Influence of the strength,drop size and viscosity of metipranolol eye drops on the concentration of the substance in human aqueous humour

Concentrations of metipranolol were determined in the aqueous humour of patients undergoing cataract surgery. At 30 min before the operation, patients were given 20- or 30 l drops of 0.1 % or 0.3% metipranolol solutions with a viscosity of 7.5 cP or drops (20 or 30 l) of a 0.3% solution with a viscosity of 1.5 cP. Samples of the aqueous humour were obtained at the beginning of the cataract operation, and desacetylmetipranolol content was determined by means of gas chromatography and mass spectroscope. The Wilcoxon signed-rank test and Jonckheere's method were used for evaluation of the results. A 3-fold increase in the strength of metipranolol was associated with an approx. 8-fold increase in the concentration of metabolite found in the aqueous humour. Drop size had no apparent effect on the concentration of this substance in the aqueous humour, but viscosity had a significant influence when large drops were applied. An increase in the amount of metipronolol applied as eye-drops was associated with an increase in the intraocular concentration of the metabolite.Offprint requests to: H. Bleckmann     

Low concentration of sodium hyaluronate temporarily elevates the tear film lipid layer thickness in dry eye patients with lipid deficiency

AIM: To investigate the effects of different concentrations of artificial tears on lipid layer thickness (LLT) and blink rate (BR) in dry eye patients. METHODS: This study included 106 eyes of 58 patients with dry eye. The lipid deficiency type was defined as the LLT baseline <75 nm. The LLT and BR were measured at baseline and 1, 5 and 15min after the instillation of 0.1% or 0.3% sodium hyaluronate (SH) eye drops by using the LipiView ocular surface interferometer. RESULTS: In the lipid deficiency group, the LLT increased from baseline at 1min post instillation. The LLT after the instillation of 0.1% SH was significantly higher than that after the instillation of 0.3% SH (P<0.001). The LLT returned to baseline at 15min post instillation of 0.1% SH and at 5min post instillation of 0.3% SH. In the non-lipid deficiency group, the LLT decreased from baseline at 1min and returned to baseline at 5min for both treatments. The BRs were not significantly different at different time points for both treatments. CONCLUSION: SH eye drops induce a short-term increase in LLT of patients with lipid deficiency. A low concentration of artificial tears have a stronger effect than a high concentration of artificial tears on the increase in LLT. In comparison, SH eye drops induce a transient and slight decrease in LLT of patients without lipid deficiency. A low concentration of artificial tears might be better for patients with lipid deficiency.     

Efficacy of the Mineral Oil and Hyaluronic Acid Mixture Eye Drops in Murine Dry Eye

Purpose

To investigate the therapeutic effects of mineral oil (MO) and hyaluronic acid (HA) mixture eye drops on the tear film and ocular surface in a mouse model of experimental dry eye (EDE).

Methods

Eye drops consisting of 0.1% HA alone or mixed with 0.1%, 0.5%, or 5.0% MO were applied to desiccating stress-induced murine dry eyes. Tear volume, corneal irregularity score, tear film break-up time (TBUT), and corneal fluorescein staining scores were measured at 5 and 10 days after treatment. Ten days after treatment, goblet cells in the conjunctiva were counted after Periodic acid-Schiff staining.

Results

There was no significant difference in the tear volume between desiccating stress-induced groups. The corneal irregularity score was lower in the 0.5% MO group compared with the EDE and HA groups. The 0.5% and 5.0% MO groups showed a significant improvement in TBUT compared with the EDE group. Mice treated with 0.1% and 0.5% MO mixture eye drops showed a significant improvement in fluorescein staining scores compared with the EDE group and the HA group. The conjunctival goblet cell count was higher in the 0.5% MO group compared with the EDE group and HA group.

Conclusions

The MO and HA mixture eye drops had a beneficial effect on the tear films and ocular surface of murine dry eye. The application of 0.5% MO and 0.1% HA mixture eye drops could improve corneal irregularity, the corneal fluorescein staining score, and conjunctival goblet cell count compared with 0.1% HA eye drops in the treatment of EDE.     

