Advances in interdisciplinary medical and engineering research of intraocular lens surface modifications to prevent posterior capsule opacification / 中南大学学报(医学版)

Posterior capsule opacification (PCO), a common complication after cataract surgery, impacts a patient's long-term visual quality to various degrees. Although a neodymium:yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy is a very effective treatment, it may lead to a serial of complications. Accordingly, the search for simple, safe, and effective methods to prevent PCO has received widespread attention. Various researchers are committed to the interdisciplinary collaboration between medicine and engineering fields, such as functionalizing the surface of the intraocular lens (IOL) via supercritical fluid impregnation, coating the surface of the IOL, high-concentration drug immersion, and application of a drug delivery system, to effectively reduce the incidence and severity of PCO.

Morphologic and molecular study on the lens anterior capsule in systemic sclerosis / Relato sobre estudo morfológico e molecular da cápsula anterior do cristalino na esclerose sistêmica

ABSTRACT This study aimed to analyze the anterior lens capsule specimens from both eyes of a patient with systemic sclerosis and compare them to the eyes of a control patient. No significant differences between systemic sclerosis and control eyes were observed in the results from the hematoxylin-eosin and picrosirius staining. In the samples obtained from both systemic sclerosis and control eyes, there were expressions of caspase, a molecule expressed in cell death by apoptosis. Heparanase was overexpressed in the systemic sclerosis sample compared to the control sample. Therefore, the anterior lens capsule of the patient with systemic sclerosis is probably affected by the disease since it showed marked expression of heparanase 1.(AU)

RESUMO Analisamos as amostras das cápsulas anteriores do cristalino de uma paciente com esclerose sistêmica e comparamos com as de um paciente controle. Não foram observadas diferenças significativas entre esclerose sistêmica e controle nos resultados da coloração com hematoxilina-eosina e picrosirius. Nas amostras obtidas da esclerose sistêmica e do controle, obtivemos expressão de caspase, uma molécula expressa na morte celular por apoptose. A heparinase foi expressa de forma mais marcante na amostra de esclerose sistêmica quando comparada ao controle. Portanto, a cápsula anterior do cristalino da paciente com esclerose sistêmica provavelmente foi afetada pela doença, uma vez que mostrou expressão aumentada de heparinase 1.(AU)

A case of late-onset capsular block syndrome and its surgical treatment / Um caso de síndrome de bloqueio capsular tardio e uma abordagem cirúrgica

ABSTRACT - Capsular block syndrome is a rare complication of phacoemulsification surgery with continuous curvilinear capsulorhexis and intraocular lens implantation. Here, we report a case of very late-onset capsular block syndrome that developed 13 years after cataract extraction and present the surgical approach used for its successful treatment.

RESUMO - Síndrome do bloqueio capsular é uma complicação incomum da cirurgia de facoemulsificação com capsulorrexis curvilínea contínua e implante de lente intraocular. Nós relatamos um caso de síndrome de bloqueio capsular de início tardio que se desenvolveu após 13 anos da extração da catarata e apresenta a abordagem cirúrgica utilizada para o sucesso do tratamento.

The influence of size and shape of Nd:YAG capsulotomy on visual acuity and refraction / A influência do tamanho e forma da capsulotomia por laser de Nd:YAG sobre a acuidade visual e refração

ABSTRACTPurpose:To evaluate the influence of size and shape of neodymium:yttrium aluminum- Garnet (Nd:YAG) laser capsulotomy on visual acuity and refraction.Methods:We retrospectively evaluated 85 eyes of 67 patients treated with Nd:YAG laser posterior capsulotomy for posterior capsule opacification (PCO). The mean age of included patients was 57.57 ± 9.26 (mean ± standard deviation, 38-75 years). The mean interval between surgery and Nd:YAG laser capsulotomy was 26.09 ± 7.08 (10-38) months. Patients were divided into four groups according to the shape and size of capsulotomy. Groups comprised patients with cruciate shape capsulotomies with openings of less than or equal to 3.5 mm (Group 1) or greater (Group 2) and patients with circular shape capsulotomies with openings of less than or equal to 3.5 mm (Group 3) or greater (Group 4).Results:The mean number and energy of laser firings were significantly higher in Group 4 (p=0.00), and significantly lower in Group 1 (p=0.00), compared with that in other groups. Pre-procedural and post-procedural mean spherical equivalent (SE) values were significantly higher in Group 1 (p=0.026 and p=0.011, respectively). No statistical difference in best-corrected visual acuities (BCVA) or intraocular pressures (IOP) were observed between groups before (p=0.44 and p=0.452, respectively) or after capsulotomy (p=0.108 and p=0.125, respectively). A significantly higher number of patients in Group 4 (p=0.001), and a significantly lower number of patients in Group 1 (p=0.001), reported floating bodies compared with that in other groups. No significant changes in SE or intraocular pressure were observed after capsulotomy in any group (p=0.074 and p=0.856, respectively). Best-corrected visual acuity was significantly improved following capsulotomy in all groups (p<0.01).Conclusion:Cruciate shape capsulotomy with an opening of 3.5 mm or less provides the greatest improvement in visual function with minimal complications.

