Sorpresa refractiva tras la cirugía de catarata en paciente con lente fáquica / Refractive surprise after cataract surgery in a patient with a phakic lens implant

El implante de una lente intraocular fáquica puede resultar una opción lógica para los pacientes sumamente miopes que buscan liberarse de las gafas y de los lentes de contacto. Esta es una alternativa para corregir los grados de miopía extremos, y se diseñaron para permanecer dentro del ojo por muchos años. Con el cursar del tiempo, fisiológicamente comienza a opacarse el cristalino. Ante la necesidad de removerlo y de calcular una lente de potencia adecuada para el saco capsular y así conseguir la emetropía, surge un nuevo reto. El cálculo inexacto de la potencia dióptrica de la lente a implantar en la intervención quirúrgica es un problema y con él aparece la sorpresa refractiva; de ahí el objetivo de presentar con este caso la causa más frecuente de sorpresa refractiva tras la cirugía de catarata en un paciente miope con lente fáquica implantada. Se destaca la importancia de la longitud axil, sobre todo si esta se modifica después del implante de la lente fáquica para el correcto cálculo de la lente a implantar, así como el método ideal para su obtención: la interferometría óptica, sin olvidar la historia clínica previa al implante de la lente fáquica(AU)

Phakic intraocular lens implantation may be a logical option for extremely myopic patients who wish to get rid of their eyeglasses and contact lenses. This alternative was developed to correct extremely high degrees of myopia and remain inside the eye for many years. However, with the passing of time and due to physiological processes, the crystalline lens tends to become opaque. A new challenge is posed by the need to remove it and select a lens with an optical power appropriate to the capsular sac, thus achieving emmetropia. Inaccurate calculation of the dioptric power of the lens to be implanted in the surgical intervention is a problem leading to refractive surprise. Hence the interest in presenting a case illustrating the most common cause of refractive surprise after cataract surgery in a myopic patient with a phakic lens implant. The importance of axial length is highlighted, particularly whether it is modified after phakic lens implantation for accurate calculation of the lens to be implanted and the ideal method to obtain it: optical interferometry, without disregarding the medical record data preceding the phakic lens implantation(AU)

Influência da orientação das ranhuras superficiais na flexão rotativa de fios de níquel-titânio / Influence of surface grooves orientation on the cyclic fatigue resistance of NiTi wire

Objetivo: Testar a hipótese nula de que a orientação das ranhuras superficiais não influencia na vida em fadiga de fios de níquel-titânio (NiTi). Material e Métodos: Segmentos de fio de NiTi (Moreli, Sorocaba/SP, Brasil) medindo 30mm e com diâmetro de 0,40mm foram utilizados. As ranhuras foram criadas em relação à direção longitudinal, em 45 e 90 graus. O fio foi analisado sob microscopia eletrônica de varredura e a rugosidade, quantificada por interferometria. O número de ciclos para a fratura (NCF) foi determinado pelo teste de flexão rotativa. Resultados: A rugosidade entre os grupos de 45 e 90 graus apresentou diferenças estatisticamente significativas (p<0,05). O grupo sem ranhuras apresentou o maior NCF (p<0,05). O grupo com ranhuras em 45 graus apresentou maior NCF, em comparação ao grupo com 90 graus (p<0,05). Conclusões: A direção das ranhuras possui influência na vida em fadiga dos fios de NiTi. O NCF aumenta com a redução do ângulo das ranhuras em relação ao longo eixo do fio, independentemente da profundidade das ranhuras (AU).

Objective: this study tested the null hypothesis that the surface grooves orientation does not influence the NiTi wire cyclic fatigue. Material and methods: Segments of NiTi wire (Moreli, Sorocaba, Brazil) measuring 30mm and with a 0.40mm of diameter were used. Grooves were created in the longitudinal direction, at 45 degrees and 90 degrees. The wire was analyzed with SEM and the roughness was quantified by interferometry. The number of cycles until fracture (NCF) was determined by the cyclic fatigue test. Results: the roughness between 45 and 90 degrees groups presented differences (p<0.05). The group without grooves presented the highest NCF (p<0.05). The group with 45 degrees grooves presented better NCF in comparison to the group with 90 degrees (p<0.05). Conclusions: the direction of the grooves influences the fatigue life. The NCF increases with the reduction of the angle of the grooves in relation to the long axis, regardless of the depth of the grooves (AU).

