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Puranen J, Ranta VP, Ruponen M, Urtti A, Sadeghi A. Quantitative intravitreal pharmacokinetics in mouse as a step towards inter-species translation. Exp Eye Res 2023; 235:109638. [PMID: 37657528 DOI: 10.1016/j.exer.2023.109638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/17/2023] [Accepted: 08/28/2023] [Indexed: 09/03/2023]
Abstract
Although mouse models are widely used in retinal drug development, pharmacokinetics in mouse eye is poorly understood. In this study, we applied non-invasive in vivo fluorophotometry to study pharmacokinetics of intravitreal fluorescein sodium (molecular weight 0.38 kDa) and fluorescein isothiocyanate-dextran (FD-150; molecular weight 150 kDa) in mice. Intravitreal half-lives of fluorescein and FD-150 in mouse eyes were 0.53 ± 0.06 h and 2.61 ± 0.86 h, respectively. These values are 8-230 times shorter than the elimination half-lives of similar compounds in the human vitreous. The apparent volumes of distribution in the mouse vitreous were close to the anatomical volume of the mouse vitreous (FD-150, 5.1 μl; fluorescein, 9.6 μl). Dose scaling factors were calculated from mouse to rat, rabbit, monkey and human translation. Based on pharmacokinetic modelling and compound concentrations in the vitreous and anterior chamber, fluorescein is mainly eliminated posteriorly across blood-retina barrier, but FD-150 is cleared via aqueous humour outflow. The results of this study improve the knowledge of intravitreal pharmacokinetics in mouse and facilitate inter-species scaling in ocular drug development.
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Affiliation(s)
- Jooseppi Puranen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70210, Kuopio, Finland.
| | - Veli-Pekka Ranta
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70210, Kuopio, Finland
| | - Marika Ruponen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70210, Kuopio, Finland
| | - Arto Urtti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70210, Kuopio, Finland; Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E, FI-00790, Finland
| | - Amir Sadeghi
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70210, Kuopio, Finland.
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Strickland RG, Garner MA, Gross AK, Girkin CA. Remodeling of the Lamina Cribrosa: Mechanisms and Potential Therapeutic Approaches for Glaucoma. Int J Mol Sci 2022; 23:ijms23158068. [PMID: 35897642 PMCID: PMC9329908 DOI: 10.3390/ijms23158068] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/28/2022] Open
Abstract
Glaucomatous optic neuropathy is the leading cause of irreversible blindness in the world. The chronic disease is characterized by optic nerve degeneration and vision field loss. The reduction of intraocular pressure remains the only proven glaucoma treatment, but it does not prevent further neurodegeneration. There are three major classes of cells in the human optic nerve head (ONH): lamina cribrosa (LC) cells, glial cells, and scleral fibroblasts. These cells provide support for the LC which is essential to maintain healthy retinal ganglion cell (RGC) axons. All these cells demonstrate responses to glaucomatous conditions through extracellular matrix remodeling. Therefore, investigations into alternative therapies that alter the characteristic remodeling response of the ONH to enhance the survival of RGC axons are prevalent. Understanding major remodeling pathways in the ONH may be key to developing targeted therapies that reduce deleterious remodeling.
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Affiliation(s)
- Ryan G. Strickland
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (R.G.S.); (M.A.G.); (A.K.G.)
| | - Mary Anne Garner
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (R.G.S.); (M.A.G.); (A.K.G.)
| | - Alecia K. Gross
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (R.G.S.); (M.A.G.); (A.K.G.)
| | - Christopher A. Girkin
- Department of Ophthalmology and Vision Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Correspondence: ; Tel.: +1-205-325-8620
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Smith SM, Salmon JH, Abbaraju S, Amin R, Gilger BC. Tolerability, pharmacokinetics, and pharmacodynamics of a brinzolamide episcleral sustained release implant in normotensive New Zealand white rabbits. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2020.102123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Talaei S, Mahboobian MM, Mohammadi M. Investigating the ocular toxicity potential and therapeutic efficiency of in situ gel nanoemulsion formulations of brinzolamide. Toxicol Res (Camb) 2020; 9:578-587. [PMID: 32905229 DOI: 10.1093/toxres/tfaa066] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 06/27/2020] [Accepted: 07/27/2020] [Indexed: 01/09/2023] Open
Abstract
Glaucoma is an ocular disease i.e. more common in older adults with elevated intraocular pressure and a serious threat to vision if it is not controlled. Due to the limitations regarding the conventional form of brinzolamide (Azopt®), two optimum formulations of in situ gel nanoemulsion were developed. To ensure the safety and efficacy of developed formulations for ocular drug delivery, the current study was designed. MTT assay was carried out on the human retinal pigmentation epithelial cells. To investigate the irritation potential of the chosen formulations, hen's egg test-chorioallantoic membrane as a borderline test between in vivo and in vitro methods has been done. The modified Draize method was utilized to evaluate eye tolerance against the selected formulations. Intraocular pressure was measured by applying the prepared formulations to the eyes of normotensive albino rabbits in order to assess the therapeutic efficacy. Based on MTT test, cell viability for NE-2 at 0.1% and NE-1 at 0.1 and 0.5% concentrations was acceptable. The results of the hen's egg test-chorioallantoic membrane test indicated no sign of vessel injury on the chorioallantoic membrane surface for both formulations. Also, during 24 h, both formulations were well-tolerated by rabbit eyes. The pharmacodynamics effects of formulations had no difference or were even higher than that of suspension in case of adding lower concentration (0.5%) of brinzolamide to the formulations. With regard to the results of the mentioned methods, our advanced formulations were effective, safe, and well-tolerated, thus can be introduced as an appropriate vehicle for ocular delivery of brinzolamide.
