Wavefront-guided treatment of symptomatic eyes using the LADAR6000 excimer laser

PURPOSE: To evaluate the clinical results of wavefront-guided customized treatment of eyes that underwent previous keratorefractive surgery with clinically significant visual symptoms related to the presence of higher order aberrations, with or without defocus/astigmatism. METHODS: Twenty-eight consecutive eyes of 19 symptomatic patients underwent wavefront-guided custom photorefractive keratectomy (PRK with mitomycin C) to correct low and high order aberrations, using the LADAR-Vision platform. All eyes had manifest refractive spherical equivalent (MRSE) error from 0.00 to -4.25 diopters (D), and high order aberrations root-mean-square (RMS) values >0.80 microm for a 6.0-mm measurement diameter (mean: 1.18 microm). Eyes were examined at 1, 3, and 6 months postoperatively. Uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA), MRSE, wavefront measurement of high order aberrations, and patient subjective evaluation were the parameters used to assess the treatment. RESULTS: Six months after treatment, all 28 eyes had an improvement in UCVA compared to preoperative values. Seventeen (60.7%) eyes gained lines of BSCVA (1 to 3 lines) whereas 1 eye lost 1 line. Although the amount of positive defocus was intentionally and empirically undercorrected in this study, MRSE was slightly hyperopic (mean +0.65 D, range: -0.25 to +1.75 D). All eyes showed a reduction in pre-existing high order aberrations, with a mean reduction of 47% (0.62 microm). Spherical aberration reduced the most (mean 60%), coma was reduced by a mean 29%, and all other terms were reduced by a mean 42% compared to preoperative values. Subjectively, all patients but 1 (both eyes treated) noticed a reduction in their pre-existing visual symptoms. Overall, the treatment was considered satisfactory by the patients in terms of visual quality gain. CONCLUSIONS: This series of consecutive treatments of symptomatic eyes indicates wavefront-guided custom ablation is an effective surgical option to reduce visually impairing high order aberrations and related visual symptoms. To avoid the resulting hyperopic shift, some significant nomogram adjustments are necessary, most often when pre-existing positive spherical aberration is present.     

CT diagnosis of spontaneous dissection of the superior mesenteric artery

We report two cases of spontaneous superior mesenteric artery dissection diagnosed by CT. In both cases lamination of the arterial wall and enhancement of both true and false lumina were the key to the diagnosis.     

A case report of a primary apocrine adenocarcinoma of the eyelid with literature review

Introduction: Primary Apocrine adenocarcinomas (PAA) are very infrequent tumors that are often confused initially with benign lesions. Little is known about this disease and there is still much to be clarified. We present a case of PAA on the eyelid successfully treated with surgery alone and a literature review regarding what is currently described about this disease.

Methods: Noncomparative, retrospective case report of a patient with PAA on the eyelid succesfully treated with surgery alone and a literautre review.

Results: A 91-year-old man with a 2 months lesion on the upper left eyelid was treated with surgery alone with oncological margins of 5mm. The Hystopathology diagnosis was a PAA of the eyelid and free margins were obtained. After 12 months of follow-up, the patient does not show any signs of local recurrence or distant metastasis. A review of the literature suggests these tumors are located more frequently in the axilla (50%) and secondly in the head and neck (35%), with similar distribution in the upper (41%) and lower eyelid (45%). The most commonly used treatment is surgical excision, but radiotherapy and chemotherapy have also been used with variable results.

Conclusions: PAA is a very rare and aggressive tumor. Because it is so infrequent, treatments are based on the sporadic cases encountered in the literature. As more cases are reported, more can be elucidated about the characteristics of this tumor, its behavior and best treatment choice and this may allow progress in the understanding and management of this disease.     

Controlled release of swine semen encapsulated in calcium alginate beads

A quick and successful encapsulation method of swine spermatozoa is described: hydroxypropylmethylcellulose and calcium chloride were added to the sampled ejaculate swine sperm (sperm-rich fraction: creamy white) and then this suspension was dropped into an aqueous solution of sodium alginate. In order to obtain different capsule thicknesses, different calcium chloride concentrations were used. The influence of different formulations on in vitro spermatozoa release behavior and on the mechanical properties has been studied. In vitro sperm kinetics (motility and average velocity) have been determined. The results obtained from motility and average velocity tests of treated seminal material are promising, especially if the difficulty of preservation of swine spermatozoa compared to bovine sperm is considered. The different membranes obtained from the different calcium concentrations have had an influence on mechanical properties and on the release profile of spermatozoa from the capsules, and therefore, it is possible to modulate the release rate of the cells.