Pingelapese achromatopsia: correlation between paradoxical pupillary response and clinical features.
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AIM: To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features. METHODS: 27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara pseudoisochromatic plates and also with a colour plate consisting of five basic colours (red, green, purple, yellow, and orange). Paradoxical pupillary response was examined and documented with a special infrared video camera. Pupils' images were analysed using the Scion Image program and the ratio of pupil size in darkness to its size in light was calculated and recorded. RESULTS: Mean visual acuity was 20/400 (range 20/80-20/800). Colour vision examination showed a mean of 3.2 (SD 1.5) (range 1-5) of Ishihara colour plates, and 0.5 (0.75) (0-3) of basic colour plates. 23 patients (85%) had paradoxical pupillary constriction in darkness. Mean dark/light ratio of pupillary area was 0.86 (range 0.5-1.6). In patients with marked paradoxical pupillary constriction there was a significant correlation of visual acuity and Ishihara score. CONCLUSIONS: Clinical manifestations of achromatopsia include total colour blindness, low visual acuity (mean of 20/400), horizontal pendular or rotatory nystagmus, and photophobia. Most patients have paradoxical pupillary constriction in darkness. When this response is brisk it seems to correlate with lower visual acuity and lower Ishihara score. (+info)
Genotypic and phenotypic heterogeneity in familial microcoria.
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AIMS: To describe the clinical features and genetic findings in two families presenting with microcoria inherited as an autosomal dominant trait. METHODS: Both affected and unaffected members of two families displaying familial microcoria were examined. Flash photography or infrared pupillography were used to assess pupils, and a full ophthalmic examination including visual acuity and field testing, refraction, biomicroscopy of anterior and posterior segments, and measurement of intraocular pressure were performed. DNA from the blood of affected and unaffected family members was investigated using standard markers to look for a possible gene defect in the chromosome 13q31-q32 region. RESULTS: All affected members of both families had pinpoint pupils which responded normally to light and accommodation. None of these subjects exhibited any other ocular abnormality. The iris of affected members showed stromal thinning and apparent absence of the iris dilator muscle in the first family, but was smooth and lacked all trabecular structure in the second family. The microcoria was present at birth in the first family but developed progressively at a later age in the second family. Haplotype analysis suggested the gene defect is not located in the chromosome 13q31-q32 region in the first family but the evidence was not conclusive in the second family. CONCLUSION: Although both families presented with similar pupil abnormalities inherited as an autosomal dominant trait, they show important phenotypic and genotypic differences suggesting that this is a heterogeneous condition. The possible mechanisms underlying the microcoria are discussed. (+info)
Impairment of the transient pupillary light reflex in Rpe65(-/-) mice and humans with leber congenital amaurosis.
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PURPOSE: To determine the impairment of the transient pupillary light reflex (TPLR) due to severe retinal dysfunction and degeneration in a murine model of Leber congenital amaurosis (LCA) and in patients with the disease. METHODS: Direct TPLR was elicited in anesthetized, dark-adapted Rpe65(-/-) and control mice with full-field light stimuli (0.1 second duration) of increasing intensities (-6.6 to +2.3 log scot-cd. m(-2)). 9-cis-Retinal was administered orally to a subset of Rpe65(-/-) mice, and TPLR was recorded 48 hours after the treatment. TPLR was also measured in a group of patients with LCA. RESULTS: Baseline pupillary diameters in Rpe65(-/-) and control mice were similar. TPLR thresholds of Rpe65(-/-) mice were elevated by 5 log units compared with those of control animals. The waveform of the TPLR in Rpe65(-/-) mice was similar to that evoked by 4.8-log-unit dimmer stimuli in control mice. Treatment of Rpe65(-/-) mice with 9-cis-retinal lowered the TPLR threshold by 2.1 log units. Patients with LCA had baseline pupillary diameters similar to normal, but the TPLR was abnormal, with thresholds elevated by 3 to more than 6 log units. When adjusted to the elevation of TPLR threshold, pupillary constriction kinetics in most patients were similar to those in normal subjects. CONCLUSIONS: Pupillometry was used to quantify visual impairment and to probe transmission of retinal signals to higher nervous centers in a murine model of LCA and in patients with LCA. Mouse results were consistent with a dominant role of image-forming photoreceptors driving the early phase of the TPLR when elicited by short-duration stimuli. The objective and noninvasive nature of the TPLR measurement, and the observed post-treatment change toward normal in the animal model supports the notion that this may be a useful outcome measure in future therapeutic trials of LCA. (+info)
Visual outcome of cataract surgery with pupillary sphincterotomy in eyes with coexisting corneal opacity.
