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Radioiodine secretion in tears.

UNLABELLED: Lacrimal secretion of radioiodine has been suspected from previous scintigraphic observations. We semiquantitated radioiodine secretion in the tears of a thyroid-ablated patient with an artificial eye while the patient was on thyroxine treatment. METHODS: After an oral dose of 555 MBq (15 mCi) 123I, 12 tear samples were collected over 24 hr by using Schirmer papers. Radioactivity in each sample was determined in a well counter 27 hr after radioiodine ingestion and was corrected for decay and counting efficiency. RESULTS: Radioactivity was detectable at 15 min and at up to 24 hr after radioiodine ingestion and peaked at around 60 min (215 Bq/microl or 39 x 10(6)% of the administered dose/microl. Considering a tear-flow rate of 1 microl/min, the total radioactivity secreted in the first 4 hr was estimated to be 56 kBq, representing about 0.01% of the administered dose. CONCLUSION: An appreciable amount of ingested radioiodine could be secreted in tears. The potential damage of the lacrimal gland after high doses of 131I treatment deserves further study.

Adult↗

Topical therapy for dry eyes.

'Artificial tear' solutions, perhaps more accurately termed 'ocular wetting' solutions, have been the mainstay of topical therapy for keratoconjunctivitis sicca (KCS). These solutions have been designed with water-soluble polymers in an attempt to increase their ocular retention time or ability to wet the ocular surface. Treatment with ocular wetting solutions has been non-specific in that there is no evidence that dry spot formation is essential to the induction of surface disease in KCS patients, nor is there evidence that water-soluble polymers are beneficial to epithelium. In KCS, tear film osmolarity is abnormally elevated by potentially complex mechanisms that result from decreased aqueous tear secretion. The abnormal osmolarities observed in KCS produce the major ocular surface abnormalities seen in this disease. In a double-masked trial, a 150 mOsm/L solution, selected from a range of hypotonic solutions for its ability to lower elevated tear film osmolarity optimally in KCS, has been shown to be superior to an isotonic 300 mOsm/L solution in providing symptom relief for KCS patients.

Animals↗

A clinical study of the hydroxyapatite orbital implant.

The hydroxyapatite orbital implant has been used in the anophthalmic patient to give good motility of the artificial eye and a cosmetic result which matches that of the natural eye. It is thought to reduce the unacceptable complication rate that has been associated with other implants, as its buried, vascularized state deters extrusion and migration of the implant. Eighty consecutive patients were followed, 33 of whom had been referred for primary enucleation or evisceration, and 47 for secondary implant surgery. Thirteen of the secondary patients already had implants in situ. There were 44 males and 36 females in the study. The age range was 2.5 to 72 years with a mean of 36 years. The follow-up time was 2 to 30 months with a mean of 15 months. Twenty patients had been pegged at the time of review. A standardised operative and post-operative protocol was followed. The patients were assessed for the results of the motility of the artificial eye for both smooth pursuit and saccades, and for the cosmetic result. The amount of upper lid sulcus deformity was assessed to give an indication of volume replacement by the implant. The nature of any complications was noted as well as any further surgical procedures undertaken. The results show the hydroxyapatite orbital implant to give good cosmetic results with good motility of the artificial eye and to be associated with a low rate of complications. Drilling of the implant is simple to perform and also not associated with any significant complications. The hydroxyapatite orbital implant can be used successfully not only as a primary but also as a secondary or exchange implant with very few contraindications.

Adolescent↗

["Dry eye" and artificial tear solutions (author's transl)].

Seventeen patients in whom "dry eye" had been diagnosed each tried four coded commercial artificial tear solutions for one week, in random sequence. The correlation of the function tests (Schirmer test, break-up tie, goblet cell count in conjunctival biopsy) did not permit a grouping of the patients. A tendency to a correlation between break-up time and goblet cell count was noted. It was not possible to show a preference on the part of certain patients for particular products; thus, with the current function tests available, a precise therapeutic classification of "dry eye" patients does not seem possible.

Adult↗

Baseball orbital implants: a review of 39 patients.

