M.F. Escano

Evaluation of the effect of aging on retinal nerve fiber layer thickness measured by optical coherence tomography.

Purpose: To evaluate the relationship between age and retinal nerve fiber layer (RNFL) thickness in normal subjects, as measured by optical coherence tomography (OCT). Methods: One hundred and forty-four normal subjects (144 eyes), ranging from 16 to 84 years of age, were enrolled in this cross-sectional study. The RNFL thickness was determined using OCT with three circle scans 3.4 mm in diameter. Results: The average RNFL thickness was inversely correlated with age (r = –0.348, p < 0.001). Analyzing the quadrants as a parameter, RNFL thickness in the superior, temporal and inferior quadrants also decreased with age. Using 30-degree segments, there were significant correlations between age and the RNFL thickness of temporal segments (7–11 o’clock). The average RNFL thickness had the highest correlation among all parameters (r = –0.348, p < 0.001). Regarding nasal quadrant thickness, RNFL ratios (average, superior, temporal and inferior RNFL thickness relative to the nasal quadrant thickness) were not significantly correlated with age. The refractive error did not affect RNFL thickness (r = 0.091, p = 0.276). Conclusion: Our study revealed that RNFL thickness, in particular in the temporal quadrant, measured by OCT significantly decreased with age. Age has to be taken into consideration when we compare RNFL thickness between normal and glaucomatous eyes.

A novel RDH5 gene mutation in a patient with fundus albipunctatus presenting with macular atrophy and fading white dots

PURPOSE To report a novel homozygous RDH5 gene mutation in a 76-year-old fundus albipunctatus who developed macular atrophy with the disappearance of white dots. DESIGN Observational case report. METHODS Direct genomic sequencing for RDH5 mutations was done after complete ophthalmic examination. RESULTS Fundoscopy revealed only macular atrophy with notable absence of white dots. A homozygous G490T (Val164Phe) missense RDH5 gene mutation was detected. CONCLUSIONS This is the first reported long-term case of fundus albipunctatus demonstrating macular atrophy with fading of the typical white dots. Gene studies may be the only method for distinguishing fundus albipunctatus from other types of macular atrophy in the elderly.

Multifocal electroretinography in patients with occult macular dystrophy

Editor,—Occult macular dystrophy (OMD), idiopathic photoreceptor dysfunction, or central cone dystrophy is an unusual form of macular dystrophy where a progressive decline of visual acuity occurs with an essentially normal fundus and normal fluorescein angiography (FA) findings.1-3 The topography of the electroretinographic responses in the central visual field in three patients with OMD was examined by means of the multifocal electroretinogram (m-ERG).4 5 To evaluate the retinal pigment epithelium (RPE) and the choroidal circulation in OMD, indocyanine green …

Altered Expression of Genes in Experimentally Induced Myopic Chick Eyes

PURPOSE To identify a casual pathway between the alteration in visual experience, due to form deprivation and hyperopic defocus, and the increase in eye growth, we searched for candidate genes having regulatory effects on eye growth under myopic conditions. METHODS The expression of the brain-derived neurotrophic factor, neurotrophin-3, sonic hedgehog, nerve growth factor, Six-3 and the Lh-2 group of genes in the transcriptional level after experimentally induced myopia (form-deprivation by goggles and by hyperopic defocus using negative spectacle lenses) were evaluated by semiquantitative reverse transcriptional polymerase chain reaction and Northern blot analysis. RESULTS Results showed that only the sonic hedgehog gene was differentially expressed in the experimentally induced myopic retinal samples compared with controls. CONCLUSIONS The sonic hedgehog gene may have regulatory functions in the signaling of the cascade of events that leads to axial elongation and vitreous enlargement of the eye under myopic conditions.

Ionizing Radiation Induces a p53-dependent Apoptotic Mechanism in ARPE-19 Cells

PurposeTo investigate the molecular mechanisms for cell growth inhibition or apoptosis in human retinal pigment epithelium (RPE) cells after ionizing radiation.MethodsCell survival studies, a TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay, and a caspase-3 immunocytochemical analysis were performed on irradiated ARPE-19 cell cultures at different time periods. Transcriptional levels of p53, p21, Bax, Fas/Fas-L, vascular endothelial growth factor (VEGF), and pigment epithelium-derived growth factor (PEDF) were evaluated by semiquantitative reverse transcriptional polymerase chain reaction. Mutations in the p53 gene were analyzed by DNA sequencing. Protein levels of p53, VEGF, and PEDF were evaluated by Western blot.ResultsCell viability was inversely related to radiation dose. TUNEL-positive cells were detected 6 h after radiation exposure. Caspase-3 immunocytochemical analysis revealed increased immunoreactivity in the TUNEL-positive cells. Levels of p53, p21, and Bax mRNA were greatest at the 2-h postradiation period. VEGF and PEDF mRNA and protein levels were constant. Protein levels of p53 were increased at the 4- and 6-h postradiation period.ConclusionsIonizing radiation induces apoptosis in normal proliferating RPE cells through p53 activation, without affecting expression of VEGF or PEDF. We documented a molecular basis for explaining the decrease in effectiveness of radiation therapy, particularly for age-related macular degeneration. In the clinical setting, selection of appropriate radiation therapy methods and the doses for specific diseases need careful evaluation. Jpn J Ophthalmol 2004;48:106–114

Indocyanine green videoangiography in macular variant of idiopathic polypoidal choroidal vasculopathy

BACKGROUND Fifty patients diagnosed with choroidal neovascularization in age-related macular degeneration were examined by indocyanine green videoangiography. Results were correlated with fundus photographs and fluorescein angiograms. Two patients were diagnosed with the macular variant of idiopathic polypoidal choroidal vasculopathy. CASES Two middle-aged hypertensive women were diagnosed with macular idiopathic polypoidal choroidal vasculopathy. Throughout the follow-up period, both cases showed improved signs and symptoms without worsening of visual acuity, and despite the absence of definitive therapy. OBSERVATIONS Indocyanine green videoangiography demonstrated the characteristic polypoidal lesions in idiopathic polypoidal choroidal vasculopathy better than fluorescein angiography, particularly when blood, exudates, or pigment epithelial detachments blocked visualization of the lesions. CONCLUSIONS Incidence of idiopathic polypoidal choroidal vasculopathy may not be as low as reported, as its presentation mimics choroidal neovascularization in age-related macular degeneration. Differentiation can be made only through indocyanine green videoangiography. Conservative management may be beneficial, as visual prognosis is good.