An association study of PITX2 polymorphism in a cohort of patients with primary open angle glaucoma and considerations on the genetics of glaucoma

Background: Glaucoma is a major cause of blindness world-wide. There is a need for methods to identify individuals at risk of developing glaucoma, so that early treatment can prevent visual loss. Genetic screening tests offer the prospect of pre-symptomatic diagnosis of at risk individuals. There is now strong evidence that a number of different genes are associated with glaucoma susceptibility. Mutations in the PITX2 homeobox transcription factor gene disrupt normal development of the anterior segment and cause overt structural abnormalities. It is possible that, as yet undetected mutations/polymorphisms in PITX2 may produce subtle and undetected abnormalities in anterior segment structure and function that could predispose to glaucoma. Purpose: The aim of this thesis is two fold: 1. Screening for the presence of single nucleotide polymorphisms in PITX2 gene in a cohort of 100 unrelated primary open angle glaucoma/ ocular hypertension patients, 10 Posterior embryotoxon subjects and 100 age and ethnically matched controls to establish the mutation spectrum. 2. Identification, phenotyping and recruitment for genetic studies of primary open angle glaucoma patients with strong family history of glaucoma. Materials and methods: 1. 100 primary open angle glaucoma patients and 60 age and ethnically matched controls were enrolled in the study. Patients and controls were phenotyped and a blood sample for DNA extraction collected. PITX2 exon-specific primers were used to PCR amplify patient and control DNA. Direct sequencing was used to screen for sequence alterations in the entire coding sequence of PITX2 gene. Concurrently, polymorphic sites reported in the PITX2 gene were identified from the NCBI and Ensemble databases and the frequency of polymorphic sites was investigated. The SHEsis and UNPHASED software packages were used for statistical analysis. 2. Patients diagnosed with glaucoma and strong family history were identified from Glaucoma Unit at Sunderland Eye Infirmary, phenotyped and enrolled in the study. The pedigrees were constructed and interested relatives enrolled in the study and phenotyped. A sample of blood for DNA extraction was collected from all people enrolled in the study. Results: 1. Direct sequencing did not identify any sequence variation in the coding region. 26 PITX2 polymorphic sites were identified from the internet databases, including five in the coding sequence. Sixteen non coding SNPs were confirmed within our study group and SNP frequencies were examined. None of the coding sequence SNPs was identified in our cohort, demonstrating a high degree of sequence conservation. Also, none of the SNPs confirmed in this study group showed an increased frequency in the primary open angle glaucoma group compared with the control group. 2. Thirty-three pedigrees were identified with strong family of glaucoma during the time allowed for patient recruitment. Of these, twenty-two agreed to take part in the study. Thirteen pedigrees are presented in this study, mostly demonstrating autosomal dominant inheritance. Conclusion: There is ample evidence to suggest that genetics play an important role in unravelling the pathogenesis of glaucoma. Identification and recruitment of patients for genetic studies is an essential step and the role of the clinician in this process is paramount. Also, developmental glaucoma genes are an important group of genes to be screened in primary open angle glaucoma/ocular hypertension patients, as they may play a role in the pathogenesis of this preventable blinding disease.EThOS - Electronic Theses Online ServiceRoyal College of Surgeons, Edinburgh : Glaucoma Research and Development at Sunderland (GRAD@S) fund : Pfizer OphthalmicGBUnited Kingdo

Rate of Diabetic Vitrectomy in a Defined Geographical Part of North East England

Purpose: To assess the yearly incidence of vitrectomy for proliferative diabetic retinopathy (PDR) over an 11-year period, in a geographically defined part of North East England. The time period covered the introduction of diabetic retinopathy screening. Methods: All patients undergoing vitrectomy for diabetic retinopathy in the Sunderland and South Tyneside area were recorded from 2000 to 2010. Incidence rates of vitrectomy specifically for the complications of PDR for the observed diabetic population, the estimated diabetic population and the population with known PDR were calculated. Results: There was a gradual and significant decline in the vitrectomy rate from 157 (95% confidence interval, CI, 135–187) to 103 (95% CI 98–109) per 100,000 of the observed diabetic population in 2000 and 2010 respectively. The rate in the estimated diabetic population showed no significant change at 68 (95% CI 48–87) in 2002 and 77 (95% CI 55–103) in 2010. The rate in the PDR population, which comprised 2.4% of the known diabetic population in 2002 and 1.8% in 2010, declined significantly from 7.7% in 2002 to 5.7% in 2010. Conclusion: This study evaluated vitrectomy rates for PDR in an area of North East England. There were apparent declining rates of vitrectomy for PDR following the introduction of diabetic retinopathy screening but these have to be interpreted in the light of several confounding factors

Visual and refractive outcome of one-site phacotrabeculectomy compared with temporal approach phacoemulsification

Background We aimed to compare visual and refractive outcome following phacoemulsification and intraocular lens implant (IOL) and combined one-site phacotrabeculectomy. Method We performed a retrospective study of case records of patients who had temporal incision phacoemulsification with IOL or one-site phacotrabeculectomy, between June 1997 and June 2001. The patients were matched for age group, operating list and IOL type. All patients were operated on under local anesthesia by the same surgeon. Each arm of the study had 90 patients, age range 60 to 75 years. We collected pre- and postoperative visual acuity, pre- and postoperative refraction within six months after surgery, and intended refraction. The intraocular pressure control was not recorded, as it was not the aim of our study. Results In the phacotrabeculectomy group, 76.6% of patients achieved aimed spherical equivalent, 15.5% of patients had against-the-rule (ATR) astigmatism induced by the surgery, and 90% of the patients had best corrected visual acuity (BCVA) more than 6/12. In the temporal incision phacoemulsification group, 81.1% of patients achieved aimed spherical equivalent, 10% of the patients had induced ATR by the surgery and 95.55% of patients achieved BCVA more than 6/12. Conclusion In this study the visual outcome of the phacotrabeculectomy group did not differ significantly from the visual outcome of temporal approach phacoemulsification

Microbiological efficiency tests of the cosmetic tools disinfection procedures

In the last decade, the cosmetic industry has experienced a massive development, but there have also been issues related to their influence on the health of the population. The application methods of the cosmetic products could trigger the appearance of the skin infectious, which raise the need for efficient disinfection processes of the cosmetic products. At the present, the economic operators in the field of cosmetics are guided by medical regulations, but, unfortunately there are not standardized procedure for the application and control of disinfection. The aim of this study was to determine an efficient procedure of disinfection for instruments used in the application of cosmetics such as the beauty blender. There were performed two different disinfection procedures, a chemical disinfection using 70% ethanol and a physical disinfection with UV radiation. The influence of foundation on disinfection procedures was also tested. A standardized S. aureus and a S. haemolyticus bacterium from a human abscess were tested and an antibiotic resistance pattern was also analyzed. The disinfection efficiency tests showed that the ethanol solution was effective after 5 minutes, decreasing the S. haemolyticus bacterial density by 50% in the absence of foundation. In the presence of the foundation, this process was no longer efficient, foundation having a possible protection and nutritional role for bacteria. The radiation with UV at 265 nm showed a complete eradication of both bacterial strains after 1 minute, regardless of foundation presence or not. The antibiotic susceptibility tested showed that both strains had the natural penicillin resistance