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At least 73 records · Page 4Linked to original sources
PubMed1990

Empirical impression technique for artificial eye fitting.

Using an impression of the anophthalmic socket to facilitate the design of an artificial eye is common practice today. The Modified Impression technique was described in the American Journal of Ophthalmology, February 1969, by Lee Allen and Howard E. Webster. It is a highly successful method that involves taking an impression of the socket using an impression tray, then making a wax casting of the impression, and final modifications to the anterior aspect of the wax model. A different technique has been in use in our office and elsewhere for more than 15 years, also with a high degree of success. We've dubbed it the "Empirical/Impression" method. It involves similar steps to the Modified Impression system, but in different order: first a wax model of the anterior aspect of the eye is designed and modified; second, an impression is made of the socket, using this wax model as an impression tray. The primary advantage of this method is efficiency. It involves one less laboratory procedure, hence making a "one-day custom eye" a reality. Although this process can be used in almost any case, the Modified Impression technique may work better for certain highly irregular sockets where "reading" the fornices by empirical means may be difficult. Either method requires a highly skilled and experienced fitter to make appropriate modifications to the anterior aspect of the prosthesis.

Eye, Artificial↗
PubMed1993

Simplified fabrication of orbital prostheses using posterior attachment for the artificial eye.

The ocular component of an orbital prosthesis can be held firmly during fabrication by attaching a plastic needle cover with autopolymerizing acrylic resin to the posterior surface of the eye in the wax-sculpted prosthesis. This index is subsequently embedded in the master cast. Compared with other techniques described in the literature, this technique spares the corneal surface of the artificial eye and allows duplicate fabrication of silicone orbital prostheses in nonmetal durable molds.

Acrylic Resins↗
PubMed1990

Plastic artificial eyes: overview and technique.

Eye prosthetics and its practitioners have evolved through self-development studies, to become an integral part of the ophthalmic plastic surgery multidisciplinary team. Eye prosthetics is a distinct art and science in dealing with the many facets of eye surgery. The ocularist must have in his armamentarium alternate procedures, flexibility, cooperation, and become knowledgeable of all the options available to him. This in turn will offer opportunities for providing the plastic artificial eye patients with the best final results possible.

Clinical Protocols↗
PubMed2003

[How can artificial eye motility be improved? The influence of fornix configuration and tissue thickness in front of hydroxyapatite-silicon implants in 66 patients].

Porous hydroxyapatite of various origins has proven to be a suitable material for orbital volume replacement. Its biocompatibility surpasses all other options. The transmitted motility to the artificial eye has nevertheless, not always been to the full satisfaction of patients, oculists and ophthalmologists. Our study has shown a strong correlation between the depth of the superior and interior fornices as well as the thickness of tissue material covering the implant anterior surface.

Adult↗
PubMed1991

Herman Snellen (1834-1908) and Müller's 'reform-auge'. A short history of the artificial eye.

The shell prothesis, originally meant to be placed over the atrophic eye, caused serious problems when used after enucleation, which became more common practice in the second half of the last century. In the nineties of the last century Snellen Sr. tried to solve these problems by designing a light prothesis that filled up the empty space. At the insistence of Snellen, the Müller brothers in Wiesbaden succeeded in 1892 to blow a hollow artificial eye which proved to be a real success.

Eye, Artificial↗
PubMed2000

[Long-term results of implantation of hydroxylapatite as artificial eye].

BACKGROUND: Since its first implantation as an eyeball replacement in the United States in 1985, hydroxyapatite has been rarely used as an orbital implant in Germany. The aim of the study was to collect data on long-term tolerance, postoperative complications and the cosmetic end results. PATIENTS AND METHODS: In the spring of 1997, 52 patients underwent a follow-up examination at our hospital. The average post-operative follow-up period was 23 (12-41) months. RESULTS: The subjective tolerance was considered good by 3/4 of the patients. In the comparison of position and prominence of the artificial eye, 8 patients achieved complete equalization. As regards defective lid position, 8 patients had a ptosis, 6 an ectropium, and there was one case of entropium. Changes in conjunctiva stretched from muciferous secretion to follicular squamous hyperplasia. There was no case of implant extrusion in the series examined. With reference to the method of implantation, far superior motility was observed in primary implantations. Statistically significant motility differences could not be shown regarding muscle attachment because of the small number of the cases. CONCLUSIONS: In the series examined, hydroxyapatite proved to be a generally well-tolerated orbital implant with few postoperative complications and good motility. Primary implantation with attachment of all six eye muscles gave the best results.

Biocompatible Materials↗
PubMed2006

Biologically inspired artificial compound eyes.

