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Biomedical subjects

V Hessemer

Publications and source records attributed to V Hessemer.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Mesoptic vision in multi- and monofocal pseudophakia and in phakic control eyes].

UNLABELLED: The mesopic visual acuity (MVA) after intraocular lens (IOL) implantation is reduced compared to phakic patients of the same age. However, previous studies from our clinic have shown no significant MVA difference between multi- and monofocal IOLs. In the present study (with the patients matched exactly for age), this topic was reevaluated. PATIENTS AND METHODS: We investigated three groups, each consisting of 28 persons, 51 to 60 years of age. Group I consisted of healthy phakic volunteers, group II of patients 3 months after cataract extraction and implantation of a monofocal posterior chamber IOL (Pharmacia 720A) and group III of patients 3 months after implantation of a diffractive multifocal posterior chamber IOL with biconvex optic configuration (3M 825X). The MVA was examined using the "Ocutrast," described by Nowak. The Ocutrast, a modification of the Mesoptometer II, provides a field luminance of 1 cd/m2 and a contrast of 1:23 between test optotype and background; the intensity of illumination under glare conditions amounts to 0.35 lx at the level of the pupil. RESULTS: The MVA without glare amounted to 0.50 +/- 0.12 (group I, healthy phakic eyes), 0.45 +/- 0.15 (group II, monofocal IOLs) and 0.32 +/- 0.11 (group III, multifocal IOLs). The MVA with glare amounted to 0.47 +/- 0.08 (group I), 0.35 +/- 0.12 (group II) and 0.24 +/- 0.10 (group III). Both for the MVA with and without glare there was a significant group difference (P < 0.05; two-factor analysis of covariance with repeated measurements). CONCLUSIONS: After implantation of diffractive multifocal IOLs of the presently used type (3M 825X), the mesopic vision--both with and without glare--is even more reduced than after monofocal IOL implantation. These findings are particularly relevant for aged pseudophakic car drivers, especially for driving at night.

Dark Adaptation↗
PubMed1994

[Anti-inflammatory effect of a local combination therapy with diclofenac and prednisolone vs. indomethacin and prednisolone. A laser flare cell photometry study].

UNLABELLED: The nonsteroidal anti-inflammatory agent diclofenac (Voltaren) has recently become commercially available in form of 0.1% eyedrops (Voltaren ophtha). In the present study, we compared the anti-inflammatory effect of a topical combination therapy with diclofenac and prednisolone vs. indomethacin and prednisolone. PATIENTS AND METHOD: The FC-1000 laser flare-cell photometer (Kowa) was used to investigate 40 patients before and after cataract surgery with IOL implantation. This method allows quantitative in vivo determination of aqueous flare and aqueous particle concentration. The patients were randomly assigned to one of the following two treatment protocols: Protocol A: diclofenac 0.1% eyedrops and prednisolone 1% eyedrops (Inflanefran forte); protocol B: indomethacin 1% eyedrops (Chibro-Amuno 3) and prednisolone 1% eyedrops. One drop of either drug was administered 4 times per day to each patient. Treatment with nonsteroidal agents started on the day before surgery, whereas prednisolone treatment started immediately at the end of surgery. No parabulbar or oral steroids were administered. RESULTS: In group A (diclofenac and prednisolone), the flare (in photon counts/ms) increased from a preoperative value of 10 +/- 4.3 (mean +/- SD) to 36.7 +/- 19.3 on the 1st postoperative day. This value is significantly (P < 0.05) higher than in group B (indomethacin and prednisolone) on the 1st postoperative day: 27.4 +/- 9.4. The aqueous particle concentration on day 1 after surgery was also significantly (P < 0.01) higher under treatment with diclofenac and prednisolone than with indomethacin and prednisolone (44.3 vs 26.3 particles/0.075 mm3, respectively). On the 3rd postoperative day, the differences between the two treatment groups were no longer present. CONCLUSIONS: In the early postoperative period after cataract surgery, the anti-inflammatory effect of a topical combination therapy with diclofenac and prednisolone is weaker than that of indomethacin and prednisolone. However, this difference is no longer observed on day 3 after surgery, so that there is probably no major difference in clinical outcome between the two treatment protocols.

