Architectural synthesis of an image processing algorithm using IRIS

Details are presented of the IRIS synthesis system for high-performance digital signal processing. This tool allows non-specialists to automatically derive VLSI circuit architectures from high-level, algorithmic representations, and provides a quick route to silicon implementation. The applicability of the system is demonstrated using the design example of a one-dimensional Discrete Cosine Transform circuit.

Iris cysts in children:Classification, incidence, and management. The 1998 Torrence A Makley Jr Lecture

Background - Iris cysts in children are uncommon and there is relatively little information on their classification, incidence, and management. Methods - The records of all children under age 20 years who were diagnosed with iris cyst were reviewed and the types and incidence of iris cysts of childhood determined. Based on these observations recommendations were made regarding management of iris cysts in children. Results - Of 57 iris cysts in children, 53 were primary and four were secondary. There were 44 primary cysts of the iris pigment epithelium, 34 of which were of the peripheral or iridociliary type, accounting for 59% of all childhood iris cysts. It was most commonly diagnosed in the teenage years, more common in girls (68%), was not recognised in infancy, remained stationary or regressed, and required no treatment. The five mid-zonal pigment epithelial cysts were diagnosed at a mean age of 14 years, were more common in boys (83%), remained stationary, and required no treatment. The pupillary type of pigment epithelial cyst was generally recognised in infancy and, despite involvement of the pupillary aperture, also required no treatment. There were nine cases of primary iris stromal cysts, accounting for 16% of all childhood iris cysts. This cyst was usually diagnosed in infancy, was generally progressive, and required treatment in eight of the nine cases, usually by aspiration and cryotherapy or surgical resection. Among the secondary iris cysts, two were post-traumatic epithelial ingrowth cysts and two were tumour induced cysts, one arising from an intraocular lacrimal gland choristoma and one adjacent to a peripheral iris naevus. Conclusions - Most iris cysts of childhood are primary pigment epithelial cysts and require no treatment. However, the iris stromal cyst, usually recognised in infancy, is generally an aggressive lesion that requires treatment by aspiration or surgical excision.

Primary cysts of the iris pigment epithelium. Clinical features and natural course in 234 patients

Objective: To describe the clinical characteristics, natural course, and complications of a large group of patients with primary iris pigment epithelium (IPE) cysts. Design: Observational case series. Participants: Two hundred thirty-four patients with primary IPE cysts participated. Results: Primary IPE cysts were classified as central in 6 patients (3%), midzonal in 50 patients (21%), peripheral in 170 patients (73%), and dislodged in 8 patients (3%). Central (pupillary) IPE cysts were found only in males, peripheral IPE cysts were found most often in females (69%), and no gender predilection was detected for midzonal and dislodged IPE cysts. Central and peripheral IPE cysts occurred in young patients (mean age, 20 and 33 years, respectively), whereas midzonal and dislodged IPE cysts were seen in slightly older patients (mean age, 52 and 45 years, respectively). Central IPE cysts were visible when the pupil was not dilated and appeared most often as a round or collapsed brown lesion arising from the pupillary margin, most commonly superonasally. Midzonal IPE cysts were brown and fusiform, best visualized after pupillary dilation. Peripheral IPE cysts produced a characteristic bulging in the iris stroma near the iris root, but they were directly visible in only 78% of cases. After wide dilation and patient and slit-lamp positioning, they appeared as a round clear lesion behind the iris, most often in the inferotemporal quadrant. Finally, dislodged IPE cysts appeared as a brown oval lesion, free floating in the anterior chamber (12%) or in the vitreous (12%), or fixed in the anterior chamber angle (75%). One hundred twenty-four patients (53%) were followed for a mean of 35 months (range, 3 months-19 years). In these patients, complications associated with IPE cysts included lens subluxation in one case (1%), iritis in one case (1%), focal cataract in two cases (2%), glaucoma in two cases (2%), and corneal touch in five cases (4%). Conclusion: Primary IPE cysts have characteristic clinical features that serve to differentiate them from intraocular malignancies. Most cysts have a benign clinical course, and treatment is rarely necessary.

Plateau iris syndrome associated with multiple ciliary body cysts:Report of 3 cases

Objective: To describe plateau iris syndrome associated with multiple neuroepithelial cysts of the pars plicata. Methods: Case reports of 3 patients with plateau iris syndrome who were found to have multiple bilateral ciliary body cysts on ultrasound biomicroscopic examination. Results: Ultrasound biomicroscopy revealed classic features of plateau iris syndrome in each patient but also showed multiple neuroepithelial cysts of the ciliary body in each eye. Conclusion: Plateau iris syndrome may be associated with multiple ciliary body cysts.