RESUMOObjetivo:Avaliar a influência do tamanho e forma da capsulotomia a laser de Neodímio: Ítrio-Alumínio-Granada (Nd:YAG) na acuidade visual e refração.Métodos:Oitenta e cinco olhos de 67 pacientes, com opacificação de cápsula posterior (PCO), que tinham sido submetidos a capsulotomia por laser de Nd:YAG, foram avaliadas retrospectivamente. A idade foi 57,57 ± 9,26 (média ± desvio padrão), variação 38-75 anos. O intervalo médio entre a cirurgia e a capsulotomia a laser de Nd:YAG foi 26,09 ± 7,08 (variação 10-38) meses. Os pacientes foram divididos em 4 grupos de acordo com a forma e o tamanho da capsulotomia. O grupo 1 incluiu pacientes com forma cruzada e tamanho igual ou menor do que 3,5 mm de abertura capsulotomia, Grupo 2, forma cruzada e tamanho maior do que 3,5 mm, Grupo 3, forma circular e tamanho igual ou menor do que 3,5 mm e Grupo 4, forma circular e tamanho superior a 3,5 mm.Resultados:A quantidade média de energia utilizada e tiros aplicadas foram significativamente maiores no Grupo 4 (p=0,00) e significativamente menores no grupo 1 (p=0,00). O equivalente esférico (SE), antes e após o procedimento, foi significativamente mais elevado no Grupo 1 (p=0,026, p=0,011). Não houve diferença estatística entre os grupos em relação à acuidade visual melhor corrigida (BCVA) e pressão intraocular (IOP) antes do procedimento (p=0,44, p=0,452) e após o procedimento (p=0,108, p=0,125). O número de pacientes com sintomas de moscas volantes foi significativamente maior no grupo 4 (P=0,001) e significativamente inferior no grupo 1 (p=0,001). SE e IOP após o procedimento não foram estatisticamente diferentes daqueles antes do procedimento (p=0,074, p=0,856, respectivamente) em todos os grupos. BCVA após o procedimento foi significativamente melhor do que antes do procedimento (p=0,00) em todos os grupos.Conclusões:Em conclusão, para complicações mínimas e máximas funções visuais, o tamanho ótimo capsulotomia deve ser igual a ou menor do que 3,5 mm e deve ser em forma cruzada.

Síndrome do bloqueio capsular tardio - relato de dois casos / Capsular block syndrome - report of two cases

Relato de dois casos de síndrome do bloqueio capsular, de ocorrência tardia, nove e cinco anos após facoemulsificação, respectivamente, em um olho com pseudoexfoliação capsular e outro operado de glaucoma, com bolha funcionante. A condição se constituiu na retenção de grande quantidade de líquido esbranquiçado, atrás da lente intraocular, o que levou à redução da AV, de quatro linhas de Snellen, nos dois casos. Houve pronta resolução do quadro com mínima capsulotomia posterior.

Two cases of late capsular block syndrome are reported. They were observed nine and five years after facoemulsification, in one eye with pseudoexfoliation syndrome and the other operated on for glaucoma with a functioning bleb. There was a large amount of milky material behind the intraocular lens, and reduction of the visual acuity (four lines of the Snellen chart in both cases). The condition was promptly resolved through minimal YAG laser posterior capsulotomy.