Thirty-five secondary and six primary 'baseball' implants--acrylic balls in envelopes of donor sclera--were followed up for a minimum of 24 months. 97.1% secondary and 50% primary implants were retained. Volume replacement was satisfactory in 83.8% with a single operation, and motility of the artificial eye was at least 14 degrees of horizontal gaze in 86%, at least 7 degrees of upgaze in 95%, and at least 14 degrees of downgaze in 62.6%. Ptosis associated with the procedure occurred in 22%, and 12.2% developed a shallow fornix with instability of the artificial eye.

Adult↗

False-positive radioiodine whole-body scan in thyroid cancer patients due to unrelated pathology.

Radioiodine whole-body scanning is the imaging modality of the highest accuracy in diagnosing metastases from differentiated thyroid cancer. However, unrelated pathology in one of several nonthyroidal tissues that normally take-up/secrete radioiodine may result in a false positive scan. The authors report cases of an ectopic kidney, chronic sinusitis, dacryocystitis, and an artificial eye, complicating differentiated thyroid cancer, that on radioiodine scanning mimicked lumbar, frontal, and left and right orbital bone metastases, respectively. The nature of the radioiodine uptake was suspected from the results of a bone scan and proven by ultrasound (ectopic kidney), by reimaging after specific treatment (chronic sinusitis, and dacryocystitis), or by postwashing reimaging (artificial eye). To our knowledge, this is the first report of such cases. Nonthyroidal pathology should be excluded before exposing patients with apparent thyroid cancer metastases that have atypical characteristics on radioiodine whole body imaging.

Adult↗

[Hema socket expander in primary conservative treatment of congenital anophthalmos].

In anophthalmos the forces which stimulate development and growth of the bony orbit are absent. As a result these cases have not only a tiny socket but also an underdeveloped bony orbit, which cannot retain an artificial eye. The small conjunctival sac and bony orbit can be mechanically enlarged by means of Hema socket expanders. This hydrophilic material can be manufactured in different forms and sizes and expands the socket and orbit by increasing in volume after hydration. After expanding the conjunctival sac to a certain size the next-larger form is fitted to the socket; the procedure is repeated until an artificial eye can be worn.

Acrylates↗

The argument against imbricating the rectus muscles over spherical orbital implants after enucleation.

Upper eyelid ptoses with migrated spherical implants resulting from imbrication of the rectus muscles over the implants after enucleation appears to constitute a syndrome. Traditionally shaped artificial eyes cannot reduce this type of ptosis. Spherical implants 18 mm in diameter do not fill Tenon's space. Imbricated muscles slip off the sphere, usually to the inferior nasal side. The sphere is displaced into the superior temporal quadrant of Tenon's space. A rolling motion is imparted to all tissues. The superior fornix and upper lid are pulled forward and downward. The inferior fornix is stretched into a rounded trough. The lower eyelid is pulled downward and backward. There is little motility to move the artificial eye. There are several better alternative types of surgery, some involving buried quasi-integrated muscle cone implants. More eye fitters will now fit these implants properly because of the educational efforts of the American Society of Ocularists. Two of those are most favored by the author because the surgical methods of their implantations do not contribute to ptosis and the resulting motility and general cosmesis are typically very good to excellent. In the order of preference they are: 18 or 16 mm diameter acrylic spheres in evisceration. The quasi-integrated implant which has become known is the Iowa Implant, specifically designed for imbrication of the rectus muscles after enucleation.

Acrylates↗

Expansion of the socket and orbit for congenital clinical anophthalmia.

BACKGROUND: Congenital clinical anophthalmia requires fitting an artificial eye, achieving a pleasing aspect of the palpebral apparatus, and stimulating growth of the orbit, as well as of the entire midface. METHODS: Out of 25 patients with clinical anophthalmia, 22 were treated according to a new protocol (first described by Wiese et al. in 1999) and followed for up to 6 years. In 10 patients, anophthalmia was bilateral, in nine patients, it was on the right side only and in three it was on the left side only. Treatment consisted of implantation of an osmotic expander to first stimulate growth of the conjunctival sac and eyelids followed by serial implantation of osmotic expanders to stimulate growth of the orbit (and thus of the midface). The material used was a copolymer of methylmethacrylate and N-vinylpyrrolidone. RESULTS: Fitting of an artificial eye was without any problem within the first year of life for the most part. Growth of the orbit was stimulated by more than 65 percent of a healthy one. Aesthetically, the results were very largely pleasing. Complications were encountered, especially when the wrong expander sizes had been implanted. CONCLUSION: Using osmotic expanders of this type, through a staged therapy of minor operations, promises to achieve all goals before the child enters school.

