Phenotypic variability and asymmetry of Rieger syndrome associated with PITX2 mutations.
(1/97)
PURPOSE: Rieger syndrome is an autosomal dominant condition characterized by a variable combination of anterior segment dysgenesis, dental anomalies, and umbilical hernia. To date, reports have shown mutations within the PITX2 gene associated with Rieger syndrome, iridogoniodysgenesis, and iris hypoplasia. The purposes of this study were to determine the range of expression and intrafamilial variability of PITX2 mutations in patients with anterior segment dysgenesis. METHODS: Seventy-six patients with different forms of anterior segment dysgenesis were classified clinically. DNA was obtained and screened by means of polymerase chain reaction (PCR)-single-stranded conformation polymorphism (SSCP) and heteroduplex analysis followed by direct sequencing. RESULTS: Eight of 76 patients had mutations within the PITX2 gene. Anterior segment phenotypes show wide variability and include a phenocopy of aniridia and Peters', Rieger, and Axenfeld anomalies. Mutations include premature terminations and splice-site and homeobox mutations, confirming that haploinsufficiency the likely pathogenic mechanism in the majority of cases. CONCLUSIONS: There is significant phenotypic variability in patients with PITX2 mutations, both within and between families. Developmental glaucoma is common. The umbilical and dental abnormalities are highly penetrant, define those at risk of carrying mutations in this gene, and guide mutation analysis. In addition, there is a range of other extraocular manifestations. (+info)
Ocular histopathology of Ehrlichial infections in the dog.
(2/97)
Histologic examination of eyes and brains of 27 dogs experimentally infected with either Ehrlichia canis, E. ewingii, E. chaffeensis, or human granulocytic ehrlichia (HGE) was conducted in the course of several experiments, the primary objectives of which were to investigate the susceptibility of the domestic dog to infection with various ehrlichial species and to assess the ability of ixodid tick species to acquire and transmit those infections. Uveitis and meningitis occurred in each of the dogs infected with E. canis but was not observed in dogs infected with the other Ehrlichia species. The inflammatory infiltrate was predominantly lymphocytic, monocytic, and plasmacytic; granulocytes were notably few. Ocular inflammation was most common and most intense in the ciliary body, becoming less intense in the choroid, iris, and retina, respectively. Meningitis was often accompanied by mild neuroparenchymal vascular cuffing and gliosis. The meningeal inflammatory cell infiltrate included a prominent monocyte population. Ocular and meningeal lesions were present in all E. canis-infected dogs from 22 through 200 days postexposure. Neither ocular nor brain lesions were observed with any of the other ehrlichial infections. (+info)
Causes of severe visual impairment and blindness in children attending schools for the visually handicapped in the Czech Republic.
(3/97)
AIMS: To describe the causes of severe visual impairment and blindness in children in schools for the visually handicapped in the Czech Republic in 1998. METHODS: Pupils attending all 10 primary schools for the visually handicapped were examined. A modified WHO/PBL eye examination record for children with blindness and low vision was used. RESULTS: 229 children (146 males and 83 females) aged 6-15 years were included in the study: 47 children had severe visual impairment (20.5%) (visual acuity in their better eye less than 6/60), and 159 were blind (69.5%) (visual acuity in their better eye less than 3/60). Anatomically, the most affected parts of the eye were the retina (124, 54.2%), optic nerve (35, 15.3%), whole globe (25, 10.9%), lens (20, 8.7%), and uvea (12, 5.2%). Aetiologically (timing of insult leading to visual loss), the major cause of visual impairment was retinopathy of prematurity (ROP) (96, 41.9 %), followed by abnormalities of unknown timing of insult (97, 42.4%), and hereditary disease (21, 9.2%). In 90 children (40%), additional disabilities were present: mental disability (36, 16%), physical handicap (16, 7%), and/or a combination of both (19, 8%). It was estimated that 127 children (56%) suffer from visual impairment caused by potentially preventable and/or treatable conditions (for example, ROP, cataract, glaucoma). CONCLUSIONS: Establishing a study group for comprehensive evaluation of causes of visual handicap in children in the Czech Republic, as well as for detailed analysis of present practice of screening for ROP was recommended. (+info)
Immunocytochemical characterization of cysts in the peripheral retina and pars plana of the adult primate.
(4/97)
PURPOSE: To better characterize the cellular constituents of cysts in the peripheral retina and pars plana of the adult monkey. METHODS: Frozen sections of the peripheral retinal margin and pars plana from monkeys (Macaca nemestrina) between 1 and 15 years of age were stained with toluidine blue or immunolabeled with a variety of glia- and neuron-specific antibodies. RESULTS: In animals 1 to 2 years of age, the nonpigmented inner layer of the pars plana is a pseudostratified columnar epithelium. In these young animals, the peripheral retina had distinct layers and did not contain cysts. In animals 6 years of age or older, there were numerous cysts in the pars plana and in the peripheral retina. In the peripheral retina, neurons were randomly distributed and did not have a laminar organization. Cells surrounding cysts were immunoreactive for different types of markers for retinal neurons. Some of the cells surrounding cysts in the pars plana were also unexpectedly immunoreactive for antigens normally expressed only in retinal neurons and glia. CONCLUSIONS: Cysts form in the peripheral retina and pars plana in adult monkeys. The peripheral retinal cysts disrupt the normal lamination of the cells, but all types of retinal neurons are still present in the cysts. In an unexpected finding, cysts in the pars plana also contained cells immunoreactive for a few of the markers of retinal cells, suggesting that neurogenesis may occur in the pars plana of the adult primate. (+info)
Frequency of ciliary body or retinal breaks and retinal detachment in eyes with atopic cataract.
