Late complications of hydrogel scleral buckle implants and a technique for effective removal.

PURPOSE: The aim of this article is to describe complications of hydrogel (MIRAgel) scleral buckle implants that may appear many years after implantation, and to describe an effective technique to facilitate safe removal of these implants, which become extremely friable with time. METHODS: Four case reports of patients with complications of hydrogel orbital implants and a technique for removal of the implants are described with review of the literature. The technique involves a conjunctival incision into each involved quadrant, followed by use of blunt instrumentation for "push" and a Frasier suction handpiece for "pull" to allow segmental removal. This technique limits the tendency of the implant to fragment, which has been a problem described with previous techniques. RESULTS: Cases typically present simulating an orbital tumor or infection, with the diagnosis not immediately apparent, as was the case in 3 of 4 cases in our series. The technique we used allowed for expeditious removal and prompt recovery in all 4 patients. CONCLUSIONS: Hydrogel scleral buckle implants can produce late complications that may be difficult to diagnose and manage. The "push-pull" technique described in this article facilitates effective removal, and may have implications for other types of orbital hydrogel implants as well.

Eye pain in preschool children: diagnostic and prognostic significance.

BACKGROUND: Preschool children often present for ophthalmologic examination because of eye pain. Although the differential diagnosis includes serious conditions, the diagnostic and prognostic importance of apparently isolated eye pain are unknown. METHODS: We reviewed records of 80 consecutive patients presenting between 2 and 6 years of age with eye pain but without a red eye or a history of an obvious cause of pain. Families of children seen in the office only once were contacted by phone to obtain follow-up information. RESULTS: Functional eye pain was diagnosed in 73 of 80 patients (91%). Of the 64 patients with follow-up between 1 week to 4 years (mean, 21 months), 56 (88%) had no other cause of eye pain. Dry eyes, allergic conjunctivitis, blepharitis, corneal foreign body, sinusitis, and trichiasis were diagnosed in 7 patients. Other children were found to have refractive error, amblyopia, blepharospasm, and nystagmus--all considered unlikely to cause eye pain. CONCLUSIONS: Absent a preexisting or obvious cause of eye pain, the symptom is usually functional in preschool children who may have difficulty communicating vague visual symptoms to caregivers. However, such children deserve examination, not only so that unapparent causes can be excluded but also because unrelated conditions may require further evaluation and treatment. Parents can be reassured that if no abnormality is found on initial ophthalmologic examination, children with eye pain are unlikely to have subsequent diagnoses.

Role of the Fas-signaling pathway in photoreceptor neuroprotection.

OBJECTIVE: To determine whether inhibiting the Fas proapoptosis pathway will result in increased photoreceptor survival after separation of the retina from the retinal pigment epithelium (RPE). METHODS: Retina/RPE separation was induced in rat and mouse eyes by the subretinal injection of hyaluronic acid, 1%. Fas-pathway signaling was inhibited by the concomitant injection of a Fas receptor-neutralizing antibody, small inhibitory RNA against the Fas-receptor transcript (siFAS), or the use of the Fas-receptor defective mouse strain LPR. Indices of photoreceptor death included terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining, cell counts, and retinal thickness measurements. Retinas were immunostained with antibodies against rhodopsin and cone opsin to evaluate rod and cone photopigment production, respectively. RESULTS: Inhibition of Fas signaling using Fas receptor-neutralizing antibody, siFas, or LPR mice resulted in a significant reduction in the number of TUNEL-positive photoreceptor cells as well as in a significant preservation of outer nuclear layer cell counts and thickness as compared with retina/RPE separation in eyes with intact Fas signaling. Fas-pathway inhibition resulted in preservation of both rhodopsin- and cone opsin-positive cells. CONCLUSIONS: Inhibition of the Fas proapoptosis pathway results in significant photoreceptor preservation after retinal separation from the RPE. CLINICAL RELEVANCE: Fas-pathway inhibition might serve as a novel mechanism for preserving photoreceptor cells during retinal disease.

Immortalized mouse inner ear cell lines demonstrate a role for chemokines in promoting the growth of developing statoacoustic ganglion neurons.

The target-derived factors necessary for promoting initial outgrowth from the statoacoustic ganglion (SAG) to the inner ear have not been fully characterized. In the present study, conditioned medium from embryonic Immortomouse inner ear cell lines that maintain many characteristics of developing inner ear sensory epithelia were screened for neurite-promoting activity. Conditioned medium found to be positive for promoting SAG neurite outgrowth and neuronal survival was then tested for the presence of chemokines, molecules that have not previously been investigated for promoting SAG outgrowth. One candidate molecule, monocyte chemotactic protein 1 (MCP-1), was detected in the conditioned medium and subsequently localized to mouse hair cells by immunocytochemistry. In vitro studies demonstrated that function-blocking MCP-1 antibodies decreased the amount of SAG neurite outgrowth induced by the conditioned medium and that subsequent addition of MCP-1 protein was able to promote outgrowth when added to the antibody-treated conditioned medium. The use of the Immortomouse cell lines proved valuable in identifying this candidate cofactor that promotes outgrowth of early-stage SAG nerve fibers and is expressed in embryonic hair cells.