Aged↗
PubMed1993

[Multifocal intraocular lenses--an assessment of current status].

UNLABELLED: Besides the diffractive multifocals, which produce a second focus for near vision by means of diffraction rings, there are different refractive multifocal IOL types with 2-7 refractive zones or an aspheric/spherical construction principle. Long-term results: 2 years after implantation of diffractive multifocal IOLs, the corrected distance and near acuities were unchanged compared to the 3-month results. The uncorrected distance acuity was, however, slightly decreased due to a minus shift of refraction to -1.2 D. The contrast sensitivity was improved after 2 years. Multi- versus monofocal IOLs: After diffractive multifocal IOL implantation, the near acuity with distance correction only was markedly improved compared to monofocal IOLs. All other acuity data did not differ between multi- or monofocal lenses. The contrast sensitivity (at low contrasts and high spatial frequencies) and mesopic visual acuity (without and with glare) were reduced compared to monofocal pseudophakic eyes. Near aniseikonia and binocular functions: In unilateral multifocal pseudophakia (monofocal IOL in fellow eye), a near aniseikonia up to 8% was found. The width of fusion was significantly lower than in bilateral multifocal pseudophakia, whereas the stereopsis showed no difference. Determinants of bifocal function: In 7.1% of our cases, no bifocal function (BFF) was present after implantation of diffractive multifocal IOLs. These patients exhibited a significantly higher age as well as higher pre- and postoperative astigmatism, when compared to patients with good BFF. Optical performance of different multifocal IOLs: By means of an optical system, described by Reiner, images of intraocular lenses can be projected into the eye ("optical implantation"); thus, the optical performance of IOLs can be judged subjectively. Using this method, the refractive 2- and 3-zone models performed best within the multifocal group (contrast sensitivity not significantly worse than that of monofocal IOL), when viewing a low-contrast chart (Regan 4%). All other multifocal lenses (diffractive, aspheric/spherical, refractive 5- and 7-zone models) were significantly inferior to the monofocal IOL. CONCLUSIONS: Implantation of multifocal IOLs should presently be restricted to special indications, particularly to the distinct patient request to dispense with wearing near or bifocal glasses, if possible. Because of the reduction in contrast sensitivity and mesopic vision and the increased glare sensibility, multifocal IOLs should not be implanted especially in professional car drivers. There are, however, differences in optical performance between the various multifocal IOL types. Further improvements, in particular concerning lens technology, will presumably extend the present spectrum of indications.

Contrast Sensitivity↗
PubMed1993

[Reproducibility of in vivo determination of protein and particle concentration with the laser flare cell photometer].

The laser flare-cell photometer was introduced as an instrument to measure anterior chamber inflammation (protein concentration and particle concentration, "cells") quantitatively and non-invasively. Thirty-two eyes with and without intraocular inflammation were examined using the laser flare-cell photometer by three different examiners under the same conditions to determine the reproducibility. The coefficients of variation of flare (Vfi) and of number of cells (Vci) were calculated for each eye (i). The median of the 32 coefficients of variation Vfi was 0.2; the median of the 32 Vci was 0.4. Furthermore, the median of the 32 flare (Mf1-Mf3) and number of cells (Mc1-Mc3) as measured by each examiner (U1-U3) were calculated. Another coefficient of variation could be calculated from Mf1-Mf3, which lay at 0.05, and from Mc1-Mc3, which lay at 0.13. The measurements of flare and number of cells with the FC-1000 have a good reproducibility if the average flare and number of cells in a group of patients are examined. This is one of the important conditions if, for example, the effect of two different drugs on two groups of patients are compared. In individual cases the laser flare-cell photometer can only be used together with further clinical examination.

Anterior Chamber↗
PubMed1993

[Modulation transfer function and contrast sensitivity of refractive multi-zone multi-focal lenses].

