Effect of topical cyclopentolate alone or combined with phenylephrine in healthy horses.

OBJECTIVE: Evaluate the effect of repeated doses of topical 1% cyclopentolate hydrochloride alone and in combination with topical 2.5% phenylephrine on pupil diameter (PD), tear production (STT-1), intraocular pressure (IOP), digestive function (gut motility and feces production), and heart rate (HR). ANIMAL STUDIED: Six healthy mares. PROCEDURES: In a prospective, randomized, controlled, and crossover design study, the left eye of six healthy mares was administered 0.2 mL of cyclopentolate alone and in combination with 0.2 mL of phenylephrine. The drugs were administered 3 times a day for 1 day, twice a day for 1 day, and then once a day for 2 days, as commonly used in practice. Daily and two days after the last topical drug administration, HR, digestive auscultation, feces production, STT-1, IOP, and PD were recorded. RESULTS: The cyclopentolate alone significantly increased the horizontal and vertical PD of the treated eye from day 2 to day 6 (p < .0001) compared with the baseline value. The combination with topical phenylephrine did not have any additional effect on mydriasis compare with the cyclopentolate alone. The other ocular and digestive parameters were not affected by repeated doses of cyclopentolate alone or combined. CONCLUSIONS: Repeated administration of cyclopentolate alone or combined with phenylephrine induce a significant mydriasis for at least 48 h after the last administration in normal horses' eyes, and do not affect STT-1, IOP, digestive function, and HR. The phenylephrine combined with the cyclopentolate did not potentiate the pupil dilation when compared with cyclopentolate alone in healthy horses.

Effects of topical 1% cyclopentolate hydrochloride on quantitative pupillometry measurements, tear production and intraocular pressure in healthy horses.

OBJECTIVE: To evaluate the effect of topical cyclopentolate hydrochloride (CH) on quantitative pupillometric readings (PR), tear production (TP), and intraocular pressure (IOP) in healthy horses. ANIMALS STUDIED: Fourteen client-owned horses. PROCEDURES: In a two-phase design study, each animal received 1% CH ophthalmic solution in the left eye [treated] and 0.9% NaCl in the right eye [control] (0.2 mL each). In the first phase (n = 7), TP, IOP, and PR assessment was performed by Schirmer tear test I, rebound tonometry and static pupillometry, at 1, 8, 24, 48, 72, 96, 120, 148, 172, and 196-hours post-instillation. In the second phase (n = 7), plateau mydriasis was evaluated by assessing PR hourly for 8 hours post-instillation. For PR assessment, pupil area (PA), vertical diameter (VPD), and horizontal diameter (HPD) were recorded. All pupillometries were obtained in a room with fixed light intensity (45-60 lux). Statistical analysis was performed by generalized estimating equations method for the effect on parameters over time. RESULTS: After topical CH, significant differences in pupil dilation were seen from 1 to 172 hours for VPD and from 8 to 24 hours for PA, without significant differences on HPD over time. In the second phase, plateau PA and VPD were reached at 3 hours, while plateau HPD at 2 hours. No significant effects were detected on TP and IOP in both eyes at any time, nor on PR of the nontreated eyes. CONCLUSIONS: Topical 1% cyclopentolate hydrochloride could be considered an effective and safe option when a mydriatic/cycloplegic drug is needed in horses.

Glyoxalase 1 (GLO1) Inhibition or Genetic Overexpression Does Not Alter Ethanol's Locomotor Effects: Implications for GLO1 as a Therapeutic Target in Alcohol Use Disorders.

