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Biomedical subjects

Y Kitazawa

Publications and source records attributed to Y Kitazawa.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Mitomycin C dissolved in a reversible thermo-setting gel: effect on aqueous flare in the rabbit eye].

PURPOSE: To determine the effects of mitomycin C (MMC) dissolved in a gel, which is as effective as a higher dose of aqueous MMC solution, on aqueous flare in rabbits. METHOD: We injected subconjunctivally a 0.1 ml solution of MMC containing 30, 10, 3.0, or 0.3 micrograms of MMC dissolved in a reversible thermo-setting gel in pigmented rabbits. As a control, a 0.1 ml aqueous solution of 30 micrograms MMC was injected subconjunctivally. Aqueous flare was measured for 28 days after the injection. RESULTS: The aqueous flare in the 30 micrograms gel group was also level similar to that in the 30 micrograms aqueous solution group, but the aqueous flare in the 10, 3.0, and 0.3 micrograms gel groups was significantly lower. The increase in the aqueous flare following the administration of MMC gel was dose-dependent. CONCLUSION: The administration of MMC dissolved in a gel can diminish the ocular inflammation by reducing the dose of MMC needed for the antiproliferative effect.

Animals↗
PubMed2000

[Optic disc blood flow measured by scanning laser-Doppler flowmetry using a new analysis program].

PURPOSE: Using a new analysis program for scanning laser-Doppler flowmetry (SLDF) by a Heidelberg retina flowmeter (HRF), we studied the relation between flow and visual field or disc morphology. SUBJECTS AND METHODS: In 42 eyes of 21 patients with normal tension glaucoma (NTG) the mean-flow of the HRF blood flow parameters at the disc rim was measured and analyzed by a new analysis program for perfusion maps (the SLDF analysis tool), to minimize the influence of large vessels or/and artifacts caused by small eye movements. We investigated whether difference of the mean-flow between a pair of eyes had any relation to differences between a pair of eyes in visual field indices and those in disc morphological measurements of the Heidelberg retina tomograph. RESULTS: We found statistically significant correlations between the mean-flow and optic disc parameters (Disk Area, Cup Area, Height Variation Contour, Cup Volume, Rim Volume, Mean RNFL Thickness). We found no statistically significant correlations between the mean-flow and visual field parameters (mean deviation, corrected pattern standard deviation). CONCLUSION: The results suggested that eyes with less flow in the optic disc rim have more advanced glaucomatous morphological changes.

Adult↗
PubMed2000

Regulation of connexin phosphorylation and cell-cell coupling in trabecular meshwork cells.

PURPOSE: To investigate the expression of functional gap junctions and the effect of protein kinase C (PKC) on such junctions in confluent cultures of bovine trabecular meshwork (TM) cells. METHODS: Expression of the gap junction protein connexin43 in TM cells was examined by immunofluorescence microscopy. Intercellular communication by gap junctions was assessed by observing the diffusion of fluorescent dye from an individual cell injected with lucifer yellow. The phosphorylation of connexin43 was evaluated by immunoblot analysis with a monoclonal antibody to this protein. RESULTS: Immunofluorescence staining revealed that connexin43 was localized to sites of contact between adjacent TM cells. Exposure of cells to the PKC activator phorbol 12-myristate 13-acetate (PMA; 10 nM, 1 hour) had no marked effect on the pattern of connexin43 immunofluorescence. Injection of a TM cell with lucifer yellow resulted in the spread of the dye into neighboring cells. Dye coupling was inhibited by PMA in a dose- and time-dependent manner, and this inhibition was prevented by pretreatment of cells with the PKC inhibitor bisindolylmaleimide I. Immunoblot analysis of control TM cell lysates yielded connexin43 bands corresponding to the nonphosphorylated protein (43 kDa) and three phosphorylated forms (47, 48, and 49 kDa). Cells exposed to PMA (10 nM, 1 hour) yielded an additional band corresponding to a 44-kDa form of phosphorylated connexin43 and showed a decrease in the intensity of the band corresponding to the nonphosphorylated protein and an increase in the intensity of the 47-kDa band. CONCLUSIONS: TM cells communicate with each other through gap junctions, and the communication is inhibited by PKC, probably, at least in part, through phosphorylation of connexin43.

Actins↗
PubMed2000

Transient ischemic injury in the rat retina caused by thrombotic occlusion-thrombolytic reperfusion.