Contrast imaging of new multifocal intraocular lens (MIOL) designs with 5 and 7 refractive zones was examined by in vitro measurement of the modulation transfer function (MTF) and by testing contrast sensitivity with Regan 96% and 11% contrast sensitivity charts after "optical implantation" of MIOLs in 20 healthy subjects by means of a new optical device developed by Reiner. The results were compared with those obtained with a monofocal IOL and a diffractive MIOL. We found that the MTF of both refractive MIOLs showed a reduction in contrast at corresponding spatial frequencies compared with the monofocal and with the diffractive IOL, resulting in a Strehl ratio of below 30%. Contrast sensitivity after "optical implantation" was significantly reduced for the refractive 5- and 7-zone models in high contrast (Regan 96%), but for all MIOL models in low contrast (Regan 11%) compared with the monofocal IOL. The refractive 5-zone MIOL and diffractive MIOL showed no statistical difference in contrast sensitivity.

Contrast Sensitivity↗
PubMed1993

[2 years results of implantation of diffractive multifocal intraocular lenses].

In an ongoing prospective study, we investigated 52 eyes of 40 patients 2 years (range: 22-26 months) after implantation of a diffractive multifocal intraocular lens (3M, type 815LE). The distance visual acuity averaged 0.48 without correction and 0.83 with best correction. The mean refraction (spherical equivalent) amounted to -1.2 D (compared to only -0.32 D 3 months postoperatively). The corrected distance acuity was > or = 1.0 in 40% and > or = 0.5 in 100% of the eyes. A near visual acuity of Nieden 1-3 was achieved in 70.3% without correction, in 75% with distance correction only, and in 100% with additional near addition. Compared to our results 3 months after multifocal lens implantation, the uncorrected distance acuity decreased and the uncorrected near acuity increased 2 years postoperatively both phenomena being attributable to the postoperative minus-shift in refraction. The other acuity values were unchanged in comparison with the 3-month results. Measured with the Ginsburg test, contrast sensitivity at low and medium spatial frequencies improved significantly compared to the 3-month results. An improvement in contrast sensitivity since the early postoperative phase was also found using the Pelli Robson contrast sensitivity chart and--in tendency--using the Regan contrast charts. Hypothetically, these findings may be traced back to a retinal or central nervous cybernetic adaptation mechanism to the implanted multifocal optic.

Aged↗
PubMed1993

[Scanning electron microscopy examination of 87 pre-injection blunted retrobulbar cannulas].

UNLABELLED: The use of blunt cannulas for retrobulbar injection (retro) is recommended to reduce the risk of retrobulbar hemorrhage and globe perforation. Retro cannulas with blunt tips--so-called Atkinson needles--are commercially available. They can also be produced by being blunted on a sterile surface immediately before injection. METHODS: In a prospective study, all retro cannulas (0.5 x 40 mm, Steriseal) used over 8 days in our hospital were collected after being blunted on a sterile Petri dish, followed by injection. Subsequently, scanning electron microscopic examination was performed. 20 unused retro needles were examined for control. RESULTS: 62% (n = 54) of the 87 used retro cannulas were satisfactory, i.e., the tips were blunted, exhibiting no undesirable hooks. 29% (n = 25) of the retro cannulas demonstrated moderate deformation, 9% (n = 8) stronger deformation of the needle tip. No complications occurred after any of the 87 injections. CONCLUSIONS: Blunting of retro cannulas immediately before injection is a possible alternative to commercially available needles with blunt tips. However, this procedure has to be performed carefully to avoid potential detrimental deformation of the needle tip, which can be detected in a low percentage by means of the scanning electron microscope.

Anesthesia, Local↗
PubMed1992

[Endocrine stress response in cataract operations with local anesthesia].

This study was undertaken to investigate the endocrine stress response during cataract surgery in local anaesthesia (LA) with or without additional sedation with midazolam (Dormicum). 20 patients for cataract surgery in LA were randomly allocated to the midazolam-group (before injection of LA, sedation with single doses of 1 mg midazolam until the patient was sleeping, but awakeable), and to the control-group without sedation. Premedication and LA were standardized. The investigation was performed at 7 measuring points starting at the arrival in the preparation room up to 30 min after surgery. Adrenaline in plasma was significantly lower in the midazolam-group. Intraoperatively, adrenaline increased in the control-group and decreased in the midazolam-group. In time course, noradrenaline in plasma decreased in the midazolam-group, in contrast to the control-group. With respect to ADH, ACTH and cortisol, no significant differences were found in group levels or time course, and concentrations remained within normal range. In contrast to the control-group, mean arterial pressure decreased in the midazolam-group during the course of time. There were no differences in heart rate or arterial oxygen saturation between the two groups. Local anaesthesia and premedication were sufficient to prevent psychic and surgical stressors. The slight sympathoadrenergic response in the control-group was significantly reduced by small doses of midazolam. Thus, a careful supplementation of local anaesthesia with midazolam appears advantageous for patients with cardiovascular disorders.