BACKGROUND: Glyoxalase 1 (GLO1) is an enzyme that metabolizes methylglyoxal (MG), which is a competitive partial agonist at GABAA receptors. Inhibition of GLO1 increases concentrations of MG in the brain and decreases binge-like ethanol (EtOH) drinking. This study assessed whether inhibition of GLO1, or genetic overexpression of Glo1, would also alter the locomotor effects of EtOH, which might explain reduced EtOH consumption following GLO1 inhibition. We used the prototypical GABAA receptor agonist muscimol as a positive control. METHODS: Male C57BL/6J mice were pretreated with either the GLO1 inhibitor S-bromobenzylglutathione cyclopentyl diester (pBBG; 7.5 mg/kg; Experiment 1) or muscimol (0.75 mg/kg; Experiment 2), or their corresponding vehicle. We then determined whether locomotor response to a range of EtOH doses (0, 0.5, 1.0, 1.5, 2.0, and 2.5) was altered by either pBBG or muscimol pretreatment. We also examined the locomotor response to a range of EtOH doses in FVB/NJ wild-type and transgenic Glo1 overexpressing mice (Experiment 3). Anxiety-like behavior (time spent in the center of the open field) was assessed in all 3 experiments. RESULTS: The EtOH dose-response curve was not altered by pretreatment with pBBG or by transgenic overexpression of Glo1. In contrast, muscimol blunted locomotor stimulation at low EtOH doses and potentiated locomotor sedation at higher EtOH doses. No drug or genotype differences were seen in anxiety-like behavior after EtOH treatment. CONCLUSIONS: The dose of pBBG used in this study is within the effective range shown previously to reduce EtOH drinking. Glo1 overexpression has been previously shown to increase EtOH drinking. However, neither manipulation altered the dose-response curve for EtOH's locomotor effects, whereas muscimol appeared to enhance the locomotor sedative effects of EtOH. The present data demonstrate that reduced EtOH drinking caused by GLO1 inhibition is not due to potentiation of EtOH's stimulant or depressant effects.

Higher-Order Aberrations After Cyclopentolate, Tropicamide, and Artificial Tear Drops Application in Normal Eyes.

PURPOSE: To determine the effect of cyclopentolate, tropicamide, and artificial tear drops on higher-order aberrations (HOAs) in normal eyes with OPD-Scan III (Nidek Inc., Tokyo, Japan). METHODS: In this study, 189 eyes of individuals aged 20 to 35 years were selected as samples. Inclusion criteria were a corrected visual acuity of 20/20 or better, a minimum size of about 5 mm for the pupil in the dark, hyperopia and myopia less than 5 D, and astigmatism less than 2 D. Moreover, participants with pathological eye problems, a history of intraocular surgery, and ocular diseases affecting the accommodation, pupil size, and corneal surface were excluded. Higher-order aberrations of the participants were assessed by the OPD-Scan III before and after cyclopentolate (Colircuss), tropicamide (Mydrax 0.5%), and artificial tears (Tearlose) drop instillation. RESULTS: After instilling cyclopentolate drops, the mean of the total root mean square (RMS) increased from 4.580 to 6.335 D, total spherical aberration increased from 0.155 to 0.381 D, and total coma increased from 0.195 to 0.369 D; the increases were significant for total RMS and total spherical aberration, but a significant relationship was not seen with total coma. After tropicamide, the mean aberrations of total RMS increased from 4.301 to 4.568 D, total spherical aberration increased from 0.146 to 0.160 D, and total coma increased from 0.213 to 0.230 D; the increase was only significant for total coma. On the other hand, after artificial tears, the average of all aberrations decreased in a nonsignificant manner. CONCLUSION: Most changes of mean aberrations were related to cyclopentolate drops. Tropicamide and artificial tears had the second and third rank according to their effect on mean errors. As a result, it seems that ocular accommodation is the most important impact on HOA than pupil size. However, the pupil size is the second factor for HOAs.

[The effects of cycloplegic eyedrops on corneal tomography]. / Effets des gouttes cycloplégiques sur la tomographie cornéenne.