PURPOSE: To establish a clinically relevant model of transient retinal ischemia by thrombotic occlusion-thrombolytic reperfusion of the central retinal artery of the rat. METHODS: Thrombus was photochemically induced in the central retinal artery by the combination of intravenous injection of photo-sensitive dye, rose bengal, and green laser irradiation focused on the artery. Transient retinal ischemia for 60 minutes was achieved by a subsequent systemic administration of tissue-type plasminogen activator to reperfuse the occluded vessel. Samples of retinas were excised from the animals killed 3, 9, 12, 24, 48, and 78 hours after the reperfusion. The experimental data were processed using the TdT-dUTP terminal nick-end labeling (TUNEL) method to detect apoptotic cells. RESULTS: The transient retinal ischemia caused time-sequential apoptotic changes in the retinal cells as evaluated by counting the number of TUNEL-positive cells. The most remarkable changes occurred in the central area of retina, and further on the sections taken 24 hours after reperfusion. The peripheral area was less affected, and the outer nuclear cell layer was almost unaffected throughout the observation period. CONCLUSIONS: The proposed method to cause retinal transient ischemia is highly reproducible, and it is easy to simulate the progress and topographical distribution of retinal changes observed in the clinical cases of central retinal arterial occlusion and its subsequent thrombolytic reperfusion. This may provide a useful tool for constructing the effective thrombolytic strategies against the central retinal arterial occlusion and for evaluating the effects of neuroprotective agents.

Animals↗
PubMed2000

[Clinical evaluation of the Heidelberg Retina Tomograph II].

PURPOSE: To evaluate the usefulness of Heidelberg Retina Tomograph (HRT) II prototype, which is an easily handled model for routine optic disc examination in glaucoma clinics. METHODS: Ten eyes of 10 normal volunteers and 18 eyes of 18 open-angle glaucoma patients followed at Gifu University were studied. The reproducibility of three consecutive optic disc measurements with a 15 degrees x 15 degrees field using HRT II and with a 10 degrees x 10 degrees field using HRT (version 2.01) were evaluated by the same examiner on the same day. We also examined the correlation of the main topographic parameters (disc area, cup area, cup/disc area ratio, rim area, cup volume, rim volume, cup shape measure) between HRT II and HRT. RESULTS: The mean (+/- standard deviation) reproducibility of optic disc measurements with HRT II and HRT were 17.5 +/- 7.6 microns and 19.3 +/- 9.6 microns, respectively. This difference was not significant. All topographic parameters obtained from HRT II and HRT (R = 0.86-0.98, p < 0.01) showed statistically significant correlations with each other. CONCLUSION: The HRT II has high reproducibility of measurements and reliable stereometric parameters comparable to the conventional HRT.

Glaucoma, Open-Angle↗
PubMed1999

Ocular effects of adrenomedullin.

The purpose of this study was to determine the expression and effects of adrenomedullin (AM), a novel vasodilator peptide, in the eye. Expression of AM mRNA was examined in the rat iris-ciliary body using reverse transcription-polymerase chain reaction (RT-PCR). In rabbits, intraocular pressure (IOP) was measured periodically after intravitreal injection (20 microl) of AM (10(-7)-10(-4)m) into one eye. In separate groups of rabbits, 30 min after intravitreal injection of either AM-(22-52) (10(-3)m), a specific AM receptor antagonist, or CGRP-(8-37) (10(-3)m), a CGRP1 receptor antagonist, into one eye, AM (10(-6)m) was injected into both eyes, and IOP was measured. Using different rabbits, aqueous protein and cAMP concentrations were determined 6 hr after injection of AM. Expression of AM mRNA was detected in the rat iris-ciliary body. In rabbits, intravitreally administered AM (10(-6)-10(-4)m) profoundly lowered IOP, and the maximum effect was observed at 4-8 h. The ocular hypotensive effect of AM was dose-dependent (10(-7)-10(-4)m). Pretreatment with CGRP-(8-37) did not significantly inhibit the ocular hypotensive effect of AM (10(-6)m), whereas pretreatment with AM-(22-52) completely abolished it. AM (10(-6)m) did not significantly affect aqueous protein concentration. The higher dose of AM (10(-5)m) induced a significant increase in aqueous protein, which was not associated with an increase in the aqueous cAMP content and was significantly inhibited by AM-(22-52) and CGRP-(8-37). These results demonstrate that AM is expressed in the iris-ciliary body and decreases IOP mainly via specific AM receptors, and suggest that AM may play a role in controlling IOP.

