Evaluation of efficacy of new lens nucleus fragmenting forceps in cataract surgery / Avaliação da eficácia de uma nova pinça fragmentadora de núcleo do cristalino para cirurgia de catarata

ABSTRACT Objective: To evaluate the efficacy of low-cost nucleus fragmenting forceps designed to reduce the use of ultrasound during phacoemulsification. Methods: A total of 60 pig eyes enucleated 10 hours before were placed in the microwave oven, at maximum power for 10 seconds, to form cataracts with hardness comparable to a grade IV nucleus in the Lens Opacities Classification System III. Cataract extraction was performed using the Centurion® phacoemulsifier (Alcon Laboratories, Geneve, Switzerland) and Leica M620 microscope. All eyes were submitted to the pre-chop technique dividing the nucleus into four parts. After the pre-chop, the quadrants in 30 eyes were phacoemulsified with the torsional mode and were fragmented in the remaining 30 eyes after the pre-chop was with the fragmentation forceps before torsional mode phacoemulsification. The device was calibrated for all eyes by applying the following parameters: 40% linear torsional phacoemulsification; intraocular pressure of 65 mmHg; the linear vacuum of 600 mmHg; aspiration flow of 40 ccs/minute. After each procedure, the following was recorded: cumulative dissipated energy; equivalent average torsional amplitude; equivalent average ultrasonic power; estimated aspirated fluid; ultrasound total time; and total aspiration time. Statistical analysis was performed using the Kruskal-Wallis test and the IBM Statistical Package for Social Sciences. The p-value <0.05 was considered statistically significant. Results: There was a statistically significant reduction favoring the use of the nucleus fragmenting forceps in all parameters, except for the average torsional amplitude. Conclusion: The use of the nucleus fragmenting forceps contributed to improving the efficacy of torsional phacoemulsification in enucleated pig eyes.

RESUMO Objetivo: Avaliar a eficácia de uma pinça fragmentadora de núcleo, de baixo custo, desenvolvida para reduzir o uso de ultrassom durante a emulsificação do núcleo. Métodos: Sessenta olhos de porco com 10 horas de enucleação foram colocados no forno de microondas, em potência máxima por 10 segundos, para a formação de catarata com dureza comparável à de um núcleo grau IV na Lens Opacities Classification System III. A extração da catarata foi realizada com o facoemulsificador Centurion® (Alcon Laboratories, Genebra, Suíça) e microscópio Leica M620. Todos os olhos foram submetidos a técnica de pre-chop, dividindo o núcleo em quatro partes. Em 30 olhos, após o pre-chop, foi feita a facoemulsificação dos quadrantes com o modo torsional e, nos outros 30 olhos, após o pre-chop, cada quadrante foi fragmentado com a pinça antes da facoemulsificação com o modo torsional. O aparelho foi calibrado para todos os olhos com os seguintes parâmetros: faco torsional linear 40%; pressão intraocular 65 mmHg; vácuo linear 600mmHg e fluxo de aspiração 40cc/minuto. Após cada procedimento, verificaram-se energia dissipada acumulada; média da amplitude do faco torsional; média equivalente do poder ultrassônico; líquido aspirado estimado; tempo total de ultrassom e tempo total de aspiração. A análise estatística foi realizada utilizando o teste de Kruskal-Wallis com o IBM Statistical Package for Social Sciences. Valor de p<0,05 foi considerado estatisticamente significante. Resultados: Houve redução estatisticamente significante em favor do uso da pinça fragmentadora de núcleo em todos os parâmetros, menos na média de amplitude do faco torsional. Conclusão: O uso da pinça fragmentadora de núcleo contribuiu para melhorar a eficácia do faco torsional em olhos de porco enucleados.