This work presents the fabrication of biologically inspired artificial compound eyes. The artificial ommatidium, like that of an insect's compound eyes, consists of a refractive polymer microlens, a light-guiding polymer cone, and a self-aligned waveguide to collect light with a small angular acceptance. The ommatidia are omnidirectionally arranged along a hemispherical polymer dome such that they provide a wide field of view similar to that of a natural compound eye. The spherical configuration of the microlenses is accomplished by reconfigurable microtemplating, that is, polymer replication using the deformed elastomer membrane with microlens patterns. The formation of polymer waveguides self-aligned with microlenses is also realized by a self-writing process in a photosensitive polymer resin. The angular acceptance is directly measured by three-dimensional optical sectioning with a confocal microscope, and the detailed optical characteristics are studied in comparison with a natural compound eye.

Animals↗
PubMedDate not supplied

Mobility of hydroxyapatite orbital implant covered with autologous sclera.

PURPOSE: To evaluate the mobility of a hydroxyapatite implant covered with autologous sclera from the enucleated globes of patients with severe atrophy of the eyeball or eyelid retraction. METHODS: This implant was used in seven patients with phthisis bulbi. We measured the movement of the implant by photographic analysis of the anterior orbit and by using a strain gauge. RESULTS: At 1-3 years after surgery, neither infection nor prolapse of the implant had occurred in any of the patients. The implant remained stable in the orbit; the extraocular muscles sutured to the sclera of the implant were functioning satisfactorily, and the implants showed great conjugate mobility to the ocular movement of the healthy eye. On photographic analysis of the anterior orbit, the adducting efficiency of the implant was 92.6 +/- 3.3%; the abducting efficiency was 85.9 +/- 5.4%; the supraducting efficiency was 84.9 +/- 5.6%, and the infraducting efficiency was 90.9 +/- 3.9%. The mean tugging weight, as determined using a strain gauge, was 344.2 +/- 29.2 g for adduction, and 327.6 +/- 33.4 g for abduction. These values corresponded to 90.4 +/- 4.4% and 89.5 +/- 5.3% of the respective movements of the healthy eye. CONCLUSIONS: Fitting an artificial eye to the peg of this implant did not greatly impair the movement of the implant, and its mobility was greater than that of the artificial eye of the controls in which a semi-integrated magnetic implant, previously available, had been used. This new technique makes it possible to wear an artificial eye earlier than with other prosthetic procedures.

Adult↗
PubMed2005

Developing a model system for teaching goniotomy.

PURPOSE: To design a model-system instruction course to prepare trainees for performing goniotomy on patients. DESIGN: Experimental study. PARTICIPANTS: Three pediatric ophthalmology fellows and 1 recent graduate of the fellowship program. METHODS: We piloted 3 model systems: human cadaver eyes with and without Marty the Surgical Simulator (Iatrotech Inc., Del Mar, CA, hereafter referred to as Marty Head) eye supporting system and artificial eyes in Marty Head. For improving intraocular view in cadaver eyes, we used epithelial scrapping, intracameral viscoelastic, and/or intracameral lubricating jelly. Each trainee underwent a training course, including background reading, didactic lecture, and video review followed by goniotomy on model systems with the operating microscope. MAIN OUTCOME MEASURES: Each trainee evaluated each step of the course using modified 5-point Likert scales. Reading material and videos were evaluated for usefulness, readability/quality, and new information obtained. Each model system was evaluated for visibility, ease of setup, surgical feel, and transferability to live surgery. In the end, each trainee was asked to assess the overall course for usefulness. RESULTS: Trainees rated the reading materials and video highly for their usefulness and quality, yet they believed they did not learn substantial amounts of new information. Visibility and ease of setup was best with artificial eyes in the Marty Head model. Human cadaver eyes in the Marty Head provided somewhat less visibility and ease of setup, but the perceived feel and transferability to live surgery was slightly better than with artificial eyes. Cadaver eyes without the Marty Head got the lowest rating in all categories. At the end of the course, all participants felt more confident and ready to perform goniotomy on patients. All recommended this course as part of pediatric ophthalmology fellowship training programs. CONCLUSIONS: This model system instruction course can assist trainees in learning to perform goniotomy while potentially lessening the risks to patients.

Gonioscopy↗
PubMed2004

Sub-50-fs laser retinal damage thresholds in primate eyes with group velocity dispersion, self-focusing and low-density plasmas.