Adrenocorticotropic Hormone↗
PubMed1991

[Ocular circulatory changes in halothane-nitrous oxide intubation anesthesia with special reference to arterial CO2 partial pressure. I. Phenomenology of changes].

UNLABELLED: In 20 patients (5 with cataract, 15 with strabismus), general anesthesia was performed using halothane (inspiratory concentration: 0.5 vol.%) and nitrous oxide (65 vol.%); thiopental was employed for induction of anesthesia, vecuronium and succinylcholine were used for neuromuscular blockade prior to intubation. In series 1, the patients were slightly hyperventilated (PCO2 33 mmHg, on average). In series 2, the arterial PCO2 was changed in a range between 20 and 45 mmHg. By means of oculo-oscillo-dynamography, we determined the systolic retinal and ciliary perfusion pressures (PPs,ret and PPs,cil) as well as the respective ocular blood pressures (Ps,ret and Ps,cil), the ocular pulsation volume (PVoc) and the pulsatile ocular blood flow (Fp,oc = PVoc x heart rate). The intraocular pressure (Pio) was measured with the Draeger hand-applanation tonometer. Results of series 1: Measured 5 and 15 min after intubation, PPs,ret was reduced by averages of 12.5 and 20.2 mmHg, respectively, corresponding to decreases of 13.1 and 21.2% compared to the initial values. Ps,ret was decreased by 15.4 mmHg (14.2%) 5 min after intubation and by 27.1 mmHg (25.0%) 15 min after intubation. The ciliary pressures (PPs,cil and Ps,cil) were changed by similar amounts. PVoc was reduced by 0.3 microliters (50.8%) during both time periods after intubation. Fp,oc was lowered by 19.5 microliters/min (41.0%) and by 26.4 microliters/min (55.5%), measured 5 and 15 min after intubation, respectively. Pio was decreased by 1.6 mmHg (11.3%) and by 7.6 mmHg (53.5%), respectively. The systolic brachial artery pressure was reduced by 12.6 mmHg (9.5%) 5 min after intubation and by 29.1 mmHg (21.9%) 15 min after intubation. The diastolic branchial artery pressure showed a slight initial increase, followed by a small decrease. All changes were highly significant (P less than 0.001; 1-factor analysis of variance plus Scheffé test). Results of series 2: In a PCO2 range between 40 and 45 mmHg (normo-until slight hypoventilation; determined 5 min after intubation), PVoc and Fp,oc averaged 0.43 microliter and 42.9 microliters/min, respectively. In a PCO2 range between 30 and 35 mmHg (slight hyperventilation), PVoc and Fp,oc averaged 0.38 microliters and 36.1 microliters/min, respectively; and in a PCO2 range between 20 and 25 mmHg (forced hyperventilation), they averaged 0.21 microliter and 22.8 microliters/min, respectively. All other variables were not dependent on the PCO2 level. CONCLUSIONS: The lowering of PVoc and Fp,oc, observed during halothane-nitrous oxide anesthesia--especially with forced hyperventilation-, may be interpreted as reduced pulsatile choroidal blood flow.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1991

[Changes in ocular circulation in halothane-nitrous oxide intubation anesthesia with special reference to the arterial CO2 partial pressure. II. Mechanisms of change].