Clinical applications of Scheimpflug imaging in cataract surgery

Since the Scheimpflug principle was first described over a century ago, there has been a great interest among ophthalmologists for the use of Scheimpflug camera in anterior segment imaging. Scheimpflug imaging has since advanced significantly and modern day instruments provide comprehensive imaging and topographic data of the anterior segment. In this article the clinical applications and limitations of Scheimpflug imaging in modern cataract surgery patients are discussed. This article reviews recent work on assessment of lens transparency for cataract grading and integrity, using preoperative lens density measurements to help predict phacoemulsification parameters, its utility in challenging situations like capsular bag distension syndrome and traumatic cataract and assessment of density of the posterior capsule for objectively quantifying posterior-capsule opacification

Posterior polar cataract: a review

Posterior polar cataract is a rare form of congenital cataract. It is usually inherited as an autosomal dominant disease, yet it can be sporadic. Five genes have been attributed to the formation of this disease. It is highly associated with complications during surgery, such as posterior capsule rupture and nucleus drop. The reason for this high complication rate is the strong adherence of the opacity to the weak posterior capsule. Different surgical strategies were described for the handling of this challenging entity, most of which emphasized the need for gentle maneuvering in dealing with these cases. It has a unique clinical appearance that should not be missed in order to anticipate, avoid, and minimize the impact of the complications associated with it

Comparative analysis of the nuclear lens opalescence by the Lens Opacities Classification System III with nuclear density values provided by Oculus Pentacam: a cross-section study using Pentacam Nucleus Staging software / Análise comparativa da opalencência nuclear cristaliniana pelo Lens Opacities Classification System III com valores de densidade nuclear fornecidos pelo Oculus Pentacam: estudo transversal utilizando o Pentacam Nucleus Staging software

PURPOSE: To compare the clinical classification of cataract using the Lens Opacities Classification System (LOCS) III with the mean values of lens density provided by the Pentacam Scheimpflug System in nuclear cataracts. METHODS: One hundred and one eyes from 101 patients with age-related nuclear cataract were submitted to clinical examination for lens grading score using LOCS III. According to LOCS III, nuclear opalescence was divided in six groups. Patients were evaluated by the Pentacam Scheimpflug System for the mean lens density using the Pentacam lens densitometry program (PLDP), the Pentacam Nucleus Staging (PNS) mean value and the PNS cataract grading score. RESULTS: A positive correlation between the mean values of lens density and LOCS III classification, considering groups 1 to 5, could be noticed with PLDP and PNS mean value. The mean values between the groups were similar using the PLDP and the PNS mean value. However, when the PNS cataract grading score was evaluated, there was low correspondence with LOCS III classification. CONCLUSION: Pentacam Scheimpflug device offers an objective measure of the lens nuclear density on nuclear cataracts. PLDP and the PNS mean value were both useful to evaluate age-related nuclear cataract up to LOCS III group 5.

OBJETIVO: Comparar a classificação clínica de catarata nuclear, utilizando o Lens Opacities Classification System (LOCS) III, e o valores médios de densidade nuclear fornecido pelo sistema Pentacam Sheimpflug. MÉTODOS: Cento e um pacientes (101 olhos) com diagnóstico de catarata nuclear senil foram submetidos a exame clínico para graduação da opalescência nuclear de acordo com o LOCS III e divididos em seis grupos de acordo com a mesma. Os pacientes foram posteriormente avaliados pelo sistema Pentacam Scheimpflug para obtenção do valor médio de densidade fornecido pelo programa de densitometria cristaliniana do aparelho (PLDP), valor médio de densidade calculado pelo Pentacam Nucleus Staging software (PNS) e o escore de graduação de catarata nuclear fornecido pelo PNS. RESULTADOS: Observou-se uma correlação positiva entre os valores médios de densidade cristaliniana fornecidos pelo PLDP e PNS e a classificação clínica LOCS III, considerando os grupos 1 ao 5. Os valores médios de densidade nuclear de cada grupo foram similares utilizando dados do PLDP e PNS. Entretanto, quando foi analisado o escore de graduação da catarata fornecido pelo PNS foi observada uma baixa correspondência com a classificação LOCS III. CONCLUSÃO: O Pentacam Scheimpflug oferece uma medida objetiva da densidade nuclear cristaliniana em cataratas nucleares. Os valores médios de densidade nuclear fornecidos pelo PLDP e PNS foram úteis na avaliação de catarata nuclear senil até o grupo 5 da classificação LOCS III.