Introduction of Lens-angle Reconstruction Surgery in Rabbit Eyes

PURPOSE: In this study, we examined the stability of the lens-angle supporter (LAS) for accommodation restoration by comparing intraocular lens (IOL) location, after-cataract and ciliary body damage after cataract surgery in rabbits. METHODS: Eight rabbits were divided into experimental and control groups of four rabbits each. Phacoemulsification and irrigation and aspiration were performed in all rabbits. This was followed by an LAS and IOL insertion in the four experimental rabbits. In the four control rabbits, only an IOL insertion was performed. Six months after the surgery, the location of the IOL, the conditions of the lens capsule and ciliary body were evaluated using a slitl-amp examination and Miyake-Apple view. RESULTS: For the experimental group, the ultrasound biomicroscope results showed normal LAS and IOL positioning in all four cases. According to the slitlamp examination and Miyake-Apple view, the IOL was positioned at the center, with less after-cataract and damage to the ciliary body. For the control group, ultrasound biomicroscope results indicated a higher IOL position than normal, as well as a single case of IOL decentering. According to the slit-lamp examination and Miyake-Apple view, the IOL was decentered with more severe after-cataract and ciliary body damage. CONCLUSIONS: The LAS has the potential to maintain a stable IOL position while producing less after-cataract when used in lens-angle reconstruction for correction of presbyopia. Moreover, LAS implantation incurs less damage to the ciliary body.

Capsulorrexe em duplo anel: estudo clínico patológico / Double ring capsulorhexis: clinic opathologic study

Apresentamos caso de capsulorrexe em duplo anel em paciente feminina de 81 anos. O espécime cirúrgico foi submetido a estudo anatomopatológico que evidenciou os achados típicos da capsulorrexe em duplo anel. Comentamos a possível relação com a exfoliação capsular verdadeira. Salientamos que é possível realizar a cirurgia com bom resultado mesmo que o duplo anel não seja completo - como no caso apresentado - , porém desde que os folhetos capsulares estejam fundidos de forma contínua.

We present a case of double ring capsulorhexis in a 81 year-old female patient. Surgical specimen was submitted to histopathologic study resulting in typical double ring capsulorhexis findings. We discuss the questioned relation to true capsular exfoliation. We call attention to the fact that it is possible to obtain a good surgical result even when the double ring is not complete - as the case presented - , since both capsular flaps are fused in a continuous form.

Cataracts among Adults Aged 30 to 49 Years: A 10-Year Study from 1995 to 2004 in Korea

PURPOSE: To investigate the long-term characteristics of cataracts among adults aged 30 to 49 years in Korean over a span of 10 years. METHODS: Subjects between the ages of 30 to 49 years who underwent cataract surgery at St. Mary's Hospital from 1995 to 2004 (n = 976) were included. Patients with a history of ocular trauma, uveitis, other ocular or systemic diseases, and congenital cataracts were excluded. Additional information including type of lens opacity, urban/rural region, and pre- and postoperative visual acuities were analyzed. Lens opacity grading was conducted using Lens Opacity Classification System III. The Cochran-Armitage proportion trend test was used to analyze vision changes with the passage of time. RESULTS: Among the patients who had undergone cataract surgeries, 8.8% (976 / 11,111) met the inclusion criteria. The mean age was 41.7 +/- 5.45 years. Gender breakdown of the patient population included 79.0% male and 21.0% female. In terms of home environment, 60.9% were from an urban region and 39.1% from a rural region. Opacity type included anterior polar (AP), posterior subcapsular (PSC), AP and PSC, cortical, and nuclear in 35.7%, 35.1%, 7.0%, 6.0%, and 5.4% of patients, respectively. At a 2-month postoperative follow-up appointment, 92.7% of patients showed a best-corrected visual acuity of more than 20 / 40. CONCLUSIONS: Predominance of AP and PSC opacities as well as male patients was observed in this study population.

