Refractive change following pseudophakic vitrectomy: a retrospective review

Background To assess the occurrence and magnitude of refractive change in pseudophakic eyes undergoing 20 gauge pars plana vitrectomy without scleral buckling and to investigate possible aetiological factors. Methods Retrospective case note review of 87 pseudophakic eyes undergoing 20 gauge pars plana vitrectomy for a variety of vitreo-retinal conditions over a three-year period. Anterior chamber depth (ACD) was measured before and after vitrectomy surgery in 32 eyes. Forty-three pseudophakic fellow eyes were used as controls. Results Eighty-seven eyes (84 patients) were included in the study. Mean spherical equivalent refraction prior to vitrectomy was -0.20 dioptres, which changed to a mean of -0.65 dioptres postoperatively (standard deviation of refractive change 0.59, range-2.13 to 0.75 dioptres) (p < 0.001). Sixty-one of the 87(70%) eyes experienced a myopic shift and 45(52%) eyes had a myopic shift of -0.5 dioptres or more. Mean fellow eye refraction was -0.19 dioptres preoperatively and -0.17 dioptres postoperatively (p = 0.14)(n = 37) Mean ACD preoperatively was 3.29 mm and postoperatively 3.27 mm (p = 0.53) (n = 32) and there was no significant change in ACD with tamponade use. Regression analysis revealed no statistically significant association between changes in anterior chamber depth, as well as a wide variety of other pre-, intra and postoperative factors examined, and the refractive change observed. Conclusion Significant refractive changes occur in some pseudophakic patients undergoing 20 g pars plana vitrectomy. The mean change observed was a small myopic shift but the range was large. The aetiology of the refractive change is uncertain

A freely accessible, evidence based, objective system of analysis of posterior capsular opacification ; Evidence for its validity and reliability

BACKGROUND: The aim of this study was to develop a system of computerised analysis of digital images of posterior capsule opacification (PCO) that is evidence based, objective and freely available. The paper will present evidence for the reliability and validity of the developed system. METHODS: The system of PCO analysis was developed considering current published evidence on visual significance of PCO and additional investigative analysis of PCO images. Details of the image processing and analysis steps are discussed and a final system that measures an entropy score weighted toward proximity to central areas is described. In order to assess validity, the systems ability to measure PCO progression is assessed along with the visual significance of its final computerised scores. Reliability of the system is also assessed. RESULTS: The final system runs successfully and is simple to use. Analyses of PCO by the system show an ability to detect early progression of PCO as well as detection of visually significant PCO. Images with no clinical PCO produce very low scores in the analysis. Reliability of the system of analysis is shown to be satisfactory. CONCLUSION: This paper presents a system of PCO analysis that is evidence based, objective and clinically useful. Substantial evidence is provided for its validity and reliability

OSCA: a comprehensive open-access system of analysis of posterior capsular opacification

BACKGROUND: This paper presents and tests a comprehensive computerised system of analysis of digital images of posterior capsule opacification (PCO). It updates and expands significantly on a previous presentation to include facilities for selecting user defined central areas and for registering and subsequent merging of images for artefact removal. Also, the program is compiled and thus eliminates the need for specialised additional software. The system is referred to in this paper as the open-access systematic capsule assessment (OSCA). The system is designed to be evidence based, objective and openly available, improving on current systems of analysis. METHODS: Principal features of the OSCA system of analysis are discussed. Flash artefacts are automatically located in two PCO images and the images merged to produce a composite free from these artefacts. For this to be possible the second image has to be manipulated with a registration technique to bring it into alignment with the first. Further image processing and analysis steps use a location-sensitive entropy based texture analysis of PCO. Validity of measuring PCO progression of the whole new system is assessed along with visual significance of scores. Reliability of the system is assessed. RESULTS: Analysis of PCO by the system shows ability to detect early progression of PCO, as well as detection of more visually significant PCO. Images with no clinical PCO produce very low scores in the analysis. Reliability of the system of analysis is demonstrated. CONCLUSION: This system of PCO analysis is evidence-based, objective and clinically useful. It incorporates flash detection and removal as well as location sensitive texture analysis. It provides features and benefits not previously available to most researchers or clinicians. Substantial evidence is provided for this system's validity and reliability

