Hironori Ozeki

ENLARGEMENT OF FOVEAL AVASCULAR ZONE IN DIABETIC EYES EVALUATED BY EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

Purpose: To evaluate the area of the foveal avascular zone (FAZ) detected by en face OCTA (AngioVue, Avanti OCT; Optovue) in healthy and diabetic eyes. Methods: Retrospective chart review of patients who underwent fundus examination including en face OCTA. Eyes with proliferative diabetic retinopathy and history of laser photocoagulation were excluded. The FAZ area in the superficial and deep plexus layers were measured and evaluated using ImageJ software. Results: The FAZ area in the superficial layer was 0.25 ± 0.06 mm2 in healthy eyes (n = 19), whereas it was 0.37 ± 0.07 mm2 in diabetic eyes without retinopathy (n = 24) and 0.38 ± 0.11 mm2 in eyes with diabetic retinopathy (n = 20). Diabetic eyes showed statistically significant FAZ enlargement compared with healthy eyes, regardless of the presence of retinopathy (P < 0.01). The FAZ area in the deep plexus layer was also significantly larger in diabetic eyes than in healthy eyes (P < 0.01). Conclusion: Our data suggest that diabetic eyes show retinal microcirculation impairment in the macula even before retinopathy develops. En face OCTA is a useful noninvasive screening tool for detecting early microcirculatory disturbance in patients with diabetes.

Effect of Particle Size of Polymeric Nanospheres on Intravitreal Kinetics

In this study, we injected nanospheres containing a fluorescein derivative into the vitreous cavity of pigmented rabbit eyes and evaluated their intraocular kinetics as drug carriers in vivo. Polystyrene nanospheres (2 µm, 200 nm and 50 nm in diameter) containing a fluorescein derivative were used in this study. A suspension of each particle was prepared by diluting with distilled water at a concentration of 10 µg/ml equivalent to sodium fluorescein. The suspension of nanospheres was injected once into the vitreous cavity of unilateral eyes of pigmented rabbits. A sodium fluorescein solution of the same concentration was injected once into the vitreous cavity of the other eye as the control. The intraocular kinetics of nanospheres was evaluated by measuring vitreous fluorescence using a scanning fluorophotometer. To investigate elimination pathways of nanospheres in detail, serial cross-sections of the eyes were examined with a fluorescence microscope. The fluorescence derived from nanospheres was observed in the vitreous cavity for over 1 month (2 µm: t1/2 = 5.4 ± 0.8 days, 200 nm: t1/2 = 8.6 ± 0.7 days, 50 nm: t1/2 = 10.1 ± 1.8 days), whereas that in the control eyes completely disappeared within 3 days (t1/2 = 7.8 ± 0.7 h). The elimination half-life from the vitreous cavity correlated well with the particle diameter (r = –0.997, p = 0.007). Histological studies using a fluorescence microscope revealed that nanospheres with a diameter of 2 µm were seen in the vitreous cavity and trabecular meshwork, while nanospheres with a diameter of smaller than 200 nm were also observed in the retina as well as these tissues. Our findings indicated that nanospheres may be beneficial as a drug carrier to the retina, vitreous and trabecular meshwork.

Retention of dye after indocyanine Green-assisted internal limiting membrane peeling ☆

PURPOSE To describe the long-term retention of indocyanine green (ICG) in the fundus after ICG-assisted internal limiting membrane peeling. DESIGN Case report. Two patients underwent vitrectomy including ICG-assisted internal limiting membrane peeling. The fundus was examined with a 780-nm infrared illumination of a scanning laser ophthalmoscope after surgery. RESULTS No ICG staining of the fundus was visible ophthalmoscopically. Examination with a scanning laser ophthalmoscope, however, detected fluorescence from residual ICG until 6 months after surgery in case 1 and 9 months in case 2. No complication related to the residual ICG was observed. CONCLUSIONS The results suggested that ICG remains in the fundus for a long period after surgery. Clearance of the dye from the diabetic retina may be prolonged.

Histopathologic evaluation of the internal limiting membrane surgically excised from eyes with diabetic maculopathy.

