Abraham Zacuto Lusitano y el aura visual migrañosa / Abraham Zacuto Lusitano and migraine visual aura

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Manejo de la perforación conjuntival y Seidel tardío poscirugía XEN® / Management of conjunctival perforation and late Seidel after XEN® surgery

Caso clínico: Mujer de 78 años con antecedentes de cirugía XEN®. A los 18 meses de seguimiento se observa perforación conjuntival a nivel del implante, decidiéndose intervención quirúrgica. En esta se constató un trayecto subconjuntival corto (0,5 mm). Se intenta, sin éxito, extraerlo mediante tracción, sin embargo, el XEN® se rompe con facilidad. Finalmente se decide seccionarlo hasta nivel escleral, y suturar la conjuntiva. Durante la primera semana poscirugía existe disminución de la presión intraocular (6 mmHg), para posteriormente aumentar progresivamente hasta 25, optándose por iniciar tratamiento médico. Discusión: La exposición conjuntival del XEN® es una complicación rara, pero potencialmente grave. Para evitarla es importante una técnica quirúrgica meticulosa durante su implantación. En caso de suceder es importante identificar la causa. Si es debida al trayecto subconjuntival corto, una alternativa terapéutica es la sección del implante a este nivel para evitar nuevas complicaciones (AU)

Clinical case: The case concerns a 78 year-old woman with a history of XEN® surgery, in whom a conjunctival perforation was observed at the implant level at 18-months of follow-up, for which surgical intervention was decided. During surgery a short subconjunctival portion was found (0.5 mm). An unsuccessful attempt was made to extract it by traction, but the XEN® broke easily. Finally, it was decided to cut it to scleral level, and suture the conjunctiva. During the first week there was a decrease in intraocular pressure (6 mmHg), to subsequently increase to 25, and deciding to start medical treatment. Discussion: Conjunctival exposure of the XEN® stent is a rare but potentially serious complication. To avoid it, a meticulous surgical technique is important when implanting it. If this occurs, it is important to identify the cause. If it is due to a short subconjunctival portion, a therapeutic alternative is to cut the implant at this level to avoid further complications (AU)

Obstrucción proximal del implante XEN: diagnóstico y tratamiento / Proximal obstruction of a XEN gel stent: Diagnosis and treatment

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Management of conjunctival perforation and late Seidel after XEN® surgery. / Manejo de la perforación conjuntival y Seidel tardío poscirugía XEN®.

CLINICAL CASE: The case concerns a 78 year-old woman with a history of XEN® surgery, in whom a conjunctival perforation was observed at the implant level at 18-months of follow-up, for which surgical intervention was decided. During surgery a short subconjunctival portion was found (0.5mm). An unsuccessful attempt was made to extract it by traction, but the XEN® broke easily. Finally, it was decided to cut it to scleral level, and suture the conjunctiva. During the first week there was a decrease in intraocular pressure (6mmHg), to subsequently increase to 25, and deciding to start medical treatment. DISCUSSION: Conjunctival exposure of the XEN® stent is a rare but potentially serious complication. To avoid it, a meticulous surgical technique is important when implanting it. If this occurs, it is important to identify the cause. If it is due to a short subconjunctival portion, a therapeutic alternative is to cut the implant at this level to avoid further complications.

Análisis cualitativo de ampollas de filtración reparadas mediante tomografía de coherencia óptica de segmento anterior / Qualitative analysis of repaired filtering blebs with anterior segment-optical coherence tomography