Adrenomedullin↗
PubMed1999

Risk factors for visual field damage progression in normal-tension glaucoma eyes.

BACKGROUND: This study was carried out to evaluate intraocular or systemic factors associated with the visual field damage progression in eyes with normal-tension glaucoma (NTG). PATIENTS AND METHODS: Forty-seven NTG eyes with a minimum follow-up of 5 years were enrolled into the retrospective study. A stepwise regression analysis was performed to correlate the visual field damage progression, expressed as the mean deviation (MD) change per year, with several independent clinical factors including age, history of disc hemorrhage, initial MD, mean intraocular pressure (IOP), peak IOP, diurnal fluctuation of IOP, presence of a beta zone of peripapillary atrophy, and use of Ca(2+)-channel blockers. RESULTS: Statistical analysis revealed that non-use of Ca(2+)-channel blockers (P = 0.01), peripapillary atrophy (P = 0.03) and disc hemorrhage (P = 0.04) were associated with visual loss progression. CONCLUSIONS: Risk factors unrelated to IOP were suggested to be associated with progression of visual field loss. Systemic use of Ca(2+)-channel blockers has a favorable effect on visual field prognosis in NTG eyes.

Adult↗
PubMed1999

Peripapillary atrophy in primary angle-closure glaucoma: a comparative study with primary open-angle glaucoma.

PURPOSE: To investigate the characteristics of peripapillary atrophy in primary angle-closure glaucoma and to compare peripapillary atrophy in primary angle-closure glaucoma with that in primary open-angle glaucoma. METHODS: Twenty-one eyes (of 21 patients) with chronic primary angle-closure glaucoma that had no evidence of an acute attack or combined-mechanism glaucoma and 31 eyes (31 patients) with primary open-angle glaucoma were enrolled in this study. The cup-to-disk area ratio and the visual field mean deviation were matched in both groups. The prevalence of peripapillary atrophy and peripapillary atrophy-to-disk area ratio of eyes with primary angle-closure glaucoma and eyes with primary open-angle glaucoma were compared. The correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation was also evaluated. RESULTS: Eight (38%) of 21 eyes with primary angle-closure glaucoma and 21 (68%) of 31 eyes with primary open-angle glaucoma had peripapillary atrophy. The peripapillary atrophy-to-disk area ratio averaged 0.16 in primary angle-closure glaucoma and 0.41 in primary open-angle glaucoma. There were statistically significant differences regarding the prevalence of peripapillary atrophy (P = .048) and peripapillary atrophy-to-disk area ratio (P = .005) between the two groups. There was no significant correlation between the peripapillary atrophy area and the cup-to-disk area ratio or the mean deviation in primary angle-closure glaucoma. In contrast, the peripapillary atrophy-to-disk area ratio significantly correlated with the cup-to-disk area ratio (P = .003) and the mean deviation (P = .0001) in primary open-angle glaucoma. CONCLUSIONS: The peripapillary atrophy in primary angle-closure glaucoma has a different relationship to the structural and functional optic disk changes than that in primary open-angle glaucoma. Different mechanisms seem to be involved in the development of the optic disk damage in the two types of glaucoma.

Adult↗
PubMed1999

Localized wedge-shaped defects of retinal nerve fiber layer and disc hemorrhage in glaucoma.

OBJECTIVE: To evaluate frequencies of localized wedge-shaped defects of the retinal nerve fiber layer (RNFL) in eyes with and without disc hemorrhage in normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG). This study also aims to define a topographic correlation between disc hemorrhage and localized RNFL defects in POAG. DESIGN: Cross-sectional study. PARTICIPANTS AND CONTROLS: The authors studied 83 eyes of 83 patients with NTG (male/female = 23/60; age, 58.8+/-12.9 years) and 20 eyes of 20 patients with POAG (male/female = 9/11; age, 61.6+/-11.4 years); subjects in both groups had developed new disc hemorrhage at the time of enrollment. The authors randomly selected 45 eyes of 45 patients with NTG (male/female = 20/25; age, 62.0+/-9.3 years) and 24 eyes of 24 patients with POAG (male/female = 13/11; age, 56.3+/-14.5 years) with no history of disc hemorrhage during the follow-up period of more than 2 years. METHODS: Visual field in the patients with POAG was matched to that of the patients with NTG regarding global indices for both the hemorrhage and the nonhemorrhage groups. Localized wedge-shaped defects of RNFL were identified by scanning laser ophthalmoscopy using an argon-blue laser. MAIN OUTCOME MEASURES: The frequency of localized RNFL defects and the relationship between the locations of disc hemorrhages and localized RNFL defects were determined. RESULTS: Localized wedge-shaped defects of RNFL occurred significantly more often in the hemorrhage group than in the nonhemorrhage group in both NTG (Fisher's exact probability test, P < 0.0001) and POAG (P < 0.05) patients. Regardless of the presence of disc hemorrhage, there was no significant difference in the frequency of localized RNFL defects between patients with NTG and those with POAG. Most disc hemorrhages were present in the vicinity of the border between localized RNFL defects and relatively healthy-looking RNFL in both patients with POAG and those with NTG. CONCLUSION: Disc hemorrhage is associated with localized damage of RNFL in both NTG and POAG.