Purpose: To histopathologically evaluate the internal limiting membrane (ILM) in diabetic eyes with macular edema as compared to nondiabetic controls. Methods: The authors ultrastructurally and immunohistochemically studied ILM specimens that were intentionally peeled from five eyes with diabetic maculopathy, comprising four with diffuse diabetic macular edema and one with macular hole accompanying diabetic retinopathy (DM group), and five with nondiabetic idiopathic macular hole (MH group). They compared ultrastructural and immunohistochemical findings between the two groups. Results: A larger amount of cellular elements was observed on the vitreous side of the ILM in the DM group. The thickness of the ILM in the DM group was significantly increased (mean 4.8 ± 1.6 &mgr;m) compared with that in the MH group (1.8 ± 0.6 &mgr;m) (P < 0.0001). Immunoreactions for heparan sulfate proteoglycan in the ILM were more abundant in the DM group than in the MH group. Conclusion: The ILM thickening and cell abundance on the vitreous surface might contribute to the course and the pathogenesis of diabetic maculopathy.

Ocular and systemic features of Peters' anomaly.

Abstract Background: To clarify the relationship between associated systemic anomalies and ocular manifestations in patients with Peters’ anomaly, a retrospective study was conducted. Methods: We classified 37 patients with Peters’ anomaly into two groups, one with (+) and one without (–) systemic anomalies. Results: The systemic anomaly (+) group consisted of 13 patients, eight males and five females, with mean age of 2.3 months. Peters’ anomaly was bilateral in six cases and unilateral in seven. Corneolenticular adhesion was observed in 11 cases. Associated ocular anomalies were seen in 12 cases, and developmental glaucoma was present in eight cases. The systemic anomaly (–) group comprised 24 patients, 13 males and 11 females, with mean age of 28.3 months. Peters’ anomaly was bilateral in 11 cases and unilateral in 13. Corneolenticular adhesion was observed in five cases. The associated ocular anomalies were observed in 10 cases, and developmental glaucoma was accompanied in six cases. The incidences of cases with corneolenticular adhesion, those with other ocular anomalies, and those with glaucoma were significantly higher in the systemic anomaly (+) group than in the systemic anomaly (–) group. Conclusions: Peters’ anomaly accompanying corneolenticular adhesion and/or other ocular anomalies should be evaluated for the presence of systemic anomalies.

Anomalies associated with Axenfeld-Rieger syndrome

Abstract · Background: To detect the associated anomalies in patients with Axenfeld-Rieger syndrome is clinically important, because early treatment for such anomalies is crucial to both visual and systemic development. This study was conducted to clarify the associated anomalies in the syndrome. · Methods: We evaluated 21 patients with Axenfeld-Rieger syndrome encountered at Nagoya City University Hospital over a 16-year period. Patients who presented with a prominent Schwalbe’s line accompanying the iris strands were diagnosed as having Axenfeld-Rieger syndrome. · Results: The series consisted of 9 males and 12 females, ranging in age from 1 month to 41 years, mean 15.4±12.7 (SD) years. The syndrome was bilateral in 17 cases and unilateral in 4 cases. Hypoplasia of the iris was observed in 10 eyes of 6 patients. The associated ocular anomalies included sclerocornea in 6 eyes of 3 patients, developmental glaucoma in 5 eyes of 3 patients, persistent pupillary membrane in 4 eyes of 2 patients, microphthalmos in 3 eyes of 2 patients, and typical iris coloboma in 1 eye. Of 10 eyes with hypoplasia of the iris, 5 exhibited glaucoma. The accompanying systemic anomalies included 9 cases of dental anomalies, 5 of facial anomalies, and 3 of Alagille syndrome. · Conclusions: All of the associated ocular and systemic anomalies appeared to arise from the maldevelopment of the neural crest cells. Patients with Axenfeld-Rieger syndrome should therefore be examined for the presence of anomalies in the tissues of neural crest origin. Patients with hypoplasia of the iris should be checked for glaucoma.

Developmental eye abnormalities in mouse fetuses induced by retinoic acid

To clarify the relationship between neural crest cells and ocular anomalies, pregnant mice were treated intraperitoneally with 12.5 mg/kg retinoic acid suspended in corn oil on day 7 of pregnancy (RA group). Control mice were given an equal volume of corn oil (control group). Each group consisted of 5 mother mice, and the offsprings were removed on day 18 of gestation. The fetal mortality was 46.3% in the RA group and 2.2% in the control group. Twenty-two live fetuses of the RA group and 45 of the control group were grossly observed, and the eyes were examined histologically. In the RA group, gross malformations such as microphthalmos (95.5%), cleft lip and palate (36.4%), and central nervous system anomalies (31.8%) were observed, and in the control group, malformations such as microphthalmos (6.7%), central nervous system anomalies (2.2%), and low set ears (2.2%) were seen. Histological examination revealed microphthalmos (47.7%), anophthalmos (38.6%), faulty closure of the embryonic fissure (36.4%), developmental abnormalities of the vitreous (34.1%), aphakia (22.7%), goniodysgenesis (18.2%), and faulty separation of the lens vesicle (15.9%) in the RA group. These anomalies arose from abnormal neural crest cell migration induced by retinoic acid. They were detected in only 3.3, 1.1, 3.3, 8.9, 1.1, 2.2 and 2.2%, respectively of the control group.

