In the process of closing scleral wounds caused by various conditions, incarceration of conjunctiva, Tenon's capsule, or vitreous in the wound can occur unexpectedly. We created such conditions experimentally in order to discover their intraocular complications. The experimental materials consisted of 12 albino rabbits (24 eyes) divided into two groups (Groups I & II). Vitrectomy was performed in the Group I rabbits (12 eyes) but not in the Group II rabbits (12 eyes). Flaps of conjunctiva and Tenon's capsule were made and inserted into the vitreous cavity through the sclerotomy site, which was soon closed. Fundal examination of the rabbits was carried out using an indirect ophthalmoscope at intervals after the procedure; first at 3 days, then at 1, 3, and 6 weeks, and then at 3 months and 6 months, respectively. Enucleation of the rabbits' eyes 4 from two different rabbits at each of these intervals was carried out, and the extracted eyes were examined under a light microscope at each interval. The results are summarized as follows: 1. All rabbit eyes studied showed intraocular fibrovascular proliferation. 2. The extent of tissue proliferation, which was proportional to the amount of vitreous hemorrhage, was greater in Group II than in Group I. 3. The proliferated tissue developed to "band" by three weeks postexperiment, after which it gradually regressed. 4. The fibrovascular band was made of fibroblasts, stromal matrix, and capillaries.
Animals ; Cell Division ; Conjunctiva/pathology ; Eye Injuries/surgery ; Fundus Oculi ; Postoperative Complications ; Rabbits ; Retinal Diseases/pathology ; Retinal Vessels/*pathology ; Sclera/*surgery ; Vitrectomy ; Vitreous Hemorrhage/pathology

Photodynamic therapy (PDT) involves the induction of endothelial cell death or occlusion of blood vessels. On the basis of this mechanism of action, PDT is used in the treatment of predominant classic choroidal neovascularization (CNV), if the classic component is over 50%, and in myopic CNV. This study describes 2 cases of distinctive, abnormal, large, subretinal new vessels that are thought to have originated from the choroids. Diminishment of the new vessels was observed following treatment with PDT.
Retinal Vessels/drug effects/*pathology ; Retinal Diseases/*drug therapy/pathology ; *Photochemotherapy ; Neovascularization, Pathologic/*drug therapy/pathology ; Middle Aged ; Male ; Humans ; Female ; Angiography

PURPOSE: To report the clinical features, clinical course, and treatment outcomes after laser photocoagulation in infants with aggressive posterior retinopathy of prematurity (APROP) and capillary-free zones in vascularized retina. METHODS: Six patients (12 eyes) with APROP and capillary-free zones in vascularized retina were retrospectively reviewed. Twelve eyes of six infants were included and were treated with laser photocoagulation for avascular retina and for capillary-free zones in vascularized retina, except for the posterior pole, and fundus findings were photographically-documented in sequence. In addition, anatomic and visual outcomes were evaluated with complications of APROP. RESULTS: Among all of the consecutive infants with APROP, capillary-free zones in vascularized retina were demonstrated in 24% of the infants. All of the infants were >27 weeks of gestation age and had birth weights >1,000 g. After laser treatment, 7 eyes (58.3%) had favorable outcomes, and late capillary filling in capillary-free zones of vascularized retina were noted, however 4 eyes (33.3%) progressed to retinal detachment and 1 eye (8.3%) was complicated by a retinal fold-distorting posterior pole. The visual outcomes were associated with anatomic outcomes. CONCLUSIONS: The anatomic outcomes in infants with APROP who had capillary-free zones were comparable to previously reported infants with APROP. The late capillary filling of capillary-free zones in vascularized retina was noted, and angiogenesis was considered to be involved. This process toward normal capillary formation or neovascularization in APROP, might determine its outcome.
Capillaries/*pathology ; Female ; Humans ; Infant ; Laser Coagulation/*methods ; Male ; Retina/*pathology/surgery ; Retinal Vessels/*pathology/surgery ; Retinopathy of Prematurity/*pathology/*surgery ; Retrospective Studies ; Treatment Outcome

