Antonio Augusto Velasco e Cruz

Digital image processing measurement of the upper eyelid contour in graves disease and congenital blepharoptosis

OBJECTIVE This study used image processing techniques to quantify the upper eyelid contour of patients with Graves upper eyelid retraction and congenital blepharoptosis. DESIGN The study design was a cross-sectional study. PARTICIPANTS A total of 29 patients with Graves disease, 22 patients with congenital blepharoptosis, and 50 patients with no history of eye disease participated. INTERVENTION The images of the palpebral fissure of all participants were transferred to a personal computer and processed with NIH Image 1.55 software. MAIN OUTCOME MEASURES The following parameters were analyzed: the curvature of the upper eyelid contour, the position of the contour peak relative to the midline, and the ratio between the temporal and nasal upper quadrant areas of the palpebral fissure. RESULTS All upper eyelid contours could be fitted with second-degree polynomial functions. The mean temporal/nasal area ratio was 1.33 mm in patients with Graves disease, 0.92 mm in patients with blepharoptosis, and 1.04 mm in control subjects. The peak of the upper eyelid contour was found to be lateral to the midline in control subjects (1.05 mm) and in patients with Graves disease (2.09 mm). In patients with blepharoptosis, the peak was 0.69 mm medial to the midline. Overall, the distance between the midpupil and the upper eyelid margin was correlated with several factors: the degree of curvature, the position of the peak of the eyelid contour, and the temporal/nasal area ratio. CONCLUSIONS In Graves eyelid retraction, the curvature of the upper eyelid is enhanced, the peak of the contour is displaced laterally, and the temporal upper quadrant area is increased. Conversely, in congenital blepharoptosis, the eyelid is almost flat, the peak of the contour is displaced medially, and the upper quadrant area is diminished. The lateral segment of the upper eyelid is more involved than the nasal segment in both Graves upper eyelid retraction and congenital blepharoptosis.

Spontaneous Eyeblink Activity

Spontaneous blinking is essential for maintaining a healthy ocular surface and clarity of vision. The spontaneous blink rate (SBR) is believed to reflect a complex interaction between peripheral influences mediated by the eye surface and the central dopaminergic activity. The SBR is thus extremely variable and dependent on a variety of psychological and medical conditions. Many different methods have been employed to measure the SBR and the upper eyelid kinematics during a blink movement. Each has its own merits and drawbacks, and the choice of a specific method should be tailored to the specific needs of the investigation. Although the sequence of muscle events that leads to a blink has been fully described, knowledge about the neural control of spontaneous blinking activity is not complete. The tear film is dynamically modified between blinks, and abnormalities of the blink rate have an obvious influence on the ocular surface.

Prevalence of pterygium and cataract in indigenous populations of the Brazilian Amazon rain forest

PurposeTo compare the prevalence of pterygium and cataract in four indigenous populations of the Brazilian Amazonian rain forest (Arawak, Tukano, Maku, and Yanomami) with different ethnic and social behaviour backgrounds.MethodsA cross-sectional pterygium and cataract survey was performed in 624 adult Indians of the Brazilian rain forest belonging to four different ethnic groups. The Indians were classified according to their social behaviour in two groups: Arawak and Tukano (group 1) and Maku and Yanomami (group 2). Slit-lamp biomicroscopy was employed to examine the entire sample. All subjects were classified as 1 or 0 according to the presence or absence pterygium and cataract. Sex and age were also recorded.Resultsχ2-tests revealed that the prevalence of pterygium and cataract differed significantly between groups 1 and 2. For pterygia: 36.6% (97/265) and 5.0% (18/359), respectively (χ2=101.2, P<0.0001), and for cataracts: 24.5% (65/265) and 13.7% (49/359) respectively (χ2=12.09, P=0.0005). Gender was not associated with pterygium (P=0.1326) and cataract (P=0.2263) in both groups. Elderly subjects showed a significantly higher prevalence of cataract (P<0.0001). The prevalence of pterygia did not increase with age (P=0.8079) in both groups.ConclusionIndians of group 1 have higher prevalence of pterygia and cataract than Indians of group 2. Social behaviour, especially the rate of sun exposure, appears to be the main factor for the different rates of pterygium and cataract displayed by these indigenous people of the Brazilian rain forest.

Eyelid abnormalities in lamellar ichthyoses

PURPOSE To describe eyelid abnormalities in lamellar ichthyoses (LI). DESIGN Retrospective observational case series. PARTICIPANTS Eight patients with classic LI and two patients with congenital ichthyosiform erythroderma. METHODS Results of eyelid and corneal examinations of 10 patients with LI were reviewed and analyzed with emphasis on the relationship between eyelid ectropion and corneal damage. RESULTS All patients presented with cicatricial lagophthalmos. Of the eight patients with classic LI, five had ectropion of the four eyelids, one had only lower ectropion, and two had no degree of ectropion. Two patients with congenital ichthyosiform erythroderma had distinct eyelid abnormalities, including madarosis and eyelash retraction. Loss of vision caused by corneal damage was found in three patients with classic LI. Of these three patients, two did not have upper eyelid ectropion. CONCLUSIONS Severe corneal damage can occur in LI even if there is no upper or lower eyelid ectropion.