Objetivo: Realizar un análisis cualitativo de las ampollas de filtración que han sido reparadas quirúrgicamente por presentar Seidel tardío. Métodos: Estudio de 10 ampollas de filtración que requirieron reparación quirúrgica mediante la OCT-SA Triton (Topcon(R)). Se analizó, a los 6 meses de la cirugía, el patrón morfológico y las estructuras internas de las mismas, así como el estado del recubrimiento. La obtención de las imágenes fue mediante longitudes de onda de 1.050 nm. Resultados: Según la clasificación de Hirooka, encontramos 3 patrones diferentes en la morfología de la ampolla que pudimos relacionar con la funcionalidad de la misma. En un 70% de los casos el recubrimiento fue completo, presentando quistes subepiteliales difusos (tipo quístico). Dos casos mostraron una retracción conjuntival completa, sin cobertura por Tenon. Las paredes estaban adelgazadas, mostrando una desestructuración de la ampolla (patrón difuso). En un tercer grupo, la imagen obtenida mostraba una retracción conjuntival parcial con cobertura por Tenon. Presentaba algún quiste subepitelial difuso y con paredes siguiendo un patrón laminar. Conclusión: Mediante la OCT-SA es posible estudiar de forma detallada las características de la ampolla y las de su cobertura en el caso de reparación con avance conjuntival por Seidel tardío. Permite visualizar precozmente la retracción de la conjuntiva que en la lámpara de hendidura no sería visible y predecir mediante la morfología de la ampolla la funcionalidad de la misma (AU)

Objective: To provide a qualitative analysis of filtering blebs after being surgically repaired due to late blebs leaks. Methods: Blebs were studied 6 months after surgical reparation using AS-OCT Triton (Topcon(R)). An analysis was made of the morphological pattern and internal structures of blebs, including the covering, in 10 patients. The images were obtained using OCTs at a wavelength of 1050 nm. Results: According to the Hirooka classification, three different patterns were found in the structure of blebs, which made it possible to correlate them with their functionality. A full covering was observed in 70% of the cases, and they showed sub-epithelial cysts (cystoid pattern). Two cases showed a full conjunctival retraction without Tenon's covering. The walls were thin, with a de-structured bleb (diffuse pattern) being visualised. In the third group, the image showed a partial conjunctival retraction with Tenon's covering. There were some sub-epithelial diffuse cysts with walls following a laminar pattern. Conclusion: Using AS-OCT, it is possible to study the bleb's characteristics in detail, as well as the cover, in the case of blebs requiring repair due to late leaks, using conjunctival advancement. It allows for the early visualisation of conjunctival retractions that were not visible in a slit lamp, and to predict the functionality of the blebs by their morphology (AU)

Estudio prospectivo de las ampollas de filtración poscirugía de implante XEN45 / Prospective study of filtering blebs after XEN45 surgery

Objetivo: Analizar cualitativamente la evolución de las ampollas de filtración mediante tomografía de coherencia óptica de segmento anterior (OCT-SA) en pacientes con implante XEN45. Métodos: Estudio prospectivo de las ampollas de filtración de 30 ojos operados de catarata y glaucoma mediante facoemulsificación e implantación XEN45 (FACO-XEN). Se realizó OCT-SA analizando la morfología y la reflectividad de la ampolla al mes 3, 6 y 12 postoperatorio. La funcionalidad se estudió considerando una presión intraocular (PIO) ≤ 18mm Hg sin medicación hipotensora. Resultados: La PIO permitió clasificar las ampollas en no funcionales: planas (6,67%) y encapsuladas (3,33%) y funcionales (90%), las cuales dividimos según su morfología en quísticas (5/27), difusas (2/27) y laminar o en capas (20/27). Las quísticas presentaron una PIO media de 12,8, 12,6 y 14,0 mm Hg a los 3, 6 y 12 meses respectivamente. En las difusas la PIO media fue 13,0, 11,5 y 13,0 mm Hg a los 3, 6 y 12 meses respectivamente. En las de patrón en capas la PIO media fue 14,45, 14,55 y 14,8 mm Hg a los 3, 6 y 12 meses respectivamente. El porcentaje de ampollas con alta reflectividad fue de 48,15%, 62,96% y 77,78% a los 3, 6 y 12 meses, con una PIO media de 14,23, 14,59 y 15,14mmHg en cada período, respectivamente. Conclusión: El análisis de OCT-SA podría ser un buen predictor de la funcionalidad de la ampollas en la cirugía FACO-XEN. Aquellas quísticas o con menor reflectividad parecen tener mejor éxito postoperatorio. Pese a ello, se requieren estudios a mayor largo plazo (AU)