PURPOSE: To report the clinical features, clinical course, and treatment outcomes after laser photocoagulation in infants with aggressive posterior retinopathy of prematurity (APROP) and capillary-free zones in vascularized retina. METHODS: Six patients (12 eyes) with APROP and capillary-free zones in vascularized retina were retrospectively reviewed. Twelve eyes of six infants were included and were treated with laser photocoagulation for avascular retina and for capillary-free zones in vascularized retina, except for the posterior pole, and fundus findings were photographically-documented in sequence. In addition, anatomic and visual outcomes were evaluated with complications of APROP. RESULTS: Among all of the consecutive infants with APROP, capillary-free zones in vascularized retina were demonstrated in 24% of the infants. All of the infants were >27 weeks of gestation age and had birth weights >1,000 g. After laser treatment, 7 eyes (58.3%) had favorable outcomes, and late capillary filling in capillary-free zones of vascularized retina were noted, however 4 eyes (33.3%) progressed to retinal detachment and 1 eye (8.3%) was complicated by a retinal fold-distorting posterior pole. The visual outcomes were associated with anatomic outcomes. CONCLUSIONS: The anatomic outcomes in infants with APROP who had capillary-free zones were comparable to previously reported infants with APROP. The late capillary filling of capillary-free zones in vascularized retina was noted, and angiogenesis was considered to be involved. This process toward normal capillary formation or neovascularization in APROP, might determine its outcome.
Capillaries/*pathology ; Female ; Humans ; Infant ; Laser Coagulation/*methods ; Male ; Retina/*pathology/surgery ; Retinal Vessels/*pathology/surgery ; Retinopathy of Prematurity/*pathology/*surgery ; Retrospective Studies ; Treatment Outcome

OBJECTIVETo evaluate the role of different oxygen concentration (FiO2) and different period of oxygen exposure on oxygen-induced retinopathy (OIR) in neonatal mice and to provide evidences for proper clinical oxygen therapy.

METHODSTwo hundred and four 7-day-old (P7) C57BL/6J mice were exposed to different FiO2 30%, 50% and 75% for 5, 7 and 9 days. The mice were divided into eight groups: groups 1 - 3 (n = 24 in each) were exposed to 30% oxygen for 5, 7 and 9 days, respectively; groups 4 - 6 (n = 24 in each) were exposed to 50% oxygen for 5, 7 and 9 days, respectively; group 7 (n = 30) was exposed to 75% hyperoxia for 5 days; group 8 (n = 30) was exposed to room air. Proliferative neovascular responses were estimated by observing vascular patterns in adenosine diphosphate-ase (ADPase) stained retina flat-mounts and quantitated by counting the number of new vascular cell nuclei extending into the internal limiting membrane in cross-sections.

RESULTS(1) Vascular patterns in retina flat-mounts: a) When FiO2 was 30%, the entire vascular pattern was completely normal after 5 and 7 days exposure; although the deep vascular system seemed slightly constricted after 9 days exposure, it recovered 2 days later and matured at P21. b) When FiO2 was 50%, after 5 days exposure (group 4), the larger vessels constricted and central perfusion decreased moderately; after exposing to room air for 2 days, neovascularization was seen; however, the entire vascular pattern was almost normal at P17. After 7 days of exposure to 50% O2 (group 5), the vascular pattern recovered a bit, seemed to be better than that of group 4; after 9 days of exposure to 50% O2 (group 6), only slight constriction could be seen and it disappeared 2 days later and all vessels matured later. c) When FiO2 was 75%, after 5 days exposure to hyperoxia, the larger vessels became tortuous and constricted, central perfusion became decreased obviously; after exposing to room air for 2 days, neovascularization was seen; and this response was maximal at P17 - P21. However, the mortality of nurser mice and pups increased dramatically when the duration of hyperoxia was prolonged. (2) Quantitative results in cross-sections: neovascular nuclei extending into the vitreous reached (41.9 +/- 2.8) per section in 75% oxygen group, while less than 1 in every other groups, which was statistically different (P < 0.0001).

CONCLUSIONSFiO2 and the duration of hyperoxia could affect retinal vascular development. Low and moderate FiO2 could induce reversible vessel changes, while high FiO2 induced irreversible changes which should be avoided in clinic.

