Daniel J. Townsend

Eyelid reanimation for the treatment of paralytic lagophthalmos : historical perspectives and current applications of the gold weight implant

Gold weight implants have been. used for over 30 years in the setting of eyelid rehabilitation following facial nerve paralysis; however, there has been a renewed interest by ophthalmologists in this reanimation technique in recent years. This article reviews the history of gold weight eyelid implantation and presents the results of gold weight eyelid implantation over a 15-month period in 23 patients. A 92% success rate was obtained (average follow-up, 12 months). Surgical technique and indications are discussed along with postoperative complications.

Identification of steroidogenic enzyme mRNAs in the human lacrimal gland, meibomian gland, cornea, and conjunctiva

Purpose: Sex steroids exert a significant influence on the health and well-being of the ocular surface and adnexa. These hormones affect multiple aspects of the lacrimal and meibomian glands, conjunctiva, and cornea, and have been linked to the development of many ocular surface pathologies. We hypothesize that these hormone actions, as in other tissues, occur predominantly after the local synthesis of androgens and estrogens from adrenal precursors. To begin to test this hypothesis, we analyzed whether human ocular surface and adnexal tissues and cells contain the steroidogenic enzyme mRNAs necessary for the intracrine synthesis and metabolism of sex steroids. Methods: Total RNA was isolated from human lacrimal and meibomian glands and immortalized corneal and conjunctival epithelial cells. Samples were reverse transcribed to cDNA and analyzed for the presence of enzyme mRNAs by real-time PCR. Positive and negative controls included human placental cDNA and the absence of template, respectively. Results: Our results show that human lacrimal and meibomian glands and corneal and conjunctival epithelial cells contain the mRNAs for steroid sulfatase, 3&bgr;-hydroxysteroid dehydrogenase (HSD)-&Dgr;-5&Dgr;4-isomerase type 1, 17&bgr;-HSD types 1 and 3, aromatase, and glucuronosyltransferase. In contrast, only lacrimal and meibomian tissues appeared to contain detectable mRNA for sulfotransferase. Conclusions: If the corresponding mRNAs are translated, our results indicate that human ocular surface and adnexal tissues contain the enzymatic machinery necessary for the intracrine synthesis and metabolism of sex steroids.

Multimodal optical microscope for detecting viability of mouse embryos in vitro.

We present a multimodal optical microscope that incorporates six imaging modalities on one common platform. The imaging modalities include three staring modes, optical quadrature microscopy (OQM), differential interference contrast (DIC) microscopy, and epi-fluorescence microscopy, and three scanning modes, confocal reflectance microscopy (CRM), confocal fluorescence microscopy (CFM), and two-photon microscopy (2PM). OQM reconstructs the amplitude and phase of an optically transparent specimen within a modified Mach-Zehnder configuration. DIC microscopy images the phase gradient along a specified direction of an optically transparent specimen. CRM detects index of refraction changes that modulate backscatter. Epi-fluorescence microscopy, CFM, and 2PM detect endogenous and exogenous fluorophores within a specimen. The scanning modes are inherently capable of producing three-dimensional (3-D) images due to optical sectioning and localized probing. Illumination and imaging are performed coaxially with minimal changes of optical components between modes. Multimodal images of embryos are shown to demonstrate the microscopes imaging capabilities.

Botulinum A toxin for treatment of aberrant facial nerve regeneration.

Twelve patients with involuntary synkinetic eyelid closure were given 40 injections of botulinum A toxin. Temporary improvement in involuntary eyelid closure was observed in all 12 patients. Eleven of the 12 patients desired repeated injections. Dose requirements for this indication were compared with doses used in 697 injections in 112 patients with essential blepharospasm and Meige syndrome. Additionally, dose comparisons were made with 269 injections in 71 patients with hemifacial spasm. Dose requirements needed to treat aberrant regeneration of the facial nerve were substantially less than needed to treat blepharospasm and Meige syndrome. The dose requirement was similar to that in hemifacial spasm treatment. The reason for the differences probably relates to existing muscular denervation associated with hemifacial spasm and aberrant facial nerve regeneration.

Hidradenoma Papilliferum of the Upper Eyelid Arising from the Apocrine Gland of Moll

Hidradenoma papilliferum is derived from apocrine sweat glands and was originally described as a tumor located in the anogenital area. The authors recently examined a 78-year-old man with a hidradenoma papilliferum at the margin of the upper eyelid. While the tumor was located in the dermis, serial sections showed a connection to the epidermis and neoplastic cells partially replacing a gland of Moll. There were glandular structures with luminal cells that showed apical decapitation-type secretion, indicating the apocrine origin of the tumor. The luminal cells also contained granules that stained with periodic acid-Schiff (PAS) stain and were diastase resistant. Results of examination of the duct-forming cells by transmission electron microscopy showed adluminal villi, focal decapitation secretion, luminal cytoplasmic debris, and electron-dense cytoplasmic secretory granules. Because the apocrine glands of Moll are localized adjacent to the eyelid cilia, hidradenoma papilliferum and other tumors of apocrine origin should be considered in the clinical setting of a mass at the eyelid margin.

