Parenteral anticholinergics in dogs with normal and elevated intraocular pressure

Application of neuromuscular blockade using Rocuronium for performing different surgeries and its reversal by Neostigmine-Glycopyrrolate combination in dogs

This study was executed in the clinical setup to investigate the effects of Rocuronium and its reversal by Neostigmine and Glycopyrrolate (Myopyrolate) combination in Propofol-Isoflurane anaesthetized dogs. Rocuronium-induced neuromuscular blockade was applied to 21 clinical cases. Out of which, 19 cases were of orthopaedic surgeries and 2 cases of ovariohysterectomy. After the animal had stabilized on the mixture of isoflurane and oxygen, the relaxation of muscle was induced using Rocuronium @ 0.5 mg/kg b.wt. Immediately IPPV was provided in volume control mode. Neuromuscular blockade was reversed using a single syringe combination drug having both Neostigmine and Glycopyrrolate (Myopyrolate) @ 0.05 mg/kg b.wt and @ 0.01 mg/kg b.wt, respectively. Rocuronium caused the centering of the ocular globe gradually in less than 30 sec. During orthopaedic surgeries, the reduction of fractured ends became easy without much tissue trauma. In ovariohysterectomy surgeries, the appropriate level of abdominal muscle relaxation further helped in the easy exteriorization of the ovarian stump. The onset time for Rocuronium was 17.64±1.10 sec and its duration of action was 27.82±0.72 min. The use of Rocuronium along with IPPV caused minimal alteration of the physiological parameters with no clinical consequences and thus can be considered a complication-free anaesthetic protocol for interventions demanding muscle relaxation.

A systematic review of the effects of injectable sedative and anesthetic drugs and inhalant anesthetics on intraocular pressure in the dog

OBJECTIVE

The purpose of this systematic review was to summarize the results of studies that have determined the effect of injectable and inhalant drugs used in anesthesia on intraocular pressure (IOP) in dogs.

DATABASES USED

A comprehensive search of research literature was performed without language restriction. The search utilized the PubMed, CAB Abstracts and the University of Georgia's Galileo electronic databases using a combination of free text terms 'Ophthalmology', 'Intraocular Pressure', 'Anesthetic', 'Anesthesia', 'Canine' or 'Dog'. The time frame searched was from 1970 to October 2018. Any published research paper that dealt with sedatives or anesthetics administered systemically and the canine eye was evaluated.

CONCLUSIONS

The effects of many anesthetic drugs in dogs with ocular pathology are largely unknown. Many anesthetic drugs do not induce clinically relevant changes in IOP in dogs with normal eyes, although some studies demonstrated results with statistically significant changes. The dose, route of administration, experimental conditions, drug combinations, timing of measurements, measurement technology and setting or individual animal characteristics may all produce some heterogeneity in results from multiple studies.

Effects of propofol on intraocular pressure in premedicated and nonpremedicated dogs with and without glaucoma

OBJECTIVE To establish a study cutoff for evidence of glaucoma on the basis of IOP measurements from a large population of healthy dogs and to assess the effects of IV propofol administration on IOPs in premedicated and nonpremedicated dogs with and without glaucoma defined by this method. DESIGN Prospective, descriptive study. ANIMALS 234 client-owned dogs. PROCEDURES IOPs measured in 113 healthy dogs (226 eyes) were used to calculate an IOP value indicative of glaucoma. The IOPs were measured in an additional 121 dogs (237 eyes) undergoing ophthalmic surgery. Midazolam-butorphanol was administered IV as preanesthetic medication to 15 and 87 dogs with and without glaucoma, respectively. A placebo (lactated Ringer solution) was administered IV to 8 and 11 dogs with and without glaucoma, respectively. Anesthesia of surgical patients was induced with propofol IV to effect. The IOPs and physiologic variables of interest were recorded before (baseline) and after preanesthetic medication or placebo administration and after propofol administration. RESULTS An IOP > 25 mm Hg was deemed indicative of glaucoma. Compared with baseline measurements, mean IOP was increased after propofol administration in nonpremedicated dogs without glaucoma and unchanged in nonpremedicated dogs with glaucoma. Propofol-associated increases in IOP were blunted in premedicated dogs without glaucoma; IOP in affected eyes of premedicated dogs with glaucoma was decreased after preanesthetic medication and after propofol administration. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that preexisting IOP influences the response to anesthetic drugs, and administration of preanesthetic medication with muscle-relaxing properties may blunt or reduce propofol-induced increases in IOP. Further research with a larger number of dogs is needed to confirm our results in dogs with glaucoma.