Cross-Sectional Studies↗
PubMed1999

Cooling effect on excimer laser photorefractive keratectomy.

PURPOSE: To evaluate the effect of cooling on pain, corneal haze, and refractive outcome after excimer laser photorefractive keratectomy (PRK). SETTING: Tokyo Medical and Dental University Hospital, Tokyo, Japan. METHODS: The corneal surface was cooled before, during, and after laser ablation using a method called cooling PRK. Thirty-eighty highly myopic eyes of 38 patients whose spherical errors ranged from -8.00 to -18.75 diopters (D) were randomized into 2 groups: 16 eyes with conventional PRK and 22 eyes with cooling PRK. Postoperative pain was measured using the Visual Analogue Scale (VAS). Refraction, visual acuity, and complications were followed for up to 2 years. All data were analyzed and compared between groups to evaluate the cooling effect on PRK. RESULTS: One day postoperatively, patients in the cooling PRK group had significantly less pain (P < .01). At 3 months, the haze score in the cooling PRK group was significantly less than in the conventional PRK group (P < .01). The residual refractive error was not significantly different between the 2 groups until 2 years, when it was greater in the conventional PRK (mean -5.09 D +/- 2.11 [SD]) than the cooling PRK group (-4.64 +/- 2.27 D). Ten eyes (62.5%) in the conventional PRK group and 15 eyes (68.2%) in the cooling PRK group were within +/- 1.00 D of the intended refraction. There were no serious complications in the cooling PRK group. Two eyes in the conventional PRK group had severe corneal haze and lost 2 Snellen lines of best corrected visual acuity. CONCLUSION: Corneal cooling on PRK effectively reduced postoperative pain, corneal haze, and myopic regression.

Adult↗
PubMed1999

Changes in optic nerve head blood flow and retrobular hemodynamics following calcium-channel blocker treatment of normal-tension glaucoma.

BACKGROUND: Because calcium channel blockers reduce vascular resistance, they may have a clinical application in the treatment of normal-tension glaucoma (NTG). This study investigates changes in both the optic disc blood flow and the hemodynamics of retrobulbar vessels in NTG patients after the systemic administration of a calcium channel blocker. METHODS: Twelve eyes of 12 NTG patients (mean age 57.6 +/- 15.3 years) were examined before and after a 4-week treatment with 2 mg b.i.d. oral nilvadipine, an L-typc calcium channel blocker. By scanning laser-Doppler flowmetry (SLDF), we obtained the velocity, flow, and volume from within a 10 x 10 pixel window placed on the temporal rim region of the optic disc perfusion map. By ultrasound color Doppler imaging (CDI), we measured the peak systolic velocity (PSV) and the end diastolic velocity (EDV) of the ophthalmic artery (OA), central retinal artery (CRA), nasal posterior ciliary artery (NPCA), and temporal posterior ciliary artery (TPCA). We then calculated a resistance index (RI) for each vessel. RESULTS: After treatment, the flow and velocity of the optic disc blood flow significantly increased (P < 0.05). Nilvadipine also significantly reduced RIs of the CRA, NPCA, and TPCA (P < 0.05), and increased both the PSV of the NPCA and the EDVs of the CRA, NPCA, and TPCA. The percent change in velocity correlated significantly with the percent changes of the CRA RI and NPCA RI. CONCLUSIONS: Oral nilvadipine appears to reduce orbital vascular resistance, which consequently increases the optic disc blood flow.

Adult↗
PubMed1999

Disc hemorrhage and peripapillary atrophy in apparently healthy subjects.