Objective: To qualitatively analyse the evolution of filtering blebs after XEN surgery, by using anterior segment optical coherence tomography (AS-OCT). Methods: A prospective study was performed on filtering blebs of 30 eyes with cataracts and glaucoma, surgically operated on using phacoemulsification and XEN45 implantation (PHACO-XEN). AS-OCT was used to analyse bleb morphology and reflectivity at 3, 6, and 12 months after surgery. Functionality was studied considering an intraocular pressure (IOP) ≤ 18 mm Hg without antihypertensive medication. Results: The IOP enabled the blebs to be classified into non-functional: flat (6.67%) and encapsulated (3.33%); and functional (90%), which were then divide by their morphology into cystic (5/27), diffuse (2/27), and layered (20/27). Cystic types had a mean IOP of 12.8, 12.6, and 14.0 mm Hg at 3, 6 and 12 months, respectively. In the diffuse type, the mean IOP was 13.0, 11.5 and 13.0 mm Hg at 3, 6 and 12 months, respectively. In the layers pattern the mean IOP was 14.45, 14.55 and 14.8 mm Hg at 3, 6 and 12 months respectively. The percentage of blebs with high reflectivity was 48.15%, 62.96%, and 77.78%, at 3, 6 and 12 months, with a mean IOP of 14.23, 14.59, and 15.14mmHg in each time period, respectively. Conclusion: AS-OCT could be a good predictor of bleb functionality in PHACO-XEN surgery. Those with a cystic pattern or low reflectivity seem to have better post-operative success. Nevertheless, more long-term studies are required (AU)

Eficacia del SENSIMED Triggerfish (R) para el seguimiento postoperatorio de la cirugía combinada FACO-ExPRESS / Efficacy of the SENSIMED Triggerfish(R) in the postoperative follow-up of PHACO-ExPRESS combined surgery

Objetivo: Estudiar la utilidad del sistema SENSIMED Triggerfish(R) en el control postoperatorio de la cirugía combinada de facoemulsificación e implante ExPRESS (FACO-ExPRESS) en pacientes con catarata y glaucoma primario de ángulo abierto (GPAA) con un seguimiento de 2 meses: Métodos Estudio prospectivo de 15 ojos intervenidos de cirugía combinada FACO-ExPRESS. Utilizando el sistema SENSIMED Triggerfish (R) (Sensimed AG, Lausanne, Suiza) se realizaron 2 registros de los patrones circadianos de la presión intraocular (PIO), uno previa y otro posterior a la cirugía. Se registró la agudeza visual mejor corregida, comorbilidades, PIO previa y de los días 7-30-60 poscirugía, medicamentos hipotensores y complicaciones. Resultados: La muestra final fue de 12 ojos. La agudeza visual mejor corregida (escala Log MAR) media preoperatoria fue 0,5 ± 0,2 y poscirugía 0,4 ± 0,1 (p = 0,02). La PIO media previa fue de 18,7 ± 3,8 mm Hg con 2,9 ± 0,7 fármacos. La PIO media en los días 7, 30 y 60 descendió a 13 ± 4,1mmHg (p = 0,002), 13,5 ± 2 mm Hg (p=0,001) y 13,9 ± 2,5 mm Hg (p=0,001) respectivamente. Las amplitudes de las curvas circadianas cambiaron significativamente entre antes y después de la cirugía (p = 0,007). Los valores medios de los periodos diurno y nocturno disminuyeron significativamente de 146,8 ± 80,9mVeq y 61,2 ± 92mVeq precirugía a 36,4 ± 36mVeq (p=0,000) y -23,2 ± 47,6mVeq (p = 0,014) poscirugía, respectivamente. Un paciente presentó complicaciones. Conclusiones: El sistema de monitorización SENSIMED Triggerfish(R) mostró cambios en los patrones circadianos, así como disminución de las amplitudes medias de las curvas tras la técnica combinada FACO-ExPRESS, lo que sugiere que este sistema puede convertirse en una herramienta útil para el seguimiento postoperatorio del GPAA (AU)