Development of a BLI assay-based method for detecting LptA/LptC interaction / 生物工程学报

In Gram-negative bacteria, lipopolysaccharide transport (Lpt) protein LptA and LptC form a complex to transport LPS from the inner membrane (IM) to the outer membrane (OM). Blocking the interaction between LptA and LptC will lead to the defect of OM and cell death. Therefore, Lpt protein interaction could be used as a target to screen new drugs for killing Gram-negative bacteria. Here we used biolayer interferometry (BLI) assay to detect the interaction between LptA and LptC, with the aim to develop a method for screening the LptA/LptC interaction blockers in vitro. Firstly, LptC and LptA with or without signal peptide (LptAfull or LptAno signal) were expressed in E. coli BL21(DE3). The purified proteins were then labeled with biotin and the super streptavidin (SSA) biosensor was blocked with diluent. The biotin labeled protein sample was mixed with the sensor, and then the binding of the protein with a series of diluted non biotinylated protein was detected. At the same time, non-biotinylated protein was used as a control. The binding of biotinylated protein to a small molecule IMB-881 and the blocking of interaction were also detected by the same method. In the blank control, the biosensor without biotinylated protein was used to detect the serially diluted samples. The signal response constant was calculated by using steady analysis. The results showed that biotinylated LptC had a good binding activity with LptAfull and LptAno signal with KD value 2.9e⁻⁷±7.9e⁻⁸ and 6.0e⁻⁷±2.8e⁻⁸, respectively; biotinylated LptAno signal had a good binding activity with LptC, with a KD value of 9.6e⁻⁷±7.2e⁻⁸. All binding curves showed obvious fast binding and fast dissociation morphology. The small molecule compound IMB-881 can bind to LptA to block the interaction between LptA and LptC, but has no binding activity with LptC. In summary, we developed a method for detecting the LptA/LptC interaction based on the BLI technology, and confirmed that this method can be used to evaluate the blocking activity of small molecule blockers, providing a new approach for the screening of LptA/LptC interaction blockers.

Analise dos dados biométricos gerados por interferometria comparada com Scheimpflug / Analysis of biometric data generated by interferometry compared with Scheimpflug

Resumo Objetivo: Observar o grau de concordância das variáveis analisadas entre os dispositivos IOL Master 500 e Pentacam AXL e descrever as medias Métodos: Foram analisados 35 prontuários, totalizando 61 olhos. Todos os pacientes se submeteram à avaliação biométrica nos dois dispositivos, no período de agosto de 2018 a agosto de 2019. Os dados coletados foram: idade, sexo, profundidade da câmara anterior, comprimento axial, K1, K2, poder dióptrico da LIO e alvo refracional. Resultados: As médias das variáveis analisadas entre os dispositivos de biométricos óptica em questão tiveram diferença estatisticamente significante (p<0,05). A regressão linear não apontou influência de nenhuma das variáveis da câmara anterior na diferença de valores do poder dióptrico da LIO e do alvo refracional entre os dispositivos. Conclusão: Não houve concordância estatística entre os dispositivos para as variáveis analisadas. Portanto, deve se evitar intercambiar o uso do Pentacam AXL com o IOL Master 500.

Abstract Objective: Observe the agreement between IOL Master 500 and Pentacam AXL and describe the averages. Methods: We analyzed 35 medical records, totaling 61 eyes. All patients underwent biometric evaluation on both devices from August 2018 to August 2019. The data collected were: age, gender, anterior chamber depth, axial length, K1, K2, biometrics and IOL target. Results: The averages of the variables analyzed between the optical biometric devices in question had a statistically significant difference (p <0.05). Linear regression showed no influence of any anterior chamber variables on the difference in biometrics and target values between the devices. Conclusion: There was no statistical agreement between the devices for the analyzed variables. Therefore, the interchange of Pentacam AXL with IOL Master 500 should be avoided.

Cirugía de catarata bilateral en paciente con lente intraocular fáquica / Bilateral cataract surgery in a patient with a phakic intraocular lens

RESUMEN La cirugía refractiva corneal es una buena opción para corregir el defecto refractivo de los pacientes y lograr una buena visión sin el uso de espejuelos o lentes de contacto; pero cuando no es posible, las lentes fáquicas constituyen una elección viable, especialmente en pacientes jóvenes que mantienen la acomodación. Se presenta el caso de una paciente con antecedentes de implante de lente fáquica desde hacía 13 años, quien acudió al Instituto Cubano de Oftalmología "Ramón Pando Ferrer" por disminución de la visión en ambos ojos. Se destaca la importancia en la obtención de las medidas biométricas, especialmente la longitud axil, si esta se modifica después del implante de la lente fáquica para el correcto cálculo de la lente a implantar y la obtención del buen resultado refractivo. La interferometría óptica es el mejor modo de obtener estas medidas y la longitud axil no parece modificarse con la presencia de una lente fáquica(AU)