PURPOSE: We estimated the prevalence of disc hemorrhage and peripapillary atrophy in apparently healthy subjects. METHODS: We reviewed consecutive plain color fundus photographs of 12,140 eyes of 6,070 subjects (male/female=4,079/1,991) who visited a health consultation center. RESULTS: We analyzed 11,934 eyes of 5,967 subjects with good quality of photographs. Disc hemorrhage was found in 36 eyes of 35 subjects (0.6%). The prevalence of disc hemorrhage was significantly greater in women 60 years of age or older (Fisher's exact test, p=0.0004). The prevalence of peripapillary atrophy (zone Beta, zone Alpha), and suspected glaucomatous excavation in eyes with disc hemorrhage was 66.7%, 86.1% and 25.0%, respectively, and significantly greater than that (29.1%, 52.9% and 1.7%) in eyes without disc hemorrhage (Fisher's exact test, p<0.0001). CONCLUSIONS: Disc hemorrhage is more frequent in women over 60 years of age and is significantly associated with peripapillary atrophy in otherwise apparently healthy Japanese people.

Adult↗
PubMed1999

Biphasic intraocular pressure response to calcitonin gene-related peptide.

PURPOSE: To examine the effects of calcitonin gene-related peptide (CGRP) on intraocular pressure (IOP). METHODS: IOP was periodically measured in rabbits treated with intravitreal injection (20 ael) of either: 1) CGRP (10(-4) approximately 10(-7) M) into one eye; 2) CGRP (10(-4) or 10(-6) M) into both eyes 30 min after intravitreal administration of CGRP-(8-37) (10( -3) M), a CGRP1 receptor antagonist, into one eye; 3) CGRP (10(-4 ) or 10(-6) M) into one eye 30 min after intravenous administration (200 mg/kg) of either Nw-nitro-L-arginine methyl ester (L-NAME), a nonselective inhibitor of nitric oxide synthase (NOS), or aminoguanidine (AG), a selective inhibitor of inducible NOS; or 4) CGRP (10(-4) or 10(-6) M) into one eye along with intraperitoneal indomethacin (50 mg/ kg at -1 and 4 h). RESULTS: CGRP (10(-4) and 10(-5) M) produced a biphasic IOP response, which consisted of an early ocular hypertensive phase and a subsequent sustained hypotensive phase. While CGRP (10(-6) M) yielded only a profound IOP reduction. CGRP-(8-37) significantly inhibited the IOP elevation induced by CGRP (10(-4) M) and completely abolished the IOP reduction induced by CGRP (10(-6) M). The IOP increase induced by CGRP (10(-4) M) was completely abolished by L-NAME, but not affected by AG. The IOP reduction induced by CGRP (10(-6) M) was not affected by L-NAME. Indomethacin did not significantly affect the IOP responses to CGRP. CONCLUSIONS: CGRP dose-dependently produces a biphasic IOP response, which is mediated by CGRP1 receptors. It is suggested that constitutive NOS is involved in the early ocular hypertensive response.

Animals↗
PubMed1999

Analysis of myocilin mutations in 1703 glaucoma patients from five different populations.

A glaucoma locus, GLC1A, was identified previously on chromosome 1q. A gene within this locus (encoding the protein myocilin) subsequently was shown to harbor mutations in 2-4% of primary open angle glaucoma patients. A total of 1703 patients was screened from five different populations representing three racial groups. There were 1284 patients from primarily Caucasian populations in Iowa (727), Australia (390) and Canada (167). A group of 312 African American patients was from New York City and 107 Asian patients from Japan. Overall, 61 different myocilin sequence variations were identified. Of the 61 variations, 21 were judged to be probable disease-causing mutations. The number of probands found to harbor such mutations in each population was: Iowa 31/727 (4.3%), African Americans from New York City 8/312 (2.6%), Japan 3/107 (2.8%), Canada 5/167 (3.0%), Australia 11/390 (2.8%) and overall 58/1703 (3. 4%). Overall, 16 (76%) of 21 mutations were found in only one population. The most common mutation observed, Gln368Stop, was found in 27/1703 (1.6%) glaucoma probands and was found at least once in all groups except the Japanese. Studies of genetic markers flanking the myocilin gene suggest that most cases of the Gln368Stop mutations are descended from a common founder. Although the specific mutations found in each of the five populations were different, the overall frequency of myocilin mutations was similar ( approximately 2-4%) in all populations, suggesting that the increased rate of glaucoma in African Americans is not due to a higher prevalence of myocilin mutations.

