latanoprost and Myopia

Intraocular pressure follows a circadian rhythm like many of the body's parameters. These fluctuations in intraocular pressure were recently identified as a risk factor for visual field loss, in addition to intraocular pressure itself. Furthermore, the pressure curve seems to have a different profile in glaucomatous patients: the peak occurs later compared with normal subjects. Better knowledge of pressure fluctuations and their physiological mechanisms is essential for optimal management of glaucomatous patients not only to interpret the single ocular tension recordings, but also to use the available treatments rationally, both drugs and surgery. The authors review different studies that have contributed to the current knowledge on the circadian rhythm of intraocular pressure, aquous humor flow regulation, and the effects of topical hypotensive drugs on the pressure curve.

Topics: Adult; Age Factors; Aged; Animals; Antihypertensive Agents; Aqueous Humor; Catecholamines; Circadian Rhythm; Glaucoma; Glaucoma, Open-Angle; Humans; Hydrocortisone; Intraocular Pressure; Latanoprost; Models, Theoretical; Myopia; Prostaglandins F, Synthetic; Rabbits; Risk Factors; Time Factors; Visual Fields

The aim of this study was to investigate the effect of latanoprost, an ocular hypotensive agent and prostaglandin analog, on choroidal thickness and structure in young adult guinea pigs. Young (three-month-old) guinea pigs (n = 10) underwent daily monocular treatment with topical 0.005% latanoprost for 2 weeks, followed by a washout period of 2 weeks. Tonometry (iCare) and retinoscopy were undertaken to monitor intraocular pressure (IOP) and refractive error (recorded as spherical equivalent refractive error; SER), respectively. Axial length (AL) and choroidal thickness (ChT) were measured using high frequency A-scan ultrasonography, with additional ChT data, as well as choroidal vessel (ChV) areas obtained from posterior segment imaging using Spectral Domain-Optical Coherence Tomography (SD-OCT). Image J was used to analyze SD-OCT images. As expected, latanoprost significantly reduced IOP in treated eyes. Mean interocular IOP difference (±SE) changed from -0.40 ± 0.31 mmHg at baseline to -2.23 ± 0.43 mmHg after 2 weeks of treatment (p = 0.05). However, SER and AL were unaffected; interocular difference changed from 0.41 ± 0.58 to 0.38 ± 0.43 D and from -0.002 ± 0.02 mm to -0.007 ± 0.01 mm (p > 0.05), respectively. Latanoprost had minimal effect on ChT. Interocular ChT differences were 0.01 ± 0.06 μm at baseline and 0.04 ± 0.06 μm after 2 weeks of treatment (SD-OCT; p > 0.05). However, treated eyes had significant increased ChV areas; interocular differences changed from -0.76 ± 69.2 to 100.78 ± 66.9 μm

Topics: Animals; Choroid; Guinea Pigs; Intraocular Pressure; Latanoprost; Myopia; Tomography, Optical Coherence; Tonometry, Ocular

In this study, we investigated the effect of latanoprost on the expression of TGF- β1 and Wnt / β - Catenin signal pathway in the choroid of form-deprivation myopia model rats. Forty rats were randomly divided into two groups: the control group and the FDM model group. Each group had 20 rats. The FDM model group was established by feeding latanoprost daily for 28 days. 15 rats in each group were used to measure the length of the ocular axis and the level of TGF-β1 in choroidal tissue; the remaining 5 rats in each group were used for choroidal fibroblast culture. After modeling, the rats were killed, the length of the ocular axis was measured with a vernier caliper, and the level of TGF - β1 protein and mRNA in the choroidal tissue of each group were measured with RT-PCR method. Results showed that compared with the control group, there was a significant difference in the axial length of the FDM model group (P< 0.05). There was a significant difference in the expression of TGF- β1 protein and mRNA between the two groups (P<0.05). The cultured cells were identified as choroidal fibroblasts by immunocytochemistry. There was no significant difference (P>0.05) in the comparison of GSK3 β protein in choroidal fibroblasts of rats in each group. TGF-β 1 and APC protein in FDM group were significantly lower than those in the control group (P<0.05), while dcl3, p21-gsk3 β and β - Catenin proteins were significantly higher (P<0.05), and there was no significant difference (P>0.05) in the ratio of various indexes protein in FDM + ddk1 group and the comparison of TGF - β1 and APC protein in FDM + ddk1 group and FDM group The expression of dcl3, p21-gsk3 β and β - Catenin decreased significantly (P<0.05). There was no significant difference in the expression of GSK3 β mRNA in the choroidal fibroblasts of each group (P>0.05). The expression of TGF - β 1 and APC mRNA in FDM group was significantly lower than that in the control group (P<0.05), while the expression of dcl3, p21-gsk3 β and β-catenin mRNA in FDM + ddk1 group was significantly higher than that in the control group (P<0.05) >In FDM + ddk1 group, TGF-β 1 and APC mRNA were significantly lower than those in FDM group (P<0.05), while dcl3, p21-gsk3 β and β-Catenin mRNA were significantly higher (P<0.05).

