
Impression
Types of acceptable scleral lens fit
Flush fit
Semi-sealed fit
Ventilated fit
Sealed fit
a haptic contact lens designed to change or improve the appearance of the patient and having optical power.
Cosmetic (prosthetic) haptic lens
cosmetic haptic shell without optics. Usually fitted over an irregular, damaged or deformed globe.
Cosmetic (prosthetic) shell
Disadvantages of scleral lenses
Long fitting time
Greater expense
Types of scleral fitting sets
Wide angle
Spherical
Off-set
FLOMS
FLOMS means
Fenestrated lenses for optic measurement
A haptic shell or lens which closely parallels the shape of the anterior eye.
Flush fit
A haptic shell or lens incorporating modifications to allow the postlens tear film to escape to the lens edge.
Semi-sealed fit
fenestrated haptic shell or lens.
Ventilated fit
For physiological reasons at least, this is an unacceptable fit.
Sealed fit
In what year Sir John F. N. Herschel discussed the concept of impression molding?
1845
Scleral lens insertion procedure
Fill lens with saline
Instruct px to lean forward, Head bowed, eyes looking straight ahead, lens not tilted
Removal of lens procedure
Patient look down
Upper lid pushed behind lens edge
Slight upward pressure from lower lid
The following symptoms should be noted when wearing scleral lenses:
Bubbles
Froth
Clicking
Photophpbia
Lacrimation
Blurred vision following lens removal
Diplopia
Haloes
Mucus
In what year does the concept of impression molding introduced?
1800s
Josef Dallos made use of material derived from seaweed which termed as _____
Negocoll
DW
daily wear
e.g.
for example
EW
extended wear
GAG
glycosaminoglycan
GPC
giant papillary conjunctivitis
HCL
hard contact lens
i.e.
that is
K
Keratometry result
R&L
Right and left
SCL
soft contact lens
TCA
TriCarboxylic Acid
ADP
adenosine diphosphate
ATP
adenosine triphosphate
NADPH
nicotinamide adenine dinucleotide phosphate
