Ziel der vorliegenden Arbeit war, die Wirkung von Mydriatika auf Ableitungen des MERGs zu untersuchen. Es wurden bei 25 Versuchspersonen MERGs unter der Bedingung transient und steady-state bei den Karogrößen 0,8° und 7,5° vor und bis 150 min nach Dilatation des rechten Auges abgeleitet. Zeigte sich bei der Visusprüfung nach der Dilatation eine Verschlechterung des Visus gegenüber dem Anfangswert, wurde versucht, den Visus durch ein zur ursprünglichen Brille zusätzliches Plusglas zu verbessern. In diesem Fall wurden getrennt MERGs mit und ohne zusätzliches Plusglas abgeleitet. Die Mydriasis führte zu signifikanten Veränderungen des MERGs. Bei den großen Karos stiegen die Amplituden des steady-state und des transienten MERGs. Bei den kleinen Karos nahmen die Amplitude des steady-state MERGs und die P50-Amplitude des transienten MERGs ab. Die N95-Amplitude des transienten MERGs änderte sich nicht. Durch die gegenläufige Veränderung der Amplitude des steady-state MERGs wurde der Amplituden-Quotient der kleinen Karos zu den großen Karos signifikant reduziert. Bei beiden Karogrößen kam es zu einer Abnahme der Phase des steady-state MERGs und der P50-Latenz des transienten MERGs. Beim nicht weitgestellten Partnerauge kam es zu einer Zunahme der Phase und P50-Latenz bei beiden Karogrößen. / The aim of the present paper was to study the effect of mydriatica on the pattern electroretinogram (PERG). 25 test subjects participated in the experiment. Transient and steady-state PERGs were recorded at checkerboard patterns with check sizes of 7,5° and 0,8° before and after the dilation of the right eye. When the test subjects during the test of the visual acutiy after the dilation showed a impairment of the visual acuity compared to the valuation before the dilation, we tried to correct the visual acuity with an additional plus lens. In this case we recorded PERGs with and without the additional plus lens. Mydriasis changed the PERG significant. At check size 7,5° the amplitude of the steady-state and the transient PERG increased. At check size 0,8° the amplitude of the steady-state and the P50-amplitude of the transient PERG decreased. The N85-amplitude of the transient PERG didn´t change. Through the alteration of the amplitudes of the steady-state PERG in the opposite direction the amplitude-quotient of check size 0,8° to check size 7,5° was significant reduced. At both check sizes we saw a decrease of the phase of the steady-state PERG and of the P50-Latency of the transient PERG. The not-dilated fellow eye showed an increase of the phase and P50-Latency at both check sizes.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Um estudo prospectivo, randomizado, duplo-cego, com grupos em paralelo e controle ativo foi conduzido para comparar os efeitos cardiovasculares da soluÃÃo aquosa de fenilefrina a 2,5% versus a 10% em pacientes diabÃticos do tipo 2, submetidos a angiografia fluoresceÃnica, e tambÃm para comparar a eficÃcia dessas soluÃÃes na dilataÃÃo pupilar. Os voluntÃrios foram atendidos no Hospital Santo InÃcio, em Juazeiro do Norte, CearÃ, e randomicamente alocados em dois grupos. Os pacientes no grupo A receberam uma gota de proximetacaÃna a 0,5%, de tropicamida a 1% e de fenilefrina a 2,5% em ambos os olhos, enquanto os do grupo B receberam proximetacaÃna a 0,5%, tropicamida a 1% e fenilefrina a 10%. A pressÃo arterial e a freqÃÃncia cardÃaca foram mensuradas cinco minutos antes e em vÃrios instantes apÃs a instilaÃÃo de fenilefrina no fÃrnice conjuntival ao longo de um perÃodo de trÃs horas. As alteraÃÃes no ritmo cardÃaco foram gravadas por uma unidade de Holter em todos os pacientes. A Ãrea pupilar foi calculada antes e sessenta minutos apÃs a instilaÃÃo de fenilefrina. Dos quarenta e trÃs pacientes envolvidos, 22 foram alocados no grupo A e 21, no grupo B. NÃo houve diferenÃa estatisticamente significante entre os grupos na mÃdia da pressÃo arterial sistÃlica apÃs a instilaÃÃo de fenilefrina. Essa observaÃÃo tambÃm foi vÃlida para todos os instantes em relaÃÃo à mÃdia da pressÃo diastÃlica, menos em um (150 minutos), onde o grupo da fenilefrina a 10% registrou valor mais alto (P = 0,0460). Um aumento significativo na mÃdia da pressÃo arterial (sistÃlica e diastÃlica - P < 0,001) foi igualmente verificado no momento da injeÃÃo endovenosa de fluoresceÃna nos dois grupos. NÃo se observou diferenÃa estatisticamente significante entre os grupos na mÃdia da freqÃÃncia cardÃaca. As mudanÃas no ritmo cardÃaco nÃo se relacionaram com o uso da fenilefrina em qualquer dos grupos. A magnitude da dilataÃÃo pupilar sessenta minutos apÃs o uso da fenilefrina nÃo foi diferente entre os grupos. Diante destes resultados, pÃde-se concluir que, apÃs uma Ãnica instilaÃÃo, a fenilefrina a 2,5% comparada à fenilefrina a 10% foi igualmente capaz de induzir e de manter adequada midrÃase em pacientes diabÃticos do tipo 2, submetidos a angiografia fluoresceÃnica. O aumento na pressÃo arterial que seguiu a injeÃÃo de fluoresceÃna, principal mudanÃa nos parÃmetros cardiovasculares analisados, provavelmente nÃo se relacionou diretamente com qualquer das concentraÃÃes de fenilefrina usadas / A prospective, randomized, double-blind study with groups in parallel and active control was conducted to compare the cardiovascular effects of aqueous solution of phenylephrine 2.5% versus 10% in diabetic type 2 patients undergoing fluorescein angiography, and also to compare their efficacy on pupillary dilation. The volunteers at the Santo InÃcio Hospital, in Juazeiro do Norte, Cearà were randomized into two groups. Patients in group A received one drop of 0.5% proxymetacaine, 1% tropicamide, and 2.5% phenylephrine in both eyes, whereas those in group B received 0.5% proxymetacaine, 1% tropicamide, and 10% phenylephrine. Blood pressure and heart rate were measured five minutes before and several times after phenylephrine eyedrop instillation for a period of three hours. Alterations in cardiac rhythm were recorded by Holter in all patients. Pupil surface was measured before and sixty minutes after phenylephrine instillation. Forty three patients were allocated into 22 patients (group A) and 21 patients (group B). There was no significant difference in the mean systolic blood pressure after phenylephrine instillation between the two groups. This observation was also valid for all but one instant where the mean diastolic blood pressure (150 minutes) was significantly higher in 10% phenylephrine group (P = 0.0460). A significant raise in mean systolic and diastolic blood pressure was registered at the moment of intravenous fluorescein injection in both groups (P < 0.001). No statistically significant difference was detected in the mean heart rate. Changes in cardiac rhythm could not be attributed to phenylephrine in either group. The amount of pupillary dilation at sixty minutes did not differ between the groups. In conclusion, after a single dose instillation, 2.5% phenylephrine compared to 10% phenylephrine was equally able to induce and keep adequate pupil dilation in diabetic type 2 patients undergoing fluorescein angiography. The raise in blood pressure following fluorescein injection was the main change observed in the cardiovascular parameters analyzed and probably did not relate to the use of any phenylephrine concentration