Asian People↗
PubMed1999

[Clinical results and complications of refractive surgery].

PURPOSE: To evaluate the efficacy of photorefractive keratectomy (PRK) with a scanning type excimer laser MEL-60 (AESCLUP-MEDITEC, Co). SUBJECTS AND METHOD: We performed PRK on 102 eyes of 62 myopic patients whose refraction ranged from-3.00 to -12.50 D (mean, -6.47 D) and examined the clinical results of postoperative refraction and complications. RESULTS: At 12, 18, and 24 months after the operation, the mean refraction was -1.57 +/- 1.25D, -1.63 +/- 1.51 D and -1.73 +/- 1.47 D. At 12 months after the operation, 36 eyes (46.2%) were within +/- 0.5 D of intended correction, 61 eyes (78.3%) within +/- 1.0 D, and 76 eyes (97.4%) within +/- 2.0 D. Twenty-four months after the operation, 12 eyes (37.5%) were within +/- 0.5 D, 18 eyes (56.3%) within +/- 1.0 D and 29 eyes (90.6%) within +/- 2.0 D. The complications were as follows: keratitis filamentosa was observed in 10 eyes (10.5%), decrease of contrast sensitivity in 7 eyes (7.4%), subepithelial corneal haze in 4 eyes (1.2%), steroid-induced glaucoma was 2 eyes (2.1%), increase of astigmatism in 2 eyes (2.1%), decrease of best corrected visual acuity in 2 eyes (2.1%), and corneal ulcer in 1 eyes (1.1%). CONCLUSION: PRK with a scanning type excimer laser MEL-60 was effective to reduce refractive error in low and mild myopia, but there were some complications, so that a long, careful follow-up seems necessary.

Adult↗
PubMed1999

[Effect of mitomycin C dissolved in a reversible thermosetting gel on outcome of filtering surgery in the rabbit].

PURPOSE: Based on our previous report that showed enhanced transfer of mitomycin C to the sclera and the conjunctiva by dissolving the antiproliferative in a reversible thermo-setting gel, we conducted a study to investigate the efficacy of the mitomycin C-gel in the rabbit. METHODS: We subconjunctivally injected 0.1 ml of the mitomycin C-gel solution containing several amounts of the drug. Trephination was performed in the injected region 24 hours later. Intraocular pressure measurement, and photography and ultrasound biomicroscopic examination of the filtering bleb were done 1, 2, and 4 weeks postoperatively. RESULTS: The gel containing 3.0 micrograms or more mitomycin C significantly enhanced bleb formation in addition to reducing the intraocular pressure. CONCLUSION: The reversible thermo-setting gel seems to facilitate filtration following glaucoma filtering surgery in the rabbit and deserves further investigation as a new method of mitomycin C application.

Animals↗
PubMed1999

Optic nerve and peripapillary choroidal microvasculature of the rat eye.

PURPOSE: To investigate the three-dimensional microvascular anatomy of the optic nerve and peripapillary choroid in the rat eye. METHODS: Gross vascular anatomy of the posterior eye segment of Wistar rats was studied in serial microsections with a light microscope. The optic nerve and peripapillary choroidal vessels were sequentially microdissected, using methylmethacrylate corrosion microvascular castings, and were examined with a scanning electron microscope to determine the three-dimensional relationships of the vessels. RESULTS: The posterior ciliary artery traveled along the inferior side of the optic nerve sheath, directly entered the optic nerve head, and divided into three branches: the central retinal artery and medial and lateral long posterior ciliary arteries, which provided several short branches to the choroid. The optic nerve head vasculature was consistently nourished by a recurrent arteriole from the central retinal artery and an arteriole from the choroidal artery at the peripapillary choroid. The central retinal vein flowed into a venous anastomosis along the optic disc border of the peripapillary choroid. Capillaries within the optic nerve drained into the central retinal vein, the marginal venous anastomosis of the peripapillary choroid, and the pial veins, all of which flowed into the posterior ciliary veins along the optic nerve sheath. CONCLUSIONS: The findings illustrate vascular anatomic differences in optic nerve and peripapillary choroidal microcirculation between rat and human. In rats, the peripapillary choroid plays a significant role in both blood supply and venous drainage of the optic nerve head. The central retinal artery also contributes to the optic nerve head circulation.

Animals↗