The effects of tolterodine on anterior segment and choroidal thickness in patients with overactive bladder syndrome

BACKGROUND

To evaluate the effects of tolterodine on anterior segment and choroidal thickness by using the Pentacam system and optical coherence tomography (OCT) (Pentacam).

METHODS

A total of 122 eyes of 61 patients (34 female; 27 male) were included in the study. All patients underwent a regular ocular examination and intraocular pressure measurements before and after 3 months of antimuscarinic drug tolterodine treatment, in addition, pupil diameter, anterior chamber depth, anterior chamber volume, anterior chamber angle, and lens thickness were measured through Pentacam (Oculus Inc., Wetzlar, Germany) system. Measurements of choroidal thickness were performed by OCT (Spectralis^®, Heidelberg Engineering, Heidelberg, Germany).

RESULTS

The mean age was 58.4 ± 7.3 years and 56.5 ± 11.1 years for female and male patients. The mean intraocular pressure was 15.10 ± 2.75 mmHg before treatment and 15.18 ± 2.65 mmHg after treatment. Pupil diameters were 3.09 ± 0.48 mm before treatment and 3.12 ± 0.43 mm after treatment. Anterior chamber depth, before and after treatment were 2.68 ± 0.65 mm and 2.70 ± 0.61 mm. The mean value for subfoveal choroidal thickness was 267.92 ± 81.35 μm before the administration of tolterodine, whereas the mean choroidal thickness was 271.83 ± 75.42 μm after the administration of tolterodine. The alterations in the subfoveal choroidal thickness were not statistically significant (p = 0.862).

CONCLUSIONS

After 3 months of therapy with tolterodine, there were no significant changes in anterior segment parameters and choroidal thickness.

Effects of intramuscular injection of glycopyrrolate on Schirmer tear test I results in dogs

OBJECTIVE To determine effects of glycopyrrolate administered IM on Schirmer tear test I (STT I) measurements in dogs. DESIGN Prospective clinical study. ANIMALS 13 client- and staff-owned dogs. PROCEDURES For both eyes of each dog, STT I measurements were recorded twice 20 minutes apart (at T1 and T2) and 2 to 4 hours later (at T3). Glycopyrrolate (0.01 mg/kg [0.005 mg/lb]) was administered IM to all dogs (3 dogs received an injection of saline [0.9% NaCl] solution on an earlier occasion), and final STT I measurements were recorded 20 minutes later (at T4). Intraocular pressures, heart rate, and respiratory rate were also recorded at each time point. RESULTS Ophthalmic variables did not differ between right and left eyes. In all dogs, variables at T1, T2, or T3 (measurements before glycopyrrolate administration) did not differ; baseline values were therefore defined at T3. At T4, STT I measurements were significantly decreased (mean ± SD decrease, 67.4 ± 15.4% [mean actual decrease, 15.8 mm/min]). During the same period, mean heart rate increased by 26.5 ± 12.0% (mean actual increase, 30.2 beats/min). Glycopyrrolate had no effect on intraocular pressure or respiratory rate. In 5 dogs at 24 hours after glycopyrrolate treatment, STT I measurement in each eye had returned to baseline value. Saline solution treatment (3 dogs) had no effect on any variables. CONCLUSIONS AND CLINICAL RELEVANCE In dogs, IM injection of glycopyrrolate resulted in a clinically relevant transient decrease in aqueous tear production. Application of lacrimomimetics beginning at the time of or within 20 minutes after glycopyrrolate premedication is recommended until STT I measurements return to baseline.