PURPOSE: Whether cycloplegics affect standard keratorefractometric and tomographic measurements is unknown. The purpose of our study was to compare the effects of cycloplegics (cyclopentolate and atropine) on corneal shape and refractive power of the eye. METHODS: This study was performed on 84 eyes of 49 study participants. Patients were randomized into two groups: atropine 1% (32 eyes) and cyclopentolate 1% (52 eyes). Corneal tomography was performed with the Orbscan IIz. To evaluate the corneal shape, simulated keratometry values, anterior and posterior best-fit sphere, white-to-white and tangential and axial corneal power were performed for the anterior and posterior corneal surfaces before and during cycloplegia. Pupil diameter, anterior chamber depth, corneal thickness at the 3, 5 and 7mm optical zones, thinnest area of the cornea and corneal thickness at the visual axis were examined. Data were analyzed using an SPSS statistical package. RESULTS: The anterior and posterior BFS (in the atropine 1% group, anterior BFS was P=0.188; anterior BFS in the cyclopentolate group was P=0.227) and tangential and axial corneal power showed no change during cycloplegia in either group. SimK showed no statistical significance. The ACD was deeper when using atropine than cyclopentolate. Corneal thickness remained unchanged during cycloplegia in both groups. Pupil diameter was larger in light-colored irides in the cyclopentolate group than the atropine group. There was no change in W to W before (P=0.473) and during cycloplegia (P=0.287) in either group. CONCLUSIONS: Our results suggest that usage of atropine or cyclopentolate does not alter corneal shape.

The effect of pupil dilation on AL-Scan biometric parameters.

The purpose of this study was to investigate the effects of pupil dilation on the parameters of the AL-Scan (Nidek Co., Ltd, Gamagori, Japan). We compared the measurements of axial length (AL), anterior chamber depth (ACD), central corneal keratometry reading, pupil diameter, and intraocular lens (IOL) power of 72 eyes of 72 healthy volunteers and patients scheduled for cataract surgery before and 45 min after instillation of cyclopentolate hydrochloride 1 % using the AL-Scan. Intraobserver repeatability was assessed by taking three consecutive recordings of ACD and AL. Only ACD readings were significantly different between predilation and postdilation (P < 0.001). The difference of the other measurements between two sessions was not statistically significant (P > 0.001). Only two cases in the study demonstrated changes in IOL power higher than 0.5 D. The intraobserver repeatability of both devices was good (CV values for ACD and AL were 0.16 and 0.20 %, respectively). Dilated pupil size did not affect the measurement of IOL power using the A-Scan optical biometer, but increase in ACD after dilation should be taken into account when performing refractive surgeries in which ACD is very important such as phakic anterior chamber IOL implantation.

Influence of cyclopentolate hydrochloride on corneal biomechanical properties in healthy individuals.

OBJECTIVE: This observational study aims to investigate the effects of cyclopentolate hydrochloride (1%) on corneal biomechanical properties, with the ocular response analyzer (ORA), in healthy individuals. METHODS: Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) measurements of 36 (15 female and 21 male) healthy individuals, before and after 45 min of 1% cyclopentolate hydrochloride instillation, were performed by the ORA. RESULTS: The mean CH and IOPcc measurements of the eyes were 10.63±1.17 mm Hg and 15.15±2.69 mm Hg, precycloplegia, and 11.09±1.32 mm Hg and 14.16±2.77 mm Hg, postcycloplegia, respectively. The differences between the precycloplegia and postcycloplegia in both measurements were statistically significant (P=0.031, P=0.016, respectively; paired t test). The mean CRF and mean IOPg measurements of the eyes were 10.40±1.16 mm Hg and 14.83±2.56 mm Hg, precycloplegia, and 10.61±1.33 mm Hg and 14.25±2.65 mm Hg, postcycloplegia, respectively. The differences between the precycloplegia and postcycloplegia measurements of the eyes were insignificant (P=0.264 and P=0.100, respectively; paired t test). CONCLUSIONS: A 1% cyclopentolate hydrochloride instillation leads to significant changes in the CH values and IOPcc measurements. This should be taken into account during the evaluation of refractive surgery candidates and in clinical conditions where ORA measurements are considered in the diagnosis and follow-up.