ABSTRACT Corneal refractive surgery is a good option to correct the refractive defect and achieve good vision without the use of eyeglasses or contact lenses. When it is not possible, phakic lenses are a viable choice, particularly in young patients who maintain accommodation. A case is presented of a female patient with an antecedent of phakic lens implantation 13 years before who presents at Ramón Pando Ferrer Cuban Institute of Ophthalmology with vision reduction in both eyes. Mention should be made of the importance of obtaining biometric measurements, especially of the axial length, if it changes after phakic lens implantation, for accurate calculation of the lens to be implanted and the achievement of a good refractive result. Optical interferometry is the best way to obtain those measurements, and axial length does not seem to change with the presence of a phakic lens(AU)

Comparing the postoperative refractive predictability of Pentacam HR and IOLMaster 500 after a multifocal intraocular lens implantation / Comparação da previsibilidade refrativa pós-operatória do Pentacam HR e IOLMaster 500 após implante de lentes intraoculares multifocais

ABSTRACT Purpose: To compare the postoperative refractive predictability of IOLMaster 500 and Pentacam HR on the basis of keratometry and anterior chamber depth values in eyes with an indication for multifocal intraocular lens (IOL) implantation. Methods: This was a retrospective study conducted on 118 eyes treated with phacoemulsification and multifocal intraocular lens implantation. Only the eyes that achieved emmetropia in the dynamic refraction performed on postoperative day 30 were included. Haigis' formula was used in each case to calculate the intraocular lens power, and the intraocular lens with the target refraction closest to emmetropia was implanted. Four lens calculation scenarios were tested by combining keratometry and anterior chamber depth measurements obtained using the two devices. Results: IOLMaster 500 and Pentacam HR differed with regard to mean keratometry (D 0.07 ± 0.03 D; p=0.0065) and anterior chamber depth (D 0.08 ± 0.01 mm; p<0.001). In the analysis of covariance, the following differences were obtained using the Haigis' formula when confronted with the biometric values obtained by inserting keratometry and anterior chamber depth values, respectively: Penta/IOL x IOL/Penta (0.13 ± 0.03; p<0.0001); Penta/Penta × IOL/Penta (0.13 ± 0.03; p<0.0001); Penta/IOL × IOL/IOL (0.11 ± 0.03; p=0.001); Penta/Penta × IOL/IOL (0.11 ± 0.03; p=0.002); IOL/IOL × IOL/Penta (0.02 ± 0.03; p=0.865); and Penta/IOL × Penta/Penta (0.002 ± 0.03; p=0.99). The difference was smaller when measuring the anterior chamber depth using the IOLMaster 500, regardless of which device was used to measure keratometry. Conclusions: Pentacam HR significantly differed from IOLMaster 500 when calculating keratometry. As regards the anterior chamber depth, the two devices were equally accurate.

RESUMO Objetivo: Comparar a previsibilidade refrativa pós-operatória do IOLMaster 500 e Pentacam HR com base nos valores de ceratometria e profundidade de câmara anterior nos olhos com indicação de implante de lentes intraoculares multifocais. Métodos: Estudo retrospectivo realizado em 118 olhos tratados com facoemulsificação e implante de lentes intraoculares multifocal. Apenas os olhos que atingiram a emetropia na refração dinâmica no 30º dia pós-operatório foram incluídos. A fórmula de Haigis foi usada em cada caso para calcular o poder das lentes intraoculares, e a lente intraocular com a refração alvo mais próxima da emetropia foi implantada. Cenários de cálculo de quatro lentes foram testados pela combinação de medidas de ceratometria e profundidade de câmara anterior obtidas usando os dois dispositivos. Resultados: IOLMaster 500 e Pentacam HR diferiram quanto à média de ceratometria (D 0,07 ± 0,03 D; p=0,0065) e profundidade de câmara anterior (D 0,08 ± 0,01 mm; p<0,001). Na análise da covariância, as seguintes diferenças foram obtidas usando a fórmula de Haigis quando confrontadas com os valores biométricos obtidos pela inserção dos valores de ceratometria e profundidade de câmara anterior, respectivamente: Penta/IOL x IOL/Penta (0,13 ± 0,03; p<0,0001); Penta/Penta x IOL/Penta (0,13 ± 0,03; p<0,0001); Penta/IOL x IOL/IOL (0,11 ± 0,03; p=0,001); Penta/Penta x IOL/IOL (0,11 ± 0,03; p=0,002); IOL/IOL x IOL/Penta (0,02 ± 0,03; p=0,865); Penta/IOL x Penta/Penta (0,002 ± 0,03; p=0,99). A diferença foi menor ao medir a profundidade da câmara anterior usando o IOLMaster 500, independentemente de qual dispositivo foi usado para medir a ceratometria. Conclusões: O Pentacam HR diferiu significativamente do IOLMaster 500 no cálculo de ceratometria. Quanto à profundidade da câmara anterior, os dois dispositivos foram igualmente precisos.