A study on the ocular and extraocular pharmacology of metipranolol

Metipranolol (Betamann) is a clinically efficacious ocular hypotensive drug and preclinical experiments were undertaken to characterize this beta-adrenoceptor antagonist. In vitro beta₁- and beta₂-adrenoceptor antagonism was evaluated using the guinea pig atrium and the rat uterus, respectively. The respective pA₂ values were 8.3 and 8.4. Topical metipranolol, 0.3% and 0.6%, blocked both the hypotension (beta₂-mediated) and the tachycardia (beta₁-mediated) elicited in ganglion-blocked, conscious rabbits by isoproterenol, 0.5 g/kg, i.v. The Ki for displacement of³H-dihydroalprenolol binding to rabbit iris + ciliary body homogenates was 34 nM. The effect of metipranolol, 0.3% and 0.6%, was not particularly striking on the intraocular pressure (IOP) of conscious, normotensive rabbits. However, the elevated IOP of the alpha-chymotrypsinized rabbit eye was significantly decreased (maximum reduction of 5.8 mm Hg) following the instillation of metipranolol, 0.3%. IOP recovery in conscious rabbits following hyperosmotic challenge (i.v. infusion of a 20% NaCl solution) was not decreased by a 1-h pretreatment with a 0.3% solution. In contrast, a significant reduction of 41% was elicited by a 0.6% solution. Hence, the ocular hypotensive effect of metipranolol may result from decreased aqueous humor inflow. Metipranolol, 0.6%, was devoid of effect on rabbit pupil diameter. However, corneal local anesthesia was elicited in the rabbit by both 0.3% and 0.6% solutions of the drug, the effect being more marked with the higher concentration.     

Effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization in high myopia mice

AIM: To evaluate effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization (CNV) in high myopia mice. METHODS: The C57BL/6J mice were deprived of the right eye for 4wk, and the high myopia was diagnosed by optometry, the diopter was less than -6.00 D, and CNV was induced by 532 nm laser. The changes of dopamine D1 receptor (DRD1), dopamine D2 receptor (DRD2), and vascular endothelial growth factor A (VEGFA) were detected by Western blot technology at 0.5, 1, 2h, and 7d after 0.01%, 0.05%, and 0.1% atropine eye drops, respectively, the area of CNV was measured. RESULTS: Significant increases were observed on the expression of DRD2 in mouse high myopia model at 0.5, 1, 2h, 7d with 0.05% and 0.1% atropine eye drops (P<0.05). Significant decreases were observed on the expression of DRD1 and VEGFA in mouse high myopia model at 0.5, 1, 2h, 7d with 0.05% and 0.1% atropine eye drops (P<0.05). The area of CNV induced by laser in the drug-treated group was significantly smaller than that in the control group, and the higher the concentration, the more significant the inhibitory effect (P<0.05). CONCLUSION: The 0.01%, 0.05%, 0.1% atropine eye drops can decrease the level of VEGFA and inhibit high myopia CNV indirectly by up-regulating the level of DRD2 and down-regulating the level of DRD1, and the effect of 0.05% and 0.1% atropine eye drops is more significant.     

Intraocular penetration and systemic absorption after topical application of dexamethasone disodium phosphate

PURPOSE: To study the dexamethasone concentration in aqueous humor, vitreous, and serum of patients after repeated topical application of dexamethasone disodium phosphate. DESIGN: Prospective nonrandomized comparative trial. PARTICIPANTS: Twenty phakic patients scheduled for a first vitrectomy. METHODS: All participants received dexamethasone disodium phosphate drops according to an application schedule intended to result in steady-state drug concentrations. Starting on the preoperative day, they received 1 drop of dexamethasone disodium phosphate (0.1%) every 1 hours until the time of vitrectomy (total, 10 or 11 drops). At night, ointment containing dexamethasone (0.3 mg/g) and gentamicin (5 mg/g) was administered once. From 7 AM on, the drop application schedule was resumed. At the start of the vitrectomy, samples were taken from the aqueous humor, vitreous, and blood. MAIN OUTCOME MEASURES: The dexamethasone concentrations in the aqueous humor, vitreous, and serum measured by radioimmunoassay. RESULTS: The mean dexamethasone concentrations in the aqueous humor, vitreous, and serum were 30.5 ng/ml (range, 7.1-57.7; standard deviation [SD] 15.0), 1.1 ng/ml (range, 0.0-1.6; SD 0.4), and 0.7 ng/ml (range, 0.0-1.2; SD 0.4), respectively. CONCLUSIONS: Compared with previously tested administration routes (peribulbar or subconjunctival injection or oral administration), the penetration of dexamethasone into the vitreous after repeated drop application is negligible. Despite the frequent dosing schedule, the dexamethasone concentration in the aqueous humor is far lower than after a subconjunctival injection with dexamethasone disodium phosphate. Systemic uptake is low.     

