Biomedical subjects
Publications and source records attributed to T R Mazzocco.
A primate model was used to compare a silicone intraocular lens (Elastic Lens, STAAR Surgical) and a conventional polymethylmethacrylate/polypropylene lens. Tolerance and stability of silicone lenses within the eye were tested.
Flexible silicone posterior chamber intraocular lenses made of a proprietary formulation were implanted in rabbits following planned extracapsular lens extraction. The lenses were of three designs: unfenestrated, partially fenestrated, and fully fenestrated haptics. Biostability and tissue reactivity of the silicone lenses and another manufacturer's polymethylmethacrylate lenses appeared equivalent as evaluated clinically by slitlamp biomicroscopy and by light microscopy. The frequency and distribution of lens precipitates were evaluated grossly and by scanning electron microscopy and appeared notably less prominent on the surfaces of the hydrophobic silicone lenses.
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This paper describes a surgical technique for implanting a secondary posterior chamber intraocular lens (IOL). Endothelial cell counts in a small series of patients are also discussed.
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Endothelial cell loss following posterior chamber phacoemulsification with and without posterior chamber lens implantation was studied. Postoperative cell counts were taken four months after surgery. Three surgeons participated in this study. Posterior chamber phacoemulsification alone (30 patients) resulted in a mean cell loss of 9%, with a maximum cell loss of 22% in one patient. Posterior chamber phacoemulsification with posterior chamber lens implantation (30 patients) resulted in a mean cell loss of 8% with a maximum cell loss of 26% in one patient. Statistical analysis shows no difference in postoperative cell loss between these two groups.
Secondary posterior chamber lens implants were performed on sixty-nine patients. Although technically the insertions were slightly more difficult than in a primary case, the results were excellent. Only one eye had vision significantly lower than preoperative level, and this, only a drop from 20/25 to 20/40. Three eyes required a second procedure to suture the lens. One eye suffered detachment later with count fingers vision as the final result.
Postoperative astigmatism was studied in two groups of patients. All patients had undergone phacoemulsification with implantation of a posterior chamber intraocular lens. The incision closure techniques in both groups were identical, with one exception: One group was closed using the Terry keratometer intraoperatively, the second group was closed without the use of this instrument. Two observations are made from the twelve-month data. First, astigmatic error in the Terry group remained constant from the postoperative keratometer readings at six weeks to the twelve-month keratometer readings. Second, while there was a considerable difference in astigmatism at six weeks between the Terry group and the control group (less astigmatism in the Terry group), the differences were no longer apparent at twelve months. Sutures were removed as necessary to improve astigmatism in the control group. No sutures were cut in the Terry group during this twelve-month period.
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Implantation of Shearing and Shearing-style J-loop posterior chamber lenses in 1000 cases was associated with an absence of corneal decompensation and a low incidence of glaucoma, cystoid macular edema, iritis, vitritis and retinal detachment. The low complication rate was attributed to the posterior chamber position of the J-loop lens, which may reduce the movement of intraocular fluid and tissue.
Representative lens styles of four different intraocular lens groups after cataract extraction by phacoemulsification are compared. Certain cases were excluded to minimize inconsistency. Postoperative visual acuities and complications of each lens type are compared.
A study was designed to evaluate the usefulness of the Terry quantitative surgical keratometer as a tool to minimize surgically induced astigmatism. Two hundred and twenty-five phacoemulsifications with Shearing-style implants were performed, using identical technique. Seventy-five control cases were closed without the keratometer and 150 were closed with the keratometer. In the control group, 29.3% cases had corneal astigmatism of 3D or more, compared to 4.6% cases in the keratometer group (P < .01). The total change in astigmatism was 2.64D in the control group and 0.91D in the keratometer group (P < .02). We believe that these data demonstrate the usefulness of the Terry keratometer.
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Explore the source record for details and available documents.