Multiple exaggerated weapon morphs: a novel form of male polymorphism in harvestmen.

Alternative reproductive tactics in animals are commonly associated with distinct male phenotypes resulting in polymorphism of sexually selected weapons such as horns and spines. Typically, morphs are divided between small (unarmed) and large (armed) males according to one or more developmental thresholds in association with body size. Here, we describe remarkable weapon trimorphism within a single species, where two exaggerated weapon morphs and a third morph with reduced weaponry are present. Male Pantopsalis cheliferoides harvestmen display exaggerated chelicerae (jaws) which are highly variable in length among individuals. Across the same body size spectrum, however, some males belong to a distinct second exaggerated morph which possesses short, broad chelicerae. Multiple weapon morphs in a single species is a previously unknown phenomenon and our findings have significant implications for understanding weapon diversity and maintenance of polymorphism. Specifically, this species will be a valuable model for testing how weapons diverge by being able to test directly for the circumstances under which a certain weapon type is favoured and how weapon shape relates to performance.

Quantitative phase measurements using a quadrature tomographic microscope

The Quadrature Tomographic Microscope measures the amplitude and phase of an image. This information allows the user to see contrast features not available in other microscopes, and is critical to any three-dimensional reconstruction. We report on development and use of test objects to measure the accuracy and repeatability of phase measurements. A simple binary phase grating, a series of glass beads, and preimplantation mouse embryos were used in these experiments. The gratings were fabricated on high-quality fused-silica substrates whose transmission phase error was determined to be less than one-tenth wave error across their 25 mm diameter before fabrication. The phase step of the binary phase grating was measured using both the optical quadrature technique and the usual fringe-counting techniques applied to the raw data. Phase unwrapping techniques were validated by measuring the diameter of glass beads of a known size. Results are presented showing that the phase measurements agree with each other, with the known data, and with the spatial resolution in preimplantation mouse embryos. More complicated objects will be fabricated in the future to validate 3-D imaging techniques.

Dermis Fat Graft in Eviscerated Sockets

Following evisceration, three patients who experienced extrusion of synthetic orbital implant underwent socket reconstruction using an autogenous dermis fat graft. An incision into the fundus of the existing sclera was necessary to provide for an adequate vascular bed for a composite fat graft, although the anterior ring of existing sclera with extraocular muscle attachments was not disturbed. Conjunctival reepithelialization of the dermal surface and enhancement of orbital volume occurred in each case. Furthermore, the autogenous fat graft retained the original excellent globe motility that was present before the socket reconstruction. After an average follow-up of 18 months, the volume restoration, integrity of conjunctival epithelium and fornices, and the graft viability have remained unchanged. As with alloplastic orbital implant extrusions in enucleated sockets, autogeneous dermis fat grafts can be useful in managing extrusions in previously eviscerated sockets.

Osteomyelitis of the Orbit: A Case Report

With the advent of the antibiotic era, the incidence of osteomyelitis has decreased remarkably. However, cases of trauma-induced orbital cellulitis, abscess, fistula formation, and osteomyelitis may still occur. The following case is illustrative of the chronicity of problems (8-year course) caused by retained orbital wooden foreign bodies.

Multimodal optical microscope for imaging biological systems

A mulitmodal microscope provides a researcher with the ability to capture images with multiple sources of contrast. Previous attempts at multimodal microscopy have been limited to capturing images at different instruments and digitally registering the images empirically using features common in the specimen. Other multimodal microscopes have combined different microscopy techniques, but have been limited in their sources of contrast. We present a unique microscope which containes 5 different imaging modalities, with four different sources of contrast. Quadrature microscopy measures the phase of the electric field of the light transmitted through an optically transparent specimen, by interference with a reference beam, using a polarimetric technique to resolve the ambiguities between phase and amplitude. Differential Interference Contrast (DIC) measures the phase gradient in an optically transparent specimen by combining two spatially separated images interferometrically. Confocal reflectance measures index of refraction changes in a plane or reflection from small scatterers. Confocal fluorescence and 2-photon laser scanning microscopy, measure fluorescent signatures of a specimen. The last three of these are inherently capable of producing three-dimensional images directly, through localized probing.