Long-term Longitudinal Changes in Choroidal Thickness with Intraocular Pressure Reduction after Glaucoma Surgery

PURPOSE: We investigated the long-term longitudinal changes in axial length (AL), mean ocular perfusion pressure (MOPP), and choroidal thickness (CT) according to the reduction of intraocular pressure (IOP) after glaucoma surgery. The potential variables associated with CT changes were also evaluated.METHODS: This was a prospective study for 1 year after glaucoma surgery, which included 71 eyes of 71 patients with primary open-angle glaucoma. The subfoveal CT (SFCT) and peripapillary CT (PPCT) were measured using spectral-domain optical coherence tomography preoperatively and 1 week, 1 month, 2 months, 6 months, and 1 year postoperatively. MOPP was calculated from the IOP and blood pressure. The AL was measured using partial coherence interferometry. Regression analysis was conducted to assess the possible association of variables.RESULTS: The AL decreased and the MOPP, SFCT, and PPCT increased significantly with IOP reduction at 1 year post-operatively (all, p < 0.001). The changes in SFCT and PPCT were significantly associated with IOP reduction at 1 year postoperatively (r = −0.519 and r = −0.528, respectively). Importantly, greater increases in SFCT and PPCT were found in patients with IOP reduction more than 30% from baseline, when compared with those with less than 30% reduction (p = 0.001 and p = 0.002, respectively). The SFCT increased more significantly in patients with AL ≤ 24 mm, compared with patients with AL > 24 mm (p = 0.044).CONCLUSIONS: Reduction in the IOP, increase in the MOPP, decrease in the AL, and increase in the CT after glaucoma surgery persisted for 1 year during a long-term follow-up. These results suggested that glaucoma surgery reduced mechanical compression on the optic nerve fiber and increased intraocular blood flow.

Clinical Aspects of Phlyctenular Keratoconjunctivitis Using a Tear Film Interferometer

PURPOSE: To evaluate clinical findings in phlyctenular keratoconjunctivitis patients and assess the function and morphology of Meibomian glands using an interferometer (LipiView®, TearScience, Morrisville, NC, USA) in such patients.METHODS: This retrospective study included 19 eyes of 13 patients diagnosed with phlyctenular keratoconjunctivitis. The lipid layer thickness (LLT) and meibograph of each eye was quantified by tear interferometry. Tear film break-up time (TBUT) and corneal staining score were measured. Meibomian gland morphology (lid margin vascularity, plugging of gland orifices, lid margin irregularity, lid margin thickening, and partial glands) was evaluated based on anterior photographs and meibographs.RESULTS: The mean age was 21.3 years (8–44 years). Mean BUT and Oxford corneal staining scores were 2.6 ± 1.2 seconds and 1.9 ± 0.8, respectively. Abnormal findings of the Meibomian glands were observed in all patients. The mean LLT was 79.6 ± 27.4 µm and the incomplete eye blinking frequency was 3.8 ± 5.9 during 20 seconds. The graphs of the tear lipid layer showed various patterns such as flat, up-hill, down-hill, and mixed.CONCLUSIONS: Meibomian gland dysfunctions and changes in the tear film lipid layer were noted in patients with phlyctenular keratoconjunctivitis. These factors are to be considered for the treatment of phlyctenular keratoconjunctivitis in young patients under 10 years of age.