Objective: To determine the usefulness of the SENSIMED Triggerfish(R) system in the postoperative control of combined phacoemulsification and ExPRESS implant (PHACO-ExPRESS) surgery in patients with cataract and chronic open angle glaucoma (COAG) during a 2 months follow-up. Methods: A prospective study conducted on 15 eyes that were subjected to PHACO-ExPRESS combined surgery. Using the SENSIMED Triggerfish (R) system, two records of the circadian patterns of intraocular pressure (IOP) were performed, one before and one after surgery. A record was made of the best corrected visual acuity (BCVA), comorbidities, previous IOP, and 7-30-60 days after surgery, as well as any hypotensive drugs and complications. Results: The final sample was 12 eyes. The mean pre-operative BCVA (log MAR chart) before surgery was 0.5 ± 0.2, and after surgery 0.14 ± 0.1 (P = .02). The previous IOP was 18.7 ± 3.8mmHg with 2.9 ± 0.7 drugs. The mean IOP at 7, 30, and 60 days after surgery decreased to 13±4.1mmHg (P =.002), 13.5 ± 2mmHg (P =.001), and 13.9 ± 2.5mmHg (P =.001), respectively. The amplitudes of the circadian curves changed significantly after surgery (P =.007). The mean values between daytime and night-time periods decreased significantly from 146.8 ± 80.9 mVeq and 61.2±92.mVeq before surgery to 36.4 ± 36 mVeq (P =.000), and -23,2 ± 47.6mVeq (P =.014) after surgery, respectively. There were complications in one patient. Conclusions: The SENSIMED Triggerfish® monitoring system showed changes in the curves of the circadian patterns, as well as decreased mean amplitudes after the combined PHACO-ExPRESS technique, suggesting that it may become a useful tool for postoperative follow-up of COAG (AU)

Un oftalmólogo Premio Nobel / An ophthalmologist Nobel Prize Winner

No disponible

Efficacy of the SENSIMED Triggerfish® in the postoperative follow-up of PHACO-ExPRESS combined surgery. / Eficacia del SENSIMED Triggerfish® para el seguimiento postoperatorio de la cirugía combinada FACO-ExPRESS.

OBJECTIVE: To determine the usefulness of the SENSIMED Triggerfish® system in the postoperative control of combined phacoemulsification and ExPRESS implant (PHACO-ExPRESS) surgery in patients with cataract and chronic open angle glaucoma (COAG) during a 2 months follow-up. METHODS: A prospective study conducted on 15 eyes that were subjected to PHACO-ExPRESS combined surgery. Using the SENSIMED Triggerfish® system, two records of the circadian patterns of intraocular pressure (IOP) were performed, one before and one after surgery. A record was made of the best corrected visual acuity (BCVA), comorbidities, previous IOP, and 7-30-60 days after surgery, as well as any hypotensive drugs and complications. RESULTS: The final sample was 12 eyes. The mean pre-operative BCVA (log MAR chart) before surgery was 0.5±0.2, and after surgery 0.14±0.1 (P=.02). The previous IOP was 18.7±3.8mmHg with 2.9±0.7 drugs. The mean IOP at 7, 30, and 60 days after surgery decreased to 13±4.1mmHg (P=.002), 13.5±2mmHg (P=.001), and 13.9±2.5mmHg (P=.001), respectively. The amplitudes of the circadian curves changed significantly after surgery (P=.007). The mean values between daytime and night-time periods decreased significantly from 146.8±80.9 mVeq and 61.2±92.mVeq before surgery to 36.4±36 mVeq (P=.000), and -23,2±47.6mVeq (P=.014) after surgery, respectively. There were complications in one patient. CONCLUSIONS: The SENSIMED Triggerfish® monitoring system showed changes in the curves of the circadian patterns, as well as decreased mean amplitudes after the combined PHACO-ExPRESS technique, suggesting that it may become a useful tool for postoperative follow-up of COAG.

Prospective study of filtering blebs after XEN45 surgery. / Estudio prospectivo de las ampollas de filtración poscirugía de implante XEN45.

