Adalmir Morterá Dantas

Effects of corneal cross-linking on contrast sensitivity, visual acuity, and corneal topography in patients with keratoconus.

Purpose: To assess the effects of corneal collagen cross-linking (CXL) on contrast sensitivity (CS), visual acuity, and corneal topography investigating possible predictors of efficacy. Methods: Sixty-eight eyes of 34 patients with progressive keratoconus were enrolled in this prospective study. CXL was performed in one eye and the other eye was left untreated as a control. CS, best spectacle–corrected visual acuity (BSCVA), simulated keratometry in the steepest meridian (SimK-s), mean power in the central 3-mm zone (C-MP), mean power in the paracentral 3- to 5-mm zone (P-MP), maximum keratometric power in the central zone (C-Kmax), and maximum keratometric power in the paracentral zone (P-Kmax) were evaluated at baseline, 40 days, 3 months, 6 months, 1 year, and after 2 years of follow-up. Results: Treated eyes showed an improvement (P < 0.001) of +0.16 logCS and −0.16 logarithm of the minimum angle of resolution (logMAR) and a reduction in SimK-s of −0.61 diopter (D), C-Kmax −1.11 D, P-Kmax −0.99 D, C-MP −0.39 D, and P-MP −0.30 D. Of the treated eyes, 43.3% had a decrease in C-Kmax greater than 1 D, 50% by 0 to 0.99 D, and 6.7% had an increase of up to +0.89 D. Treated eyes with keratometric apex in the central 3-mm zone (CKA) improved BSCVA −0.19 logMAR and CS +0.19 logCS; whereas in treated eyes with paracentral keratometric apex (PKA), the improvement was −0.13 logMAR and +0.16 logCS. Conclusions: CXL with riboflavin and UV-A improved CS and inhibited the progression of keratoconus. As a predictor of treatment efficacy, eyes with CKA showed greater improvement in BSCVA after CXL when compared with eyes with PKA.

Reticulação do colágeno corneano com radiação ultravioleta e riboflavina para tratamento do ceratocone: resultados preliminares de um estudo brasileiro

PURPOSE: Assess the clinical and topographical effects of corneal collagen crosslinking in patients with keratoconus on Brazilian population. METHODS: Thirty seven eyes of 37 patients (22 female and 15 male) with diagnosis of progressive keratoconus and corneal paquimetry higher than 395 micra, were treated with riboflavin and ultraviolet A radiation, over 30 minutes, to induce corneal collagen crosslinking. Keratometric values were compared as well as the best corrected visual acuity, before and after the procedure, with ranges of 40 and 90 days. RESULTS: There was a reduction of mean dioptric power (PDM) in central 3mm in 83.8% of patients after three months.The PDM reduced 0.4D on average in central 3mm (p<0,01) and 0.33D in central 5mm (p<0,01). The maximum keratometric value decreased 0.6 D on average (p<0,01). The corrected visual acuity of the treated eye evolved with improvement average of 6,27 letters (p<0,01) after 90 days. CONCLUSION: We could observe a less pronounced improvement of the topographical values and visual acuity in comparison of the findings in other populations. Further studies with a larger number of patients and longer follow-up are necessary to confirm this techniques purpose of stabilizing the disease with only one application, and allow that to become the method of choice for keratoconus treatment.

Síndrome de Leigh: relato de caso

The authors describe for the first time in the Country a case of a 10-year-old female child, assisted at the Ophthalmology Clinic of the Hospital Universitario Clementino Fraga Filho UFRJ, with Leighs syndrome that is part of a metabolic disease group known as mitochondrial encephalomyopathies. It is an hereditary disease transmitted by a different mode of inheritance: mitochondrial, X-linked recessive and autosomal recessive. The beginning of clinical manifestations is varied and occurs usually in the first two years of life, with progressive and insidious evolution and exacerbation periods. Diagnosis is difficult because pleomorphic presentation, based on clinical findings and complementary study related to mitochondrial production of ATP and cytochrome c oxidase deficiencies. Considering that there is no specific treatment, this is based on a palliative procedure. So, the identification of this syndrome is very important to keep it under control, since its evolution is progressive.The authors describe for the first time in the Country a case of a 10-year-old female child, assisted at the Ophthalmology Clinic of the Hospital Universitário Clementino Fraga Filho UFRJ, with Leighs syndrome that is part of a metabolic disease group known as mitochondrial encephalomyopathies. It is an hereditary disease transmitted by a different mode of inheritance: mitochondrial, X-linked recessive and autosomal recessive. The beginning of clinical manifestations is varied and occurs usually in the first two years of life, with progressive and insidious evolution and exacerbation periods. Diagnosis is difficult because pleomorphic presentation, based on clinical findings and complementary study related to mitochondrial production of ATP and cytochrome c oxidase deficiencies. Considering that there is no specific treatment, this is based on a palliative procedure. So, the identification of this syndrome is very important to keep it under control, since its evolution is progressive.