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Affiliation(s)
- Sima Talaei
- Department of Toxicology and Pharmacology, School of Pharmacy, Hamadan University of Medical Sciences, Shahid Fahmideh Boulevard, Hamadan 6517838678, Iran
| | - Mohammad Mehdi Mahboobian
- Department of Pharmaceutics, School of Pharmacy, Hamadan University of Medical Sciences, Shahid Fahmideh Boulevard, Hamadan 6517838678, Iran
| | - Mojdeh Mohammadi
- Department of Toxicology and Pharmacology, School of Pharmacy, Hamadan University of Medical Sciences, Shahid Fahmideh Boulevard, Hamadan 6517838678, Iran
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Drug delivery to the eye anterior chamber by intraocular lenses: An in vivo concentration estimation model. Eur J Pharm Biopharm 2018; 133:63-69. [PMID: 30292794 DOI: 10.1016/j.ejpb.2018.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 11/22/2022]
Abstract
Drug loaded intraocular lenses have been proposed as an alternative to the conventional post-cataract removal prophylaxis through topical drug administration, since the drug or combination of drugs released from the lenses are delivered directly to the target site. In this work, a mathematical model to estimate the concentration of drug released from such lenses in the eye aqueous humor was developed. To attain these estimated concentration profiles, partition and effective diffusivity coefficients for the specific lens material were obtained from standard in vitro release experiments. The model was validated by comparing the predicted aqueous humor concentrations with those obtained in in vivo studies where hydrophilic acrylic intraocular lens loaded with an antibiotic (moxifloxacin) were implanted in rabbits. Subsequently, other partition and effective diffusivity values were determined for levofloxacin, diclofenac and ketorolac in the same hydrophilic acrylic and in a second material, a silicone hydrogel. Predicted drug concentrations in the aqueous humor allowed an initial screening and evaluation of the most promising system for post-cataract removal prophylaxis, with the hydrophilic acrylic material presenting promising results, especially for moxifloxacin and diclofenac controlled release.
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Controlled delivery of pirfenidone through vitamin E-loaded contact lens ameliorates corneal inflammation. Drug Deliv Transl Res 2018; 8:1114-1126. [DOI: 10.1007/s13346-018-0541-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Di Y, Luo XM, Qiao T, Lu N. Intraocular pressure with rebound tonometry and effects of topical intraocular pressure reducing medications in guinea pigs. Int J Ophthalmol 2017; 10:186-190. [PMID: 28251075 DOI: 10.18240/ijo.2017.02.02] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 07/26/2016] [Indexed: 12/25/2022] Open
Abstract
AIM To investigate the intraocular pressure (IOP) of adult guinea pig eyes with rebound tonometry (RBT), and assess the effects of four distinctive topical IOP reducing medications including Carteolol, Brimonidine, Brinzolamide and Latanoprost. METHODS The IOPs of twenty-four 12-week-old guinea pigs (48 eyes) were measured every two hours in one day with RBT as baselines. All the animals were then divided into four groups (Carteolol, Brimonidine, Brinzolamide and Latanaprost groups, n=6). The IOPs were measured and compared to the baseline 1, 2, 3, 5, 7, 9, 15 and 24h after treatment. RESULTS The mean baseline IOP of 24 guinea pigs (48 eyes) was 10.3±0.36 mm Hg (6-13 mm Hg) and no binocular significant differences of IOPs were observed (t=1.76, P>0.05). No significant difference of IOP in Carteolol group at each time point was observed before and after treatment (t=1.48, P>0.05). In Brimonidine group, IOP was 2.2±1.9 mm Hg lower than the baseline after one hour (t=3.856, P=0.003) and lasted for one hour. In Brinzolamide group, IOP was 1.4±1.1 mm Hg lower than the baseline after one hour (t=4.53, P=0.001) and lasted for 7h and the IOP declined most at 3h. In Latanaprost group, IOP was 2.1±1.3 mm Hg lower than the baseline after one hour (t=6.11, P=0.001) and lasted for one hour. CONCLUSION The IOP of guinea pig eyes is relatively stable compared to human eyes. In four reducing IOP medications, no significant effect of Carteolol is observed. Brinzolamide has the longest duration, while the Brimonidine has the shortest duration and the maximum level of treatment.