OBJECTIVE: To qualitatively analyse the evolution of filtering blebs after XEN surgery, by using anterior segment optical coherence tomography (AS-OCT). METHODS: A prospective study was performed on filtering blebs of 30 eyes with cataracts and glaucoma, surgically operated on using phacoemulsification and XEN45 implantation (PHACO-XEN). AS-OCT was used to analyse bleb morphology and reflectivity at 3, 6, and 12 months after surgery. Functionality was studied considering an intraocular pressure (IOP)≤18mmHg without antihypertensive medication. RESULTS: The IOP enabled the blebs to be classified into non-functional: flat (6.67%) and encapsulated (3.33%); and functional (90%), which were then divide by their morphology into cystic (5/27), diffuse (2/27), and layered (20/27). Cystic types had a mean IOP of 12.8, 12.6, and 14.0mmHg at 3, 6 and 12 months, respectively. In the diffuse type, the mean IOP was 13.0, 11.5 and 13.0mmHg at 3, 6 and 12 months, respectively. In the layers pattern the mean IOP was 14.45, 14.55 and 14.8mmHg at 3, 6 and 12 months respectively. The percentage of blebs with high reflectivity was 48.15%, 62.96%, and 77.78%, at 3, 6 and 12 months, with a mean IOP of 14.23, 14.59, and 15.14mmHg in each time period, respectively. CONCLUSION: AS-OCT could be a good predictor of bleb functionality in PHACO-XEN surgery. Those with a cystic pattern or low reflectivity seem to have better post-operative success. Nevertheless, more long-term studies are required.

Qualitative analysis of repaired filtering blebs with anterior segment-optical coherence tomography. / Análisis cualitativo de ampollas de filtración reparadas mediante tomografía de coherencia óptica de segmento anterior.

OBJECTIVE: To provide a qualitative analysis of filtering blebs after being surgically repaired due to late blebs leaks. METHODS: Blebs were studied 6 months after surgical reparation using AS-OCT Triton (Topcon®). An analysis was made of the morphological pattern and internal structures of blebs, including the covering, in 10 patients. The images were obtained using OCTs at a wavelength of 1050nm. RESULTS: According to the Hirooka classification, three different patterns were found in the structure of blebs, which made it possible to correlate them with their functionality. A full covering was observed in 70% of the cases, and they showed sub-epithelial cysts (cystoid pattern). Two cases showed a full conjunctival retraction without Tenon's covering. The walls were thin, with a de-structured bleb (diffuse pattern) being visualised. In the third group, the image showed a partial conjunctival retraction with Tenon's covering. There were some sub-epithelial diffuse cysts with walls following a laminar pattern. CONCLUSION: Using AS-OCT, it is possible to study the bleb's characteristics in detail, as well as the cover, in the case of blebs requiring repair due to late leaks, using conjunctival advancement. It allows for the early visualisation of conjunctival retractions that were not visible in a slit lamp, and to predict the functionality of the blebs by their morphology.

Un Papa oftalmólogo / An ophthalmologist Pope

No disponible

Cirugía combinada mediante facoemulsificación e implante XEN45 con acceso temporal y 2 únicas incisiones / Combined phacoemulsification and XEN45 surgery from a temporal approach and 2 incisions

OBJETIVO: Analizar la eficacia y seguridad de la técnica combinada de facoemulsificación e implante XEN45 empleando acceso temporal y 2 únicas incisiones, en casos de catarata y glaucoma crónico de ángulo abierto, con seguimiento de 12 meses. MÉTODOS: Estudio prospectivo de 30 ojos que requerían facoemulsificación y que precisaban, al menos, dos medicamentos para controlar presión intraocular (PIO). Se efectuó cirugía combinada de facoemulsificación e implante XEN45 a los 15 min de administrar mitomicina C subconjuntival. El procedimiento se realizó a través de 2 incisiones temporales, separadas por 90°, utilizando la inferior para introducir el XEN45 e implantarlo en región nasal superior. Se registró agudeza visual mejor corregida, PIO previa y en días 1-30-90-180-270 y 365 poscirugía, número de medicamentos hipotensores y complicaciones. RESULTADOS: La agudeza visual mejor corregida preoperatoria fue 0,37 ± 0,2 y 0,72 ± 0,15 a los 12 meses. La PIO previa fue 21,2 ± 3,4 mmHg con 3,07 fármacos, descendiendo un 61,65% el primer día, 37,26% al mes, 35,05% al tercer mes, 31% al sexto mes, 30,6% al noveno mes y 29,34% a los 12 meses. El número de fármacos disminuyó un 94,57%. Solo hubo complicaciones destacables en 3 ojos, de ellos, 2 se excluyeron al no poder completar implantación (uno por hemorragia subconjuntival en 280° y otro, por extrusión del XEN al intentar recolocarlo). En un tercero, la ampolla se encapsuló a los 5 meses poscirugía. CONCLUSIONES: La cirugía combinada de facoemulsificación e implante XEN45 reduce eficazmente la PIO y el número de medicamentos en el glaucoma crónico de ángulo abierto leve-moderado, al tiempo que rehabilita la AV. El empleo de solo 2 incisiones posibilita una cirugía microinvasiva sencilla, rápida y segura con escasas complicaciones tras 12 meses de seguimiento