Anterior Segment Parameters Using Pentacam and Prediction of Corneal Endothelial Cell Loss after Cataract Surgery

PURPOSE: We evaluated various preoperative anterior segment parameters measured with a Pentacam rotating Scheimpflug camera and compared them with those of conventional methods. We also evaluated the effect of different parameters on corneal endothelial cells after cataract surgery. METHODS: Pentacam examination was performed in 88 eyes from 88 patients to evaluate central anterior chamber depth (ACD(pentacam)), nuclear density (Densitometry(pentacam)), anterior chamber volume (ACV), and lens thickness (LT(pentacam)). We compared values of ACD(pentacam) with those of ultrasound (ACD(sono)) and also compared Densitometry(pentacam) values with those of Lens Opacities Classification System (LOCS III) classification. We evaluated the effect of the following preoperative values measured with Pentacam on postoperative endothelial cell loss: pupil size measured both preoperatively and before capsulorrhexsis (Pupil(CCC)), amount of viscoelastics, and LT measured by ultrasound (LT(sono)). RESULTS: A significant concordance was found between the two grading methods of nuclear opacity: Densitometry(pentacam) and LOCS III classification (tau(b) = 0.414, p = 0.000). We also found a positive correlation between ACD(pentacam) and ACD(sono) (r = 0.823, p = 0.000) and between ACD(pentacam) and ACV (r = 0.650, p = 0.000). There were significant differences between the results of LT(pentacam) and LT(sono). The final regression model identified Densitometry(pentacam), viscoelastics and Pupil(CCC) as independent predictors of decreased postoperative corneal endothelial cell density (CD) at postoperative day 3, and Densitometry(pentacam), viscoelastics, and ACV as independent predictors of decreased CD two months postoperatively (p<0.05). CONCLUSIONS: Good agreement was found between all results obtained with the Pentacam and conventional methods except LT. Analyzing anterior chamber parameters preoperatively using Pentacam could be helpful to predict postoperative endothelial cell loss.

The Comparison between Torsional and Conventional Mode Phacoemulsification in Moderate and Hard Cataracts

PURPOSE: To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts. METHODS: Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thickness, and central endothelial cell counts) were performed for each patient. Cataracts were subdivided into moderate and hard, according to the Lens Opacities Classification System III grading of nucleus opalescence (NO). Eyes in each cataract group were randomly assigned to conventional and torsional phaco-mode. Intraoperative parameters, including ultrasound time (UST), cumulative dissipated energy (CDE), and the balanced salt solution plus (BSSP) volume utilized were evaluated. Best corrected visual acuity (BCVA) was checked on postoperative day 30; mean central corneal thickness and central endothelial cell counts were investigated on postoperative days 7 and 30. RESULTS: Preoperative BCVA and mean grading of NO showed no difference in both groups. Preoperative endothelial cell count and central corneal thickness also showed no significant difference in both groups. In the moderate cataract group, the CDE, UST, and BSSP volume were significantly lower in the torsional mode than the longitudinal mode, but they did not show any difference in the hard cataract group. Torsional group showed less endothelial cell loss and central corneal thickening at postoperative day seven in moderate cataracts but showed no significant differences, as compared with the longitudinal group, by postoperative day 30. CONCLUSIONS: Torsional phacoemulsification showed superior efficiency for moderate cataracts, as compared with longitudinal phacoemulsification, in the early postoperative stage.

El estrés oxidativo y su impacto en las cataratas / Oxidative stress: its impact on cataracts

Las cataratas, una acumulación opaca de proteínas dañadas en el cristalino del ojo, representan la causa principal de disminución visual en aquellas personas de mßs de 65 años de edad. De hecho, la mayoría de las personas en ese grupo de edad por lo menos presentan el inicio de formación de estas. En dicha afección se han identificado varios factores que predisponen su aparición. Se considera la enfermedad como un proceso multifactorial en cuanto a su agente causal. En los últimos años se ha sugerido que los radicales libres y el estrés oxidativo forman parte de este proceso, hecho que se corrobora en muchas ocasiones, pues se ha demostrado que la utilización preventiva de antioxidantes exógenos o la estimulación de los sistemas antioxidantes endógenos retardan la aparición de los principales signos y síntomas de la enfermedad.