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Affiliation(s)
- Yue Di
- Department of Ophthalmology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai 200062, China; Department of Ophthalmology, Jinshan Hospital, Fudan University, Shanghai 201508, China
| | - Xiu-Mei Luo
- Department of Ophthalmology, Jinshan Hospital, Fudan University, Shanghai 201508, China
| | - Tong Qiao
- Department of Ophthalmology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai 200062, China
| | - Na Lu
- Department of Radiology, Huashan Hospital North, Fudan University, Shanghai 201907, China
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Millar JC, Pang IH. Non-continuous measurement of intraocular pressure in laboratory animals. Exp Eye Res 2015; 141:74-90. [PMID: 25933714 DOI: 10.1016/j.exer.2015.04.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 04/21/2015] [Accepted: 04/27/2015] [Indexed: 01/02/2023]
Abstract
Glaucoma is a leading cause of blindness, which is treatable but currently incurable. Numerous animal models therefore have both been and continue to be utilized in the study of numerous aspects of this condition. One important facet associated with the use of such models is the ability to accurately and reproducibly measure (by cannulation) or estimate (by tonometry) intraocular pressure (IOP). At this juncture there are several different approaches to IOP measurement in different experimental animal species, and the list continues to grow. We feel therefore that a review of this subject matter is timely and should prove useful to others who wish to perform similar measurements. The general principles underlying various types of tonometric and non-tonometric techniques for non-continuous determination of IOP are considered. There follows discussion of specific details as to how these techniques are applied to experimental animal species involved in the research of this disease. Specific comments regarding anesthesia, circadian rhythm, and animal handling are also included, especially in the case of rodents. Brief consideration is also given to possible future developments.
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Affiliation(s)
- J Cameron Millar
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA; Department of Cell Biology and Immunology, University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA.
| | - Iok-Hou Pang
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA; Department of Cell Biology and Immunology, University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
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Sharif NA, May JA. Potential for serotonergic agents to treat elevated intraocular pressure and glaucoma: focus on 5-HT2receptor agonists. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.10.69] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Crumley WR, Rankin AJ, Allbaugh RA. Evaluation of the aqueous humor flow rate in the eyes of clinically normal cats by use of fluorophotometry. Am J Vet Res 2012; 73:704-8. [DOI: 10.2460/ajvr.73.5.704] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Sigle KJ, Camaño-Garcia G, Carriquiry AL, Betts DM, Kuehn MH, McLellan GJ. The effect of dorzolamide 2% on circadian intraocular pressure in cats with primary congenital glaucoma. Vet Ophthalmol 2012; 14 Suppl 1:48-53. [PMID: 21923823 DOI: 10.1111/j.1463-5224.2011.00913.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the extent of fluctuation in circadian intraocular pressure (IOP) and the efficacy of topical dorzolamide 2% q 8 h in lowering IOP and blunting circadian fluctuation in IOP in glaucomatous cats. ANIMALS STUDIED Seven adult cats with primary congenital glaucoma (PCG). PROCEDURES Measurements of IOP and pupil diameter were obtained for both eyes (OU) of each cat q 4 h for 12 days. Cats were housed in a laboratory animal facility with a 12-h light:dark cycle. Baseline values were established for 2 days. For the next 5 days, placebo (1.4% polyvinyl alcohol) was administered OU q 8 h. Dorzolamide 2% was then administered OU q 8 h for a further 5 days. A multivariate mixed linear model was fitted to the data, with parameters estimated from a Bayesian perspective. The 4 am time point was selected as the reference for the purposes of comparisons. RESULTS Estimated mean IOP for the reference time point pre-treatment was symmetric (about 33 mmHg OU). In all cats, IOP was significantly lower during the diurnal phase, relative to the 4 am measurements, with highest IOP observed 2-6 h after the onset of the dark phase. Circadian fluctuations in IOP were dampened during the treatment period. There was a significant decrease in IOP in all cats during the dorzolamide treatment period (estimated mean for the treatment period reference = 17.9 mmHg OU). CONCLUSIONS Topical dorzolamide 2% q 8 h is effective in reducing IOP and IOP fluctuation in cats with PCG.