Abnormalities, Multiple↗

Reconstruction of the contracted ocular socket.

Totally contracted ocular sockets are difficult to reconstruct and many patients resort to wearing a black patch. One reason for surgical failure is that many popular techniques attach a mucous membrane or a skin-lined vertical stent to the superior or inferior orbital rim. This produces a vertical space that commonly shrinks and becomes too small to retain an artificial eye. The normal anatomy of the ocular cul-de-sac is C-shaped rather than vertical. It passes under the orbital roof superiorly and over the floor inferiorly. A technique has been devised in which the mid-aspect of a custom-made C-shaped mucous membrane-lined conformer is secured to the superior and inferior orbital rims. This attachment forces the posterior periphery of the conformer deep into the socket to form a space that stimulates the normal anatomy of the ocular cul-de-sac. The described technique has been successful in producing a spacious cul-de-sac in 36 patients with total socket contractures. A modification of the technique has been successful in treating 12 patients with partial contractures. All patients have easily retained an artificial eye after operation.

Contracture↗

The hydroxyapatite orbital implant: a prospective study.

The hydroxyapatite orbital implant was first released for use as an orbital implant in humans in August 1989. It has been shown to be well tolerated, providing good motility of the artificial eye with a low complication rate when used as a primary implant. This prospective study evaluated the hydroxyapatite orbital implant used as both a primary and a secondary implant. Sixty patients were implanted between October 1992 and November 1994, 28 being implanted as a primary procedure at the time of enucleation or evisceration, and 32 as a secondary procedure. Seven patients underwent second-stage drilling and pegging of the implant. The mean follow-up time was 13 months (range 2-26 months). A standardised operative and post-operative protocol was followed. The patients were evaluated post-operatively for the amount of enophthalmos, degree of upper lid sulcus deformity, motility of the prosthesis, location of the implant in the socket, socket status and the presence or absence of discharge, position of the drill hole and coverage of the implant. Complications and their management were documented. Both patient and surgeon made a subjective assessment of cosmesis and the patient's satisfaction with the overall result was noted. The results of this study show the hydroxyapatite orbital implant to provide excellent motility of the artificial eye and good cosmesis with a low rate of complications when used both as a primary and as a secondary implant.

Adolescent↗

Correction of the aberrations in the human eye with a liquid-crystal spatial light modulator: limits to performance.

We evaluated the performance of a liquid-crystal spatial light modulator for static correction of the aberrations in the human eye. By applying phase-retrieval techniques to pairs of double-pass images we first estimated the wave aberration of the eye to be corrected. Then we introduced the opposite phase map in the modulator, which was placed in a plane conjugated with the eye's pupil, and we recorded double-pass images of a point source before and after correction of the aberrations. In a slightly aberrated artificial eye a clear improvement was obtained after correction, and, although diffraction-limited performance was not achieved, the results were close to the theoretical predictions. In the two living eyes that we studied some benefit also appeared in the correction, but the performance was worse than that expected. We evaluated possible explanations for the relatively poor performance that was obtained in the human eye: an incorrect estimate of the ocular aberration, the limited spatial resolution of the modulator, and the dynamic changes in the ocular aberrations. Based on the results in the artificial eye, the first problem was not considered to be a major source of error. However, we showed that the spatial resolution of the liquid-crystal spatial light modulator limits the maximum correction to be attained. In addition, the changes in the ocular optics over time also impose a limit in the performance of static corrections.

Adult↗

[Surface changes in glass eye prostheses].

The exposed surface of new glass eye protheses becomes rough and is destroyed in use. The changes in the exposed surfaces have been demonstrated by scanning electron microscopy and with thin sections under optical microscopes. The alteration process depends on the length of time the artificial eye is worn. The main cause is chemical attack of the glass surface in the tear fluid, which is usually slightly alkaline. Chronic conjunctival inflammation, appearing after a long period of wearing the same artificial eye, may be caused by mechanical irritation from the surface roughness.