Animals ; Disease Models, Animal ; Humans ; Hyperoxia ; pathology ; Infant, Newborn ; Mice ; Mice, Inbred C57BL ; Oxygen ; adverse effects ; Oxygen Inhalation Therapy ; adverse effects ; Retinal Neovascularization ; pathology ; Retinal Vessels ; pathology ; Retinopathy of Prematurity ; pathology

This paper is aimed to fulfill a prototype system used to classify and retrieve retinal image automatically. With the content-based image retrieval (CBIR) technology, a method to represent the retinal characteristics mixing the fundus image color (gray) histogram with bright, dark region features and other local comprehensive information was proposed. The method uses kernel principal component analysis (KPCA) to further extract nonlinear features and dimensionality reduced. It also puts forward a measurement method using support vector machine (SVM) on KPCA weighted distance in similarity measure aspect. Testing 300 samples with this prototype system randomly, we obtained the total image number of wrong retrieved 32, and the retrieval rate 89.33%. It showed that the identification rate of the system for retinal image was high.
Algorithms ; Fundus Oculi ; Humans ; Image Processing, Computer-Assisted ; methods ; Information Storage and Retrieval ; methods ; Numerical Analysis, Computer-Assisted ; Ophthalmoscopy ; standards ; Pattern Recognition, Automated ; methods ; Retina ; pathology ; Retinal Vessels ; pathology

INTRODUCTIONThis study describes the pathologic changes in the retina of a group of young Asian subjects with myopia worse than -10 diopters spherical equivalent (SE) refraction.

MATERIALS AND METHODSThe study population consists of 20 male subjects undergoing preemployment screening for public service for a 1-year period from 2009 to 2010. A detailed series of visual tests of function, fundus examination and grading, ocular biometry and posterior segment optical coherence tomography were performed for all eyes.

RESULTSA total of 21 eyes with mean SE of -10.88 diopters, [standard deviation (SD) , 1.28 diopters], and mean age of 21.8 years (SD, 1.3 years) were included. Out of 21 eyes, 17 (81.0%) had beta peripapillary atrophy, 10 (47.6%) had clinically detectable optic disc tilt, 1 (4.8%) had positive T-sign and 18 (85.7%) had retinal tessellation, 4 (19.0%) had posterior vitreous detachment and 14 (66.7%) had peripheral retina degeneration. The mean retinal nerve fibre layer (RNFL) thickness was 92.48 mm (SD, 9.99 mm).

CONCLUSIONNone of the 21 highly myopic eyes had features of myopic retinopathy but most of these young males had clinically visible myopia-associated abnormalities of the optic disc, vitreous and peripheral retina. Generally, these eyes had thinner RNFL. Further longitudinal studies are required to investigate if these eyes will eventually develop complications of pathological myopia.

Adolescent ; Adult ; Age of Onset ; Choroid Diseases ; diagnosis ; Fluorescein Angiography ; Humans ; Male ; Myopia ; classification ; pathology ; Nerve Fibers ; pathology ; Ophthalmoscopy ; Optic Atrophy ; diagnosis ; Optic Disk ; pathology ; Optic Nerve Diseases ; diagnosis ; Posterior Eye Segment ; pathology ; Retina ; pathology ; Retinal Degeneration ; diagnosis ; Retinal Diseases ; diagnosis ; Retinal Vessels ; pathology ; Singapore ; Tomography, Optical Coherence ; methods ; Vision Tests ; Visual Acuity ; Vitreous Detachment ; diagnosis ; Young Adult

The whole retina, except for the medullary fiber zone in a rabbit eye, is supplied by choroidal circulation. Therefore, the histopathological changes of the sensory retina due to choroidal circulatory disturbance in rabbits may be comparable to that of the human sensory retina in the case of ophthalmic artery occlusion. This study was carried out to evaluate the histopathological changes of the ischemic retina secondary to the occlusion of choroidal circulation. The experimental occlusion of all posterior ciliary arteries and anterior ciliary arteries in the horizontal rectus muscle of rabbit eyes was performed and the subsequent histopathological changes of the sensory retina were observed by transmission electron microscopy. The morphological changes of the sensory retina following the occlusion of the ciliary arterial system are as follows: severe loss of the inner and outer segments of the photoreceptor, mild to moderate degeneration of the ganglion cells, and excellent preservation of the Muller's cell fibers and the extension of the cytoplasmic villous processes to the cytoplasmic vacuolar spaces of other degenerated cells. These findings indicate that the Muller's fibers in the ischemic condition of retina might contribute to the formation of gliosis or scarring of a damaged retina.
Animals ; Arterial Occlusive Diseases/*complications ; Arteries ; Choroid/*blood supply ; Ciliary Body/*blood supply ; Ischemia/*etiology/pathology ; Rabbits ; Retina/*ultrastructure ; *Retinal Vessels

OBJECTIVETo investigate the association of retinal vascular calibers with hyperuricemia in a middle-aged and elderly population.