(5/97)
AIM: To determine the frequency of ciliary body or retinal breaks and retinal detachment in eyes with atopic cataract. METHODS: The records of 106 eyes (74 patients) with atopic cataract that underwent cataract extraction were reviewed. The frequency of ciliary body or retinal breaks and retinal detachment was classified by their presence preoperatively and postoperatively, and by cataract type. RESULTS: Breaks were detected preoperatively in 27 eyes (25.5%) of 17 patients in the ciliary body (20 eyes, 18.9%), near the ora serrata (five eyes, 4.7%), and in undefined locations (two eyes, 1.9%). Among these, 16 eyes (15.1%) had already developed retinal detachment. After surgery, a ciliary body break occurred in one eye (0.9%) and retinal detachment in four eyes (3.8%) of three patients. The breaks that caused postoperative retinal detachment were in the ciliary body. When classified by cataract type, the highest frequency of breaks was associated with mature cataracts (35.0%), and all eyes with breaks developed retinal detachment. CONCLUSIONS: One fourth of eyes with atopic cataract had breaks in the ciliary body or ora serrata, or retinal detachment preoperatively. The highest frequency of either breaks or retinal detachment was associated with mature cataract. The frequency of breaks or detachment that occurred postoperatively (approximately 5%) was lower than that present preoperatively. (+info)
The indocyanine green findings in idiopathic uveal effusion syndrome.
(6/97)
We report two cases clinically diagnosed as idiopathic uveal effusion syndrome, where indocyanine green angiogram suggest non-specific choroidal inflammation as the underlying cause. Treatment with non-steroidal anti-inflammatory drugs was beneficial. (+info)
Ultrasound biomicroscopic findings in rabbit eyes undergoing scleral suction during lamellar refractive surgery.
(7/97)
PURPOSE: To evaluate changes of the central anterior chamber depth, cilio-angular cross-sectional surface area, and intraocular pressure in rabbit eyes undergoing application of the scleral suction ring during lamellar refractive surgery. METHODS: Thirty eyes of 30 rabbits were used in the study. The eyes were assigned to one of the following five surgical groups: group 1, no application of the suction ring; group 2, suction for 2 minutes; group 3, suction for 1 minute; group 4, suction for 20 seconds; and group 5, suction for 10 seconds. Ultrasound biomicroscopy (UBM) was performed to determine tomographic features, including central anterior chamber depth, cross-sectional surface area of the ciliary body, and chamber angle structure before and 10 minutes, 1 hour, 2 hours, 1 day, 2 days, 1 week, and 2 weeks after surgery. Intraocular pressure was also measured at each of these time points. RESULTS: Swelling of the ciliary body occurred in groups 2 to 5 of eyes from 10 minutes up to 1 day after the operation, and its severity was positively related to the duration of suction. Shallowness of the chamber angle was positively related to swelling. All UBM-detectable changes became insignificant compared with baseline values at 2 days after the operation. No significant change was found in the central anterior chamber depth and intraocular pressure during the 2-week postoperative observation period. CONCLUSIONS: Transient change in the ciliary body and the chamber angle occurred frequently after application of the scleral suction ring during lamellar refractive surgery in rabbit eyes. Its severity was positively related to the duration of suction. Swelling of the ciliary body corresponded with the shallowness of the chamber angle without alteration of the corneal-lenticular distance and intraocular pressure. (+info)
Gyrate atrophy of the choroid and retina: clinical, ophthalmologic, and biochemical considerations.
(8/97)
A case of gyrate atrophy of the choroid and retina associated with hyperornithinemia has been subjected to extensive clinical and biochemical investigation. The familial occurrence of the ocular disease and of abnormality of amino acid was unique to this 28-year-old male, being absent in parents and siblings. He presented with progressive visual loss, and was found to have cataracts and large areas of peripheral lacunar atrophy. Clinically there was no other abnormality. However, he was hyperuricemic and has an abnormal EEG. Despite otherwise normal biochemical indices of hepatic, renal, and muscle function; selective catheterization of an artery, the hepatic vein, the renal vein, and a deep forearm vein showed all of these circulatory beds to be producing ornithine according to arteriovenous difference measurements. Cerebrospinal fluid and urine contained increased amounts of ornithine. Though electromyography was normal, the muscle biopsy was abnormal. Clinical tests including arginine loading, glucose tolerance testing, and other measurements of blood variables provided inferences as to the metabolic locus of the abnormality. The syndrome is a systemic multiorgan disorder in which the choroid and retina would appear to be target organs and the hyperornithinemia to be of, as yet, undetermined cause and pathogenic significance. (+info)