Impact of changing oxygenation policies on retinopathy of prematurity in a neonatal unit in Argentina.

AIMS: To assess the impact of different oxygenation policies on the rate and severity of retinopathy of prematurity (ROP). METHODS: Between January 2003 and December 2006, infants of 1500 g birthweight (BW) or less and/or 32 weeks gestational age (GA) or less, and larger, more mature infants with risk factors for ROP were examined through three different time periods: period 1: high target oxygen saturation levels (88-96%) and treatment at threshold ROP; period 2: low target oxygen saturation levels (83-93%) and treatment at threshold ROP; period 3: low target oxygen saturation and treatment at type 1 ROP. RESULTS: Type 1 ROP was detected more frequently in babies of 32 weeks GA or less (50/365, 13.7%) than in more mature babies (15/1167, 1.3%; p<0.001). The rate of type 1 ROP in period 1 was 6.9%; period 2, 3.6% and period 3, 1.8%. Rates of stage 3 ROP declined over time in both BW/GA groups (from 9.0% to 4.1% to 2.0%) as did rates of plus disease (from 7.5% to 3.6% to 1.8%). Mean BW and GA declined from period 1 to period 3, and death rates remained unchanged. 74.4% of babies received all the examinations required; 48.1% of treatments were undertaken after discharge from the neonatal unit. CONCLUSIONS: Lower target oxygen saturation was associated with a lower rate of severe ROP without increasing mortality, and changed the characteristics of affected babies. Screening criteria need to remain wide enough to identify all babies at risk of ROP needing treatment

Genetic Background and Climatic Droplet Keratopathy Incidence in a Mapuche Population From Argentina

Purpose To determine whether the incidence of and susceptibility to climatic droplet keratopathy (CDK), an acquired, often bilateral degenerative corneal disease, is influenced by the genetic background of the individuals who exhibit the disorder. Methods To determine whether the disease expression was influenced by the genetic ancestry of CDK cases in native Mapuche of the northwest area of Patagonia in Argentina, we examined mitochondrial DNA and Y-chromosome variation in 53 unrelated individuals. Twenty-nine of them were part of the CDK (patient) population, while 24 were part of the control group. The analysis revealed the maternal and paternal lineages that were present in the two study groups. Results This analysis demonstrated that nearly all persons had a Native American mtDNA background, whereas 50% of the CDK group and 37% of the control group had Native American paternal ancestry, respectively. There was no significant difference in the frequencies of mtDNA haplogroups between the CDK patient and control groups. Although the Y-chromosome data revealed differences in specific haplogroup frequencies between these two groups, there was no statistically significant relationship between individual paternal genetic backgrounds and the incidence or stage of disease. Conclusions These results indicate a lack of correlation between genetic ancestry as represented by haploid genetic systems and the incidence of CDK in Mapuche populations. In addition, the mtDNA appears to play less of a role in CDK expression than for other complex diseases linked to bioenergetic processes. However, further analysis of the mtDNA genome sequence and other genes involved in corneal function may reveal the more precise role that mitochondria play in the expression of CDK

Myopia as a risk factor for subsequent retinal tears in the course of a symptomatic posterior vitreous detachment

Abstract Background Retinal tears complicating the course of a posterior vitreous detachment (PVD) may be unique or multiple, and when multiple they may occur simultaneously or subsequently at different moments in the evolution of a PVD. The purpose of our study was to analyze the prevalence of subsequent retinal tears (SRT) in patients with a PVD, and to identify possible risk factors for SRT. Methods One hundred and seventy six eyes in 165 consecutive patients that presented one or more retinal tears in the evolution of a symptomatic PVD, with a minimum follow-up of 12 months, were retrospectively evaluated. The primary outcome measure was to characterize the clinical features associated with SRT formation against those eyes with non-subsequent retinal tear (NSRT-retinal tear/s diagnosed at initial examination) formation. For that purpose, this cohort of patients was divided into two different groups: group 1 included eyes presenting one or multiple retinal tears only at initial examination (NSRT), and group 2 eyes that progressed to a further retinal tear/s (SRT) during follow-up. Results Group 1 comprised 154 eyes from 145 patients, 48.7% males and 51.3% females with a mean age of 56.9 ± 14.0 years (range = 15-89); 17.2% of patients had a previous retinal tear or retinal detachment in the fellow eye; mean number of retinal tears per eye 1.42 ± 0.8 (range = 1-5); 20.8% presented bilateral retinal tears; 59.1% were myopic eyes (p < 0.05). Group 2 comprised 22 eyes from 20 patients; mean age was 53.3 ± 13.6 years (range = 30-69); 63.6% were male (p = 0.13), and 7 patients (31.8%) had a history of SRT or retinal detachment in the fellow eye (p = 0.13). The mean number of retinal tears per eye was 1.36 ± 0.5 (range = 1-2); bilateral retinal tears were noted in 18.2% of eyes; 86.4% were myopic eyes (p = 0.01); 81.8% occurred within a 120 days-period following diagnosis of the first retinal tear. Conclusions Multiple retinal tears may be diagnosed in the evolution of a PVD. SRT are most frequently observed in myopic patients, and are usually symptomatic. Follow-up must extend for at least 4 months after the initial symptoms