METHODSA cross-sectional design was applied in this study and 869 participants aged =40 years from a high-risk group for diabetes were recruited. All participants received the anthropometrical measurements and laboratory tests. Retinal arteriolar and venular caliber of the participants were measured with a semi-automated system. Hyperuricemia was defined as a serum uric acid level >420 μmol/L in men and >360 μmol/L in women. Linear regression models were used to assess the association of hyperuricemia with retinal vascular calibers. These models were additionally adjusted for age, central obesity, hypertension, dyslipidemia, weekly activity, smoking status, and education.

RESULTSAmong the 869 participants, 133 (15.3%) suffered from hyperuricemia. The crude mean serum uric acid level was 312.3 μmol/L (Standard Deviation 79.5); mean concentration was 355.0 μmol/L (SD 75.5) in male participants, and 288.0 μmol/L (SD 71.1) in female participants (age-adjusted difference 58.1 μmol/L, 95% Confidence Internal 48.5, 67.6). After adjusting for additional covariates, male participants with hyperuricemia had 3.77 μm (95% CI -0.46, 8.00) smaller arteriolar caliber and 6.20 μm (95% CI 0.36, 12.04) larger venule than those without hyperuricemia; the corresponding numbers among female participants were 1.57 μm (95% CI -1.07, 4.21) for retinal arteriolar caliber and 2.28 μm (95% CI -1.72, 6.27) for retinal venular caliber.

CONCLUSIONHyperuricemia was associated with smaller retinal arteriolar caliber and larger venular caliber mainly in male participants in this study.

Adult ; Aged ; China ; epidemiology ; Diabetes Mellitus ; epidemiology ; Female ; Humans ; Hyperuricemia ; complications ; Male ; Middle Aged ; Retinal Vessels ; pathology ; Risk Factors ; Sex Characteristics

PURPOSE: To evaluate and compare the clinical and angiographic characteristics of retinal vein occlusion (RVO) in glaucomatous and non-glaucomatous eyes with unilateral RVO in the fellow eye. METHODS: Twenty-one glaucomatous eyes (GL group) and 25 age-matched non-glaucomatous eyes (non-GL group) with unilateral RVO in the fellow eye were included in this study. Fluorescein angiographic images were assessed in both groups by 3 retina specialists in order to determine the RVO occlusion site. The occlusion site was divided into 2 types: arteriovenous (AV)-crossing and non-AV-crossing (optic cup or optic nerve sited). The clinical characteristics and prevalence of AV-crossing and non-AV-crossing RVO were compared between the 2 groups. RESULTS: The mean baseline intraocular pressures of the RVO eye and the fellow eye did not differ between the 2 groups (RVO eye: 14.3 +/- 2.5 mmHg [non-GL group], 15.5 +/- 3.9 mmHg [GL group], p = 0.217; fellow eye: 14.4 +/- 2.5 mmHg [non-GL group], 15.7 +/- 3.7 mmHg [GL group], p = 0.148). The prevalence of systemic disease did not differ between the 2 groups (e.g., diabetes mellitus and hypertension, p = 0.802 and 0.873, respectively). AV-crossing RVO was significantly more frequent in the non-GL group (19 eyes; 76%) than in the GL group (4 eyes, 19%, p < 0.001). CONCLUSIONS: Non-AV-crossing RVO, i.e., optic cup- or optic nerve-sited RVO, is more frequently associated with glaucomatous changes in the fellow eye. Therefore, this type of RVO should be monitored more carefully for indications of glaucoma in the fellow eye.
Female ; Fluorescein Angiography/*methods ; Follow-Up Studies ; Fundus Oculi ; Glaucoma, Open-Angle/*diagnosis ; Humans ; Male ; Middle Aged ; Retinal Vein Occlusion/*diagnosis ; Retinal Vessels/*pathology ; Retrospective Studies ; Severity of Illness Index