Eye Capsule Research Articles

In vitro and in vivo evaluation of a hydrophilized silicone intraocular lens

The surface of a silicone-disc intraocular lens (IOL) was hydrophilized by plasma etching (oxygen plasma) and compared to an untreated but otherwise identical IOL. Various methods of surface analysis were used to characterize the modification (e.g., X-ray photoelectron spectroscopy, contact angle estimation). A cytotoxic effect of the modified surface was excluded by cell culture experiments evaluating cell spreading, cell morphology, DNA and protein synthesis. In vivo experiments on rabbits indicated that the postoperative foreign-body reaction was not significantly affected by the hydrophilization of the IOL surface. Throughout the entire followup (12 weeks) we found less induced posterior synechias in the eves with bydrophilized lenses than in those with untreated lenses (P = .009). While the IOL dislocations out of the capsular bag and the posterior capsular opacification rate did not differ significantly between the two groups of eyes, we did see special patterns of posterior capsular opacification on the posterior capsules of eyes with the hydrophilized IOL.

Myxobolid parasites (Myxozoa: Myxobolidae) infecting fishes of western Montana, with notes on histopathology, seasonality, and intraspecific variation

Cypriniform and salmonid fishes of the Columbia River drainage of western Montana harbor five members of the myxozoan family Myxobolidae. Myxobolus muelleri inhabits Ptychocheilus oregonensis (northern squawfish), Mylocheilus caurinus (peamouth), Richardsonius balteatus (redside shiner), and Catostomus macrocheilus (largescale sucker). Cysts appeared in gills, musculature, subcutis, and visceral mesenteries. Unencysted spores infiltrated mesenteries and viscera. Spore size and shape in the various tissues and hosts were highly varied. Muscle and subcutaneous cysts were associated with connective tissue proliferation and muscle degeneration; cyst rupture was associated with diffuse inflammation and rodlet cell proliferation. Infection prevalence in muscles and kidneys was high in adult and juvenile hosts (78–100%) throughout the year. Seasonal prevalence of gill and subcutaneous infections fluctuated markedly. Cysts of Myxobolus dujardini occurred in gills of the northern squawfish, peamouth, and redside shiner. Unicauda sp. was found in the eye capsule, gall bladder, mesenteries, and kidney of northern squawfish. Henneguya zschokkei occurred in intermuscular connective tissue of Prosopium coulteri (pygmy whitefish) and Prosopium williamsoni (mountain whitefish). Myxobolus sp. occurred in the gills of Catostomus catostomus (longnose sucker).

Ultrastructure of the lateral eye ofProtzia constans(Marshall) (Acarina: Hydryphantidae)

Abstract The eyes of Protzia constans consist of anterior and posterior biconvex lenses that are lamellate and have a thin cuticular layer with pore canals on the dorsal surface. There are four retinula cells beneath each lens and no vitreous cone or preretinal membrane is associated with either lens. The rhabdomeres are in direct contact with the lenses and are fused into a single rhabdom. The visual pigments are situated under each rhabdomere and along the sides. Secondary pigments are concentrated between the cuticule of the body and the retinula cells, and between the retinular regions under each lens. These pigments are a type of lipid(s) that provide a barrier to extraneous light. The cuticle of the eye capsule forms a long extension that reaches into the body cavity and a muscle is attached to the cuticular estension. This muscle is probably capable of changing the position of the lateral eye in respect to the light

Fine structure and convergent development of the Cirolana compound eye (Crustacea Isopoda)

Each sessile eye comprises about 60 ommatidia with large lenses (diameter 100–150 μm), spherical crystalline cones, and hypertrophied rhabdoms (diameter about 100 μm). The cones are formed by two main cone cells, and in addition two accessory cone cells are present. Seven retinula cells contribute to the rhabdom, which is fused distally and open proximally (separated rhabdomeres). A special cell type, previously designated ‘hyaline cells’ are shown to be reflecting pigment cells. These cells form a well-developed tapetal layer. Distal pigment cells screen neighbouring ommatidia. Further, the eye is delimited by two membranes homologous to the fenestrated and eye capsule membranes present in several other isopod groups. The hypertrophied rhabdoms and the elaborate tapetal layer separate the morphology of the Cirolana eye from that of other isopod eyes. These structural features makes the Cirolana eye a case of convergent development with several other deep water living crustaceans.