Influence of (E)-5-(2-Bromovinyl)-2′-deoxyuridine on corneal epithelium healing

When applied as 0.1% or 0.5% eye drops 9 times a day at hourly intervals, BVDU [(E)-5-(2-bromovinyl)-2-deoxy-uridine] did not retard the regeneration of rabbit corneal epithelium. Nor did it exert any toxic effects on the cells. Likewise, IDU (5-iodo-2-deoxyuridine) 0.1% eye drops did not significantly reduce the rate of epithelium wound closure. However, IDU produced toxic alterations in the cells.     

【In Press】 Low concentration of artificial tears temporarily elevates the tear film lipid layer thickness in dry eye with lipid deficiency

AIM: To investigate the effects of different concentrations of artificial tears on lipid layer thickness (LLT) and blink rate (BR) in dry eye patients. METHODS: This study included 106 eyes of 58 patients with dry eye. The lipid deficiency type was defined as the LLT baseline <75 nm. The LLT and BR were measured at baseline and 1, 5 and 15min after the instillation of 0.1% or 0.3% sodium hyaluronate (SH) eye drops by using the LipiView ocular surface interferometer. RESULTS: In the lipid deficiency group, the LLT increased from baseline at 1min post instillation. The LLT after the instillation of 0.1% SH was significantly higher than that after the instillation of 0.3% SH (P<0.001). The LLT returned to baseline at 15min post instillation of 0.1% SH and at 5min post instillation of 0.3% SH. In the non-lipid deficiency group, the LLT decreased from baseline at 1min and returned to baseline at 5min for both treatments. The BRs were not significantly different at different time points for both treatments. CONCLUSION: SH eye drops induce a short-term increase in LLT of patients with lipid deficiency. A low concentration of artificial tears have a stronger effect than a high concentration of artificial tears on the increase in LLT. In comparison, SH eye drops induce a transient and slight decrease in LLT of patients without lipid deficiency. A low concentration of artificial tears might be better for patients with lipid deficiency.     

FK506及其纳米粒的房水药代动力学的实验研究

目的探讨FK506及其纳米粒的房水药代动力学特征。方法42只新西兰白兔分为:(1)FK506纳米胶体液滴眼组(18只兔)和注射组(16只兔):双眼结膜囊滴入或结膜下注射10μgFK506的纳米胶体溶液;(2)不含纳米微粒的FK506滴眼组(8只兔):再分为2个亚组,即双眼结膜囊分别滴入20μg和40μg FK506的滴眼液。不同时间点采集房水,酶联免疫法测定房水中FK506含量,计算药代动力学参数。结果含10μg FK506的纳米胶体溶液结膜下注射和滴眼后房水有效药物浓度可分别维持96 h和16 h;结膜下注射后2 h房水浓度为(1.15±0.25)ng/m、l6~96 h房水浓度为(9.62±2.19)~(2.60±0.21)ng/m l,滴眼16 h内房水浓度为(15.50±3.39)~(2.59±0.83)ng/m l;药代动力学参数分别为:达峰时间(Tm ax)(64.00±13.86)h和(1.25±0.50)h,达峰浓度(Cm ax)(10.16±1.37)ng/m l和(15.52±2.37)ng/m l,曲线下面积(AUC0→t)(612.48±54.39)ng.m l-1.h-1和(152.44±16.74)ng.m l-1.h-1,吸收速率常数(Ka)0.040±0.004和3.790±0.730,平均滞留时间(MRT)(58.53±5.42)h和(8.20±1.28)h。房水中FK506质量浓度呈一室模型。不含纳米微粒的FK506(20μg和40μg)液滴眼后房水有效药物浓度维持均≤4 h;其中含20μgFK506液的Tm ax为1 h,Cm ax为(18.93±6.95)ng/m l;含40μg FK506液的Tm ax为2 h;Cm ax为(28.33±1.31)ng/m。l结论采用FK506纳米粒胶体溶液行结膜下注射和滴眼时均可延长FK506药物在房水中的滞留时间,而且结膜下注射能使房水中维持的有效药物浓度相对较低和时间更长     

The effect of argon laser trabeculoplasty on the blood-aqueous barrier and intraocular pressure in human glaucomatous eyes treated with diclofenac 0.1%

