Bilateral third eyelid ectopic cilia in an adult horse.

A 15-year-old Cob mare presented with a 4-month history of chronic epiphora and intermittent blepharospasm in the right eye. On ophthalmic examination, two translucent aberrant hairs were identified at the third eyelid margin corresponding to an area of corneal fibrosis and neovascularization. Partial excision of the third eyelid was performed, and histopathology confirmed ectopic hair follicles. Two weeks later, clinical signs recurred in the same eye. Examination revealed another pair of aberrant hairs on the bulbar surface of the third eyelid near its leading edge. This portion of the third eyelid was also excised, and histopathology confirmed two additional ectopic hair follicles. Eight months later, the horse developed similar clinical signs in the left eye. Ophthalmic examination showed a single aberrant translucent hair at the third eyelid margin associated with focal fibrosis and neovascularization of the ventromedial cornea. Partial excision of the third eyelid was performed, and histopathology confirmed an ectopic hair follicle within the third eyelid conjunctiva. Excision was curative at 4 years postoperatively with no further recurrence in either eye.

Ocular biometry by computed tomography in different dog breeds.

OBJECTIVE: To (i) correlate B-mode ocular ultrasound (US) and computed tomography (CT) (prospective pilot study), (ii) establish a reliable method to measure the normal canine eye using CT, (iii) establish a reference guide for some dog breeds, (iv) compare eye size between different breeds and breed groups, and (v) investigate the correlation between eye dimensions and body weight, gender, and skull type (retrospective study). PROCEDURE: B-mode US and CT were performed on ten sheep cadaveric eyes. CT biometry involved 100 adult pure-bred dogs with nonocular and nonorbital disease, representing eleven breeds. Eye length, width, and height were each measured in two of three planes (horizontal, sagittal, and equatorial). RESULTS: B-mode US and CT measurements of sheep cadaveric eyes correlated well (0.70-0.71). The shape of the canine eye was found to be akin to an oblate spheroid (a flattened sphere). A reference guide was established for eleven breeds. Eyes of large breed dogs were significantly larger than those of medium and small breed dogs (P < 0.01), and eyes of medium breed dogs were significantly larger than those of small breed dogs (P < 0.01). Eye size correlated with body weight (0.74-0.82) but not gender or skull type. CONCLUSIONS: Computed tomography is a suitable method for biometry of the canine eye, and a reference guide was established for eleven breeds. Eye size correlated with breed size and body weight. Because correlation between B-mode US and CT was shown, the obtained values can be applied in the clinical setting, for example, for the diagnosis of microphthalmos and buphthalmos.

Crystallin-ß-b2-overexpressing NPCs support the survival of injured retinal ganglion cells and photoreceptors in rats.

PURPOSE: Crystallin ß-b2 (crybb2) is known to support the regeneration of retinal ganglion cell (RGC) axons in culture. We investigated whether neuronal progenitor cells (NPCs) overexpressing crybb2 (crybb2-NPC) affect secondary retinal degeneration due to optic nerve crush in vivo. METHODS: NPCS were produced by dissociation and propagation of rat embryonic neural tube and eye primordial cells at embryonic days 13.5 and 15. Retinal degeneration was induced by injured optic nerve crush (BY suture, 20 seconds). Several groups were built: crybb2-NPC were injected into the vitreous body, while the Controls were comprised of recombinant crybb2-injected and PBS-injected groups. The eyes, in particular the retina, were analyzed by immunohistochemistry and Western blotting for different antigens at 2 and 4 weeks after surgery. RESULTS: At 2 and 4 weeks post surgery, crybb2-NPC resided within the vitreoretinal compartment, and were persistently nestin-positive throughout the experimental period. The cells stained positive for various neurotrophins and acted as "living" cell factories to support the survival of injured RGCs. The crybb2-NPC migrated throughout the eye structures and sometimes became integrated within the tissue. Most of the ocular cells responded to the appearance of crybb2-NPC with marked changes of certain proteins, including Iba-1 (microglia), vimentin (glial cells), and rhodopsin (photoreceptors). Photoreceptors also displayed a better survival after crybb2-NPC injection compared to control groups. CONCLUSIONS: Crybb2-NPC exert beneficial effects on the vitreoretinal compartment, which suggests that modified crybb2-NPC could be used in a novel strategy for the treatment of degenerative vitreoretinal diseases. However, future studies must determine the safety of in vivo administration of crybb2-NPC.

Long-term morphometric stabilization of regenerating retinal ganglion cells in the adult rat.

PURPOSE: Adult retinal ganglion cells (RGCs) can regenerate their cut axons within peripheral nerve grafts used to replace the distal optic nerve stump. We examined the long-term stabilization of RGCs by guiding their regenerating axons into different termination areas. METHODS: The optic nerve (ON) of adult rats was completely cut intraorbitally and its ocular stump was connected with different visual target areas (cortex, midbrain) or with non-visual areas (e.g. muscle). Control groups consisted of blind ending graft and ON cut without graft. The function of the retina was regularly examined by electroretinography. At one, six and nine months postsurgery RGCs were retrogradely labelled with 4-(4-(didecylamino)styryl)-N-methylpyridinium iodide and examined morphometrically. Regenerating RGCs were categorized into three major classes representing the morphological types I, II and III. RESULTS: Our data show that regenerating RGCs remain stable up to nine months after grafting at the ON, although the numbers of axons are low, that is less than 1%, and this number is not significantly effected by reconnection with targets. However, there are significant quantitatively and morphometrically assessable differences between the experimental groups depending on the tissue the RGCs are connected with visual targets. Regenerating RGCs show the highest stability in morphology if reconnected with visual target tissue. CONCLUSIONS: Adult RGCs of the rat can be reconnected with visual centers using a peripheral nerve graft. This reconnection stabilizes the cells at morphological and the retina at functional levels for a long period of time, although it does not significantly increase cell survival.

Deciphering proteins and their functions in the regenerating retina.

Neurons of the mammalian CNS, including retinal ganglion cells, lack, in contrast to the PNS, the ability to regenerate axons spontaneously after injury. Regeneration of the CNS is extremely complex and involves various molecular factors and cells. Therewith the regenerative process remains an enormous scientific and clinical challenge. This article provides an overview of proteins that play a crucial role in axon regeneration of retinal ganglion cells and their underlying signaling pathways. In this context, we elucidate the role of 2D gel electrophoresis and highlight some additional proteins, altered upon regeneration by using this highly sensitive method.