Effect of Haptic Material and Number of Intraocular Lens on Anterior Capsule Contraction after Cataract Surgery

PURPOSE: To evaluate changes over time of the anterior capsule opening size after phacoemulsification, based on haptic number and composition of three acrylic intraocular lenses (IOLs). METHODS: Fifty-five patients (70 eyes) were included. All underwent phacoemulsification followed by implantation of either an acrylic IOL with two-haptic (one-piece, 26 eyes; three-piece, 22 eyes), or four-haptic (one-piece, 22 eyes). The area of the anterior capsule opening size was measured one week postoperatively (baseline) and at three months. RESULTS: There was a significant reduction in the area of the anterior capsule opening from one week as compared to three months postoperatively in all groups (p < 0.001). However, there was no significant difference in the reduction in the anterior capsule opening between the IOLs (p = 0.36). CONCLUSIONS: The number and material of the haptic of the three acrylic IOLs did not influence the degree of anterior capsule opening shrinkage.

Staining of Lens Capsule with Trypan Blue for Capsulorrhexis in Eyes with White Cataract.

Objective: To evaluate the efficacy and safety of intracameral 0.1% Trypan blue dye for staining the anterior lens capsule during cataract surgery. Methods: 110 Patients who underwent Manual Small Incision Cataract Surgery (MSICS) and phacoemulsification for intumescent, mature or hypermature cataract in the Department of Ophthalmology, Tripura Medical College during the period of June 2009 to July 2010 were included in the study. Results: Satisfactory staining of the anterior lens capsule was seen in all cases with no major complications. Conclusion: Direct intracameral injection of trypan blue dye is an effective method for staining the anterior lens capsule during cataract surgery.

Técnica Tied Out Open Sky: fixação iriana de lente intraocular combinada com transplante penetrante de córnea / Tied Out Open Sky technique: new method for iris fixation of intraocular lens in the absence of capsular support during penetrating keratoplasty

O objetivo é descrever uma nova técnica cirúrgica para fixação iriana de lente intraocular durante transplante de córnea em pacientes sem suporte capsular. A técnica de fixação iriana Tied Out Open Sky é uma técnica de fácil execução comparado com as técnicas já descritas, dispensando manobras cirúrgicas complexas, minimizando a manipulação e as complicações pós-operatórias.

To describe a new method for iris fixation of intraocular lens in the absence of capsular support during penetrating keratoplasty. Its a new technique of iris fixation of intraocular lens without capsular support during penetrating keratoplasty. This technique is used in cases with a healthy iris and partial or total absence of capsular support during penetrating keratoplasty. Tied Out Open Sky is a technique easy to perform for iris fixation of intraocular lens during penetrating keratoplasty. The big advantage is being able to tie off the intraocular lens off the eye and fasten it securely.

A capsulotomia descontínua durante a facoemulsificação / Discontinuous capsulotomy during phacoemulsification

OBJETIVO: Descrever a prevalência, localização e causas da capsulotomia descontínua durante a cirurgia de catarata por facoemulsificação. MÉTODOS: Estudo retrospectivo, consecutivo, não comparativo de 971 cirurgias de catarata com capsulotomia descontínua no per-cirúrgico entre janeiro de 2009 a junho de 2010. RESULTADOS: Observou-se uma prevalência de 0,02 por cento e a descontinuação da cápsula ocorreu em 100 por cento das vezes durante o tratamento do núcleo. Em 58.33 por cento dos olhos o implante foi realizado no saco capsular e em 41.67 por cento no sulco ciliar. A AV > 20/30 em 100 por cento dos olhos. CONCLUSÃO: apesar de ser uma intercorrência pouco frequente, pode comprometer o resultado final.

OBJECTIVE: To describe the prevalence, location and causes of discontinuous capsulotomy during phacoemulsification cataract surgery. METHODS: Retrospective, consecutive, non-comparative study of 971 cataract surgeries - with discontinuous capsulotomy during surgery - performed from January 2009 to June 2010. RESULTS: it was observed a prevalence of 0.02 percent and capsule discontinuation occurring 100 percent of the time during the treatment of the nucleus. In 58.33 percent of the eyes the implant was done in the capsular bag and in 41.67 percent in the ciliary sulcus. VA > 20/30 in 100 percent of the eyes. CONCLUSION: despite the fact that it is a not too frequent event, it may compromise the final result.