Eye, Artificial↗

Adhesion and growth of Serratia marcescens on artificial closed eye tears soaked hydrogel contact lenses.

The adhesion to hydrogel contact lenses and growth of Serratia marcescens on artificial tear fluid (ATF) soaked lenses was investigated. Results indicated that a corneal ulcer isolate adhered more avidly to lenses; ATF increased adhesion for all strains tested. The contact lens induced acute red eye (CLARE) isolate adhered poorly, however, it grew to a larger extent on ATF-coated lenses. The ability of the corneal ulcer isolate to adhere to lenses may be an important factor in its pathogenicity whereas the ability of the CLARE isolate to grow on the lens in the presence of antimicrobial tear proteins may be important in the development of inflammation.

Bacterial Adhesion↗

Activation during endogenous orienting of visual attention using symbolic pointers in the human parietal and frontal cortices: a functional magnetic resonance imaging study.

Brain activation induced by endogenous orienting with a motor response was investigated by functional magnetic resonance imaging. We conducted four cued-attention experiments in which peripheral attention was caused by one of three symbolic pointers (eyes, squares as artificial eyes, or an arrow) that was predictive or not predictive of the target location. Attentional shift caused by the predictive and non-predictive cues induced right and left parietal activation across cue modalities, respectively. Regardless of the predictability of the target location, the eyes and arrow induced left parietal and frontal activation, and the arrow induced left parietal activation more than the squares. These results suggested that the left parieto-frontal network was involved in motor attention caused by natural or familiar pointers, whereas the right parietal cortex was involved in endogenous orienting.

Adult↗

Axial and peripheral eye length measured with optical low coherence reflectometry.

An optical low-coherence reflectometer (OLCR device) is described that allows the precise and noncontact measurement of eye length. The device measures eye length both on-axis and off-axis, thus enabling the determination of eye shape, an ocular parameter thought to be important in the development of refractive error. It is essential for several applications in ophthalmology and vision science. This improved OLCR device operates using a single-beam interferometer with a beam deflection mechanism that allows the precise measurement of eye length along the visual axis and within 15 deg horizontally and vertically from the fovea. The validity of this instrument and its revised software is evaluated by measuring the reproducibility of axial length results in an adult eye and an artificial eye, and by correlating axial eye length measured in a group of ten adult eyes with axial eye length obtained with A-scan ultrasound in the same eyes. The precision obtained with adult subjects is compared with that obtained with children.

Adult↗

Intraocular humidity immediately after fluid-air exchange in pars plana vitrectomy.

PURPOSE: To study vitreous cavity humidity during fluid-air exchange in pars plana vitrectomy. METHODS: Intraocular humidity in the vitreous cavity was recorded for 2 min in six artificial eyes, six enucleated pig eyes, and ten patient eyes, after the eyes had been filled with either humidified air (75% humidity) or dry air (8% humidity). RESULTS: In artificial eyes the humidity levelled off at a value that was approximately equal to the humidity of the infused air, i.e., a mean of 71.9% when humidified air was used and a mean of 14.4% when dry air was used. In enucleated pig eyes humidity increased slightly with humidified air and remained stable with dry air. In patients intraocular humidity increased to over 90%, regardless of whether humidified or dry air was used. CONCLUSION: In the living eye, dry air deprives the retinal tissue of humidity, which is lost into the vitreous cavity. This effect can be reduced by using humidified air.

Acetates↗

[Bilateral rehabilitation with an implant-anchored orbital prosthesis].

From the aesthetic point of view, a patient can be completely rehabilitated after the loss of an eye with the insertion of an artificial eye made of glass. If the delicate structures of the eyelids have been severely damaged, however, or if the eye socket does not provide adequate retention for an eye prosthesis, rehabilitation becomes more difficult, and sometimes cannot be achieved with a cosmetically satisfactory result. In such cases, a facial prosthesis offers an alternative solution. Stable retention can be ensured with craniofacial implants. Single-sided rehabilitation by this method is quite common, but bilateral treatment is a rarity. We report on the prosthetic rehabilitation of a patient after exenteration on both sides due to retinoblastomas.

Adult↗