The short-term and long-term adverse ocular effects of fesoterodine fumarate

AIM

To evaluate the short-term and long-term effects of fesoterodine fumarate treatment which is used for overactive bladder (OAB) on pupil diameter (PD), intraocular pressure (IOP) and accommodation amplitude (AA).

METHOD

Ophthalmic examination was performed before and after receiving medication (on the 30th and 90th day) on 120 eyes of 120 women whom were planned to begin anticholinergic treatment (fesoterodine fumarate, 4 mg/day, peroral) for OAB, prospectively. The changes in PD, IOP and AA were analyzed statistically.

RESULTS

The mean age of 120 women was 52.06 ± 9.39 years (30-70 years). The mean PD, IOP and AA values were 4.12 ± 0.61 mm (3.00-5.70 mm), 15.58 ± 1.74 mmHg (11-20 mmHg) 2.28 ± 1.26 Diopter (D) (0.50-5.50 D) at baseline; 4.68 ± 0.65 mm (3.20-5.80 mm), 16.11 ± 1.72 mmHg (11-20 mmHg), 1.68 ± 1.04 D (0.25-4.50 D) at 30th day; and 4.28 ± 0.58 mm (3.10-5.70 mm), 16.09 ± 1.96 mmHg (11-19 mmHg), 2.18 ± 1.19 D (0.50-5.00 D) at 90th day, respectively. Although increases in PD values and decreases in AA values were statistically significant (p < 0.001 for each), the changes in IOP values were not as such (p = 0.642). Visual complaint was not observed in any patient.

DISCUSSION

The newest anticholinergic medication in women with OAB increased the PD and decreased the AA statistically significantly. Clinically, it seems to be well-tolerated by the patient.

The effect of oral solifenacin succinate treatment on intraocular pressure: glaucoma paradox during overactive bladder treatment

INTRODUCTION AND HYPOTHESIS

Anticholinergic medication is the mainstay of pharmacotherapy for overactive bladder (OAB). The aim of the study is to investigate the effect of oral solifenacin succinate on intraocular pressure (IOP) in female OAB patients and to discuss the ocular drawbacks during treatment.

METHODS

The female patients with a clinical diagnosis of OAB in whom use of oral solifenacin succinate 5 mg/day (group I) and age-matched healthy female subjects (group II) underwent complete ophthalmological examination, including IOP measurement at the beginning of the oral treatment and after 4 weeks. The patients with a history of previous ocular surgery and those with ocular diseases besides refraction disorders and presbyopia were excluded.

RESULTS

The data from the right eyes of 60 consecutive patients in group I and 30 consecutive patients in group II were used for analysis. No statistically significant change was detected in the IOP (from 16.05 ± 2.30 mmHg to 16.30 ± 2.25 mmHg at the 4th week in group I, p = 0.160; from 15.60 ± 2.14 mmHg to 15.60 ± 2.09 mmHg at the 4th week in group II, p = 0.864) of the eyes in both groups.

CONCLUSIONS

Since the power of the study is not enough to draw a clear conclusion, a 4-week course of solifenacin succinate treatment in women with OAB seemed to have no clinically significant effect on IOP values. Further larger studies are needed to determine the effect of anticholinergics on anterior chamber parameters and to evaluate their safety in glaucoma patients.

Evaluation of the effect of tolterodine on pupil diameter and anterior chamber parameters with the Pentacam

BACKGROUND

To evaluate the effect of tolterodine on pupil diameter and anterior chamber parameters, including volume, depth, and angle, with the Pentacam.

