To overcome the problems of surgical treatment of tumors of the posterior segment, we have developed a ring-shaped instrument. This is sutured to the sclera or the area ivhere resection should be performed. Besides stabilizing the operative area, the two side arms of the instrument prevent collapse of the eyeball. The fidl-thickness eye wall resection i? performed with the cutting needle of the...

Concussion injury to the globe, if not severe enough to rupture the outer coat, causes a temporary expansion of the posterior sclera. This may pass unnoticed without producing any lesion, or may be severe enough to rupture the adjacent vascular structures. The circle of Zinn, by its particular situation around the optic nerve and within the sclera, is liable to such injury and its rupture is a ...

A standard 23-gauge or 25-gauge valved trocar is positioned externally next to the sclera at an area corresponding to the most elevated retina. During internal visualization, the trocar is advanced at an angle of 15°, penetrating the sclera and the choroid, and entering the subretinal space (Figure 2). Once it has been visually confirmed that the cannula entered the subretinal space, the trocar...

Tests were conducted on small samples of sclera taken from cattle eyes and human eyes to determine the mechanical properties of the tissue in compression. It was found that the elastic modulus for radial compressive stress of human sclera was more than a factor of 100 less than the modulus for circumferential tensile stress. The stress-strain relationship was found to be mildly nonlinear and ex...

purpose : to investigate intraocular pressure (iop) changes due to different serum level heights by using tonopen in acquired globes from the iran eye bank (ieb). methods : in this interventional prospective case series, serum were infused into 18 normal globes acquired from ieb by using 21g needle inserted in vitreal space through optic nerve head to change the iop by different fluid level hei...

PURPOSE To characterize the cellular events responsible for the exaggerated ocular growth associated with experimental myopia in chicks, the accumulation and synthesis of proteoglycans and collagen were measured in the posterior sclera of control and form vision-deprived chick eyes. METHODS Buttons (10 mm) from the posterior sclera of control and deprived eyes were used for biochemical measur...