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BACKGROUND: To evaluate the visual outcome following cataract surgery with pupillary sphincterotomy in eyes with coexisting corneal opacity. METHODS: Patients with leucomatous corneal opacity with significant cataract were enrolled for the study. The uncorrected visual acuity and best-corrected visual acuity (BCVA) were recorded and the anterior segment was thoroughly evaluated by a slit lamp biomicroscope before the surgery. Only those patients who had some amount of clear peripheral cornea were selected. Posterior segment pathology was ruled out by indirect ophthalmoscopy after pupillary dilatation, if possible, or by B-scan ultrasonography. Conventional extracapsular cataract extraction with pupillary sphincterotomy was performed and an intraocular lens was implanted. Postoperatively, the eyes were evaluated on day 1, and 1 week and 6 weeks following surgery for similar parameters. RESULTS: Fourteen eyes of 14 patients were included in the study, of which 13 (92.85%) patients were male. The mean age of the patients was 47.85 +/- 7.37 years. All the eyes had a dense central leucomatous corneal opacity. Twelve (85.71%) eyes had two or more quadrants of deep vascularisation. Sphincterotomy was performed mostly (71.42%) in the nasal or inferonasal quadrant. The intraocular lens was implanted in 13 (92.85%) eyes, and one (7.1%) eye was left aphakic due to the occurrence of a large posterior capsular tear. Preoperatively, all eyes had BCVA < 6/60. At 6 weeks after surgery, all eyes had BCVA >or= 6/60 and four (28.57%) eyes had BCVA >or= 6/18. The mean BCVA preoperatively in these eyes was 0.015 +/- 0.009, which changed to 0.249 +/- 0.102 at 6 weeks following surgery. CONCLUSIONS: Extracapsular cataract extraction and intraocular lens implantation with pupillary sphincterotomy provides ambulatory and useful vision to patients of cataract with coexisting central leucomatous corneal opacity. (+info)
Haploinsufficiency for Phox2b in mice causes dilated pupils and atrophy of the ciliary ganglion: mechanistic insights into human congenital central hypoventilation syndrome.
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Dilp1 is a semi-dominant mouse mutation that causes dilated pupils when heterozygous and is lethal when homozygous. We report here that it is caused by a point mutation that introduces a stop codon close to the start of the coding sequence of the paired-like homeobox transcription factor Phox2b. Mice carrying a targeted allele of Phox2b also have dilated pupils and the two alleles do not complement. Phox2b is necessary for the development of the autonomic nervous system and when absent one of the consequences is that all parasympathetic ganglia fail to form. Constriction of the pupil is a parasympathetic response mediated by the ciliary ganglion and we find that in Phox2b heterozygous mutants it is highly atrophic. The development of other parasympathetic and sympathetic ganglia appears to be largely unaffected indicating that the ciliary ganglion is exquisitely sensitive to a reduction in dose of this transcription factor. PHOX2B has been implicated in human disease. Mutations, principally leading to polyalanine expansions within the protein, have been found in patients with congenital central hypoventilation syndrome (CCHS), the cardinal feature of which is an inability to breathe unassisted when asleep. Additionally, some CCHS patients have ocular abnormalities, including pupillary defects, although they principally have constricted rather than dilated pupils. The apparent phenotypic differences observed between mice carrying a loss-of-function mutation of Phox2b and CCHS patients indicate that PHOX2B mutations found in CCHS patients, all of which can produce proteins with intact DNA-binding domains, are gain-of-function mutations that alter rather than abolish protein function. (+info)
Pupillary anomaly masquerading as a glaucomatous visual field defect: a case report.