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Affiliation(s)
- Kelly J Sigle
- Department of Veterinary Clinical Sciences, Iowa State University, Ames, IA 50011, USA
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Liu JHK, Medeiros FA, Slight JR, Weinreb RN. Comparing Diurnal and Nocturnal Effects of Brinzolamide and Timolol on Intraocular Pressure in Patients Receiving Latanoprost Monotherapy. Ophthalmology 2009; 116:449-54. [PMID: 19157559 DOI: 10.1016/j.ophtha.2008.09.054] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 09/23/2008] [Accepted: 09/30/2008] [Indexed: 11/30/2022] Open
Affiliation(s)
- John H K Liu
- The Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California 92093-0946, USA.
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Sharif NA, McLaughlin MA, Kelly CR, Katoli P, Drace C, Husain S, Crosson C, Toris C, Zhan GL, Camras C. Cabergoline: Pharmacology, ocular hypotensive studies in multiple species, and aqueous humor dynamic modulation in the Cynomolgus monkey eyes. Exp Eye Res 2008; 88:386-97. [PMID: 18992242 DOI: 10.1016/j.exer.2008.10.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 09/19/2008] [Accepted: 10/01/2008] [Indexed: 12/11/2022]
Abstract
The aims of the current studies were to determine the in vitro and in vivo ocular and non-ocular pharmacological properties of cabergoline using well documented receptor binding, cell-based functional assays, and in vivo models. Cabergoline bound to native and/or human cloned serotonin-2A/B/C (5HT(2A/B/C)), 5HT(1A), 5HT(7), alpha(2B), and dopamine-2/3 (D(2/3)) receptor subtypes with nanomolar affinity. Cabergoline was an agonist at human recombinant 5HT(2), 5HT(1A) and D(2/3) receptors but an antagonist at 5HT(7) and alpha(2) receptors. In primary human ciliary muscle (h-CM) and trabecular meshwork (h-TM) cells, cabergoline stimulated phosphoinositide (PI) hydrolysis (EC(50)=19+/-7 nM in TM; 76 nM in h-CM) and intracellular Ca(2+) ([Ca(2+)](i)) mobilization (EC(50)=570+/-83 nM in h-TM; EC(50)=900+/-320 nM in h-CM). Cabergoline-induced [Ca(2+)](i) mobilization in h-TM and h-CM cells was potently antagonized by a 5HT(2A)-selective antagonist (M-100907, K(i)=0.29-0.53 nM). Cabergoline also stimulated [Ca(2+)](i) mobilization more potently via human cloned 5HT(2A) (EC(50)=63.4+/-10.3 nM) than via 5HT(2B) and 5HT(2C) receptors. In h-CM cells, cabergoline (1 microM) stimulated production of pro-matrix metalloproteinases-1 and -3 and synergized with forskolin to enhance cAMP production. Cabergoline (1 microM) perfused through anterior segments of porcine eyes caused a significant (27%) increase in outflow facility. Topically administered cabergoline (300-500 microg) in Dutch-belted rabbit eyes yielded 4.5 microMM and 1.97 microM levels in the aqueous humor 30 min and 90 min post-dose but failed to modulate intraocular pressure (IOP). However, cabergoline was an efficacious IOP-lowering agent in normotensive Brown Norway rats (25% IOP decrease with 6 microg at 4h post-dose) and in conscious ocular hypertensive cynomolgus monkeys (peak reduction of 30.6+/-3.6% with 50 microg at 3h post-dose; 30.4+/-4.5% with 500 microg at 7h post-dose). In ketamine-sedated monkeys, IOP was significantly lowered at 2.5h after the second topical ocular dose (300 microg) of cabergoline by 23% (p<0.02) and 35% (p<0.004) in normotensive and ocular hypertensive eyes, respectively. In normotensive eyes, cabergoline increased uveoscleral outflow (0.69+/-0.7 microL/min-1.61+/-0.97 microL/min, n=13; p<0.01). However, only seven of the eleven ocular hypertensive monkeys showed significantly increased uveoscleral outflow. These data indicate that cabergoline's most prominent agonist activity involves activation of 5HT(2), 5HT(1A), and D(2/3) receptors. Since 5HT(1A) agonists, 5HT(7) antagonists, and alpha(2) antagonists do not lower IOP in conscious ocular hypertensive monkeys, the 5HT(2) and dopaminergic agonist activities of cabergoline probably mediated the IOP reduction observed with this compound in this species.