UNLABELLED: In part I of this study [Hessemer and associates, Klin. Mbl. Augenheilk. 199 (1991) 346-355] the phenomenology of the ocular circulatory changes, found during general anesthesia using halothane and nitrous oxide, has been described. These changes are analyzed with respect to their mechanisms.-- RESULTS: There was a significantly (P less than 0.05) linear relation between the anesthesia-induced reduction of the systolic ocular (retinal and ciliary) blood pressures and the decrease of the systolic brachial artery pressure (delta Ps,bra). The same relation was present between the reduction of the systolic ocular (retinal and ciliary) perfusion pressures and delta Ps,bra. The correlation coefficients for the designated relations ranged between 0.37 and 0.58. The relation between the anesthesia-induced intraocular pressure reduction and delta Ps,bra was--in tendency--linear (P = 0.07), at least for the time period 5-15 min after intubation; the correlation coefficient amounted to 0.37. The reduction of both the ocular pulsation volume (PVoc) and the pulsatile ocular blood flow (Fp,oc) did not depend on the systemic blood pressure, but on the arterial CO2 tension (PCO2): Decreasing PCO2--i.e., increasing hyperventilation--was paralleled by decreases of PVoc and Fp,oc. The relations PVoc vs. PCO2 and Fp,oc vs. PCO2 were significantly linear (P less than 0.01), the correlation coefficients ranged between 0.58 and 0.7.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Endotracheal↗
PubMed1991

[Anesthesia effects on ocular circulation. Synopsis of a study].

UNLABELLED: In a study of 280 patients (265 with cataract, 15 with strabismus), we investigated the ocular circulatory effects of 3 methods of anesthesia widely used in ophthalmic surgery, retrobulbar, peribulbar and general anesthesia. Retrobulbar anesthesia (RETRO) was performed with 2, 5 or 8 ml of a mixture (BLH-Mix) of bupivacaine 0.75%, lidocaine 2% and hyaluronidase; with 5 ml BLH-Mix and addition of adrenaline in a low (1:500,000) or a higher (1:200,000) concentration; with 5 ml bupivacaine 0.75% or lidocaine 2% or mepivacaine 2%; with 5 ml mepivacaine 2% and addition of 150 units hyaluronidase; or with 5 ml BLH-Mix plus adrenaline and additional oculopression. Peribulbar anesthesia (PERI) was performed with 8 ml BLH-Mix (5 ml inferotemporally/3 ml superonasally) or 10 ml BLH-Mix (8/4) injected outside the muscle cone. General anesthesia was performed using halothane (inspiratory concentration 0.5 vol%) and nitrous oxide (65 vol%); respiration was adjusted to produce slight hyperventilation (alveolar pCO2 33 mmHg) or forced hyperventilation (pCO2 20-25 mmHg), respectively. The following variables were measured; systolic ciliary perfusion and blood pressures (PPs,cil and Ps,cil, respectively) and ocular pulsation volume (PVoc) using oculo-oscillodynamography of Ulrich, and the intraocular pressure (IOD) using the Draeger handapplanation tonometer. RESULTS: (1) Measured 15 min after injection, PVoc was reduced by all local anesthesia (LA) methods by a range of 17-65%. The changes were dependent on the following factors: (a) increasing injection volume: larger PPs,cil reduction; (b) addition of adrenaline: larger reduction of all hemodynamic variables; (c) addition of hyaluronidase: more pronounced PVoc reduction; (d) type of local anesthetic: most marked PVoc reduction induced by RETRO with mepivacaine and bupivacaine, smallest reduction by lidocaine; (e) site of injection: less marked reduction of all hemodynamic variables during PERI than during RETRO with equal (8 ml) or equipotent (PERI 10, RETRO 5 ml) injection volumes; (f) additional oculopression: more marked Ps,cil reduction. The IOP, measured 15 min after injection, was increased by most LA types. The degree of IOP elevation was dependent on the following factors: (a) increasing injection volume: higher IOP elevation; (b) type of local anesthetic: lowest IOP elevation induced by bupivacaine, more marked effect of lidocaine, highest elevation after mepivacaine injection. After additional oculopressure, the IOP was reduced as expected. (2) During general anesthesia with slight hyperventilation, PPs,cil and Ps,cil were reduced by 20.6 and 27.6 mmHg, respectively, measured 15 min after intubation. PVoc was decreased by 50.8% and the IOP by 7.6 mmHg. With forced hyperventilation, the reduction of PVoc was even more pronounced. CONCLUSIONS: The anesthesia-induced lowering of both ocular perfusion and blood pressures as well as of the ocular pulsation volume, which is a measure of the pulsatile choroidal blood flow, can be interpreted as reflecting an inhibitory influence on ocular circulation. We suggest the following mechanisms to account for the changes during LA: elevation of IOP, adrenaline-induced retrobulbar vasoconstriction, LA-induced retrobulbar vasoconstriction (hypothetical), improved penetration of LA brought about by the orbital compression occurring during oculopression. The relative significance of the separate mechanisms differs, however, between the various LA types. The changes found during general anesthesia are attributable to the halothane-induced reduction of systemic blood pressure and cardiac stroke volume as well as to a relative hyperventilation-induced choroidal vasoconstriction. The results are relevant for ophthalmic surgery with respect to the prevention of complications and problems depending on pathologic or at least unphysiological changes in ocular circulation, e.g...