ROP screening tool assessment and validation in a third-level hospital in argentina: A pilot study

Purpose: To evaluate whether a mathematical tool that predicts severe retinopathy of prematurity (ROP) using clinical parameters at 6 weeks of life (ROPScore calculator smartphone application; PABEX Corporation) can be useful to predict severe ROP in a population of premature infants in Argentina. Methods: In this retrospective study, data from the clinical records of all premature infants examined between 2012 and 2018 in the ophthalmology department of a public third-level hospital in Córdoba, Argentina, were obtained. ROPScore screening was applied using a Microsoft Excel spreadsheet (Microsoft Corporation). The sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values of the algorithm were analyzed. Results: Between 2012 and 2018, a total of 2, 894 pre-term infants were examined and 411 met the inclusion criteria, of whom 34% (n = 139) presented some form of ROP and 6% (n = 25) developed severe forms that required treatment. The sensitivity of the algorithm for any ROP and severe ROP was 100%. The PPV and NPV were 35.64% and 100%, respectively, for any ROP and 9.88% and 100% for severe ROP. Conclusions: One-time only calculation of the ROPScore algorithm could identify severe cases after validation, reducing the number of screened infants by 38% in infants with a birth weight of 1, 500 g or less or a gestational age of 32 weeks or younger.Fil: Esposito, Evangelina. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Department of Ophthalmology; ArgentinaFil: Knoll, Erna. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Department of Ophthalmology; ArgentinaFil: Knoll, Erna. Hospital Materno Neonatal Ramón Carrillo. The Department of Ophthalmology; ArgentinaFil: Guantay, Carla. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Department of Ophthalmology; ArgentinaFil: Gonzalez-Castellanos, Alejandro. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Department of Ophthalmology; ArgentinaFil: Miranda, Alejandra. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Department of Ophthalmology; ArgentinaFil: Barros Centeno, Maria F. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Department of Ophthalmology; ArgentinaFil: Flores, Martha Gomez. Hospital Materno Neonatal Ramón Carrillo. The Department of Ophthalmology; ArgentinaFil: Urrets-Zavalia, Julio A. Universidad Católica de Córdoba. Clínica Universitaria Reina Fabiola. Department of Ophthalmology; Argentin

Altered expression of matrix metalloproteinases and their tissue inhibitors as possible contributors to corneal droplet formation in climatic droplet keratopathy

Climatic droplet keratopathy (CDK) is an acquired corneal disease characterized by progressive scarring of the cornea. In several corneal diseases, matrix metalloproteinases (MMPs) are upregulated during the degradation of epithelial and stromal tissues. We investigated the levels, degree of activation and molecular forms of MMP-2, MMP-9, MMP-8 and MMP-13 and their tissue inhibitors TIMP-1 and TIMP-2 in tear fluid of patients with CDK. Seventeen CDK patients and 10 controls living in Argentine Patagonia received a complete eye examination, and MMPs and TIMP-1/2 were determined by immunofluorometric assay (IFMA), gelatin zymography and quantitative Western immunoblot analysis in tear samples. The MMPs were detected mostly in their latent forms. The levels of MMP-9 and MMP-2 were found to be significantly elevated in CDK patients, whereas latent and active MMP-8 levels were significantly enhanced in controls. There was no significant difference in the level of MMP-13. TIMPs were found as part of complexes, and the TIMP-1 levels were significantly lower in patients than controls. Elevated MMP-2 and MMP-9 levels have been implicated in the failure of corneal re-epithelialization, and enhanced MMP-2 and MMP-9 levels in CDK patients suggest that these MMPs may play a role in corneal scarring in CDK. Elevated levels of MMP-8 suggest a defensive role for this MMP in inflammatory reactions associated with recurring corneal traumas. Decreased expression of TIMP-1 in CDK patients suggest deficient antiproteolytic shield likely to render the corneas of CDK patients vulnerable to enhanced MMPs. Overall, these data suggest a mechanistic link between MMPs and TIMP-1 level in cornea and tears with corneal scarring in CDK