Cataracts, an opaque accumulation of damaged proteins in eye lens, are the major cause of visual decrease in those persons aged over 65. In fact, most of persons included in that age group at least have the onset of cataracts. In such affection are identified some factors predisposing its appearance. This disease is considered like a multifactorial process, fact corroborated in many opportunities, since it has demonstrated that the preventive use of exogenous antioxidant or stimulation of endogenous antioxidant systems delays appearance of main signs and symptoms of this disease.

Fidelidade do "potential acuity meter" (PAM) no prognóstico da acuidade visual pós-operatória de cirurgia de catarata / Fidelity of the potential acuity meter in the postoperative visual acuity of cataract surgery

OBJETIVO: Avaliar a relação da acuidade visual (AV) obtida pelo "potential acuity meter" (PAM) no pré-operatório de cirurgia de catarata com a acuidade visual obtida no pós-operatório, bem como, sua correlação com a classificação morfológica dominante da catarata. MÉTODOS: Trata-se de um estudo prospectivo realizado no setor de Catarata do Centro de Estudos do Hospital Monumento envolvendo 63 olhos de 45 pacientes avaliados de julho a setembro de 2006, submetidos à cirurgia de catarata sob a técnica de facoemulsificação com implante de lente intra-ocular, sendo posteriormente excluído 1 olho. No período pré-operatório, foi realizado o PAM sob midríase e seu resultado foi comparado à melhor acuidade visual pós-operatória do terceiro mês e correlacionado com a classificação morfológica da catarata, sendo denominado satisfatório aquele resultado que não variou mais do que duas linhas na tabela de Snellen. RESULTADOS: A média de idade foi de 45,3 anos com média da acuidade visual obtida pelo PAM de 0,64 logMAR. No terceiro mês pós-operatório, a média da melhor acuidade visual corrigida (MAVC) foi de 0,09 logMAR. O PAM hiperestimou o resultado da MAVC em 8 olhos (13 por cento), hipoestimou em 41 olhos (66 por cento) e nos 13 olhos restantes (21 por cento), as acuidades foram idênticas. Este apresentou uma fidelidade inversamente proporcional à intensidade de opacidade do cristalino no caso da catarata nuclear (1+ com 75,5 por cento e 4+ com 33,3 por cento), entretanto esta acurácia foi maior nos casos de subcapsular posterior (85,7 por cento). CONCLUSÃO: O PAM hipoestimou ou manteve da acuidade visual na maioria dos casos (87 por cento). Apresentou uma fidelidade inversamente proporcional à intensidade de opacidade do cristalino no caso da catarata nuclear, 1+ com 75,5 por cento e 4+ com 33,3 por cento; entretanto esta acurácia foi maior nos casos de subcapsular posterior (85,7 por cento).

PURPOSE: To evaluate the correlation between the preoperative visual acuity (VA) obtained by the potential acuity meter (PAM) and the postoperative VA in a patient submitted to cataract surgery, as well as its correlation with the dominant morphologic classification of the cataract. METHODS: This is a prospective study performed at the Hospital Monumento Study Center. Sixty-three eyes of 45 patients submitted to phacoemulsification with intraocular lens implantation were enrolled in this study and 1 eye had been excluded. Besides the complete examination in the preoperative period, PAM was used and its results were compared with the VA at the third postoperative month and correlated with the dominant morphologic cataract classification. The result was called satisfactory when the variation was equal to or less than two lines at the Snellen chart. We transformed the AV into logMAR for comparison with the literature. RESULTS: The mean age was 45.3 years with a mean VA of 0.64 logMAR by the PAM. At the third postoperative month, the mean best corrected visual acuity (BCVA) was 0.09 logMAR. The PAM overestimated the BCVA in 8 eyes (13 percent), underestimated it in 41 eyes (66 percent) and in 13 eyes (21 percent) the BCVA were the same. The satisfactory results regarding nuclear cataract were reduced in cases of higher density (1+/4 with 75.5 percent e 4+/4 with 33.3 percent) and increased in the posterior subcapsular cataracts (85.7 percent). CONCLUSION: PAM revealed an underestimation or maintenance of the BCVA in most cases (87 percent). Its fidelity was inversely proportional in the nuclear cataracts (1+/4 with 75.5 percent e 4+/4 with 33.3 percent) and higher in the posterior subcapsular cataracts.