Evolución de la biometría de coherencia óptica y las nuevas plataformas / Evolution of optical coherence biometry and the new platforms

RESUMEN La interferometría de coherencia óptica es un procedimiento esencial para calcular la potencia óptica de la lente intraocular. La presente revisión describe la evolución de la biometría óptica por interferometría, las nuevas plataformas, las características técnicas, los parámetros de calibración, la interpretación de los resultados y las situaciones especiales con indicación de cirugía de catarata. Para efectuar el trabajo fueron consultadas las bases de datos de la plataforma Infomed, específicamente en la Biblioteca Virtual de Salud, PubMed, Cochrane Database-Wiley Online Library, LILACS y Scielo. El IOL Máster favorece la medición de los parámetros biométricos oculares, ya que realiza mediciones sólidas y repetibles que incluye fórmulas de cuarta generación para el cálculo de potencia de lentes intraoculares. Actualmente se dispone en el mercado de varias plataformas para la biometría ocular usando los métodos interferométricos de alta resolución que tienen el potencial de mejorar significativamente los resultados refractivos. Estos estudios son de alta predictibilidad, lo cual permite obtener una buena agudeza visual y evita la sorpresa refractiva((AU)

ABSTRACT Optical coherence interferometry is an essential procedure for calculating the optical power of the intraocular lens. The present review describes the evolution of optical biometry by interferometry, the new platforms, technical features, calibration parameters, interpretation of results, and special situations in which cataract surgery is indicated. Information was collected from the databases on the Infomed platform, specifically the Virtual Health Library, PubMed, Cochrane Database-Wiley Online Library, LILACS and Scielo. IOL Master facilitates the measurement of ocular biometric parameters, since it performs solid, repeatable measurements that include fourth-generation formulas for the calculation of intraocular lens power. Several ocular biometry platforms are currently available in the market which use high resolution interferometric methods with the potential to significantly improve refractive results. These studies are characterized by their high predictability, making it possible to obtain good visual acuity and avoid refractive surprise(AU)

Effect of Serous Retinal Detachment on the Measurement of Axial Length in Central Serous Chorioretinopathy

PURPOSE: To evaluate the changes of axial length (AXL) in eyes with unilateral idiopathic central serous chorioretinopathy (CSC) after resolution of serous retinal detachment. METHODS: A total of 31 patients diagnosed with idiopathic unilateral CSC were included in this study. The changes of AXL according to serous retinal detachment were examined. The keratometric value and AXL were measured using partial coherence interferometry. Serous retinal detachment and central macular thickness (CMT) were measured by spectral domain optical coherence tomography. RESULTS: The mean age of the 31 CSC patients, including 19 males, was 42.7 years. The AXL was significantly increased from 23.41 to 23.58 mm after resolution of serous retinal detachment (p < 0.001). The CMT was significantly decreased from 413.4 to 226.8 µm after resolution of serous retinal detachment (p < 0.001). The differences in AXL correlated with CMT differences and subretinal fluid height (r = −0.616, p < 0.001 and r = −0.637, p < 0.001, respectively), and the best-corrected visual acuity was significantly different after resolution of serous retinal detachment (p < 0.001). CONCLUSIONS: In unilateral idiopathic CSC with serous retinal detachment, a shortened AXL in the acute phase was restored after resolution of serous retinal detachment.

Corneal Astigmatism in cataract surgery candidates / Astigmatismo Corneano em candidatos à cirurgia de catarata

Abstract Purpose: To report the prevalence and analyse corneal astigmatism patterns in cataract surgery candidates. Methods: Researchers examined 2136 eyes from 1204 patients for cataract surgery from 1 January to 31 December 2016. All the candidates were evaluated with partial coherence interferometry (IOLMaster). The results were analysed statistically in relation to qualitative and quantitative variables. Results: The mean age of the patients was 71.9 years with a female predominance. Mean corneal astigmatism was 1.0 dioptre (D). Against the rule (ATR) astigmatism increased with age. Women presented with steeper corneas than men. In those patients who had both eyes measured, we found strong correlations between amount of right and left eye astigmatism, axis and keratometry. Overall, 39% of the eyes had corneal astigmatism > 1.00 D and 19% >1.50 D. Conclusions: A significant percentage of our population presents with corneal astigmatism > 1.00 D with a shift from WTR (with the rule) to ATR with increasing age. Our findings, in a population that has never been described before, will be helpful to surgeons to enhance surgical techniques, patients to improve visual outcomes, IOL (intraocular lens) manufacturers to make better designs and health agents to optimise resources.

