Biomicroscopia ultrassônica na viscocanalostomia / Ultrasound biomicroscopy in viscocanalostomy

OBJETIVO: Estudar por biomicroscopia ultrassônica (UBM) de alta frequência as características anatômicas da viscocanalostomia, e a relação dessas características com a redução da pressão intraocular. MÉTODOS: Estudo transversal, que incluiu nove olhos (sete pacientes) submetidos à viscocanalostomia, e posteriormente examinados por UBM de alta frequência (80 MHz). Os parâmetros da UBM avaliados após um follow-up mínimo de seis meses foram: presença de espaço intraescleral, comprimento e altura máximos do espaço intraescleral, e a espessura mínima da membrana trabéculo-descemética (MTD) residual. O sucesso cirúrgico definiu-se como pressão intraocular (PIO) <22mmHg ou redução de 20% da PIO sem medicação tópica. Possíveis associações entre as variáveis da UBM e o resultado cirúrgico foram avaliados. RESULTADOS: O tempo médio entre a cirurgia e a realização da UBM foi de 15,5 ± 8,8 meses (6 - 29 meses). Verificou-se uma redução da PIO de 23,5 ± 6,9 mmHg (13,7-32,0) pré-operatória para 14,5 ± 2,4 mmHg (10,7-17,3) pós-operatória (p<0,05). Identificou-se a presença de espaço intraescleral em todos os olhos. A média do comprimento máximo do espaço intraescleral era 1,83 ± 0,51mm; a média da altura máxima do espaço intraescleral era 0,36 ± 0,17mm; e a média da espessura mínima da MTD era 0,14 ± 0,07mm. Não foram encontradas correlações significativas entre o valor da PIO pós-operatória e o comprimento do espaço intraescleral (r²=0,359), a altura do espaço intraescleral (r²=0,017) e a espessura da MTD (r²=0,003). CONCLUSÃO: Em pacientes submetidos à viscocanalostomia, a UBM após um follow-up mínimo de seis meses identificou o espaço intraescleral em todos os olhos. Não se encontrou qualquer correlação estatisticamente significativa entre os valores de PIO pós-operatória e as características anatômicas do espaço intraescleral.

PURPOSE: To evaluate by high frequency ultrasound biomicroscopy (UBM) the anatomical characteristics of viscocanalostomy and their relationship with the intraocular pressure (IOP) lowering. METHODS: A transversal study which included 9 eyes (7 patients) undergoing viscocanalostomy and examined by high frequency UBM (80 MHz). Several UBM variables were evaluated, including the presence of the intrascleral space, the maximum length and height of the intrascleral space and the minimum thickness of residual trabeculo-Descemet membrane (TDM). Surgical success was considered to be achieved when IOP was <22mmHg or the IOP was lowered 20% or more without the use of any medication. The possible association between UBM variables and the surgical outcome was determined. RESULTS: The mean time between surgery and the UBM examination was 15.5 ± 8.8 months (range 6-29). The mean IOP decreased from a preoperative value of 23.5 ± 6.9 mmHg (range 13.7-32.0) to 14.5 ± 2.4 mmHg (range 10.7-17.3) postoperative (p<0.05). The presence of an intrascleral space was a constant finding. The mean length of the intrascleral space was 1.83 ± 0.51mm, the mean height was 0,36 ± 0,17mm; and the mean TDM thickness was 0.14 ± 0.07mm. There were a poor correlation between the level of IOP at the time of UBM and the lenght of the intrascleral space (r²=0.359), the height of the intrascleral space (r²=0.017) or the thickness of the remaining TDM (r²=0.003). CONCLUSION: In patients undergoing viscocanalostomy, UBM examination after a minimum of 6-month follow-up period showed the presence of an intrascleral space in all patients. There was no statiscally significant relationship between the level of IOP and the anatomical characteristics of the intrascleral space.

Completion rates of anterior and posterior continuous curvilinear capsulorrhexis in pediatric cataract surgery for surgery performed by trainee surgeons with the use of a low-cost viscoelastic.

Context: Pediatric cataract surgery is traditionally done with the aid of high-molecular-weight viscoelastics which are expensive. It needs to be determined if low-cost substitutes are just as successful. Aims: The study aims to determine the success rates for anterior and posterior capsulorrhexis and intraocular lens (IOL) implantation in the bag for pediatric cataract surgery performed with the aid of a low-molecular-weight viscoelastic. Settings and Design: Nonrandomized observational study. Materials and Methods: Children less than 6 years of age who underwent cataract surgery with IOL implantation in the period May 2008–May 2009 were included. The surgeries were done by pediatric ophthalmology fellows. A standard procedure of anterior capsulorrhexis, lens aspiration with primary posterior capsulorrhexis, anterior vitrectomy, and IOL implantation was followed. Three parameters were studied: successful completion of anterior and posterior capsulorrhexis and IOL implantation in the bag. Results: 33 eyes of 28 children were studied. The success rate for completion was 66.7% and 88.2 % for anterior and posterior capsulorrhexis, respectively. IOL implantation in the bag was successful in 87.9%. Conclusions: 2% hydroxypropylmethylcellulose is a viable low-cost alternative to more expensive options similar to high-molecular-weight viscoelastics. This is of great relevance to hospitals in developing countries.

Viscoexpression technique in manual small incision cataract surgery.

Viscoexpression method of nucleus delivery in manual small incision cataract surgery is described in this article. The practical modifications to the conventional technique in special situations are presented. Intraoperative and postoperative problems likely to be encountered and the steps to avoid them and tackle them effectively are discussed.