Estudo comparativo entre a curva diária de pressão intra-ocular e a associação da curva ambulatorial com o teste de sobrecarga hídrica no glaucoma primário de ângulo aberto, glaucoma de pressão normal e olhos normais

PURPOSE To evaluate and correlate the peaks and the fluctuation of intraocular pressure seen in the association of the ambulatory intraocular pressure curve with the water-drinking test versus the peaks and the fluctuation seen in the daily intraocular pressure curve. METHODS The sample was as follows: 77 eyes belonging to 77 patients who were divided into three groups composed of 31 eyes belonging to 31 patients with primary open-angle glaucoma, 26 eyes belonging to 26 patients with normal tension glaucoma and 20 normal eyes belonging to 20 individuals. RESULTS A significant correlation could be observed between the pressure peaks collected from the daily intraocular pressure curve and the pressure peaks seen in the ambulatory intraocular pressure curve, on the water-drinking test, as well as in the association of the ambulatory intraocular pressure curve with the water-drinking test. The procedure which showed the highest rate of correlation between the pressure peaks and the peaks of the daily intraocular pressure curve was the ambulatory intraocular pressure curve (r2= 0.81). However, no statistically significant difference was found between the pressure peaks and the correlation coefficients observed in the other methods. The correlation between the fluctuation of intraocular pressure obtained in the association of the ambulatory intraocular pressure curve with the water-drinking test and the fluctuation of the pressure seen in the daily intraocular pressure curve showed a slight association (r2= 0.21). CONCLUSIONS The association between ambulatory intraocular pressure curve and water-drinking test was not efficient to estimate peaks and the fluctuation of daily intraocular pressure curve. The ambulatory intraocular pressure curve and the water-drinking test must be analyzed separately. When predicting the peak and the fluctuation of the daily intraocular pressure curve, the ambulatory intraocular pressure curve was the most efficient procedure.

Exame de paciente com doença neurológica

A neurologia oftalmologica e otologica tem se desenvolvido nos ultimos anos ate constituir uma extensa disciplina especializada. Dispomos na atualidade de importantes manuais sobre a mesma, os quais tem, ante tudo, o carater de obras de consulta; em troca, se faz sentir, sem duvida, a necessidade de descricoes compreendidas que destaquem o mais essencial e definitivamente adquirido da bibliografia, quase inabarcavel, em relacao aos dominios desta especialidade; assim, temos demonstrados os repetidos desejos de alunos, solicitando a publicacao de nossas conferencias para pos-graduados sobre esta materia. Fizemos uma exposicao resumida da neurologia com interesse neurooftalmologico para que os estudantes desta materia possam se interessar sobre a mesma.

Cyclopia and Synophthalmia: Congenital Facial Anomalies with Neurological Defects

We studied two cases of congenital malformations. In the first case, a male baby presented with synophthalmia and semilobar holopros-encephaly. In the second case, the newborn presented with cyclopia, synotia and alobar prosencephaly. The first baby died immediately after birth and the second was already dead. We present a review of the literature on these malformations and describe the results of the autopsies.

Avaliação da onda b do eletrorretinograma na Athene cunicularia

PURPOSE: To evaluate b-wave of the electroretinogram of the burrowing owl (Athene cunicularia), differentiating the retinal electric reply in photopic and scotopic environment. METHODS: Transversal observational study was carried through, with the register of the full field electroretinogram of fourteen eyes; seven were stimulated in photopic environment and seven in scotopic environment using with white light according to the ISCEV protocol. RESULTS: The electrical responses of the retina of the species studied showed no statistically significant difference for the applied spectrum of white light in both scotopic photopic environments. CONCLUSION: The data allow us, therefore, to infer that the perception of the Athene cunicularia of the white color is the same one, in clear and dark environments, what it can be responsible for the adaptive capacity of the species in their natural habitat.

