Canopy vegetation influences ant (Hymenoptera: Formicidae) communities in headwater stream riparian zones of central Appalachia.

In the eastern United States, eastern hemlock Tusga canadensis (L.) Carriere forests are threatened by the invasive hemlock woolly adelgid, Adelges tsugae, a pest that is causing widespread hemlock mortality. Eastern hemlock is an essential component of forested communities. Adelgid-induced hemlock mortality is causing a shift in forest composition and structure, altering ecosystem function and thereby influencing the arthropod community. Using pitfall traps at three sites, we monitored ground-dwelling arthropods at 30-d intervals in hemlock-dominated and deciduous-dominated forests in central Appalachia over 2 yr. Here, we focus on the ant community (Hymenoptera: Formicidae) collected in the summer months. Ants form a ubiquitous and integral component of the invertebrate community, functioning at various trophic levels as predators, herbivores, and omnivores, and fulfilling important roles in forest ecosystems. We found no difference in overall ant abundance between hemlock-dominated and deciduous-dominated forests but did detect significant differences in the genera Prenolepis between forest types (P < 0.01) and Aphaenogaster across study locations (P = 0.02). Three genera were unique to deciduous forests; one was unique to hemlock forests. Not surprisingly, total formicids and several genera demonstrated temporal differences in abundance, with greater numbers captured in July than in August. As hemlock woolly adelgid-induced mortality of eastern hemlock becomes more pervasive, changes in forest composition and structure are imminent, accompanied by shifts in hemlock associates.

Intraocular pressure changes during injection of microincision and conventional intraocular lenses through incisions smaller than 3.0 mm.

PURPOSE: To compare intraocular pressure (IOP) during insertion of a new microincision intraocular lens (IOL) (Akreos AO MI60) and a conventional IOL (AcrySof Natural SN60AT) and to determine the minimum incision sizes for insertion in a cadaver eye model. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: After phacoemulsification in phakic cadaver eyes, multiple IOL insertions were attempted through 1.8 mm to 2.5 mm wounds. The final incision size and insertion success were evaluated in each case. A pressure transducer placed in the vitreous cavity measured real-time IOP changes (100 readings per second), including the mean and peak IOP during IOL implantation. RESULTS: The minimum incision size for the microincision IOL insertion was 1.9 mm using a wound-assisted technique and 2.2 mm using a cartridge-insertion technique. The minimum incision size for wound-assisted implantation of the conventional IOL was 2.4 mm. During successful implantation, the mean and peak IOPs were similar between the 2 IOL types. The peak IOPs exceeded 60 mm Hg (retinal perfusion pressure). In unsuccessful attempts, the mean and peak IOPs were higher for the conventional IOL, reaching 306.05 mm Hg in 1 eye. CONCLUSIONS: Monitoring during implantation of both IOL types confirmed that IOP increases during insertion, including during microincision surgery using a wound-assisted technique. Further studies are necessary to evaluate the effect of pressure spikes on the optic nerve during IOL insertion.

Acanthamoeba and fungal keratitis in a woman with a history of Intacs corneal implants.

PURPOSE: To report a case of corneal perforation secondary to Acanthamoeba and fungal keratitis in a patient with a history of Intacs corneal implants. METHODS: The patient's history, clinical presentation, and pathologic analysis were reviewed. RESULTS: A 56-year-old woman with keratoconus was referred to the university eye center for a corneal perforation secondary to a chronic corneal ulcer initially diagnosed as herpes simplex keratitis. The patient had Intacs inserted in the same eye 14 months earlier, but had them removed approximately 1 month before her visit. After emergency keratoplasty, the patient's corneal tissue was sent for histopathologic examination, which showed an Acanthamoeba and fungal coinfection. CONCLUSIONS: Atypical sources of keratitis should be considered in patients with a chronic corneal ulcer and a history of Intacs corneal implants.

Pigmentary dispersion syndrome with a secondary piggyback 3-piece hydrophobic acrylic lens. Case report with clinicopathological correlation.

We describe a case of pigmentary dispersion syndrome resulting from secondary piggyback implantation of a 3-piece hydrophobic acrylic squared-edged intraocular lens (IOL) in the ciliary sulcus. The intraocular pressure remained elevated despite pharmacological treatment, with a heavily pigmented trabecular meshwork. The piggyback IOL was subsequently explanted and replaced by a silicone IOL with smooth round edges. Examination of the explanted IOL under light and scanning electron microscopy showed clusters of pigment epithelial cells located around the periphery of the anterior optic surface.