Resumo Objetivo: Relatar a prevalência e analisar os padrões de astigmatismo corneano em candidatos à cirurgia de catarata. Métodos: Os pesquisadores examinaram 2136 olhos de 1204 pacientes a cirurgia de catarata de 1 de janeiro a 31 de dezembro de 2016. Todos os candidatos foram avaliados com interferometria de coerência parcial (IOLMaster). Os resultados foram analisados estatisticamente em relação às variáveis qualitativa e quantitativa. Resultados: A média de idade dos pacientes foi de 71,9 anos, com predomínio do sexo feminino. A média de astigmatismo corneano foi de 1,0 dioptria (D). Contra a regra (ATR), o astigmatismo aumentou com a idade. As mulheres apresentaram córneas mais íngremes que os homens. Nos pacientes que tiveram os dois olhos medidos, encontramos fortes correlações entre quantidade de astigmatismo nos olhos direito e esquerdo, eixo e ceratometria. No geral, 39% dos olhos tinham astigmatismo corneano >1,00 D, e 19% > 1,50 D. Conclusões: Uma percentagem significativa da nossa população apresenta astigmatismo corneano >1,00, D com uma mudança de WTR (a favor da regra) para ATR (contra a regra) com o aumento da idade. Nossas descobertas em uma população que nunca foi descrita antes serão úteis para os cirurgiões melhorarem suas técnicas cirúrgicas, os pacientes melhorarem seus resultados visuais, os fabricantes de LIOs (lentes intraoculares) criarem projetos melhores, e os agentes de saúde otimizarem os recursos.

Is partial coherence interferometry more accurate than a scan ultrasonography in the estimation of anterior chamber depth?

Purpose: To assess the degree of agreement of anterior chamber depth [ACD] measurements by optical device [NIDEK AL-scan biometer] and contact ultrasound A-scan [Mentor [[R]] - Advent [[TM]] A/B system US biometry]

Setting: Department of Ophthalmology at ALAZHAR University, Cairo, Egypt

Methods: This prospective observational cross sectional comparative study of 50 normal healthy eyes were included in this study, ACD estimation was done by 2 methods partial coherence interferometry[PCI], and contact ultrasound A-scan. The measurements was performed by the same observer. The difference in measurements between the two methods was assessed using the t-test

Results: The mean ACD [ +/- SD] by the two methods were [2.8 mm] and [3.5 mm], respectively. There was a statistically significant difference between measurements recorded by the 2 methods [P<0.01]

Conclusion: there was a statistically different between the two methods the PCI values were significantly higher [by 0.7 mm] than the U/S values with no correlation between the two sets of values. So PCI is more accurate but we still need U/S measurements in some situations [e.g., tear film abnormalities, corneal pathologies]

Change in Axial Length in Highly Myopic Adults Using Partial Coherence Interferometry

PURPOSE: To investigate the change in axial length (AL) in highly myopic adults using partial coherence interferometry, and to identify the factors associated with the increase in AL. METHODS: Medical records of highly myopic adults (≥ −6 diopters [D] or AL ≥ 26.0 mm) were retrospectively reviewed. The AL of each patient was measured using partial coherence interferometry at least three times over 2 years, and the yearly change in AL was calculated. Associations between age, AL, choroidal thickness, and the rate of AL change were evaluated using multiple regression analysis. RESULTS: In total, 24 patients (4 males, 20 females) and 44 eyes were included in this study. The mean age was 54.9 ± 10.4 years, the initial AL was 29.335 ± 2.006 mm, the choroidal thickness was 72.7 ± 41.80 µm, the average spherical equivalent was −11.86 ± 3.85 D (−5.1~−22.0 D), and the mean follow-up period was 2.2 ± 0.5 years. A significant increase in AL of ≥0.05 mm was observed in 38 eyes (86.4%) at 2 years. The mean AL was significantly increased, to 29.409 ± 2.007 mm (p < 0.001), at 1 year and to 29.476 ± 2.028 mm (p < 0.001) at 2 years. The average rate of AL change was 0.071 ± 0.049 mm (−0.01~0.19 mm) per year. None of the included factors showed an association with the rate of AL change in multiple regression analysis. CONCLUSIONS: In this study, an increase in AL in highly myopic adults was more frequent than in previous reports using A-scan. Periodic measurements are therefore recommended for the early detection of complications.

Comparative color and surface parameters of current esthetic restorative CAD/CAM materials

PURPOSE: The purpose of this study was to derive and compare the inherent color (hue angle, chroma), translucency (TP(SCI)), surface gloss (ΔE* SCE-SCI), and surface roughness (Ra) amongst selected shades and brands of three hybrid CAD/CAM blocks [GC Cerasmart (CS); Lava Ultimate (LU); Vita Enamic (VE)]. MATERIALS AND METHODS: The specimens (N = 225) were prepared into square-shaped (12 × 12 mm2) with different thicknesses and shades. The measurements of color, translucency, and surface gloss were performed by a reflection spectrophotometer. The surface roughness and surface topography were assessed by white light interferometry. RESULTS: Results revealed that hue and chroma values were influenced by the material type, material shade, and material thickness (P CS > VE, whereas the order of chroma was VE > CS > LU. TP(SCI) results demonstrated a significant difference in terms of material types and material thicknesses (P ≤ .001). TP(SCI) values of the tested materials were ordered as LU > CS > VE. ΔE* SCE-SCI and Ra results were significantly varied amongst the materials (P VE ≥ CS, whereas the order of Ra was CS ≥ VE > LU. CONCLUSION: Nano-ceramic and polymer-infiltrated-feldspathic ceramic-network CAD/CAM materials exhibited different optical, inherent color and surface parameters.