Topics: Animals; beta Catenin; Cells, Cultured; Choroid; Female; Fibroblasts; Latanoprost; Male; Myopia; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta1; Wnt Signaling Pathway

The purpose of this study was to investigate the effects of latanoprost, an ocular hypotensive prostaglandin analog, on scleral collagen fibers and laminar pores in myopic guinea pigs. Young guinea pigs underwent monocular form deprivation (FD; white plastic diffusers) from 14-days of age for 10-weeks. After the first week, FD eyes also received daily topical A) latanoprost (Lat, 0.005%, n = 5) or B) artificial tears (AT; n = 5). At the end of the treatment period, animals were sacrificed, eyes enucleated and optic nerve heads (ONH) excised to include a 4 mm diameter ring of surrounding sclera for scanning electron microscopy (SEM), and an additional 6 mm ring of sclera surrounding the ONH was excised for transmission electron microscopy (TEM). For SEM, ONH samples were first immersed in 0.2M NaOH for 30 h to isolate the collagenous structures. All samples were stained with osmium tetroxide, dried through an ethanol series and finally subjected to critical point drying before imaging. Image J was used to analyze the dimensions of laminar pores (SEM images) and scleral collagen fibers (TEM images). As previously reported in a related study, latanoprost was effective in inhibiting myopia progression in FD eyes of the guinea pigs. The scleral fibers of FD myopic eyes treated with AT were smaller and more variable in cross-sectional areas compared to untreated (fellow) eyes (mean areas: 0.0059 ± 0.0013 vs. 0.0085 ± 0.002 μm

Topics: Administration, Ophthalmic; Animals; Antihypertensive Agents; Axial Length, Eye; Guinea Pigs; Intraocular Pressure; Latanoprost; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Myopia; Ophthalmic Solutions; Optic Disk; Sclera; Sensory Deprivation

Retinal arachidonic acid (ARA) levels in form-deprived eyes decline in guinea pigs. As prostaglandin F2α (PGF2α) is an ARA metabolite and endogenous agonist of prostaglandin F receptor (FP), we have been suggested that down-regulation of PGF2α-FP receptor signalling pathway contributes to myopia onset. To test this hypothesis, this study determines whether: (i) retinal PGF2α levels decline during the development of form deprivation myopia (FDM) in guinea pigs; (ii) FP receptor agonism and antagonism alter emmetropization and myopia development. Pigmented guinea pigs were randomly assigned to normal vision and form-deprived groups. Ultraperformance liquid chromatography coupled with a mass spectrometer (UPLC-MS) measured retinal PGF2α levels 2 weeks after form deprivation (FD). The selective FP agonist, latanoprost acid (LAT) and its corresponding antagonist, AL8810, were peribulbarly injected into each group. An eccentric infrared photorefractor (EIR) monitored refraction. A-scan ultrasonography measured axial elongation (AL) and vitreous chamber depth (VCD). Tonometry measured the intraocular pressure (IOP). Retinal PGF2α levels declined in form-deprived eyes compared to those in normal eyes. Neither LAT nor AL8810 affected IOP with or without FD. On the other hand, after 4 weeks of daily 0.5 μg AL8810 treatment, a myopia of -1.99 ± 0.34 dioptre (D) developed, but LAT had no effect on emmetropization in a normal visual environment. Nevertheless, daily 30 μg LAT treatment for 4 weeks inhibited FDM development by 41% (vehicle control: -8.39 ± 0.45 D; LAT: -4.95 ± 0.39 D; two-way anova with repeated measures, p < 0.05). Down-regulation of PGF2α-FP receptor signalling pathway may contribute to myopia onset as retinal PGF2α declined in myopic eyes and antagonism of FP receptor by AL8810 induced a myopic shift in normal vision environment. Meanwhile, up-regulation of this pathway by LAT inhibited FDM development. However, the mechanism underlying LAT-induced FDM inhibition needs further clarification. This uncertainty exists because its inhibition of FDM suggests that LAT strengthens the scleral framework which reduces axial elongation. On the other hand, its IOP-lowering effect is attributed to thinning and weakening the scleral framework in glaucoma treatment.