Background: We studied the effect of argon laser trabeculoplasty (ALT) on the bloodaqueous barrier (BAB) in 41 eyes of 41 patients with primary open-angle glaucoma, pseudoexfoliation glaucoma, or pigment dispersion glaucoma using the Fluorotron Master II. Methods: Fluorophotometry was performed the day before ALT and on the 3rd day after surgery at 30 and 60 min after intravenous injection of 7 mg/kg body weight sodium fluorescein 10%. Intraocular pressure (IOP) was measured using Goldmann applanation tonometry on the day before surgery and at 3rd days and 1 year (mean) after ALT. Patients were treated with argon laser by one surgeon (180°, 0.1 s, 50 m 0.6–1.0 W 56 laser burns). Eyes were randomly assigned to either diclofenac-sodium 0.1 % eye drops or vehicle. Eye drops were applied six times 1 h before ALT into the operated eyes and five times daily for 3 days postoperatively. Results: On the 3rd day after ALT there was significant disruption of the BAB in the placebo-treated eyes compared to the diclofenac 0.1%-treated eyes. In the placebo-treated eyes as well as in diclofenac-sodium 0.1 %-treated eyes there was a significant decrease of IOP postoperatively for up to 1 year. There was no significant difference concerning the IOP reduction after 1 year. Diclofenac-sodium 0.1 % eye drops significantly stabilized the BAB on the 3rd day after ALT, compared to placebo, in this model. Conclusion: Diclofenac-sodium 0.1 % significantly stabilized the disruption of the blood-aqueous barrier on the 3rd day after ALT. Concerning the IOP-lowering effect of ALT, the postoperative application of steroids should be avoided.     

Three-month evaluation of dorzolamide hydrochloride/timolol maleate fixed-combination eye drops versus the separate use of both drugs

Purpose

To investigate the ocular hypotensive effect and safety of dorzolamide hydrochloride 1?%/timolol maleate 0.5?% fixed-combination eye drops.

Methods

The study cohort comprised 34 patients with either primary open-angle glaucoma or ocular hypertension who were being concomitantly treated with dorzolamide hydrochloride 1?% eye drops and timolol maleate 0.5?% eye drops. The dorzolamide hydrochloride 1?% and timolol maleate 0.5?% eye drops were replaced with dorzolamide hydrochloride 1?%/timolol maleate 0.5?% fixed-combination eye drops without any washout period. The intraocular pressure (IOP) was evaluated both before and 1 and 3?months after the treatment change. The patients were asked to complete a questionnaire on adherence to the treatment protocol 1?month after the change in treatment.

Results

The IOP was 15.5?±?2.7?mmHg at the time of treatment change, 15.2?±?2.7?mmHg at 1 month post-change, and 15.5?±?2.9?mmHg at 3?months post-change, which is consistent with that before the treatment change (p?=?0.286). Based on the completed questionnaire, following the treatment change, 50?% of patients felt a stinging sensation following administration of the eye drops and 11.8?% experienced blurred vision. In no case were the eye drops discontinued due to adverse reactions or insufficient IOP decrease.

Conclusion

The replacement of concomitant treatment with dorzolamide hydrochloride 1?% and timolol maleate 0.5?% eye drops with dorzolamide hydrochloride 1?%/timolol maleate 0.5?% fixed-combination eye drops improved protocol adherence and preserved the IOP.     

Penetration of 1% voriconazole eye drops into human vitreous humour: a prospective, open-label study

Purpose:  Although there have been reports describing the use of 1% voriconazole eye drops in the treatment of fungal infections, little is known about the penetration of voriconazole eye drops into the vitreous humour. The aim of this study was to elucidate if topical application of 1% voriconazole eye drops could reach therapeutic levels in the vitreous humour.
Methods:  A prospective, open-label trial involving 10 participants selected from patients scheduled to undergo elective, posterior segment surgery. Participants received 1% voriconazole solution, preserved with 0.01% benzalkonium chloride, hourly for four doses or four times a day for 3 days. Vitreous humour was obtained at the start of surgery and analysed using a validated high-performance liquid chromatography assay.
Results:  The minimum and maximum voriconazole concentration after hourly dosing ( n  = 5) was 0.1 and 1.1 µg/mL, respectively, whereas the median was 0.3 µg/mL. Samples were taken between 0.8 and 5.4 h after the last dose, with the median at 1.2 h. Almost all voriconazole concentrations from the four times a day group ( n  = 5) were below the limit of quantification.
Conclusions:  One per cent voriconazole eye drops are able to penetrate into human vitreous humour. Adequate concentration for treatment of sensitive Candida species can be achieved upon hourly administration.     