Long-term microwaving of denture base materials: effects on dimensional, color and translucency stability

Abstract While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet. Objective The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials. Material and Methods Thirty two specimens (32 mm x 10 mm x 2.5 mm) from polyamide (Valplast) and PMMA (Vertex Rapid Simplified) denture base materials were made. Eight specimens from each material were immersed in distilled water (control) and 8 were subjected to microwave exposure at 450 W for 3 minutes for a period simulating 224 days of daily disinfection. Linear dimension, color change (ΔE*) and translucency parameter (TP) were measured at baseline and after certain intervals up to 224 cycles of immersion, using a digital calliper and a portable colorimeter. The results were analysed using two-way repeated measures ANOVA to estimate possible differences among predetermined cycles and material type. Regression analysis was also performed to estimate the trend of changes with time. Statistical evaluations performed at a significance level of 5%. Results Data analysis showed significant changes in length at baseline with an increasing number of cycles (p<0.05) and a significant interaction of cycle-material (p<0.001). The ΔΕ* parameter was significantly higher with a higher number of cycles (p<0.001), but it did not vary between materials (p>0.05). TP decreased similarly in both materials following microwave action but in a significantly higher level for Valplast (p<0.001). Conclusions The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. Differences between PMMA and polyamide material were noted only in dimension and translucency changes.

Axial eye length assessment in silicone oil-filled eyes

Purpose: To compare the reliability of axial eye length [AEL] measurement in silicone oil-filled phakic eyes by conventional B-scan ultrasonography through the eyelid, after a correcting factor, to partial coherence interferometry [PCI] measurement

Methods: A prospective and comparative study was performed at Al-Zahraa University Hospital clinic from [January 2016 - December 2016]. In total 13 phakic eyes of 13 patients who underwent vitrectomy and silicone oil filling were enrolled into the study. AEL was measured by B-scan and compared to measurement by PCI

Results and Conclusions: There was no significant difference in AEL measurement by either B-scan ultrasonography through the eyelid, after a correcting factor, and PCI

Anterior Segment Changes after Laser Iridotomy for the Treatment and Prevention of Angle-closure Glaucoma

PURPOSE: To evaluate the changes and characteristics of the anterior segment of the eye after laser peripheral iridotomy (LPI) conducted on patients with acute angle closure crisis (AACC) for both therapeutic purposes and prophylactic purposes in the fellow eye. METHODS: Anterior segments were examined by topography, laser interferometry, anterior segment optical coherence tomography, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), angle opening distance (AOD), central corneal thickness (CCT), and axial length as compared to prior procedures in 20 eyes with glaucoma (treatment group) and 20 contralateral eyes (prophylactic group) in 20 patients diagnosed with AACC. RESULTS: Before laser treatment, there were no significant differences in pre-LPI ACV, ACA, AOD and axial length, although differences in the CCT and ACD existed between the groups. Compared to prior laser treatment at 1 and 3 months after laser treatment, the ACV, ACA, AOD 500, and AOD 750 increased in both groups. When both groups were compared 1 month after their laser treatments, the AOD 750 was increased in the treatment group. There were no significant differences between two groups 3 months post LPI. CONCLUSIONS: Other than changes in the ACD and CCT, no significant differences were observed in the anterior segment characteristics in AACC affected and contralateral eyes prior to LPI. After LPI, the treatment group showed greater changes in their anterior segments; however, the open angle was maintained at 1 month post treatment.