Estudo eletrorretinográfico de visão cromática

PURPOSE: To describe the electroretinogram of the South-American opossum (Didelphis aurita) obtained by chromatic stimulus of specific wavelengths. The electroretinogram records voltage variations of retinal cells triggered by light stimulation. The electroretinogram represents the combination of electric activity of many different cells and varies according to retinal physiology and examination methods. METHODS: We recorded the electroretinogram of six animals in dark adaptation using chromatic Kodak Wratten® filters, and recorded the spectral sensitivity to specific wavelengths in the spectrum of blue, green, yellow, orange and red light bands. RESULTS: The most consistent electrorretinographic results were obtained when the animals were stimulated by selective spectral bands instead of white light. These results are consistent with the absorbance curve of the opsins described in marsupial photoreceptors. Previous studies using microspectrophotometry of opsins and retinal immunohistochemistry suggested marsupial trichromacy. This morphologic knowledge has not before been physiologically demonstrated by electroretinographic methods. CONCLUSION: The South-American opossum has proven to be an interesting experimental animal for comparative visual physiology studies among other mammals, especially studies on phylogenetic of chromatic vision. The opossum represents a retinal model that superimposes both the photopic and scotopic systems; and the Didelphis genus shows few changes when compared to the fossils of the Pleocene period. Therefore the marsupials visual system retrieves characteristics from ancient mammal evolution to the retinal patterns found in modern mammals.

Neuroprotective effects of erythropoietin on rat retinas subjected to oligemia

OBJECTIVES: Erythropoietin may have neuroprotective potential after ischemia of the central nervous system. Here, we conducted a study to characterize the protective effects of erythropoietin on retinal ganglion cells and gliotic reactions in an experimentally induced oligemia model. METHODS: Rats were subjected to global oligemia by bilateral common carotid artery occlusion and then received either vehicle or erythropoietin via intravitreal injection after 48 h; they were euthanized one week after the injection. The densities of retinal ganglion cells and contents of glial fibrillary acidic protein (astrocytes/Müller cells) and cluster of differentiation 68 clone ED1 (microglia/macrophages), assessed by fluorescence intensity, were evaluated in frozen retinal sections by immunofluorescence and epifluorescence microscopy. RESULTS: Retinal ganglion cells were nearly undetectable one week after oligemia compared with the sham controls; however, these cells were partially preserved in erythropoietin-treated retinas. The contents of glial fibrillary acidic protein and cluster of differentiation 68 clone ED1, markers for reactive gliosis, were significantly higher in retinas after bilateral common carotid artery occlusion than those in both sham and erythropoietin-treated retinas. CONCLUSIONS: The number of partially preserved retinal ganglion cells in the erythropoietin-treated group suggests that erythropoietin exerts a neuroprotective effect on oligemic/ischemic retinas. This effect could be related to the down-modulation of glial reactivity, usually observed in hypoxic conditions, clinically observed during glaucoma or retinal artery occlusion conditions. Therefore, glial reactivity may enhance neurodegeneration in hypoxic conditions, like normal-tension glaucoma and retinal ischemia, and erythropoietin is thus a candidate to be clinically applied after the detection of decreased retinal blood flow.

Comparative electrophysiological responses in anisometropic and strabismic amblyopic children

Purpose To compare anisometropic hypermetropic amblyopic and strabismic amblyopic responses to pattern electroretinogram (PERG) and pattern visual evocated potential (PVEP). Materials and methods Fifty-six patients – 18 hypermetropic anisometropic amblyopic children (mean age 9.70±2.5 years), 19 strabismic amblyopic children (mean age 10.30±2.6 years) and 19 normal emetropic subjects (mean age 10.10±2.2 years) – were enrolled in this study. After routine ophthalmic examination, PERG and PVEP were recorded in response to checks reversed at the rate of two reversals/second stimulating macular area. Results The difference between hypermetropic anisometropic amblyopia and strabismus amblyopia with respect to P100/P50/N95 wave latencies (P=0.055/0.855/0.132) and P100/P50/N95 amplitudes (P=0.980/0.095/0.045) was not statistically significant. However, there was a significant statistical difference between strabismic amblyopia group and controls for P100/P50/N95 latencies (P=0.000/0.006/0.004). Conclusion Our findings indicated that despite clinical differences between anisometropic amblyopic and strabismic amblyopic patients, no differences were found in the responses of PVEP and PERG. The abnormal components of the PVEP and PERG in amblyopic subjects could reflect a retinal dysfunction in the visual pathway.