Prevalence of Keratoconus Among High School Students in Southern Brazil: A Community-Based Study.

OBJECTIVES: This study aimed to determine the prevalence of keratoconus (KC) in teenagers who live in Southern Brazil and detect any possible associated factors. METHODS: This prospective, observational, mobile clinic-based cross-sectional study collected data from students between 14 and 21 years from seven high schools who were living in the Greater Porto Alegre metropolitan region in Southern Brazil. Subjects were clinically surveyed and examined using a slitlamp and rotational Scheimpflug corneal tomography system. All data were collected at the mobile clinic during a single visit. RESULTS: Eight-hundred twenty-six students were evaluated (357 boys and 469 girls) with an average age of 16.7±1.2 years. Six subjects were classified as having KC (four girls), yielding a prevalence rate of 0.73% (95% confidence interval, 0.27%-1.57%) or one per 137 teenagers in Southern Brazil. Logistic regression showed an association between KC and positive history of eye rubbing ( P =0.02). CONCLUSION: According to our investigation, this is the first KC prevalence study in South America using the latest technologies (Scheimpflug imaging). The prevalence of KC among teenagers in Southern Brazil is within the highest reported worldwide. We also found an association between KC and history of eye rubbing. Keratoconus is not an uncommon disorder in our population, and the efforts to identify the disease and reduce its risk factors in an earlier phase are justified.

Polyhexamethylene Biguanide Multipurpose Solutions on Bacterial Disinfection: A Comparison Study of Effectiveness in a Developing Country.

OBJECTIVE: The aim of this study was to compare the antimicrobial action of commercially available multipurpose disinfection solutions (MPDS) with and without hydrogel contact lens for disinfection of isolated corneal bacteria. METHODS: Five commercially available MPDS in Brazil (BioSoak, Clear Lens, OPTI-FREE, Renu, and UltraSept) were tested against Pseudomonas aeruginosa , Staphylococcus aureus , and Staphylococcus epidermidis . All five MPDS were also tested on P. aeruginosa and S. aureus biofilm in a Hioxifilcon A lens. RESULTS: OPTI-FREE and Renu were effective against all bacterial isolates without contact lenses. BioSoak was effective in inhibiting P. aeruginosa and S. epidermidis but not against S. aureus . UltraSept was effective for inhibiting S. epidermidis and S. aureus but not against P. aeruginosa . Clear Lens was effective in inhibiting only S. epidermidis but not P. aeruginosa and S. aureus . In contact lens bacterial biofilms, OPTI-FREE was the only MPDS to demonstrate significantly higher disinfection. CONCLUSIONS: MPDS containing dual biocides polyquaternium-1 and myristamidopropyl dimethylamine possess the highest disinfection action against multiple ocular pathogens with and without contact lenses when compared with other MPDS. Current single-action polyhexamethylene biguanide solutions are not entirely effective and should not be recommended.

Descemet's membrane folds in ochronosis: a case report.

BACKGROUND: We present this report of a new ophthalmic finding in a patient with ochronosis. CASE PRESENTATION: An 85-year-old Caucasian male patient with bilateral dark temporal and nasal pigmentation of conjunctiva and sclera was referred to our hospital owing to low visual acuity. On biomicroscopic examination, bilateral horizontal Descemet's membrane folds were observed. Corneal tomography revealed irregular and asymmetric "against-the-rule" astigmatism in both eyes. Anterior segment optical coherence tomography demonstrated numerous central Descemet's without edema or other corneal structure alterations. CONCLUSION: This is the first report of Descemet's membrane folds in ochronosis. These corneal findings suggest that the accumulation of homogentisic acid in the sclera leads to thickening and stiffness of this region. These alterations could remarkably decrease visual acuity owing to topographic corneal curvature alterations, especially in elderly patients.

The role of environment in the pathogenesis of keratoconus.

PURPOSE OF REVIEW: This study was conducted to demonstrate the importance of the environment in keratoconus (KC) genesis. RECENT FINDINGS: Genetic-related connective tissue disorders demonstrate the inconsistency of theories regarding KC pathogenesis since no corneal steepening was observed in the majority of these patients. Despite recent advances and decades of research into the genetics of KC, the identification of disease-causing KC genes has been frustrating. Variants found based on genome-wide and next-generation sequencing only seem to account for a small number of cases or play a limited role in KC pathogenesis. SUMMARY: The literature shows that mechanical manipulation may be the common underlying factor or the indispensable act precipitating the cascade of events leading to permanent corneal deformation. Hence, ophthalmologists have the opportunity to increase patient awareness about eye manipulation repercussions and treatment for ocular surface disorders. VIDEO ABSTRACT: http://links.lww.com/COOP/A42.

A new case of osteogenesis imperfecta type VIII and retinal detachment.

Osteogenesis imperfecta (OI) type VIII (OMIM: 610915) is a rare autosomal recessive disorder characterized by white sclerae, severe growth deficiency, and bone fragility. This condition results from pathogenic variants of P3H1, a gene that codes for P3H1, an important protein involved in the prolyl-3-hydroxylation complex required for collagen type I folding. Here, we described a woman with OI type VIII due to a homozygous mutation of c.1914+1G>C (NM_001243246.1) in P3H1 and retinal detachment. We compared our case to five severe OI and retinal detachment cases reported in the literature. The only case previously reported with a molecular diagnosis had a similar mutation in P3H1 c.1914+1G>A and a giant retinal detachment. We suggest that individuals with OI type VIII should be submitted to careful fundoscopic examination.