Effects of 1% cyclopentolate hydrochloride on anterior segment parameters obtained with Pentacam in young adults / Efeitos do cloridrato ciclopentolato 1% sobre os parâmetros do segmento anterior obtidos com Pentacam em adultos jovens

Purpose: To investigate the effects of topically applied 1% cyclopentolate hydrochloride on anterior segment parameters obtained with a Pentacam rotating Scheimpflug camera in healthy young adults. Methods: Anterior segment analyses of 25 eyes from 25 young adults (Group 1), before and after 45 min of 1% cyclopentolate hydrochloride application, were performed. For a control group (cycloplegia-free, Group 2), 24 eyes of 24 age- and sex-matched healthy cases were evaluated twice at 45 min intervals. The results obtained from the groups were compared statistically. Results: The mean ages of the groups were 23.04 ± 3.42 (range, 18-29) and 22.4 ± 2.05 (range, 18-27) years for Groups 1 and 2, respectively (p=0.259). In Group 1, measurements between the two analyses were significantly different for the values of anterior chamber depth (ACD), anterior chamber angle (ACA), and anterior chamber volume (ACV) (p<0.05), whereas no statistical difference was found for the central corneal thickness (CCT) and keratometry (K1, K2) measurements. In Group 2, none of these parameters were statistically different between the two analyses. Conclusions: Topically applied 1% cyclopentolate hydrochloride caused an increase in the ACD and ACV values, and a decrease in the ACA value. However, it had no significant effect on the CCT and keratometry measurements. It is important to consider these effects when using the Pentacam device on young adults with cycloplegia and when applying it for various reasons. .

Objetivo: Pesquisar os efeitos do cloridrato de ciclopentolato a 1%, aplicado topicamente, em parâmetros do segmento anterior medidos com a câmera de Scheimpflug Pentacam em adultos jovens e saudáveis. Métodos: A análise do segmento anterior, de 25 olhos de 25 jovens adultos (Grupo 1), antes e após 45 minutos da aplicação de cloridrato ciclopentolato a 1%, foram realizados. Como grupo controle (sem cicloplegia, Grupo 2), 24 olhos de 24 pacientes saudáveis pareados por idade e sexo, foram avaliados duas vezes em intervalos de 45 minutos. Os resultados obtidos com os grupos foram comparados estatisticamente. Resultados: A média de idade dos grupos foram 23,04 ± 3,42 (18-29 anos) e 22,4 ± 2,05 (18-27) anos, respectivamente (p=0,259). No Grupo 1, as medidas entre os dois exames foram significativamente diferentes para os valores de profundidade da câmara anterior (ACD), ângulo da câmara anterior (ACA), e do volume da câmara anterior (ACV) (p<0,05 para todos), enquanto que não foram diferentes para a espessura corneana central (CCT) e ceratometria valores (K1, K2). No Grupo 2, nenhum destes parâmetros foi diferente entre os dois exames. Conclusões: Aplicação tópica de cloridrato de ciclopentolato a 1% causou um aumento nos valores de ACD e ACV e uma diminuição nos valores da ACA. No entanto, ele não teve nenhum efeito significativo sobre as medidas de CCT e ceratometria. É importante considerar esses efeitos sobre as medidas tomadas com Pentacam em adultos jovens com cicloplegia quando aplicá-las em diferentes situações. .

Comparison of 3 pupillometers for determining scotopic pupil diameter.

PURPOSE: The pupil diameter under low ambient illumination is diagnostically valuable for refractive surgery. The aim of study was to compare the NeurOptics® Pupillometer, Sirius®, and Ocular Wavefront Analyser® in determining scotopic pupil diameter. MATERIALS AND METHODS: A total of 96 eyes of 48 subjects were included. The scotopic pupil size was measured with 3 instruments and the measurements repeated following instillations of 1% cyclopentolate. Agreement between the instruments was assessed. RESULTS: The mean measurement obtained by Sirius was significantly larger than Ocular Wavefront Analyser and NeurOptics. The Ocular Wavefront Analyser measured significantly smaller than the others. The mean cycloplegic pupillary diameters (7.73±0.70 mm with NeurOptics, 7.42±0.45 mm with Ocular Wavefront Analyser, and 8.06±0.76 mm with Sirius) were significantly different obtained by 3 instruments (p<0.001, for each; one-way analysis of variance and paired t tests). CONCLUSIONS: The differences between measured pupil diameters with or without cycloplegia obtained by the NeurOptics, Sirius, and Ocular Wavefront Analyser were significant and have unacceptable levels of disagreement. These results may not be related to illumination and accommodation only, but also to measurement algorithms and technical differences of the devices.