Comparison of the effects of carteolol and metipranolol eyedrops on the ventilatory and cardiovascular functions in asthmatics

Systemic effects of two topical B adrenergic blocking agents, carteolol and metipranolol, recently introduced in the treatment of open angle chronic glaucoma, were investigated in two groups of 10 asthmatic patients, according to a controlled trial device. Saline eye drops as placebo, then, 30 mn later beta blocker eye-drops, were instillated at usual dose. Heart rate, systolic and diastolic blood pressure, vital capacity (VC) and expiratory outflow (FEV1), were checked every 15 mn during 90 mn. They did not vary under placebo. After carteolol and metipranolol, heart rate decreased more than 10% in 7 out of 10 patients in each group (extreme individual changes: -16.7 and -25.0%). Bradycardia was always sino atrial. FEV1 was lowered in 3 patients with carteolol and in 6 with metipranolol (extreme individual values: -32.3 and -31.8%). If time is not taken in consideration, the lowest values were -8.6 +/-4.6% with carteolol and -17.9 +/- 3.3% with metipranolol. CV was reduced only in 1 patient under carteolol and 2 patients under metipranolol. Systemic blood pressure remained unchanged. 7 patients complained of ocular pain when metipranolol was instillated. Comparison of both ocular topics shows that metipranolol lowers heart rate and FEV1 more than carteolol, which has a sympathomimetic intrinsic activity. These two drugs have the same clinical efficiency. Our results point out the risks outcoming from their systemic diffusion, and the absolute necessity to comply with the general rules of good use of beta blockers, even with eye drops, mainly the contra-indications and the strict adjustment of individual doses.     

3Alpha,5beta-tetrahydrocortisol effect on outflow facility.

3Alpha,5beta-Tetrahydrocortisol (THF) was administered topically and intracamerally to ocular normotensive cynomolgus monkeys to determine whether it affects outflow facility. Monkeys received THF either topically at a dose of 2 x 5 microl drops of 300 microg/10 microl twice daily for 4 days (n = 4) or 3 times daily for 10 days (n = 4) with 10% DMSO as vehicle to the control eye, or intracamerally via 2 ml anterior chamber (AC) exchange of 30 microg/ml THF with vehicle, 0.1% DMSO, to the control eye followed by a second AC exchange using 300 microg/ml THF with vehicle to the control eye. Outflow facility was measured by a two-level constant pressure AC perfusion after administration of eye drops or after baseline outflow facility measurement and AC exchange with THF solution. The results showed no effect on outflow facility in normotensive cynomolgus monkeys.     

Effects of corneal thickness on the intraocular penetration of travoprost 0.004%

Purpose

To determine whether the intraocular penetration of travoprost 0.004% is affected by central corneal thickness.

Methods

Sixty-four patients who were scheduled for cataract surgery without any other ophthalmologic pathology of significance were enroled in this study. At 120 min before surgery, one drop of travoprost 0.004% was instilled in the eye to be operated on. At the start of surgery, a sample of aqueous humour was extracted to subsequently determine its AL-5848 concentration. These concentrations were compared among three groups of patients established according to central corneal thickness measurements obtained by ultrasound pachymetry.

Results

Mean AL-5848 concentrations were 3.27±2.03 ng/ml in Group I (CCT<511 microns), 3.27±2.44 ng/ml in Group II (CCT≥511 and ≤574 microns), and 2.73±2.15 ng/ml in Group III (CCT>574 microns), indicating no significant differences among the groups.

Conclusions

We were unable to demonstrate the greater or lesser penetration of travoprost depending on corneal thickness, which could explain differences in patient responses to this drug.     

Topical non-steroidal anti-inflammatory drugs for the treatment of cystoid macular edema post Descemet’s stripping automated endothelial keratoplasty

Purpose

To investigate the effectiveness of topical non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of cystoid macular edema (CME) post Descemet’s stripping automated endothelial keratoplasty (DSAEK).

Study design

Retrospective observational study

Methods

In this study of 334 patients who underwent DSAEK at the Baptist Eye Institute, Kyoto, Japan between July 2011 and December 2015, 18 patients with postoperative CME (determined by optical coherence tomography) treated with topical NSAIDs after the onset of CME were included.