Trasplante autólogo de células límbicas y recubrimiento con membrana amniótica / Limbic cell autologous transplantation and coating with amniotic membrane

Se trata de una paciente con antecedentes de quemadura corneal en el ojo izquierdo desde hacía un trienio, a quien además de haberle realizado una queratoplastia terapéutica, la extracción extracapsular del cristalino y la colocación de una lente intraocular un año después, evolucionó con insuficiencia de células límbicas, conjuntivalización de la córnea y simbléfaron. Luego de un trasplante autólogo de las mencionadas células y recubrimiento con membrana amniótica (primer caso informado en la provincia), mejoró considerablemente a los 6 meses de seguimiento clínico, después de lo cual se le realizó una queratoplastia penetrante con finalidad óptica.

This is a patient with history of cornea burn in the left eye for three years. After having performed a therapeutic keratoplasty, extracapsular lens extraction and intraocular lens implantation a year later she progressed with limbic cell failure, cornea conjunctivalization and symblepharon. Once autologous transplantation of these cells and coating with amniotic membrane (first case informed in the province) were performed, the patient improved significantly at 6 months of clinical follow-up, after which she underwent penetrating keratoplasty with optical purposes.

Outcome of in-the-bag implanted square-edge polymethyl methacrylate intraocular lenses with and without primary posterior capsulotomy in pediatric traumatic cataract.

Purpose: To study the outcome of in-the-bag implanted square-edge polymethyl methacrylate (PMMA) intraocular lenses (IOL) with and without primary posterior capsulotomy in pediatric traumatic cataract. Materials and Methods: The study was undertaken in a tertiary care center. Thirty eyes of 30 children ranging in age from 4 to 16 years with traumatic cataract which underwent cataract extraction with capsular bag implantation of IOL were prospectively evaluated. Group A included 15 eyes of 15 children where primary posterior capsulotomy (PPC) and anterior vitrectomy with capsular bag implantation of square-edge PMMA IOL (Aurolab SQ3602, Madurai, Tamil Nadu, India) was performed. Group B comprised 15 eyes of 15 children in which the posterior capsule was left intact. Postoperative visual acuity, visual axis opacification (VAO) and possible complications were analyzed. Results: Best corrected visual acuity (BCVA) of 20/40 or better was achieved in 12 of 15 eyes in both groups. Amblyopia was the cause of no improvement in visual acuity in the remaining eyes. Visual axis opacification was significantly high in Group B as compared to Group A (P=0.001). Postoperative fibrinous uveitis occurred in most of the eyes in both groups. Pupillary capture was observed in one eye in each group. Conclusion: Primary posterior capsulotomy and anterior vitrectomy with capsular bag implantation of square-edge PMMA significantly helps to maintain a clear visual axis in children with traumatic cataract.

New technique to demonstrate corneal magnification using trypan blue in cataract surgery / Nova técnica para demonstrar a magnificação corneana utilizando azul de tripan na cirurgia de catarata

PURPOSE: To demonstrate the corneal magnification using trypan blue in cataract surgery. METHODS: Eight eyes of eight patients undergoing phacoemulsification with an intraocular lens implantation were enrolled in this study. After staining the anterior capsule with Trypan Blue 0.1 percent and performing the capsulorhexis, the excised anterior capsule was placed on the corneal surface. By observing and measuring the relationship between the border of the excised anterior capsule and the intracameral capsulorhexis opening, the effect of corneal magnification was clearly demonstrated and calculated by linear method. RESULTS: The average magnification of the cornea was 20.88 percent using linear method with an average area magnification of 47.53 percent. CONCLUSION: The capsulorhexis stained by trypan blue is useful to demonstrate the magnification provided by the cornea helping to design an intended opening size.

OBJETIVO: Demonstrar a magnificação corneana utilizando o azul de tripan na cirurgia de catarata. MÉTODOS: Oito olhos de oito pacientes submetidos à facoemulsificação com implante de lente intraocular foram envolvidos neste estudo. Após corar a cápsula anterior do cristalino com azul de tripan 0,1 por cento e realizar a capsulotomia circular contínua, a cápsula excisada foi colocada sobre a superfície corneana. Após observar e aferir a relação entre a borda da cápsula anterior excisada e a abertura da cápsula intracameral, o efeito da magnificação corneana foi claramente demonstrada e calculada através do método linear. RESULTADOS: A média estimada da magnificação corneana foi de 20,88 por cento com uma média de magnificação de área de 47,53 por cento. CONCLUSÃO: A capsulorrexis corada pelo azul de tripan é útil na demonstração da magnificação corneana, auxiliando assim na correta confecção do seu tamanho.