Concentrações plasmáticas e eritrocitárias de zinco em idosos portadores e não-portadores de catarata senil em um serviço oftalmológico especializado de Teresina-Piauí / Plasma and erythrocyte zinc concentrations in elderly patients with and without senile cataract in a tertiary eye care center at Teresina-Piauí

OBJETIVO: Determinar as concentrações plasmáticas e eritrocitárias de zinco em idosos portadores e não-portadores de catarata senil em um serviço oftalmológico especializado, em Teresina-Piauí. MÉTODOS: Estudo quantitativo, transversal e controlado, realizado no Hospital de Olhos Francisco Vilar, Piauí, Brasil. Participaram 56 idosos (37 mulheres, 19 homens) sem condições associadas a modificações nos níveis de zinco ou aumento do risco de catarata. Escore > II foi utilizado para definir a presença de catarata, de acordo com o Lens Opacities Classification System II. As concentrações de zinco foram determinadas por espectrometria de absorção atômica em chama. Análise estatística incluiu os testes t de Student e qui-quadrado e 0,05 como nível de significância. RESULTADOS: Catarata senil foi identificada em 58,9 por cento dos participantes, predominando o tipo nuclear (51,8 por cento), seguido pelo cortical (26,8 por cento) e subcapsular posterior (8,9 por cento). Deficiência de zinco no plasma (<70 μg/dL) e no eritrócito (<40 μg/gHb) foi constatada em 49,1 por cento e 30,4 por cento dos idosos, respectivamente. Não houve diferenças significativas entre portadores e não-portadores de catarata, independente do tipo, quanto às concentrações de zinco plasmático (p=0,165) ou eritrocitário (p=0,426). CONCLUSÃO: Deficiência de zinco no plasma ou eritrócito foi comum entre os idosos; porém, os dados indicam não haver diferenças significativas nos referidos parâmetros quanto à presença de catarata senil, independente do tipo.

PURPOSE: To determine plasma and erythrocyte zinc concentrations in elderly with and without senile cataract in a tertiary eye care center at Teresina-Piauí. METHODS: A quantitative, transversal and controlled study was developed at the Hospital de Olhos Francisco Vilar, Piauí, Brasil. Fifty-six elderly subjects (37 females, 19 males) with no known conditions that modify zinc blood levels or increase risk of cataract were included. A score >II was used to define cataract, according to Lens Opacities Classification System II. Plasma and erythrocyte zinc concentrations were determined by flame atomic absorption spectrometry. Statistical tests included Student's t and chi-square tests, with a probability level of 0.05 as significant. RESULTS: Senile cataract was present in 58.9 percent of the subjects. The most common type was nuclear (51.8 percent), followed by cortical (26.8 percent) and posterior subcapsular (8.9 percent). Zinc deficiencies in plasma (<70 μg/dL) and erythrocyte (<40 μg/gHb) were found in 49.1 percent and 30.4 percent of participants, respectively. There were no significant differences between elderly with or without cataract, regardless of type, in relation to plasma (p=0.165) or erythrocyte (p=0.426) zinc concentrations. CONCLUSION: Zinc deficiency in plasma or erythrocyte were common among the elderly. However, the data suggest that no significant differences exist between elderly with or without senile cataract, regardless of type, in relation to the referred parameters of zinc evaluation.