Adult↗
PubMed1991

[Effect of hyaluronidase on ocular circulatory changes caused by retrobulbar anesthesia].

Twenty patients had retrobulbar anesthesia with 5 ml mepivacaine (Scandicain) without or with addition of 150 units of hyaluronidase (Kinetin). Before and 15 min after injection, we determined--by means of oculo-oscillo-dynamography--the systolic retinal and ciliary perfusion pressures, the respective ocular blood pressures (intramural pressures) and the ocular pulsation volume (PVoc) as well as the intraocular pressure (Pio; hand-applanation tonometer). Without hyaluronidase, the ocular perfusion and blood pressures were lowered by 11.8 and 3.9 mmHg, respectively, and PVoc was reduced by 0,40 microliters, whereas Pio was increased by 7.9 mmHg With hyaluronidase, the ocular perfusion and blood pressures were decreased by averages of 12.7 and 6.8 mmHg, respectively, PVoc was reduced by 0.42 microliters, and Pio was increased by 6.0 mmHg. Within each group, all changes were significant. There were, however, no significant differences between the two groups, i.e., the "spreading factor" hyaluronidase does not influence the inhibitory effects of retrobulbar anesthesia on ocular circulation.

Aged↗
PubMed1990

[Changes in the circulation of the eye caused by Vörösmarthy preoperative ocular pressure].

Prior to, directly after and 15 minutes after preoperative Vörösmarthy oculopression (30, 40, or 50 mm Hg; 15 min), 30 patients were examined by oculooscillodynamography after Ulrich. Systolic retinal and ciliary perfusion pressures were higher directly after oculopression, whereas the systolic and diastolic ocular blood pressures (intramural pressures) were lower. These changes did not depend significantly on the level of oculopression. Fifteen minutes after oculopression, the ocular perfusion and blood pressures were largely normalized. The hemodynamic changes observed reflect the decrease in intraocular pressure resulting from oculopression. The changes are thought to have a beneficial effect on ocular perfusion (reduction in tissue pressure, decrease in vascular resistance, increase in transmural pressure). The authors' results are consistent with the finding in animal experiments that blood flow to the retina, optic nerve, and uvea increases for a short time after oculopression (Jay et al., Acta Ophthalmol. 1986).

Aged↗
PubMed1990

[Pre- and postoperative non-contact tonometry].

The AO II non-contact tonometer (NCT) was compared with the Goldmann applanation tonometer (GAT) in 50 patients preoperatively and on the first day after cataract surgery. After pooling the preoperative and postoperative values, the relationship between NCT (y axis) and GAT (x axis) was described by the following regression: y = 1.01x - 0.69, where 1.01 is the slope and -0.69 (in mm Hg) is the y intercept of the regression line. The standard deviation (SD) in relation to the regression line was 2.19 mm Hg (y values). After separating the preoperative (n = 100; pressure range 6-21 mm Hg) and postoperative values (n = 47; pressure range 6-30 mm Hg) the following equations were obtained: preoperatively: y = 0.89x + 0.82 (SD 2.2 mm Hg); postoperatively: y = 1.06x - 1.15 (SD 2.24 mm Hg). Since the postoperative regression line comes close to that required for legal verification, the NCT may - with limitations - also be recommended for measuring IOP after cataract surgery. Both preoperatively and postoperatively, a significantly linear relationship was found between corneal thickness and the difference GAT minus NCT readings. This implies that in normal eyes with thin corneas the NCT tends to underestimate IOP, while in eyes with thick corneas there is a tendency to overestimate IOP. Even slight corneal edema (postoperatively) reduces this effect.