Perception of difficulties with vision-related activities of daily living among patients undergoing unilateral posterior capsulotomy

OBJECTIVES: To assess the influence of Nd:YAG (neodymium: yttrium-aluminum- garnet) laser unilateral posterior capsulotomy on visual acuity and patients' perception of difficulties with vision-related activities of daily life. METHODS: We conducted an interventional survey that included 48 patients between 40 and 80 years of age with uni- or bilateral pseudophakia, posterior capsule opacification, and visual acuity <0.30 (logMAR) in one eye who were seen at a Brazilian university hospital. All patients underwent posterior capsulotomy using an Nd:YAG laser. Before and after the intervention, patients were asked to complete a questionnaire that was developed in an exploratory study. RESULTS: Before posterior capsulotomy, the median visual acuity (logMAR) of the included patients was 0.52 (range 0.30-1.60). After posterior capsulotomy, the median visual acuity of the included patients improved to 0.10 (range 0.0-0.52). According to the subjects' perceptions, their ability to perform most of their daily life activities improved after the intervention (p<0.05). CONCLUSIONS: After patients underwent posterior capsulotomy with an Nd:YAG laser, a significant improvement in the visual acuity of the treated eye was observed. Additionally, subjects felt that they experienced less difficulty performing most of their vision-dependent activities of daily living.

Completing phaco following anterior capsular tear

A primary tear-out of the capsulorrhexis or a later anterior capsule tear occurs in less than 1% of phacoemulsification procedures [Marques et al., 2006]. It is a relatively uncommon complication but a hazardous and important one, although comparatively little has been published on its management. With the nucleus still in the bag at this stage, the surgeon is faced with the sizeable challenge of completing surgery without propagating a wrap-around tear to the posterior capsule. These are perilous conditions to face, but by using the right techniques the surgeon can still prevail. There is a clear set of principles that are based on self-knowledge of the surgeon's own skills and experience, combined with their understanding of how to control the forces acting on the tear and the tolerances of the capsular bag to surgical manipulation. Applying these principles in practice has enabled the development of a range of techniques now available to safely remove the nucleus under these challenging conditions. However, by far the most important principle of all is that if in doubt, not to proceed

Correlación entre la localización del lente intraocular, según biomicroscopia ultrasónica,y diferentes parámetros quirúrgicos en pacientes operados de catarata / Correlation between the location of the intraocular lens according to ultrasonic biomicroscopy and several surgical parameters in patients operated from cataract

OBJETIVO: Determinar la correlación entre la localización del lente intraocular en cámara posterior por biomicroscopia ultrasónica, diferentes parámetros quirúrgicos en pacientes operados de catarata. MÉTODOS: Se realizó un estudio descriptivo, prospectivo y transversal en el Instituto Cubano de Oftalmología Ramón Pando Ferrer durante el período de enero a junio del 2007. Se estudiaron variables como: edad, sexo, etiología de la catarata, técnica quirúrgica, localización del lente intraocular según biomicroscopia ultrasónica, así como complicaciones transoperatorias y posoperatorias. RESULTADOS: El 79 por ciento de todos los pacientes operados tenían entre 60 y 79 años de edad y algo más de la mitad correspondió al sexo femenino con un 59 por ciento. La catarata senil fue la etiología que predominó con un 74 por ciento y en el 68 por ciento de los casos el lente se localizó por biomicroscopia ultrasónica en el saco capsular. En los ojos donde el lente intraocular se localizó fuera del saco, la proporción de complicaciones transoperatorias y posoperatorias fueron significativamente mayoritarias, mientras que en los ojos donde el lente intraocular se encontraba en el saco, la mayoría no presentó complicaciones transoperatorias ni posoperatorias. CONCLUSIONES: Las diferencias entre las distintas localizaciones del lente intraocular se encontraron con significación estadística en el tipo de catarata, la presencia de complicaciones transoperatorias y posoperatorias, sin embargo, no se encontró relación estadística significativa entre la localización del lente intraocular con la técnica quirúrgica utilizada