Results

At CME onset, 17 of the 18 patients were treated with bromfenac eye drops and 1 was treated with nepafenac eye drops. Post initiation of treatment with topical NSAIDs, CME in 17 (94.4%) of the 18 patients improved at 1 month and all cases completely recovered within 3 months. At 12-months post initiation of treatment, 61.1% (n?=?11) of patients achieved a visual acuity (VA) of 20/40 or better, and there was no significant difference of VA between the patients with or without an episode of postoperative CME (P?=?0.55).

Conclusion

The administration of topical NSAID eye drops was found to be effective in treating patients with CME post DSAEK.

     

Metipranolol attenuates lipid peroxidation in rat brain: a comparative study with other antiglaucoma drugs

Background Free radical production seems to be involved in the pathogenesis of a number of ocular diseases. Certain -adrenoceptor antagonists display antioxidant properties, but these have not been ascribed to any of the presently used ophthalmic -adrenoceptor antagonists. Therefore, we examined the influence of ophthalmic -adrenoceptor antagonists and other antiglaucoma drugs on stimulated lipid peroxidation in rat brain homogenates.Methods Lipid peroxidation in rat brain homogenates was stimulated by iron/ascorbate or sodium nitroprusside. Lipid peroxidation was assessed by the formation of thiobarbituric acid reactive species (TBARS).Results Of the antiglaucoma drugs tested (brimonidine, carteolol, dorzolamide, latanoprost, levobetaxolol, levobunolol, metipranolol, pilocarpine, timolol, travoprost and unoprostone), only metipranolol and its active metabolite, desacetylmetipranolol, were found to significantly reduce iron/ascorbate-induced lipid peroxidation in rat brain homogenates with IC₅₀ values of 6.9 and 1.1 M, respectively. Metipranolol and desacetylmetipranolol also concentration-dependently inhibited sodium nitroprusside-stimulated lipid peroxidation in rat brain homogenates, displaying IC₅₀ values of 25.1 and 2.6 M, respectively.Conclusion These data indicate that metipranolol and desacetylmetipranolol exhibit remarkable antioxidant properties, with an effect not dissimilar from the reference antioxidant trolox.     

Counterfeiting von Augentropfen?

Introduction

Counterfeit drugs are often ineffective and are considered a problem with an immense risk potential especially in the treatment of infectious diseases. Emerging and developing countries are particularly affected. Little is known about the extent of counterfeit antibiotic drugs used in eye care. In the present study we investigated antibiotic eye drops purchased in two African countries with respect to the active substance and its concentration in the sample.

Methods

A total of 33 antibiotic eye drops purchased in Kenya and the Democratic Republic of Congo were tested. The bottles were labeled to contain one of the following substances: the quinolones ciprofloxacin, levofloxacin and ofloxacin and the aminoglycosides gentamicin and tobramycin. Imported quality products as well as cheaper generic drugs were tested. Fluoroquinolones were determined by high pressure liquid chromatography (HPLC) and quantified by fluorescence measurement and aminoglycosides were tested by using a fluorescence polarization immunoassay.

Results

All samples were found to contain the declared drug. Nine samples (27%) showed an under-concentration by 10% or less and ten (30%) showed an increased concentration of 10% or more than indicated on the label. 75% of the original drugs but only 12% of the generic drugs had measured concentrations within the standard advisory ranges of ±5% from the nominal value.

Conclusion

Our results provide no evidence for significant criminal counterfeiting of eye drops in the studied countries. The frequent deviation from the stated concentration in the generic samples is cause for concern and justifies further investigation.     

Penetration of topically applied levofloxacin into eyes with thin-wall filtering bleb after trabeculectomy

PURPOSE: To investigate the comparative penetration of 0.3% levofloxacin eye drops into the aqueous humour between cataract patients with or without (control) thin-wall filtering blebs. METHODS: One drop of 0.3% levofloxacin was administered to the eyes at 30-min intervals for 3.5 h before phacoemulcification for both groups. Aqueous humour samples (0.1-0.2 ml) were aspirated during surgery. The concentration of levofloxacin in the aqueous humour was determined by high-performance liquid chromatography. The Student's t-test, Pearson correlation, and chi(2) test were used to compare the data of the two groups. A P<0.05 was required for results to be considered statistically significant. RESULTS: The levofloxacin concentration in the aqueous humour was significantly increased (P<0.0001) in the bleb (mean+SD: 3.7+/-2.3 microg/ml) vscontrol group (0.4+/-0.2 microg/ml). Intraocular pressure and the bleb area were not correlated with levofloxacin concentration. CONCLUSION: The presence of thin-wall filtering blebs increases intraocular penetration of topically administered levofloxacin.