Cholinergic innervation of the guinea-pig isolated vas deferens.

Recently, a cholinergic neurogenic component of contraction has been characterised in the aganglionic mouse vas deferens. In this paper, a cholinergic component of contraction in the guinea-pig vas deferens is characterised pharmacologically. A residual, tetrodotoxin-sensitive (TTX, 0.3 microM), neurogenic contraction was revealed after prolonged exposure (5 h) to the adrenergic neurone blocker bretylium (20 microM) or in the presence of prazosin (100 nM) and alpha,beta-methylene ATP (1 microM), a purinergic agonist which desensitizes P2X receptors. The bretylium-resistant component was potentiated by the acetylcholinesterase (AChE) inhibitor neostigmine (10 microM) and inhibited by the muscarinic-receptor (mAChR) antagonist cyclopentolate (1 microM). Nicotine (30 microM) enhanced the bretylium-resistant component. Neostigmine increased the second component of contraction in the presence of prazosin and alpha,beta-methylene ATP, whilst yohimbine (1 microM), an alpha(2) adrenergic receptor antagonist, enhanced both the first and second components of the electrically evoked contraction. These enhanced contractions were blocked by cyclopentolate in both cases. Nicotine enhanced the cholinergic component of contraction revealed by neostigmine but failed to have any detectable effects in the presence of cyclopentolate. Neostigmine alone increased the slow component of contraction which was reversed by cyclopentolate to control levels. The M(3) receptor-antagonist 4-DAMP (10 nM) markedly inhibited the cholinergic component of contraction to a level comparable with cyclopentolate. Laser microscopy has shown that neostigmine also increased the frequency of spontaneous Ca(2+) transients remaining in smooth muscle cells after perfusion with prazosin and alpha,beta-methylene ATP, an effect blocked by 4-DAMP. These experimental data show that there is a functional cholinergic innervation in the guinea-pig vas deferens whose action is limited by acetylcholinesterase, blocked by cyclopentolate and mediated through M3 receptors. Moreover, by blocking the cholinesterase, the increased amount of ACh generates spontaneous Ca(2+) transients in smooth muscle cells.

Cholinergic innervation of the mouse isolated vas deferens.

Recently, a population of nerves has been described in the aganglionic mouse vas deferens, in which electrically evoked contractions were insensitive to high concentrations of the adrenergic neurone blocker, bretylium. In this paper, the pharmacology of this nerve-evoked contraction has been examined in more detail. Bretylium (20 microM) revealed, after 5 h exposure, a new residual neurogenic contraction (20 stimuli at 10 Hz) that was tetrodotoxin-sensitive. The muscarinic antagonist, cyclopentolate (0.1 and 1 microM), reduced this residual component and the inhibition was reversed by the acetylcholinesterase inhibitor, neostigmine (1 and 10 microM). Nicotine (30 microM) enhanced the residual component revealed by bretylium, suggesting that there are prejunctional nicotinic receptors (nAchRs) influencing acetylcholine (Ach) release. In the presence of prazosin (0.1 microM), a selective alpha(1)-adrenoceptor antagonist, and alpha,beta-methylene ATP (1 microM), a purinergic agonist that desensitise P2X receptors, neostigmine increased the hump component of contraction and yohimbine (0.3 microM), an alpha(2)-adrenoceptor antagonist, enhanced both components of the electrically evoked stimulation. The contraction was blocked by cyclopentolate (1 microM). In the absence of bretylium, neostigmine alone increased the hump component of contraction in a frequency-dependent manner. This increase was reversed by atropine (1 microM) and cyclopentolate (1 microM) to control levels. However, in control experiments, atropine or cyclopentolate did not detectably influence the delayed neurogenic contraction. Ach (10 microM) induced a contraction in the mouse vas deferens, either when applied alone or in the presence of neostigmine.Thus, it has been demonstrated unequivocally that the mouse vas deferens is innervated by functional cholinergic nerves, whose action is terminated by cholinesterase. Furthermore, Ach release can be enhanced by activation of prejunctional nAchRs presumably located on the cholinergic nerve terminals.