OBJECTIVE: To determine the correlation between the location of the intraocular lens in the posterior chamber using ultrasonic biomicroscopy and the different surgical parameters in patients operated from cataract. METHODS: A prospective, descriptive and cross-sectional study was carried out in Ramón Pando Ferrer Cuban Institute of Ophthalmology in the period of January to June 2007. The studied variables were age, sex, etiology of cataracts, surgical technique, location of the intraocular lens using ultrasonic biomicroscopy, as well as transoperative and postoperative complications. RESULTS: Seventy nine percent of all the surgical patients were 60-79 years of age and 59 percent were females. The senile cataract was the prevailing etiology for 74 percent and the lens was located in the capsular sac using ultrasonic biomicroscopy in 68 percent of the cases. In those eyes where the intraocular lens was off the sac, the ratio of transoperative and postoperative complications was significantly higher, whereas most of the eyes with the IOL placed in the sac did not have either transoperative or postoperative complications. CONCLUSIONS: The differences between the different locations of the intraocular lens were statistically significant in terms of the type of cataract; however, there was not any significant statistical association between the location of the intraocular lens and the surgical technique

Estrategias de prevención de la opacidad de la cápsula posterior / Strategies for the prevention of the posterior capsule opacification

La opacidad de la cápsula posterior es actualmente el aspecto más importante en la cirugía de catarata de los tiempos modernos. Sigue siendo la complicación posoperatoria tardía más frecuente tras la cirugía de catarata asociada con disminución de la agudeza visual, deterioro de la sensibilidad al contraste y problemas de deslumbramiento que conllevan importantes repercusiones sociales, médicas y económicas. La capsulotomía láser aunque es un proceder efectivo para el tratamiento de esta complicación dista mucho de ser el método ideal puesto que se puede asociar a múltiples complicaciones. Debido a esto las investigaciones recientemente han dirigido su atención a estrategias de prevención de la opacidad de la cápsula posterior. Estas incluyen el diseño de los lentes intraoculares, técnicas quirúrgicas modificadas y/o mejoradas, implantes adicionales, empleo de fármacos y agentes citotóxicos así como el uso de nuevas tecnologías. La terapia génica, entre las novedosas intervenciones en estudio, parece ser una estrategia prometedora en este campo. No existe hasta ahora un método único que evite de modo definitivo la aparición de la opacidad capsular. El oftalmólogo debe usar la combinación de todos aquellos métodos que están a su alcance y han demostrada probada efectividad en la reducción de la opacidad de la cápsula posterior. Obtener excelentes resultados visuales a largo plazo es el objetivo de la cirugía moderna de la catarata así como abrir el camino a intervenciones quirúrgicas novedosas para el tratamiento de la presbicia en pacientes mayores de 40 años. Para lograrlo resulta fundamental impedir que la cápsula posterior se opacifique, aún más con el uso de lentes multifocales y acomodativos, que son más vulnerables a la opacidad que los lentes monofocales. Es por ello que nos atrevemos a decir que el mayor salto en la cirugía de la catarata moderna aún está por dar: la erradicación definitiva de la opacidad del saco capsular

The posterior capsule opacification (PCO) is the most important aspect in the cataract surgery nowadays. It continues being the more frequent late postoperative complication after cataract surgery associated with decrease of the visual acuity and other visual problems that lead to important social, economical and medical impacts. The laser capsulotomy is an effective procedure for the treatment of this complication but it is far from being the ideal method since it can be associated to considerable complications. This is the reason why several research studies recently have directed their attention to PCO-preventing strategies such as the design of intraocular lenses, modified and/or improved surgical techniques, additional implants, use of cytotoxic agents and drugs as well as new technologies. The gene therapy, among the novel interventions in study, seems to be a promising strategy in this field. Up to the present, there is not a unique method that avoids in a definitive way the development of the capsular opacification. The ophthalmologists should use the combination of all these methods available which have demonstrated a proved effectiveness in the reduction of PCO. Attaining long-term excellent visual result is the main purpose of the modern cataract surgery as well as paving the road towards novel surgical interventions for the treatment of presbyopia in patients older than 40 years. In order to achieve that goal, it is essential to avoid the opacification of the posterior capsule, even more with the use of multifocal and accommodative lenses that are more vulnerable to the opacity than the monofocal lenses. Therefore, we may dare to say that the biggest breakthrough in the modern cataract surgery is still awaiting: the definitive eradication of posterior capsule opacification