The Prevalence and Demographic Characteristics of Anterior Polar Cataract in a Hospital-Based Study in Korea

PURPOSE: Anterior Polar Cataract (APC) develops by a mechanism different from that of other age-related cataracts, and outside of Korea, it is an extremely rare condition. We investigated the prevalence and epidemiological characteristics of APC in Koreans. METHODS: The evaluation on the prevalence of APC in comparison to the other age-related cataracts was performed on the 2,108 cataract patients who were treated at 5 different areas in Korea from August 2003 to December 2003. The demographic characteristics of APC were studied on the, 656 cataract patients who were treated from January 2004 to January 2005 at one hospital. These patients were classified according to the type of lens opacity (nuclear, cortical, posterior subcapsular, mixed and APC). RESULTS: The prevalence of patients with APC among all the cataract patients was 6.02% during the 5 months in this hospital-based study. Eighty-seven per cent of patients with APC were male. In contrast, the proportion of female was greater than 50% in the other cataracts. The mean age of APC patients was 52.7 years. Among the APC patients, 38.9% were under 50 years of age, 42.6% in their 50s, 14.8% in their 60s, and 3.7% were in their 70s. However, 80% of patients were over the age of 60 years in nuclear, cortical, and mixed-type cataracts. CONCLUSIONS: The prevalence of APC among all cataracts was high in comparision with another country. The proportion of APC was high in individuals younger than 60 years of age, and in males.

Clinical Outcomes of Surgical Techniques in Congenital Cataracts

PURPOSE: To investigate the general clinical features of congenital cataracts and to determine their relationship to visual prognosis and surgical complications according to age at operation and surgical procedure adopted. METHOD: We retrospectively evaluated 92 eyes in 61 patients with congenital cataracts who underwent cataract surgery between January 1996 and December 2006. The demographic data, surgical technique, post-operative complications, and final visual prognosis were evaluated. RESULTS: The average age at surgery was 3.17 years (range 1 month to 11 years), and the mean follow-up was 40.02 months (range 6 to 46 months). Of the 56 eyes that could be checked for visual acuity after cataract extraction, 29 (51.7%) had a BCVA of > or =0.5 at last visit. Unilateral congenital cataracts (p=0.025) and congenital cataracts with strabismus (p=0.019) showed significantly poorer visual outcomes. Patients with nystagmus also experienced a poor visual outcome; 6 patients (67%) had a BCVA of <0.1. Posterior cataracts had the worst visual prognosis (p=0.004). No statistically significant differences in posterior capsular opacity (p=0.901) or synechia formation (p=0.449) were observed between surgical techniques, but children younger than one year showed a higher tendency for PCO and synechia formation. CONCLUSIONS: Anterior vitrectomy did not reduce postoperative complications. Higher rates of complications (PCO, posterior synechia) developed in children younger than one year of age.

Intraoperative performance and longterm outcome of phacoemulsification in age-related cataract.

PURPOSE: To evaluate intraoperative performance and longterm surgical outcome after phacoemulsification of age-related cataracts. METHODS: Prospective, observational, non-comparative study of 165 consecutive eyes undergoing phacoemulsification with nuclear sclerosis Grade I to III (Scale I to V). Preoperative evaluation included specular microscopy. Phacoemulsification was performed by a single surgeon using a standardised surgical technique under topical anaesthesia. Intraoperatively, effective phaco time (EPT), wound site thermal injury (WSTI), serious complications (eg. vitreous loss, posterior capsule rupture, zonulolysis) and intraoperative posterior capsule opacification (plaque) were evaluated. Postoperatively, posterior capsule opacification (PCO), Neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate, corneal endothelial count, best corrected visual acuity and cystoid macular oedema were evaluated. Eyes were examined at 6 months and then yearly for 3 years. RESULTS: Mean ages of 78 males and 87 females were 59.12 +/- 8.56 and 58.34 +/- 7.45 years respectively. EPT was 36 +/- 19 seconds and WSTI occurred in 7 eyes (4.7%). No serious intraocular complications occurred. Intraoperative posterior capsule opacification (plaque) was present in 21 eyes (13.93%). Postoperatively, PCO occurred in 8 eyes (4.84%) and Nd:YAG laser posterior capsulotomy was performed in 3 eyes (1.8%). Endothelial cell loss was 7.1% at 3 years follow-up. At the end of 3 years follow-up, 146 eyes (88.89%) maintained a best corrected visual acuity of > or = 6/12. Cystoid macular oedema did not occur in any eye at 1 and 6 months' follow-up. CONCLUSION: PCO rates and endothelial cell loss were acceptable. Consistent and reproducible outcome can be obtained after phacoemulsification of age related cataracts (grade I to III).