Topics: Animals; Arachidonic Acid; Chromatography, High Pressure Liquid; Dinoprost; Disease Models, Animal; Down-Regulation; Guinea Pigs; Intraocular Pressure; Latanoprost; Mass Spectrometry; Myopia; Prostaglandins F, Synthetic; Receptors, Prostaglandin; Retina; Signal Transduction; Tonometry, Ocular; Up-Regulation

To determine whether latanoprost, a prostaglandin analog proven to be very effective in reducing intraocular pressure (IOP) in humans, can also slow myopia progression in the guinea pig form deprivation (FD) model.. Two-week-old pigmented guinea pigs underwent monocular FD and daily topical latanoprost (0.005%, n = 10) or artificial tears (control, n = 10) starting 1 week after the initiation of FD, with all treatments continuing for a further 9 weeks. Tonometry, retinoscopy, and high-frequency A-scan ultrasonography were used to monitor IOP, refractive error, and ocular axial dimensions, respectively.. Latanoprost significantly reduced IOP and slowed myopia progression. Mean interocular IOP differences (±SEM) recorded at baseline and week 10 were -0.30 ± 0.51 and 1.80 ± 1.16 mm Hg (P = 0.525) for the control group and 0.07 ± 0.35 and -5.17 ± 0.96 mm Hg (P < 0.001) for the latanoprost group. Equivalent interocular differences for optical axial length at baseline and week 10 were 0.00 ± 0.015 and 0.29 ± 0.04 mm (P < 0.001; control) and 0.02 ± 0.02 and 0.06 ± 0.02 mm (P = 0.202; latanoprost), and for refractive error were +0.025 ± 0.36 and -8.2 ± 0.71 diopter (D) (P < 0.001; control), and -0.15 ± 0.35 and -2.25 ± 0.54 D (P = 0.03; latanoprost).. In the FD guinea pig model, latanoprost significantly reduces the development of myopia. Although further investigations into underlying mechanisms are needed, the results open the exciting possibility of a new line of myopia control therapy.

Topics: Administration, Ophthalmic; Animals; Antihypertensive Agents; Axial Length, Eye; Disease Models, Animal; Disease Progression; Guinea Pigs; Intraocular Pressure; Latanoprost; Myopia; Ophthalmic Solutions; Retinoscopy; Sensory Deprivation; Tonometry, Ocular

