Procedure for Fitting Phase I Scleral Trial Shell
(For the Acquired Dysfunctional
or Phthisical Globe)
here for Procedure for Custom
Fitting an Ocular Prosthesis
Following an Enucleation]
This is the climactic stage for information you will receive
on the Internet prior to the actual fabrication and fitting
of the Phase I Impression Moulded (Clear Acrylic) Scleral
Trial Shell, and the Phase II Impression Moulded Plastic
Scleral Ocular Prosthesis. The web site will now transfer
you via the Contact
Us to meet with the Jahrling team of ocularists.
You should have your itinerary planned as to the mode of
transportation (public or private) to our office for the
first two (a.m. and p.m.) same-day appointments. These
two sessions are planned for the Phase I: Impression Moulded
(Clear Acrylic) Scleral Trial Shell. The afternoon
scleral fitting will help us establish a wearing timetable
(dependent upon corneal sensitivity), and project a return
for a series of three or four fabrication sessions for the
flush fitting Phase II scleral prosthesis. (This is
determined by the anterior-posterior thickness of the prosthesis.)
In order to allay any fears, anxiety or uneasiness caused
by this upcoming new experience, we will explain the process
in a detailed step by step manner.
Session #1 (Estimated Duration: 45 minutes)
At the reception desk you will be escorted into one of the
fitting rooms to meet your ocularists.
Review: History (Hx) and Diagnosis
(Dx) that lead to the blind, scarred, disfigured eye and/or
External Evaluation: Since there
is a loss of global volume, there can be a prolapse
of the lower eyelid, if this is evident you may have irritation
of the palpebral
conjunctiva. This would be caused by a pseudoptotic
upper lid (drooping eyelid, caused by a non-supportive shrunken
globe) whose eyelashes are now rubbing on the lower eyelid
Eyeball Evaluation: The dysfunctional
globe will be tested for corneal sensitivity. If there
is a clear cornea it may be necessary to receive a prescription
from your doctor for a topical anesthetic. (This would
be used to make the cornea insensitive the globe at the time
of impression taking.) The eyeball and the under part
of the lids will also be checked for symblepharon (adhesions
of the lid to the eyeball).
Impression moulding of the eyeball begins with a verbal and
visual description of the impression moulding technique and
what it entails. The paraphernalia consists of a series
of fenestrated impression acrylic trays with projecting hollow
stems, a 10cc syringe (no needles), alginate impression material,
distilled water, mixing bowl and spatula.
The morning impression moulding process begins by selecting
a proper size acrylic tray, and inserting it under the eyelids.
It is held carefully away from the globe by the hollow stem.
The alginate and water is mixed and placed into the syringe
for easy injection into the impression tray. It has a cool
sensation when the gel flows over the globe, (if the topical
anesthetic is not used.) The mixture sets within two
minutes and the entire tray and impression of the globe is
A soft mixture of dental stone is then poured into the gelatin
impression to make a duplicate copy of the contour of the
dysfunctional globe. Once the dental stone has hardened,
the impression tray is then separated from the alginate gel.
This void in thickness of the impression is replaced with
a soft base plate dental wax for the anterior curvature of
the soon to be made clear acrylic trial shell.
Session #2 (Estimated Duration: 1 hour)
The afternoon fitting session of the flush fitting impression
moulded clear acrylic scleral trial shell will allow us to
- for any tight areas that would obstruct the vascular
- periphery of shell for displacement with lateral excursion
- for rotation of the shell when looking to the four quadrants
- for displacement with ordinary blinking
- patient's reaction for wearing tolerance and comfort
Once we have timed your tolerance level, a wearing schedule
will be setup. (The goal is to have you comfortably
wear it all of your waking hours.) You will then be
taught the proper technique of insertion and removal of the
trial scleral shell. This will be followed up with
printed instructions of
this procedure, plus hygiene instructions
on its care.
At this juncture we would look forward to your (successful
wearing) return for the next
procedure, which is the fabrication and fitting of the
Phase II Impression moulded scleral ocular prosthesis.