Immediate sequential vs delayed sequential bilateral cataract surgery: systematic review and meta-analysis

the main aim of this systematic review and meta-analysis was to evaluate the safety and efficacy profile of immediate sequential bilateral cataract surgery (ISBCS) compared with delayed sequential bilateral cataract surgery (DSBCS). MEDLINE Ovid, EMBASE, and CENTRAL databases were searched. Outcome measures were postoperative visual acuity, postoperative spherical equivalent (refractive outcome), endophthalmitis, corneal edema, pseudophakic macular edema, and posterior capsule rupture (PCR). 13 articles met criteria for final inclusion. A total of 11 068 622 participants (18 802 043 eyes) were included. No statistically significant differences between ISBCS and DSBCS were identified in all the postoperative outcomes evaluated. However, a higher risk for PCR was identified in the ISBCS group from the pooled analysis of nonrandomized studies (risk ratio, 1.34, 95% CI, 1.08-1.67, P =.0081). In our view, the ISBCS approach has an acceptable safety-efficacy profile, comparable with DSBCS. Future investigations are warranted, with a focus on the analysis of risk factors for surgical complications, patient-reported outcome-measures, and cost effectiveness

Anel de tensão capsular isolado e associado à lente intraocular acrílica dobrável na opacidade de cápsula posterior após facoemulsificação em cães

The purpose of the study was to determine whether capsular tension ring (CTR) alone or associated with the implantation of an intraocular lens (IOL) could decrease the occurrence of posterior capsular opacification (PCO) after phacoemulsification cataract surgery in dogs. Twenty eyes of client-owned dogs with immature or mature cataracts were included in this study. In all the animals, any ophthalmic or systemic concurrent disease was excluded. The eyes were randomly selected to receive CTR alone or in association with the IOL. Laser flaremetry and clinical evaluations were conducted on post-operative days 2, 7, 14, 21 and 28. Fundus photographs were taken at the 28th and then every 30 days, up to 180 days. The results showed more inflammatory response on eyes with IOLs, although among the parameters evaluated, solely the synechiae showed significant statistical differences. Nevertheless, in both techniques almost no PCOs occurred at the end of the evaluations. These results suggest that the CTRs can be useful in the prevention of the post-operative capsular opacities, with minor complicationsO objetivo do estudo foi determinar se o anel de tensão capsular (ATC), isoladamente ou associado à implantação de uma lente intraocular, poderia diminuir a ocorrência de opacificação da cápsula posterior (OCP) após a cirurgia de catarata por facoemulsificação em cães. Para tanto, cães portadores de catarata imatura ou madura foram avaliados, perfazendo um total de vinte olhos. Em todos os animais, foram excluídas quaisquer doenças oftálmicas e sistêmicas concomitantes. Os olhos foram selecionados aleatoriamente para receber o anel (ATC) isolado ou em associação com a lente. Flaremetria a laser e avaliações clínicas foram realizadas aos 2, 7, 14, 21, e 28 dias de pós-operatório. Fotografias foram tomadas aos 28 e a seguir a cada 30 dias, até os 180 dias. Os resultados mostraram inflamação mais importante nos olhos com IOL, embora, entre os parâmetros avaliados, apenas nas sinéquias houve diferença estatisticamente significativa. No entanto, em ambas as técnicas, quase nenhuma OCP ocorreu até o momento final das avaliações. Tais resultados sugerem que os anéis de tensão capsular (ATC) podem ser úteis na prevenção da opacidade capsular pós-operatória, sem complicações decorrentesFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ)Universidade Estadual Paulista (UNESP) - Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal (FCVAJ),14884-900, Jaboticabal, SP, Brasil.Universidade Estadual Paulista (UNESP) - Faculdade de Medicina Veterinária de Araçatuba (FMVA), UNESP, Araçatuba, SP, Brasil.Universidade Estadual Paulista (UNESP) - Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal (FCVAJ),14884-900, Jaboticabal, SP, Brasil.Universidade Estadual Paulista (UNESP) - Faculdade de Medicina Veterinária de Araçatuba (FMVA), UNESP, Araçatuba, SP, Brasil.FAPESP: 2009/51773-4CNPq: 300833/2010-