Comparison of Ocular Biometry and Refractive Outcomes Using IOL Master 700, IOL Master 500, and Ultrasound

PURPOSE: To compare the new swept-source optical coherence tomography based IOL Master 700 to both the partial coherence interferometry based IOL Master 500 and ultrasound A-scan in terms of the ocular biometry and the prediction of postoperative refractive outcomes. METHODS: A total 67 eyes of 55 patients who received cataract surgery were included in our study. The axial length, anterior chamber depth, and keratometry were measured using IOL Master 700, IOL Master 500, and A-scan. The predictive errors, which are the differences between predictive refraction and post-operative refraction 1 month after surgery, were also compared. RESULTS: Axial length measurements were not successful in 5 eyes measured using IOL Master 700 and in 12 eyes measured using IOL Master 500. The mean absolute postoperative refraction predictive errors were 0.63 ± 0.50 diopters, 0.66 ± 0.51 diopters, and 0.62 ± 0.51 diopters for IOL Master 700, IOL Master 500, and A-scan, respectively, and these values exhibited no statistically significant differences. The mean axial lengths were 24.25 ± 2.41 mm, 24.24 ± 2.40 mm, and 24.22 ± 2.39 mm; the mean anterior chamber depths were 3.09 ± 0.39 mm, 3.17 ± 0.39 mm, and 3.15 ± 0.46 mm; and the mean keratometry values were 44.12 ± 1.82 diopters, 44.57 ± 2.10 diopters, and 43.98 ± 1.84 diopters for the IOL Master 700, IOL Master 500, and A-scan groups, respectively. None of these parameters showed statistically significant differences between the three groups. Regarding pair-wise comparison, there were significant differences between the IOL Master 700 and the other devices. CONCLUSIONS: The ocular biometric measurements measured using IOL Master 700, IOL Master 500, and A-scan showed no significant differences. However, IOL Master 700 demonstrated a superior ability to successfully take biometric measurements compared to IOL Master 500. Therefore, IOL Master 700 is capable of measuring ocular biometry for cataract surgery in clinical practice.

Comparison of Biometric Measurements and Refractive Results among Low-coherence Reflectometry, Partial Interferometry and Applanation Ultrasonography

PURPOSE: To compare the measurement results and the accuracy of the predicted refractive error after cataract surgery among 3 ocular biometry devices; OA-2000®, IOL Master® and A-scan ultrasound in posterior subscapular cataracts. METHODS: Biometry measurements including axial length, anterior chamber depth and the keratometry of 80 cataractous eyes were measured using ultrasonography, OA-2000® and IOL Master®. To calculate the intraocular lens (IOL) power, the SRK/T formula was used and 3 months after cataract surgery, the refractive outcome was compared to the preoperatively predicted refractive error. RESULTS: The number of eyes measured by the 3 devices (A-scan, IOL Master® and OA-2000®) was 57 (group A) and the number of eyes measured by 2 devices (A-scan and OA-2000®) was 22 (group B). When cataract grading was performed based on the Lens Opacity Classification system III, the severity of posterior subscapular opacity was significantly different between the 2 groups (p = 0.001). Although no difference was observed in the measured biometry values including axial length, anterior chamber depth and keratometry in groups A and B, the predicted refractive error was significantly different in group B; OA-2000® showed a significantly higher accuracy in predicting IOL power than A-scan. CONCLUSIONS: In cataract patients whose posterior subscapular opacity is not severe, the accuracy for predicting refractive error after cataract surgery was not significantly different among the 3 devices included in our study (A-scan, IOL Master® and OA-2000®). However, in patients with severe posterior subscapular opacity, OA-2000®, that provides a Fourier domain light source-calculated predicted refractive error of IOL may be more accurate.

Incidence of Complications in Cataract Surgery according to the Availability of Partial Coherence Laser Interferometry

PURPOSE: To validate the possibility of IOLMaster measurement as a predictor of intraoperative and postoperative complications during phacoemulsification surgery. METHODS: In this study, 2,107 eyes from 1,456 patients who underwent phacoemulsification with intraocular lens (IOL) implantation were divided into two groups according to the possibility of performing optical biometry with the IOLMaster (measurable group: 1,746 eyes from 1,141 patients, unmeasurable group: 361 eyes from 315 patients). The intraoperative and postoperative complication rates were compared between the two groups. RESULTS: Three hundred sixty-one eyes (17.1%) could not be measured using optical biometry. Dense posterior subcapsular cataract (56.0%) was the main factor resulting in failed measurements with optical biometry, followed by anterior subcapsular cataract (12.5%). The rates of posterior capsule rupture and radial tear were significantly higher in the unmeasurable group than in the measurable group (p = 0.001, p < 0.001, respectively). Corneal edema was significantly higher in the unmeasurable group (16.1%) than in the measurable group (5.3%) at postoperative 1 week (p < 0.001). CONCLUSIONS: Possibility of optical biometry measurement can be used as a simple predictor of intraoperative and postoperative complications of phacoemulsification surgery. Surgeons should pay close attention to patients who cannot be measured using IOLMaster.