METHODS

The 56 eyes of 28 patients who were diagnosed as having overactive bladder and planned to be treated with tolterodine were followed up prospectively in the study. All the patients underwent full ophthalmic examination and scanning with the Pentacam (Oculus, Inc., Wetzlar, Germany) before and 4 weeks after the start date of tolterodine therapy. In addition, the 30 eyes of 15 healthy volunteers were analyzed twice as a control group for repeatability of the measurements.

RESULTS

The quantitative descriptors of the anterior chamber before and after the treatment, respectively, were as follows: pupil diameter, 3.02 ± 0.56 mm and 3.01 ± 0.55 mm; anterior chamber depth, 2.74 ± 0.35 mm and 2.75 ± 0.34 mm; anterior chamber volume, 150.23 ± 33.95 mm(3) and 150.27 ± 34.48 mm(3); and anterior chamber angle, 34.56° ± 5.68° and 35.03° ± 5.99°. For all the measurements, the differences did not reach statistical significance (p > .05). Also, the comparison of the same parameters obtained from the first and second measurements of healthy volunteers was not statistically significant (p > .05).

CONCLUSION

Our study demonstrates that tolterodine does not affect pupil diameter and anterior chamber parameters, including angle, volume, and depth. Most likely, it is an organ-selective agent, inhibiting muscarinic receptors in the bladder rather than in the anterior segment of the eye.

Ocular side-effects of tolterodine and oxybutynin, a single-blind prospective randomized trial

AIM

To evaluate the effects of tolterodine and oxybutynin on visual accommodation, pupillary diameter, intraocular pressure and tear secretion in women with overactive bladder.

METHODS

One hundred and four eyes from 52 consecutive female patients (age range: 22-60 years) with a urodynamic diagnosis of overactive bladder were prospectively investigated. Patients with a history of ocular disease or surgery were excluded. The subjects were randomly assigned to one of two groups: Group I received 2 mg tolterodine bid and Group II received 5 mg oxybutynin tid. All patients were evaluated at baseline (day 0) and after 1 month of treatment (day 28) by an ophthalmologist who was blinded to the medication. At each time point, a complete ophthalmic examination was performed and accommodation amplitude (AA), and pupillary diameter (PD) in dim and bright light were recorded. As well, tear secretion was assessed based on tear film break-up time and Schirmer I-test results. Statistical comparisons were made using the chi-square test, Student's t-test and Mann-Whitney U-test, as appropriate.

RESULTS

Twenty-eight patients (56 eyes) received tolterodine and 24 patients (48 eyes) received oxybutynin. The mean ages of the two groups were similar (P = 0.523). After 4 weeks of treatment, AA was significantly lower in the oxybutynin treated group (P = 0.003, 95% CI 0.15, 0.62) whereas there was no significant change in AA in the tolterodine treated group (P = 0.155, 95% CI -0.042, 0.86). At day 28, PD in dim light was significantly larger in the tolterodine treated group (P = 0.031, 95% CI -0.82, -0.06), whereas no significant change in PD in dim light was noted in the oxybutynin treated group (P = 0.330, 95% CI -0.38, 0.18). Neither group showed a significant change in PD in bright light values on day 28 (P > 0.05 for both). In each group, the differences from day 0 to day 28 for intraocular pressure, and Schirmer-I results were insignificant (P > 0.05 for all). Both groups had significantly shorter tear film break-up time after 1 month of therapy (P = 0.014 (95% CI 0.47, 3.81) and P = 0.02 (95% CI 1.14, 4.61) for the tolterodine and oxybutynin treated groups, respectively).

CONCLUSION

Four weeks of standard-dose oxybutynin treatment in women with overactive bladder decreases AA significantly, whereas the same duration of standard-dose tolterodine does not have this effect. However, tolterodine seemed to affect PD in dim light. One month of treatment with either of these anticholinergic drugs shortens tear film break-up time significantly. Concerning ocular side-effects, tolterodine seems to offer an advantage over oxybutynin because it does not affect AA, however, the shorter tear film break-up time with both agents suggests potential problems for patients who already have dry eye.