Potentially accommodating intraocular lenses--an in vitro and in vivo study using three-dimensional high-frequency ultrasound.

PURPOSE: To investigate the accommodative performance of new intraocular lenses (IOL) using the advantages of three-dimensional ultrasound biomicroscopy. METHODS: An in vitro simulation device was designed to study IOL performance using an artificial capsular bag and a stretching device. The haptic region of the Akkommodative 1CU (HumanOptics AG) and CrystaLens AT-45 (Eyeonics Inc) was visualized in vitro in three dimensions, using an in-house developed three-dimensional ultrasound biomicroscope. The in vitro results were used to describe the in vivo situation in four patients with accommodative implants. RESULTS: The haptic position and angulation in consideration of the accommodation state was distinguished and analyzed. In the simulation model, a maximal angulation change of 4.5 degrees and 4.3 degrees and a maximal forward shift of 0.33 mm and 0.28 mm was observed for the AT-45 and 1CU, respectively. In vivo, a change in haptic angulation <100 and a maximal forward shift of 0.50 mm was observed for the 1CU. These changes correspond to a theoretical approximate value of 0.50 diopters. CONCLUSIONS: The in vitro simulation device examined with three-dimensional ultrasound biomicroscopy provided information on the accommodative performance of these potentially accommodative IOL designs. Using three-dimensional ultrasound biomicroscopy, corresponding changes in haptic angulation during pharmacological-induced accommodation were observed.

Intraocular lens movement caused by ciliary muscle contraction.

PURPOSE: To investigate intraocular lens (IOL) movement, measured as a change in anterior chamber depth (ACD) caused by pilocarpine-induced ciliary muscle contraction. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: In this prospective study, the ACD was measured using high-precision, high-resolution, dual-beam partial coherence interferometry in 62 pseudophakic eyes of 55 patients under pilocarpine- and cyclopentolate-induced ciliary muscle contraction and relaxation. The following were studied: 2 models of a ring-haptic IOL (designed to accommodate), a plate-haptic IOL, and 3 types of 3-piece IOLs. Measurements were performed 3 months after surgery. RESULTS: The ring-haptic IOLs and plate-haptic IOL showed a forward movement (ring haptic 43A, -116 microm; ring haptic 43E, -222 microm; plate haptic -162 microm). The 3-piece IOLs showed no change in ACD except in 1 IOL type in which there was backward movement (156 microm). CONCLUSIONS: Pilocarpine-induced ciliary muscle contraction caused forward movement of ring- and plate-haptic IOLs that resulted in an estimated accommodative amplitude of less than 0.50 diopter in most cases. The accommodating ring-haptic IOLs did not perform better than the conventional plate-haptic IOL.

Estudo comparativo da acomodaçäo residual após instilaçäo de colírios de tropicamida a 1 por cento, ciclopentolato a 1 por cento e associaçäo de tropicamida a 1 por cento + ciclopentolato a 1 por cento / Comparative study of residual accomodation after instillation of the eye drops with 1 per cent tropicamide, 1 per cent cyclopentolate, and association of 1 per cent tropicamide + 1 per cent cyclopentolate

Objetivo: Avaliar a acomodaçäo residual após a instilaçäo de duas drogas ciclopégicas, o ciclopentolato a 1 por cento e a tropicamida a 1 por cento e a associaçäo entre elas. Material e métodos: Selecionamos pacientes de 15 a 25 anos, com íris grau 4 e 5 pela classificaçäo de Seddon e sem nenhum tipo de doença ocular, que procuraram de maneira espontânea o ambulatório de Oftalmologia da Santa Casa de Säo Paulo no período de outubro de 1997 a setembro de 1998. Os 46 pacientes foram submetidos a três exames oftalmológicos completos, em que se testava o potencial de acomodaçäo monocularmente, após a instilaçäo de tropicamida a 1 por cento, com tempo de espera de 20 minutos, ciclopentolato a 1 por cento com tempo de espera de 40 minutos e tropicamida a 1 por cento + ciclopentolato a 1 por cento com intervalo entre as drogas de 5 minutos e com latência de 30 minutos. O intervalo entre os exames era de no mínimo sete dias. Resultados: Näo houve diferença entre os grupos dos emétropes, dos hipermétropes e dos míopes com nenhuma droga instilada (p>0,005). O ciclopentolato a 1 por cento e a associaçäo entre as drogas proporcionaram menor acomodaçäo residual estatisticamente significante, em comparaçäo com a tropicamida a 1 por cento no grupo dos hipermétropes e dos míopes. Conclusäo: O ciclopentolato a 1 por cento e a associaçäo entre as drogas säo seguras para o exame refratométrico estático em pacientes jovens, com íris escura e sem doença ocular, pois proporcionaram uma média da acomodaçäo residual em todos os grupos pesquisados de no máximo 1,21 + ou - 0,7 dioptrias esféricas (DE).