Apoptosis is associated with formation and persistence of the embryonic fissure

PURPOSE The role of apoptosis in the transitory ocular embryonic structures has not been clarified yet, therefore, in the present study we focused on one of the transitory ocular structures, the embryonic fissure. To elucidate the developmental mechanism of the embryonic fissure, we observed cell death by apoptosis in the optic cup during early development in mice. METHODS Pairs of C57BL6N/Jcl mice, each comprising an estrous female and a potent male, were caged together overnight. Females that had vaginal plugs the next morning were considered at day 0 of pregnancy. The embryos or fetuses were removed by laparotomy on days 9, 10, 11, 12, 13, 14, 16, and 18 of gestation. Tissue blocks of the eyes were fixed and embedded in paraffin wax. Serial frontal sections of the eye were cut and stained with the TUNEL method and then counterstained by hematoxylin or methyl green solution. We examined TUNEL-positive cells in the optic cup by light microscopy. RESULTS TUNEL-positive cells were seen at the lower nasal side of the optic cup, corresponding to the presumed embryonic fissure area, on day 9 of gestation before the formation of the embryonic fissure. Many TUNEL-positive cells were present at the lips of the embryonic fissure on days 10, 11, and 12. In contrast, TUNEL-positive cells were not detectable in the corresponding area on day 13 after the complete closure of the embryonic fissure. CONCLUSIONS Apoptosis is anatomically closely associated, and appears to be essential for the formation and persistence of the embryonic fissure.

Maldevelopment of neural crest cells in patients with typical uveal coloboma.

PURPOSE To clarify the pathogenesis of ocular and systemic anomalies associated with typical uveal coloboma. METHODS The records of 72 patients with typical uveal coloboma (35 males and 37 females) treated at Nagoya City University Hospital during a 16-year period were reviewed. RESULTS Typical uveal coloboma was bilateral in 33 patients and unilateral in 35 patients; 4 patients were unclassified because of severe contralateral microphthalmos. Uveal coloboma was an isolated defect in 23 (37%) patients. Other ocular anomalies were present in 19 (31%) patients, systemic anomalies were found in 7 (11%) patients, and both other ocular and systemic anomalies were noted in 13 patients (21%). The associated ocular anomalies included microphthalmos in 28 eyes of 23 patients, persistent pupillary membrane in 28 eyes of 18 patients, and posterior embryotoxon in 20 eyes of 15 patients. The accompanying systemic anomalies included ear anomalies, retarded growth, and retarded development in 18 patients; heart anomalies in 13 patients; genital hypoplasia in 12 patients; and congenital facial palsy in 10 patients. The collection of malformations known as the CHARGE association was diagnosed in 14 (19%) patients. CONCLUSION Abnormal development of neural crest cells appeared to be responsible for the majority of associated ocular and systemic anomalies in patients in the present series, suggesting that typical uveal coloboma may be related to maldevelopment of the neural crest cells. The present findings indicated that ophthalmologists should be aware of the possible association of typical uveal coloboma with systemic anomalies.

Clinical Evaluation of Posterior Embryotoxon in One Institution

To elucidate the pathogenesis of posterior embryotoxon, we estimated its incidence in our clinic and evaluated its associated ocular and systemic anomalies. Slit-lamp and gonioscopic examinations were performed on 440 randomly selected patients at Nagoya City University Hospital over a 10-month period. Posterior embryotoxon was detected in 107, 50 bilateral and 57 unilateral, cases (24.3%). Twelve (11.2%) of the 107 cases had open-angle glaucoma. Accompanying ocular anomalies included six cases of sclerocornea, two each of persistent pupillary membrane and familial exudative vitreoretinopathy, and 1 each of melanocytoma of the optic nervehead, choroidal nevus and subconjunctival dermoid cyst. Associated systemic anomalies included three cases of Alagille syndrome, two of congenital biliary atresia, and one each of congenital facial palsy with microtia, congenital adrenal hyperplasia, empty sella syndrome, Hirschsprung disease and Wilson disease. Many of these ocular and systemic anomalies were caused by the maldevelopment of neural crest cells. Patients with posterior embryotoxon should be examined for the possible presence of open-angle glucoma and for ocular and systemic anomalies related to maldevelopment of neural crest cells.