Procedure for Fitting Phase I Scleral Trial Shell
(For the Acquired Dysfunctional or Phthisical Globe)
 

[Click 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 shrunken globe.

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 tissue.

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).

Hands-on: 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 removed.

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 check:

1. for any tight areas that would obstruct the vascular pattern
2. periphery of shell for displacement with lateral excursion
3. for rotation of the shell when looking to the four quadrants
4. for displacement with ordinary blinking
5. 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.