The efficacy of 2.5% phenylephrine and flurbiprofen combined in inducing and maintaining pupillary dilatation during cataract surgery.

PURPOSE: To evaluate the effectiveness of phenylephrine 2.5% and flurbiprofen 0.03% combined in inducing and maintaining mydriasis during extracapsular cataract extraction (ECCE). METHODS: One hundred patients undergoing ECCE + intraocular lens (IOL) implantation were randomly divided into four groups. The first group was given phenylphrine 10%, the second group phenylephrine 10% + flurbiprofen, the third group phenylephrine 2.5% and fourth group phenylephrine 2.5% + flurbiprofen. Cyclopentolate 1% was used in all patients. Phenylephrine and cyclopentolate were instilled preoperatively four times during 1 hour and flurbiprofen was given four times the day before surgery and twice with an hour's interval before operation. Pre-operative and post-cortex aspiration horizontal pupil diameters were measured with callipers viewed through the operating microscope. RESULTS: Pupil diameters in pre-operative and post-cortex aspiration were no different in the 2.5% and 10% phenylephrine groups (p>0.05). Both diameters were larger and pupillary constriction was smaller in the flurbiprofen groups (p<0.05). CONCLUSIONS: 2.5% phenylephrine was as effective as 10% phenylephrine, with and without flurbiprofen, in inducing and maintaining pupil dilatation during ECCE surgery.

In vivo observation of the axial movement of intraocular lenses through an anterior eye segment analysis system.

The small axial movement of the anterior surface of implanted intraocular lenses (IOLs) were examined in pseudophakic eyes with one-piece and three-piece IOLs using an anterior eye segment analysis system. The movement was calculated as the distance between the posterior surface of the cornea and the anterior surface of an IOL under a normal pupil size, following the instillation of 1% pilocarpine and 1% cyclopentolate solutions, respectively. The axial movement including movement after instillation of pilocarpine and cyclopentolate was 0.17 +/- 0.06, 0.05 +/- 0.07 and 0.13 +/- 0.06 mm, in phakic eyes and eyes with one-piece and three-piece IOLs, respectively. Image analysis techniques using Scheimpflug images proved its usefulness in the research field of IOL implantation.

Reduced mydriasis from repeated doses of tropicamide and cyclopentolate.

Pupils are often dilated for examination the day before surgery and again on the day of surgery. The following experiment was performed to determine the effect of serial doses of two commonly used mydriatic agents: on two consecutive days the pupil of one of the eyes of 28 subjects was dilated with tropicamide 1%, and the pupil of one of the eyes of 30 subjects was dilated with cyclopentolate hydrochloride 1%. The other eyes in both groups were dilated only on the second day, and thus served as controls. Pupil sizes were measured from photographs before and after dilation. The pupils of the eyes treated twice with either drug did not dilate as well after the second dose as those of the control eyes (P less than .005 for tropicamide, P less than .001 for cyclopentolate). The pupils of the eyes twice-treated with tropicamide were an average of 0.15 mm smaller than the control pupils; those twice-treated with cyclopentolate were 0.36 mm smaller. For subjects treated with cyclopentolate, this decreased mydriasis was related to age (P less than .05) and to eye color (P less than .025): the younger and blue-eyed subjects dilated less on the second day than the older and brown-eyed subjects. If full mydriasis is required at surgery, pupils should probably not be dilated with either tropicamide or cyclopentolate the day before surgery.