BACKGROUND: In vivo retinal injury studies using sub-50-femtosecond laser pulses in the near-infrared must consider nonlinear effects such as group velocity dispersion (GVD), self-focusing, laser-induced breakdown (LIB) and low-density plasmas (LDPs). In this paper we present the results of our theoretical calculations of nonlinear effects and our experimental measurements for the visible lesion thresholds in live eyes. We compare these values with the measured LIB and LDP thresholds in an artificial eye. All three thresholds were measured with and without pre-chirping the input pulse to compensate for GVD effects. METHODS: We recorded the minimum visible lesion (MVL) thresholds in vivo for sub-50-fs laser pulses, with and without pre-chirping the input pulses. In addition, we measured the LIB and LDP thresholds, with and without pre-chirping, within an artificial eye. Different degrees of pre-chirping were required to give optimal compensation for GVD in the live eye and the artificial eye. Probit analysis was used on all data, and comparisons among thresholds were made, to determine the effects on the three thresholds of chirp compensation for GVD. RESULTS: Results of our nonlinear modeling and calculations for GVD compensation, self-focusing, LIB, and low-density plasmas were compared with our experimental results using live eyes and the artificial eye. The damage threshold in live eyes dropped in energy from 0.25 microJ, for the flat-phase input, to 0.17 microJ when optimally chirped pulses were used, while the LIB threshold was reduced from 0.29 microJ to 0.19 microJ with optimally chirped pulses. The LDP threshold dropped from 0.21 microJ to 0.14 microJ with the pre-chirped pulse. At 44 fs, these energies produced peak powers at least twice the calculated critical power that produces nonlinear self-focusing and beam collapse, for propagation of non-aberrated gaussian beams in a uniform medium. CONCLUSIONS: Based on our measurements of the MVL thresholds, with and without GVD compensation, we conclude that the visible lesion thresholds produced by 44 fs pulses in rhesus eyes are increased in energy due to GVD. The MVL ED50 was reduced by one third when the pulse was pre-chirped to compensate for GVD in the eye. This reduction in amplitude also holds true in the artificial eye for the LIB ED50 bubble thresholds and the LDP ED50 plasma channels, when using pre-chirped pulses versus non-chirped pulses. We also conclude from the data presented that low-density plasmas, and not LIB cavitation bubbles, are the probable mediating factor at the visible lesion thresholds observed within live eyes, for pulse durations at and below 50 fs. Therefore, the plasma channel created by LDPs is the major damage mechanism, if not the only damage mechanism, at MVL threshold energies for these pulse durations.

Animals↗
PubMed2006

[Evaluation of the cosmetic effect of orbital endoimplantation after removal the eyeball].

The purpose of our study was to evaluate the cosmetic effect of endoimplantation after removal the eyeball. The removal of the globe creates anatomic and physiological alteration of the orbital tissue and orbital bones. A volume deficit occurs when an eye is enucleated. Deep upper lid sulcus, ptosis, lower lid laxity, and enophthalmus of the artificial eye together constitute the postenucleation socket syndrome, which creates an asymmetry of the face. The orbital prosthesis by placing it in the orbital cavity allows correcting volume deficit, so the implant with attached extraocular muscles, together with an artificial eye, creates an illusion of real eye. Forty patients were operated on in Clinic of Eye Diseases of Kaunas University of Medicine Hospital. Twenty patients underwent removal of the eye and procedure of orbital implant insertion (main group). Twenty patients had just an eyeball removal without insertion of an orbital implant (control group). There was a statistically significant difference in exophthalmometry data between main and control groups (14.20+/-2.73 vs. 10.35+/-1.23 mm, respectively; p<0.05). The motility of artificial eye laterally (4.30+/-1.66 mm), medially (3.65+/-1.23 mm), up (3.70+/-1.13 mm), and down (3.40+/-1.19 mm) in the main group was significantly better as compared to the control group (p<0.05), where motility of the artificial eye was 0.60+/-0.68 mm laterally, 0.70+/-0.92 mm medially, 0.30+/-0.66 mm up, and 0.30+/-0.47 mm down. Therefore, a much better symmetry, better movement of the artificial eye, and less severe form of postenucleation syndrome were observed in patients who underwent orbital endoimplantation after eyeball removal.

Adolescent↗
PubMed1982

Complications associated with use of tantalum-mesh--covered implants.

In 1948, ophthalmologists started implanting plastic spheres partially covered with tantalum mesh (eg, the Valley Forge Implant) in anophthalmic sockets. Numerous patients have developed complications ten to 15 years after surgery: pain ("pinching" or "deep"), headache, heavy mucopurulent discharge and diffuse conjunctival inflammation, migration of the implant, thinning or erosion of tissues covering the implant (extrusion), and inability to wear an artificial eye. Management includes refabrication of the artificial eye and replacement of the implant with a dermis-fat graft or a silicone ball plus scleral graft. Tantalum-mesh--covered orbital implants should probably not be used.

Conjunctivitis↗