Catarata em pequenos animais: classificaçäo e tratamento / Cataract in small animals: classification and treatment

Por catarata, entende-se qualquer opacidade presente no cristalino, cápsula do cristalino ou ambos. As opacidades podem variar quanto ao tamanho, localizaçäo, forma e velocidade de progressäo. Através da biomicroscopia com lâmpada de fenda é possível examiná-las com precisäo, determinando sua localizaçäo e peculiaridades, propiciando um diagnóstico acurado e seguro. Devido à origem e aparência variáveis, muitos métodos de classificaçäo têm sido utilizados. Classificaçäo quanto à etiologia, grau de maturidade, localizaçäo e idade do paciente säo apresentados nesta revisäo. A remoçäo cirúrgica é a única forma de terapia efetiva para a enfermidade. Dentre as técnicas existentes, destaca-se a facoemulsificaçäo endocapsular, por seus melhores resultados, näo obstante seus altos custos, comparativamente às facectomias intra e extracapsulares clássicas

Catarata traumática ultrasonográfica / Ultrasonographic traumatic cataract

El presente trabajo realizado en el Servicio de Oftalmología del Hospital Universitario de Caracas, tuvo como objetivo el diagnosticar las lesiones del segmento posterior del globo ocular mediante estudio ultrasonográfico, en pacientes que acudieron en el período 90-91 con diagnóstico de catarata traumática y correlacionar la clínica con los hallazgos ultrasonográficos. Se estudiaron 100 pacientes a los cuales se les realizó ultrasonografía como examen complementario. Se evidenció una alta incidencia de lesiones del segmento posterior en los traumas contusos; al igual que en los pacientes que presentaron hipotonía ocular, hifema y no percepción de rojo-verde. Las lesiones más frecuentes fueron: hemorragia vítrea (62,84 por ciento); desprendimiento de retina (31,36 por ciento) y organización vítrea (15,68 por ciento). Se puede concluir que el estudio ultrasonográfico es de gran valor en el diagnóstico de lesiones del segmento posterior, en ojos lesionados y catarata traumática, y la correlación clínica con los hallazgos ultrasonográficos es de relevante importancia para la valoración inicial de la lesión

Visual acuity testing in cataract--an insight (cataract classification density based).

The senile cataracts have been graded on the basis of density objectively. The letter visual acuity, laser interferometric visual acuity and pin hole visual acuity were compared in various grades of cataracts and controls (phakic and aphakic) in 140 eyes. It was found that good correlation exists in all eyes except when cataract density is grade III or IV. The laser interferometry has good prognostic value when the predictability is assessed in early stages of cataract (Grade I & II).

A simple accurate method of cataract classification. Cataract-I.

A simple and accurate system of cataract classification using slit lamp and direct ophthalmoscope is reported. Lens opacities are classified into cortical (anterior and posterior), nuclear and posterior sub-capsular and each sub-type of opacity is graded, extent and density wise, using both slit lamp and direct ophthalmoscope. A circle representing enface view of opacity divided into 100 equal parts is used in calculating the area of each opacity. This classification takes into account both the area and depth of opacity in arriving at the total extent of sub-type of each opacity. For density determination, we do not recommend the use of a resolution target projection ophthalmoscope. Intra-observer and inter-observer variability studies using this classification system indicated that the classification system is fairly reliable.

Methodology for studies on medical therapy of cataracts: cataract-II.

The methodology for testing any possible effect of potential anti-cataract agents is described. This is based on slit lamp and ophthalmoscopic cataract classification and on visual acuity. The difficulties encountered in such studies are highlighted. The presented methodology is suggested to be fairly adequate in assessing usefulness of any possible medical therapy of cataracts.