Neonatal orbital abscess

PURPOSE To describe two cases of orbital abscess in neonates and to review the literature of orbital cellulitis in neonates. DESIGN Two interventional case reports. METHODS Photographs, orbital computed tomography scans, and full pediatric examination were obtained in two cases of orbital abscess in neonates. RESULTS Acute ethmoiditis with orbital abscess formation was found in both infants. In one of them, Staphylococcus aureus was identified as the source of infection. CONCLUSIONS The clinical findings of our cases concur with the literature (eight cases) indicating that orbital abscess caused by Staphylococcal ethmoiditis is the most common form of orbital cellulitis in neonates.

Trachoma and ethnic diversity in the Upper Rio Negro Basin of Amazonas State, Brazil

A trachoma survey was carried out among three culturally different populations of the Upper Rio Negro Basin in the Brazilian rain forest of Amazonas State. The results indicate that trachoma is prevalent in the region, reaching hyperendemic levels (between 50.9% and 56.4%) in all communities studied. However, the severity of the disease appears to be related to the ethnic origin of the tribes, following the rank of social and cultural values that regulate the complex interactions between the Indian groups of the region.

Trachoma among the Yanomami Indians

The Yanomami are one of the last primitive groups of Indians living in Brazil. They have almost no contact with other cultures. The epidemiology of eye disease among Yanomami is virtually unknown. For the first time, a trachoma survey was conducted among Yanomami Indians in the State of Amazonas near the Venezuelan border of the Brazilian rain forest. Ophthalmic examination was carried out on a total of 613 individuals (338 males and 275 females) from eight Yanomami villages along the Maraui River located in the upper Rio Negro Basin. Age was classified into three categories (children, adults, and elderly) and trachoma was classified into five grades: follicular, inflammatory intense, cicatricial, trichiasis, and corneal opacity. Trachoma was endemic in all villages visited. Overall, 30.3% of the subjects had trachoma. Females were significantly more affected (37.4%) than males (23.9%). The inflammatory trachoma rate reached 24.9% in children and the cicatricial form increased with age, reaching 13.9% among adults and 35.21% among the elderly. Trichiasis or corneal opacities were not detected and treatment of the entire population was initiated with 1 g azithromycin. The detection of endemic trachoma among the Yanomami is relevant for the understanding of the epidemiology of this disease in the Brazilian rain forest and underscores the necessity for a program of trachoma control in this region.

Comparison of palpebral fissure obliquity in three different racial groups.

Purpose: To compare the obliquity of the palpebral fissures of three different racial populations. Methods: Prospective observational study. Frontal views of the palpebral fissures of three different groups of subjects (Brazilian whites, Brazilian Japanese, and Brazilian Indians from the Upper Rio Negro Basin of the Amazonas State) were acquired with a photographic camera and transferred to a Macintosh computer. Using the National Institutes of Health Image software (NIH Image), the angle formed by the inner and the outer canthi was measured for all images. Results: The mean fissure angle of the Japanese (9.39 degrees) was not statistically different from the mean angle of the Indians (9.64 degrees). On the other hand, both were significantly greater than the mean angle of the whites (4.60 degrees). Conclusions: Marked fissure obliquity is found more frequently among Asians than among whites.

The geometrical basis of the eyelid contour

Purpose To derive a two-dimensional, frontal-view model of eyelid contour. Methods Observational study. Palpebral fissure images of 110 normal subjects were acquired with a charge-coupled device camera and processed with National Institutes of Health Image software on a Macintosh computer. Monocular frontal-view images of the palpebral fissures were recorded and second-degree polynomial functions were fitted to both upper and lower eyelid contours for two areas: the whole eyelid margin (ciliated and inner canthal portions) and the ciliated portion alone. In addition, frontal and lateral palpebral fissure images were obtained. From the frontal view, the upper and lower ciliated contours were fitted with quadratic functions. From the lateral view, the upper and lower lateral angles, formed by the upper and lower eyelid margins and the axial axis, were measured. Results Exclusion of the inner canthal portion of the eyelid contour led to a much better quadratic fit for the contours. The sine (sin) of the upper lateral angle was strongly correlated with the parameter A of the quadratic function fitted to the upper eyelid (the parameter A determines the curvature of the function around its extremum point). For the lower eyelid, this correlation was not significant. Conclusions The parabolic shape of the upper ciliated contour seen in two-dimensional images can be justified geometrically in a simple way, allowing a precise quantification of its shape. The same was not true for the lower eyelid. The parabolic shape of the upper eyelid can be demonstrated, using the Taylor series, to be a close approximation of the arc of a circle.

Orbital complications of acute rhinosinusitis: a new classification

UNLABELLED Rhinosinusitis is a severe sickness and may have serious complications. Orbital complications happen more often, due to anatomical particularities and are lethal in 5% of patients. They vary from inflammatory signs to proptosis, loss of ocular motility and blindness. AIM We propose a new classification of acute rhinosinusitis complications. METHODS A review of 83 patients with CT scan and clinical reports. Patients were evaluated at HCFMRP-USP between 1995 and 2005 and were diagnosed with complicated rhinosinusitis. RESULTS In sixty-six patients, were identified three types of orbital complications: orbital cellulitis (46.9%), subperiosteal abscess (40.9%) and orbital abscess (12.1%). Seventeen were considered as eyelid infections and excluded from this new classification system. CONCLUSIONS The existing classifications of orbital complications, as Chandlers, do not consider the orbits anatomical characteristics and became obsolete after the development of the CT scan. This study proposes a new, more objective classification to guide the physician in establishing lines of conduct for each case.