Five-year incidence of Nd:YAG laser capsulotomy and association with in vitro proliferation of lens epithelial cells from individual specimens: a case control study

BACKGROUND: The aims of this study were to determine the 5-year incidence of posterior capsule opacification (PCO) requiring Nd:YAG laser capsulotomy in a representative mixed cohort of cataract patients, to determine risk factors for PCO and to investigate possible association with growth of human lens epithelial cells (HLEC) in vitro. METHODS: Pieces of the anterior lens capsule and adhering HLEC were obtained at cataract surgery and cultured individually. After one and two weeks respectively, cultured cells were stained with carboxy-fluorescein diacetate succinimidyl ester (CFDA SE), after which image processing software was used to determine the area of the confluent cell layer. The 5-year incidence of Nd:YAG laser capsulotomy in this cohort was determined through medical records and by mail or telephone interviews. For statistic analyses Mann–Whitney U-test, Fisher’s exact test and binary logistic regression were used. RESULTS: Data on treatment/no treatment for PCO was obtained from 270 patients with a median follow-up time of 57 months (range 50–64 months). The three-year cumulative incidence of PCO was 5.2% and the cumulative 5-year incidence was 11.9%. Patients who had undergone Nd:YAG laser capsulotomy were significantly younger (median 71 years) than patients who did not receive treatment for PCO (median 75 years, p = 0.022). Logistic regression demonstrated that apart from younger age, follow-up time and type of intraocular lens (IOL) were associated with risk of PCO, with hydrophilic 1-piece IOLs conferring a higher risk than hydrophobic acrylic 1-piece or 3-piece IOLs (adjusted OR = 9.4, 95% CI 2.5-35.7, p = 0.001). Of the 270 patients from whom information could be retrieved regarding PCO treatment, in vitro cell culture could be established and quantified from 185 patients. No significant difference in cell growth in vitro was shown between patients subsequently requiring/not requiring Nd:YAG laser capsulotomy. CONCLUSIONS: The cumulative 5-year incidence of 11.9% is comparable or slightly higher than reported in other recent studies. The type of IOL was the most important risk factor for PCO in this study, whereas intrinsic proliferative capacity of the individual’s lens epithelial cells seems to be less important for subsequent PCO development

Twenty-four-hour intraocular pressure and ocular perfusion pressure characteristics in newly diagnosed patients with normal tension glaucoma

PurposeTo determine the mean 24-h intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) characteristics of newly diagnosed, previously untreated, Caucasian, normal tension glaucoma (NTG) patients and to identify relationships between these features and visual field (VF) loss at diagnosis.MethodsConsecutive newly diagnosed NTG patients underwent 24-h habitual IOP and blood pressure (BP) monitoring. Parameters from pooled measurements obtained in the sitting (0800-2200 hours) and supine (1200-0600 hours) positions were compared and associations were sought with VF mean deviation (MD) and pattern standard deviation (PSD).ResultsSixty-two Caucasian NTG patients (24 men and 38 women) successfully completed circadian IOP and BP monitoring. In habitual position, 8 subjects (12.9%) exhibited a diurnal acrophase, 42 subjects (67.7%) demonstrated a nocturnal acrophase, one subject (1.6%) showed a flat rhythm and 11 patients (17.7%) revealed a biphasic/polyphasic rhythm. Nighttime MOPP values (supine position) were significantly greater than diurnal values (sitting position); (P<0.001). No association could be demonstrated between glaucomatous damage, as indicated by VF parameters, and either mean habitual 24-h IOP (P=0.20 and P=0.12 for MD and PSD, respectively), or habitual 24-h MOPP (P=0.96 and 0.29, for MD and PSD, respectively).ConclusionsIn this cohort of Caucasian NTG patients, most patients exhibited a nocturnal IOP acrophase when evaluated in a habitual position. No association was found between 24-h IOP or MOPP and VF damage.Eye advance online publication, 29 July 2016; doi:10.1038/eye.2016.168