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BACKGROUND: Patients are often referred to ophthalmologists with focal visual field defects on routine testing, possibly related to a potential diagnosis of glaucoma. However, examination of the individual patient's ocular characteristics as well as facial characteristics may often reveal a cause of the visual field defect. CASE PRESENTATION: We describe a patient who was found to have a superior visual field defect on routine testing by the optician. Repeat perimetry with pharmacological dilatation of the pupil revealed that the cause of the field defect was related to an eccentric inferiorly displaced pupil, secondary to trauma some years previously. DISCUSSION: Individual patient characteristics, including both ocular, as well as facial, need to be considered, when interpreting any visual field defect. (+info)
Triple-A syndrome with prominent ophthalmic features and a novel mutation in the AAAS gene: a case report.
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BACKGROUND: Triple-A syndrome (Allgrove syndrome) is an autosomal recessive disorder characterized by adrenal insufficiency, alacrima, achalasia, and - occasionally - autonomic instability. Mutations have been found in the AAAS gene on 12q13. CASE PRESENTATION: We present the case of a 12 year-old boy with classic systemic features of triple-A syndrome and several prominent ophthalmic features, including: accommodative spasm, dry eye, superficial punctate keratopathy, and pupillary hypersensitivity to dilute pilocarpine. MRI showed small lacrimal glands bilaterally. DNA sequencing of PCR-amplified fragments from the 16 exons of the AAAS gene revealed compound heterozygosity for a new, out-of-frame 5-bp deletion in exon 15, c1368-1372delGCTCA, and a previously-described nonsense mutation in exon 9, c938C>T, R286X. CONCLUSIONS: In addition to known ophthalmic manifestations, triple-A syndrome can present with accommodative dysregulation and ocular signs of autonomic dysfunction. (+info)
Role of early radial optic neurotomy in central retinal vein occlusion.
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PURPOSE: To determine safety, clinical and visual results, and potential complications of early radial optic neurotomy (RON) surgery in eyes with central retinal vein occlusion (CRVO), with relative afferent pupillary defect and visual acuity MATERIALS AND METHODS: This prospective, interventional case-series included 24 patients of CRVO who underwent RON within 2 months of disease onset. The preoperative examination included slitlamp biomicroscopy, fundus photography and fluorescein angiography. Foveal thickness was measured using optical coherence tomography (OCT) in the last 6 eyes only. In each case, RON was performed after informed consent. Two radial incisions were placed in the nasal quadrant of the optic disc, using a micro-vitreoretinal blade. The postoperative change in vision, clinical picture, fundus photographs, angiograms and foveal thickness by OCT were the main outcome variables studied. The Wilcoxan signed test was used to assess the results. RESULTS: Average symptom duration was 37.8 +/- 15.2 days (range 15-60 days, median: 34.5 days) and follow-up 7.7 +/- 2.1 months (range 1-12 months, median: 8 months). Visual outcome: 2 (8.33%) eyes each had fall and preservation of pre-RON visual acuity respectively. Twenty eyes (83.33%) showed increase in vision (of average 3 lines). Pre and postoperative vision ranged from 0.017-0.1 (average:0.061) and 0.017-0.667 (average: 0.17) respectively (P < 0.05). Clinical and angiographic outcome: decline in macular oedema, decreased or resolved intraretinal haemorrhages, resolution of venous dilatation and disc oedema could be appreciated in all cases. Foveal thickness: average pre and postoperative foveal thickness was 834.17 microm and 556.17 microm respectively (P < 0.05) in the 6 eyes where it was measured before and after RON. One eye developed retinal-detachment. CONCLUSION: Radial optic neurotomy is better than the natural course in eyes with CRVO, with vision < 6/60. (+info)