The final posterior corneal tissue should be of adequate thickness as measured by pachymetry. Over the past 6 months at the Michigan Eye Bank, the mean pre-processing corneal thickness was 558 microns, and post-processing thickness of the posterior corneal tissue was 158 microns. Eighty-seven percent of microkeratome-dissected donor tissue measured between 100-200 microns, 10.9% measured >200 microns, and 2.1% measured <100 microns.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671837/
Procedure. 1  Using forceps, gently grasp cornea by scleral rim. Open stopcock to flush system with BSS while carefully centering cornea on top of the piston with the endothelial side down. 2  Position anterior chamber cover on base locking ring so that the tabs of the cover fit into the open spaces on the base.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671837/
After tissue dissection, the two lamellae are separate but the anterior lamella (cap) is positioned back onto the remained corneal bed for transportation to the surgeon. In the operating room, the surgeon uses a trephine to cut the central corneal tissue vertically through both anterior and posterior lamella.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671837/
Procedure. 1  Using forceps, gently grasp cornea by scleral rim. 2  Position anterior chamber cover on base locking ring so that the tabs of the cover fit into the open spaces on the base. 3  With a sterile gloved finger, touch top of cornea to ensure that there is sufficient pressure to perform procedure.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671837/
1. Setup: Aseptic Technique11. 1  Turn on Laminar Flow Hood (LFH). 2  Turn on the Nitrogen gas control unit. Ensure that hose is connected between console unit and Nitrogen tank. Turn gas on. Gas setting should be set to 50-60 PSI on regulator tank. Turbine pressure on unit should read 3.3 to 3.4 Bars. 3  Press Test button.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671837/
Laser iridotomy. Perkins ES. A ruby laser has been used to produce a permeable lesion in the iris to establish a communication between the anterior and posterior chambers. In a preliminary study in nine patients the technique gave satisfactory results in the prophylactic treatment of four cases of incipient closed-angle glaucoma and of two cases of iris bombé following uveitis.
https://www.ncbi.nlm.nih.gov/pubmed/5526615
There are also variations in the method for determining the location in which the microkeratome incision should be initiated. Different eye banks and different corneal surgeons may have particular preferences as to how the cornea is marked for identification of the anterior corneal cap or posterior lamellar orientation. It should be noted that manufacturers make similar equipment to that used in this protocol.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671837/
Further, it is critical to confirm that the lamellar cut is centered and complete in order to ensure that the posterior lamella will be suitable for use in surgery 13. Corneal donor perforation is a dreaded complication of this procedure; it becomes less frequent with experience.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671837/
performed to establish a new pathway for tear drainage from the lacrimal sac to the middle meatus of the nose is done for chronic dacryocystitis iridectomy surgical treatment for chronic wide angle glaucoma which reestablishes communication between the posterior and the anterior chambers of the eye trephine cutting instrument that makes circular incision
https://quizlet.com/181080944/opthalmic-surgery-ch-16-flash-cards/
talking and movement kept at a minumum, patient is often awake; non-powdered gloves should be used; keep lint of the instruments and sterile field; procedure performed under a microscope; and when portable microscope is used it should be brought over the patient from the side opposite the operative eye.
https://quizlet.com/181080944/opthalmic-surgery-ch-16-flash-cards/
what procedure is used to establish communication between the anterior and posterior chambers
A ruby laser has been used to produce a permeable lesion in the iris to establish a communication between the anterior and posterior chambers.