To assess whether tonometric measurements of the drop in intraocular pressure (IOP) induced by 0.005% latanoprost are modified after photorefractive keratectomy (PRK).. Data from 24 randomly selected eyes of 24 patients (12 men and 12 women, mean age +/- SD: 31.7 +/- 6.2 years) who were undergoing bilateral PRK for myopia (-6.38 +/- 2.26 D) were obtained. Objective refraction, central corneal thickness (CCT), anterior radius of corneal curvature (R), and IOP measurements at baseline and 24 hours after 1 drop of 0.005% latanoprost, were performed before and 6 months after PRK. All measured IOPs were recalculated by a correction factor for CCT and R and expressed as true IOP (IOPT) measurements.. The mean CCT +/- SD was 544.58 +/- 36.03 and 463.21 +/- 38.59 micro m, and the anterior radius of corneal curvature was 7.73 +/- 0.26 and 8.33 +/- 0.37 mm, before and after PRK, respectively. The mean IOP at baseline was 15.8 +/- 2.92 and 12.23 +/- 2.37 mm Hg, and after latanoprost administration was 12.54 +/- 1.97 and 10.19 +/- 1.47 mm Hg, before and after PRK, respectively. The mean IOPT at baseline was 15.46 +/- 1.08 and 16.18 +/- 2.31 mm Hg, and after latanoprost administration was 11.85 +/- 1.56 and 12.96 +/- 1.71 mm Hg, before and after PRK, respectively. The mean IOP and IOPT reductions after latanoprost administration were, respectively, 3.25 +/- 1.66 and 3.61 +/- 1.7 mm Hg before PRK, and 2.03 +/- 1.42 and 3.22 +/- 1.79 mm Hg after PRK. Pre- and postoperative IOP reduction significantly differed (P < 0.001), but not IOPT.. The effect of hypotensive drugs on IOP readings may be underestimated because of measurement errors due to CCT reduction and R increase after PRK for myopia. Misdiagnosis of reduced pharmacologic efficacy may be avoided if the measured IOP is corrected by a proper nomogram.

Topics: Adult; Antihypertensive Agents; Cornea; Female; Humans; Intraocular Pressure; Lasers, Excimer; Latanoprost; Male; Manometry; Middle Aged; Myopia; Ophthalmic Solutions; Photorefractive Keratectomy; Prospective Studies; Prostaglandins F, Synthetic; Random Allocation

Topics: Antihypertensive Agents; Blood-Retinal Barrier; Brimonidine Tartrate; Diagnosis, Differential; Drug Therapy, Combination; Fluorescein Angiography; Glaucoma; Humans; Latanoprost; Male; Middle Aged; Myopia; Prostaglandins F, Synthetic; Quinoxalines; Retinal Detachment; Visual Acuity

Topics: Antihypertensive Agents; Disease Progression; Female; Glaucoma, Open-Angle; Humans; Intraocular Pressure; Latanoprost; Middle Aged; Myopia; Optic Disk; Optic Nerve Diseases; Prostaglandins F, Synthetic; Retinal Hemorrhage; Vision Disorders; Visual Acuity; Visual Fields

Topics: Acetazolamide; Acute Disease; Adult; Anticonvulsants; Epilepsies, Partial; Female; Fructose; Glaucoma, Angle-Closure; Humans; Intraocular Pressure; Latanoprost; Myopia; Prostaglandins F, Synthetic; Topiramate; Treatment Outcome

Topics: Cornea; Female; Humans; Intraocular Pressure; Keratomileusis, Laser In Situ; Latanoprost; Middle Aged; Myopia; Ocular Hypertension; Prostaglandins F, Synthetic; Timolol; Vision Disorders; Visual Acuity; Visual Fields

To investigate the possible role of endogenous prostaglandins in the development of form deprivation myopia, as well as the effects of exogenous prostaglandins using atropine as a positive control.. Monocular form deprivation was accomplished by mounting a translucent occluder on one eye of 2-3 day old chicks for 1-4 weeks. Ocular occlusion for 1-2 weeks was used for pharmacological blocking experiments. The axial length of the eye was measured by ultrasonography.. Indomethacin, administered intramuscularly, subconjunctivally or intravitreally had no significant effect on myopia development. Exogenous PGE2, PGF2alpha and latanoprost acid administered subconjunctivally, or topically as isopropyl ester eyedrops had no statistically significant effect on the myopia development. However, PGF2alpha significantly (p<0.01) attenuated the development of myopia after intravitreal injection. The other two prostaglandins had no statistically significant effect.. Endogenous prostaglandins are unlikely to play a significant role in the development of form deprivation myopia in the chick. However, PGF2alpha suprisingly seems to retard the development of form deprivation myopia, but only when administered intravitreally. Whether the mechanism of the myopia retardation is direct or indirect remains unknown.

Topics: Administration, Topical; Animals; Anthropometry; Atropine; Chickens; Conjunctiva; Dinoprost; Drug Administration Routes; Eye; Indomethacin; Injections, Intramuscular; Latanoprost; Male; Myopia; Prostaglandins F, Synthetic; Sensory Deprivation; Ultrasonography; Vitreous Body