Cataract Extraction↗
PubMed1990

[Ocular circulatory changes caused by retrobulbar anesthesia with and without added adrenaline].

UNLABELLED: In 80 patients, retrobulbar anesthesia (RBA; 5 ml of a lidocaine-bupivacaine mixture with hyaluronidase) with or without addition of adrenaline (after-mixing concentration 1:500,000) was performed preoperatively. In 2 examination series, the acute and medium-term effects of RBA on the following ocular circulatory variables were investigated: ocular pulsation volume (PVoc), systolic ciliary and retinal perfusion pressures or blood pressures, respectively (method: oculo-oscillo-dynamography). RESULTS: RBA with adrenaline: Directly after injection, PVoc was reduced by an average of 49%, the ocular perfusion and blood pressures were lowered by averages of 8.0 and 4.3 mmHg, respectively, and the intraocular pressure (Pio; hand-applanation tonometer) was elevated by 3.5 mmHg. 15 min after injection, PVoc and the ocular perfusion and blood pressures were even slightly more reduced, whereas Pio had reassumed its pre-injection level. RBA without adrenaline: During both time periods after injection, the reduction of PVoc averaged 10% less compared to RBA with adrenaline. The changes in ocular perfusion and blood pressures and in Pio, however, were not significantly different from RBA with adrenaline. CONCLUSIONS: The lowering of PVoc--which variable is determined mainly by the pulsatile choroidal blood flow--in concert with the lowered ciliary perfusion and blood pressures is indicative of a reduced ciliary blood flow during RBA. Because of the decreased retinal perfusion and blood pressures, there is also a higher risk of reduced blood supply to the retina. Only to some degree, the observed inhibitory RBA effects on ocular circulation can be explained by adrenaline, and to an even smaller degree by the only transient Pio elevation.

Adult↗
PubMed1990

[Plasma level of lidocaine and adrenaline in local anesthesia with addition of colloid in eye surgery].

This study was undertaken to investigate the plasma levels of lidocaine and adrenaline after local anaesthesia for ophthalmic surgery and the influence of addition of hydroxyethyl starch (HES) on the resorption of the local anaesthetic solution. Prior to cataract surgery, two groups (each consisting of 10 patients) received a retrobulbar block (5 ml) and a facial nerve block (5 ml; O'Brien technique) with lidocaine 2% and adrenaline 1:80000, with or without addition of 10% HES 200/0.5 (relation 1:1) in equal volumes and concentrations. The plasma levels of lidocaine and adrenaline were measured by high-pressure liquid chromatography. In both groups, the individual peak concentrations of lidocaine (8.62 micrograms/ml) and adrenaline (7.514 pg/ml) reached the toxic range. There was no evidence of intravascular injection, and no severe cardiovascular reactions were observed. In 9 patients, resorption was slow and led to low peak concentrations. A rapid resorption with high peak concentrations was found in 11 patients. Peak levels of lidocaine were reached after 15 min and those of adrenaline after 3-5 min. Plasma levels of lidocaine and adrenaline were not significantly influenced by the addition of HES, although the highest peak concentrations were found in the group without the addition of HES.

Aged↗
PubMed1990

[Prospective study of the incidence of secondary cataract with various types of lenses with and without laser ridge].

In this randomized, prospective clinical study, a plano-convex (plano-posterior) intraocular lens (IOL) with a laser ridge was compared with a plano-convex (plano-posterior) IOL without a laser ridge. The 100 patients (40 male/60 female) with senescent cataracts all underwent ECCE performed by the same surgeon from November 1986 to March 1987. The operative technique consisted of capsulorhexis, irrigation-aspiration and in-the-bag implantation. The first group of 50 patients (50 eyes) received a sort of IOL without a laser ridge and the second group, a sort with a laser ridge. Our prospective 5-year clinical study is not yet complete and no statistical analysis has been performed. As an intermediate result, however, we have found a rate of 11.7% for after-cateract in the group with an IOL without laser ridge and a rate of 28.6% in the group with an IOL with laser ridge.

Aged↗