OBJECTIVE: To assess the safety and effectiveness of phacoemulsification combined with XEN45 implant surgery in patients with cataract and open-angle glaucoma, with 12-month follow-up. METHODS: A prospective study conducted on 30 eyes requiring phacoemulsification with, at least, 2 medications to control intraocular pressure (IOP). Phacoemulsification combined with XEN45 implant surgery was performed within 15minutes of administering subconjunctival mitomycin C. Surgery was performed through 2 temporal incisions, separated by 90°, using the inferior to enter the XEN45 and to implant it in the superior nasal region. A record was made of the best corrected visual acuity, IOP before and 1 day, 1 month, 3 months, 6 months, 9 months, and 12 months after surgery, the number of antiglaucomatous medications, and complications. RESULTS: The best corrected visual acuity was 0.37±0.2 and 0.72 ± 0.15 before and 12 months after surgery, respectively. The pre-operative IOP was 21.2 ± 3.4 mmHg, with 3.07 drugs, decreasing by 61.65% on the first day, 37.26% at 1 month, 35.05% at 3 months, 31% at 6 months, 30.6% at 9 months, and 29.34% at 12 months. The number of medications decreased by 94.57%. Complications occurred in 3 eyes, 2 of them were excluded because we could not complete the implantation (280° subconjunctival haemorrhage and XEN extrusion when trying to reposition). In a third case, the bleb was encapsulated at 5 months after surgery. CONCLUSIONS: The phacoemulsification combined with XEN45 implant surgery can effectively reduce IOP and the number of drugs in mild-moderate open-angle glaucoma, as they rehabilitate the VA. The use of only 2 micro-invasive incisions makes it simple, quick and safe, with few complications at 12 months follow-up from surgery

Combined phacoemulsification and XEN45 surgery from a temporal approach and 2 incisions. / Cirugía combinada mediante facoemulsificación e implante XEN45 con acceso temporal y 2 únicas incisiones.

OBJECTIVE: To assess the safety and effectiveness of phacoemulsification combined with XEN45 implant surgery in patients with cataract and open-angle glaucoma, with 12-month follow-up. METHODS: A prospective study conducted on 30 eyes requiring phacoemulsification with, at least, 2 medications to control intraocular pressure (IOP). Phacoemulsification combined with XEN45 implant surgery was performed within 15minutes of administering subconjunctival mitomycin C. Surgery was performed through 2 temporal incisions, separated by 90°, using the inferior to enter the XEN45 and to implant it in the superior nasal region. A record was made of the best corrected visual acuity, IOP before and 1 day, 1 month, 3 months, 6 months, 9 months, and 12 months after surgery, the number of antiglaucomatous medications, and complications. RESULTS: The best corrected visual acuity was 0.37±0.2 and 0.72±0.15 before and 12 months after surgery, respectively. The pre-operative IOP was 21.2±3.4mmHg, with 3.07 drugs, decreasing by 61.65% on the first day, 37.26% at 1 month, 35.05% at 3 months, 31% at 6 months, 30.6% at 9 months, and 29.34% at 12 months. The number of medications decreased by 94.57%. Complications occurred in 3 eyes, 2 of them were excluded because we could not complete the implantation (280° subconjunctival haemorrhage and XEN extrusion when trying to reposition). In a third case, the bleb was encapsulated at 5 months after surgery. CONCLUSIONS: The phacoemulsification combined with XEN45 implant surgery can effectively reduce IOP and the number of drugs in mild-moderate open-angle glaucoma, as they rehabilitate the VA. The use of only 2 micro-invasive incisions makes it simple, quick and safe, with few complications at 12 months follow-up from surgery.