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Affiliation(s)
- Najam A Sharif
- Discovery Ophthalmology Research, Alcon Research Ltd, Fort worth, TX, USA.
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Nakamoto K, Yasuda N. Effect of Concomitant Use of Latanoprost and Brinzolamide on 24-hour Variation of IOP in Normal-tension Glaucoma. J Glaucoma 2007; 16:352-7. [PMID: 17570997 DOI: 10.1097/ijg.0b013e318033b491] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To study the effect of the concomitant use of latanoprost and brinzolamide on the 24-hour variation in the intraocular pressure (IOP) in patients with normal-tension glaucoma (NTG). METHODS We studied a total of 44 eyes from 22 NTG patients. Mean 24-hour IOP variation was determined after a washout period of > or =4 weeks. Latanoprost monotherapy was continued in both eyes for 8 weeks. Thereafter, patients were randomized to continue latanoprost monotherapy in 1 eye whereas brinzolamide was added as an adjunct to latanoprost therapy in the other eye. Eight weeks after the initiation of brinzolamide treatment, the 24-hour IOP variation was remeasured. IOP was measured in the sitting position 8 times daily using a Goldmann applanation tonometer before and after treatment. RESULTS The eyes treated with latanoprost monotherapy and those treated with latanoprost and brinzolamide showed a significant decrease in IOP at all time points. Percent reductions in the diurnal mean IOP (mean IOP at 10 AM, 1 PM, and 4 PM) and in nocturnal mean IOP (mean IOP at 10 PM, 1 AM, and 3 AM) were significantly greater in the eyes treated with the combination of latanoprost and brinzolamide than those with latanoprost alone (diurnal mean IOP: latanoprost and brinzolamide=19.8%, latanoprost=14.1%, P<0.001; nocturnal mean IOP: latanoprost and brinzolamide=13.4%, latanoprost=10.0%, P<0.05). CONCLUSIONS For the treatment of NTG, the combination of latanoprost and brinzolamide demonstrated additive effects in lowering IOP, not only during the day, but also at night.
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Abstract
PURPOSE OF REVIEW This review evaluates current concepts regarding the effects of glaucoma medication on aqueous humor dynamics and the impact of this on intraocular pressure control and drug selection in clinical practice. RECENT FINDINGS Calculations based on the Friedenwald and Goldmann equations have predicted that glaucoma medications that increase pressure-sensitive aqueous outflow will dampen intraocular pressure spikes and therefore may be advantageous over drugs that do not increase outflow facility. SUMMARY Further experimental research is required to verify the influence of increased outflow facility on intraocular pressure fluctuation and the effect of this on glaucoma progression.
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Affiliation(s)
- Jonathan G Crowston
- Hamilton Glaucoma Center, University of California San Diego, La Jolla, California 92093-0946, USA.
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Morrison JC, Johnson EC, Cepurna W, Jia L. Understanding mechanisms of pressure-induced optic nerve damage. Prog Retin Eye Res 2005; 24:217-40. [PMID: 15610974 DOI: 10.1016/j.preteyeres.2004.08.003] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Patients with glaucoma can suffer progressive vision loss, even in the face of what appears to be excellent intraocular pressure (IOP) control. Some of this may be secondary to non-pressure-related (pressure-independent) factors. However, it is likely that chronically elevated IOP produces progressive changes in the optic nerve head, the retina, or both that alter susceptibility of remaining optic nerve fibers to IOP. In order to understand the nature of these progressive changes, relevant, cost-effective animal models are necessary. Several rat models are now used to produce chronic, elevated IOP, and methods exist for measuring the resulting IOP and determining the extent of the damage this causes to the retina and optic nerve. A comparison of damage, pressure and duration shows that these models are not necessarily equivalent. These tools are beginning to uncover clear evidence that elevated IOP produces progressive changes in the optic nerve head and retina. In the optic nerve head, these include axonal and non-axonal effects, the latter pointing to involvement of extracellular matrix and astrocyte responses. In the retina, retinal ganglion cells appear to undergo changes in neurotrophin response as well as morphologic changes prior to actual cell death. These, and other, as yet uncovered, abnormalities in the optic nerve head and retina may influence relative susceptibility to IOP and explain progressive optic nerve damage and visual field loss, in spite of apparent, clinically adequate IOP control. Ultimately, this knowledge may lead to the development of new treatments designed to preserve vision in these difficult patients.
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Affiliation(s)
- John C Morrison
- Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Sciences University, 3375 S.W Terwilliger Blvd., Portland, OR 97239, USA.
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