[Brimonidine absorption and release from 1. Day acuvue disposable contact lenses]. / Absorción y liberación de brimonidina por lentes de contacto desechables 1.Day acuvue.

PURPOSE: We studied absorption and release of brimonidine tartrate while wearing 1 Day Acuvue contact lenses. MATERIAL AND METHOD: A regression chart was obtained from 320 nm ultraviolet absorption (UV) for different dilutions of brimonidine tartrate in ophthalmic solutions (Alphagan(R)). 40 microliter of opthalmic solution was placed in the concavity of the contact lens; after a series of time intervals, lens was drained and introduced in a test-tube containing 2 ml of saline and underwent a quick cleansing. Next, lens was withdrawn from this tube and introduced into another test tube containing 2 ml of saline. Test tube was changed at intervals of 5 minutes. UV absorption is measured on each resulting tube until reading is 0. Contents of tubes in microgram of product were calculated according to regression chart. Total absorption will show substance penetration in lens. Release of substance is appreciated when lens is loaded during 1 minute and then placed in a tube containing 2 ml of saline introduced in the spectrophotometer which measures UV absorption minute by minute. RESULTS: Within the first minute, 51.54 microgram of product are absorbed (64.42% of a total of 80 microgram contained in a drop of ophthalmic solution), 20% found in lens surface and 44% penetrated the lens. If soaked during 3 minutes, lens takes 71% of fluid, 20% on surface and 50% into the lens itself. Release in 2 ml of saline is 19.33 microgram (37.5% of 51.54 microgram) in 1 hour, 25.57 microgram (49.6%) in 2 hours and 29.7 microgram (57.6%) after 3 hours. If saline is changed every 5 minutes, 100% of product is released in 35 minutes. CONCLUSION: Disposable contact lenses 1. DAY ACUVUE(R) are able to take and release brimonidine tartrate in vitro.

Absorción y liberación de brimonidina por lentes de contacto desechables 1.Day Acuvue / Brimonidine absorption and release from 1.Day acuvue disposable contact lenses

Objetivo: Estudiar la absorción y liberación de tartrato de brimonidina por LC desechables 1.Day Acuvue. Métodos: Se obtiene la fórmula de ajuste por regresión de la curva de absorción de rayos ultravioleta de 320 nm (UV), de distintas diluciones del colirio de tartrato de brimonidina (Alphagan®). Ponemos en la concavidad de la LC 40 µl del colirio y, tras distintos períodos de tiempo, escurrimos la lente y la introducimos en un tubo de ensayo con 2 ml de suero fisiológico (SF), donde se hace un lavado rápido de la superficie de la lente, luego la pasamos a otro tubo con otros 2 ml de SF, donde permanece 5 minutos pasándola posteriormente a nuevos tubos cada 5 minutos. Medimos la absorción de UV de los sucesivos tubos, hasta que ésta es nula, y con la fórmula convertimos las unidades de absorción en µg del producto, que sumados nos da la cantidad total absorbida. Si a esta cantidad le restamos la del primer lavado rápido, que era la adherida a la superficie, obtenemos la que penetra dentro de la lente. Para ver como se libera el producto, cargamos la LC durante 1 minuto y la colocamos en un tubo con 2 ml de SF introducido en el espectrofotómetro, que mide cada minuto la absorción de UV. Resultados: Con un minuto se absorben ya 51,54 µg del producto, equivalente al 64,42 por ciento del total de 80 µg de una gota del colirio, de los que un 20 por ciento queda adherido a superficie y un 44 por ciento penetra dentro de la LC. Empapada durante 3 minutos la LC coge un 71 por ciento: 20 por ciento en superficie y 50 por ciento dentro de la lente. La liberación, en 2 ml de SF, es 19,33 µg (37,5 por ciento de 51,54 µg) en 1 hora, 25,57 µg ( 49,6 por ciento) en 2 horas y 29,7 µg (57,6 por ciento) en 3 horas. Cambiando el SF cada 5 minutos, se libera el 100 por ciento a los 35 minutos. Conclusiones: Las LC desechables, 1.DAY ACUVUE®, in vitro, son capaces de absorber y liberar el tartrato de brimonidina (AU)

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