Nuclear expression of p53 in mature tumor endothelium of retinoblastoma

The present study aimed to investigate the p53 expression pattern in tumor cells and in mature tumor vascular endothelium of retinoblastoma. Nuclear p53 accumulation was observed in most of the tumor cells in both the human and orthotopic retinoblastoma animal models using SNUOT-Rb1 and Y79 cells. In the orthotopic animal model, some of the tumor vascular endothelium also demonstrated nuclear p53 immunoreactivity, and the ratio of p53 positivity among the total mature tumor vascular endothelium was slightly higher in the Y79 cell model when compared with the SNUOT-Rb1 cell model. In addition, in the human retinoblastoma specimens, 32.9% of the tumor vascular endothelium showed p53 nuclear staining. In conclusion, some of the mature tumor vascular endothelium in both the human and orthotopic models of retinoblastoma share the same cytogenetic abnormality (an abnormal nuclear accumulation of p53) with retinoblastoma cells.

Factors associated with the angle of exodeviation in patients with recurrent exotropia

AIMS

To compare preoperative and postoperative distance deviation angle in recurrent exotropes, and to determine factors associated with large-angle recurrent exotropia.

METHODS

In recurrent exotropes who were followed-up more than 2 years postoperatively, the largest angle after recurrence (LAAR) was compared with the preoperative deviation angle (PA). Patients were classified into those who had LAAR<PA and LAAR≥PA. Differences in clinical factors between groups were examined.

RESULTS

Among 242 exotropes who underwent surgery, and followed-up for more than 2 years postoperatively, 83 showed recurrent exotropia. Mean age at surgery was 5.7 ± 2.4 years, and mean postoperative follow-up was 36.2 ± 11.3 months. The bigger the preoperative angle, the bigger the angle of recurrence is. However, the smaller the preoperative angle, the angle of recurrence grows closer to the preoperative one. Only six showed bigger recurrence (LAAR≥PA), and these patients had a smaller mean preoperative angle (p=0.01) compared to patients whose angle of recurrence was smaller than the preoperative one. Among the patients with LAAR<PA, type of exotropia (p=0.03) and preoperative constant deviation (p=0.02) was associated with PA-LAAR≤5(Δ).

CONCLUSIONS

Although the overall incidence of recurrent exotropia with a relatively large angle (LAAR≥PA) is low among patients who underwent surgery for exotropia (2.5%), the possibility of this phenomenon should be noted. The ratio of relatively large angle recurrence was higher in patients with a small preoperative exodeviation and basic type exotropia.

Surgical dose-effect relationship in single muscle advancement in the treatment of consecutive strabismus

PURPOSE

To evaluate the dose-effect relationship for single muscle advancement in consecutive esotropia and consecutive exotropia.

METHODS

Medical records from 22 patients with consecutive esotropia (n = 11) or exotropia (n = 11) were retrospectively reviewed. All patients had undergone either single lateral rectus or medial rectus advancement surgery. The alterations in muscle position and the angle deviation were measured in millimeters and prism diopters (PD) and the change in deviation was determined by subtracting the postoperative angle of deviation at 1 week from the preoperative angle. To quantify the clinical effect of muscle advancement, the ratio of the change in muscle position to the change in visual angle deviation was calculated (ie, the surgical dose-effect relationship).

RESULTS

The mean deviation was 25.5 ± 10.4 PD preoperatively and 0 ± 6.9 PD at 1 week postoperatively. The success rate was 82% in the consecutive esotropia group and 91% in the consecutive exotropia group. The average correction ratio was 4.31 ± 0.96 PD/mm. In multiple regression analysis of total patients with consecutive strabismus and the consecutive esotropia group, the amount of muscle advancement and preoperative angle deviation were positively correlated with the correction ratio. In the consecutive exotropia group, there was no significant relationship between variables.

CONCLUSIONS

Single muscle advancement generally provides enough correction for most consecutive strabismus cases. Surgical dose-effect relationship increases with preoperative angle deviation and amount of muscle advancement. Surgeons should consider reducing the amount of muscle advancement in patients with larger angle deviations, especially patients with consecutive esotropia.

Changes in Visual Function over Time in Koreans with Non-arteritic Anterior Ischaemic Optic Neuropathy

Non-arteritic anterior ischaemic optic neuropathy (NAION) causes severe visual loss in elderly patients. However, there are not much data of clinical course of NAION in Asian patients. To evaluate changes in visual acuity and visual field defects associated with non-arteritic anterior ischaemic optic neuropathy (NAION) among Korean patients, the medical records of 50 eyes from 43 patients with NAION patients seen from 1989 to 2011 were reviewed. A significant change in visual acuity was defined as a three-line change in Snellen acuity. Visual field defects were evaluated with Goldmann perimetry. Changes in the visual field were evaluated using the grid method. Thirty-eight percent of eyes showed improvement, 54% showed no change, and 8% showed deterioration of visual acuity at the last follow-up. Thirty-four percent of eyes showed improvement, 54% showed no change, and 12% showed deterioration of the visual field at the last follow-up. Most improvement in visual acuity occurred during the first month after the initial visit and in visual field between the first and third months of follow-up. The prognosis of visual acuity in association with NAION was worse in Korean patients as compared with Western studies. However, improved prognosis of visual field defects might come from the use of different methods for evaluation of the visual field.

Surgical outcomes after intraocular lens implantation for posterior lenticonus-related cataract according to preoperative lens status

PURPOSE

To address the surgical outcomes of pediatric patients with cataracts associated with posterior lenticonus who required cataract extraction and intraocular lens (IOL) implantation according to preoperative lens status.

SETTING

Department of Ophthalmology, Seoul National University Children's Hospital, Seoul, South Korea.

DESIGN

Comparative case series.

METHODS

Patients who had cataract extraction and IOL implantation for posterior lenticonus were divided into 2 groups according to the preoperative lens status. Clinical features and visual outcomes in both groups were comparatively analyzed.

RESULTS

Forty-seven eyes of 43 patients were studied. Thirty-five eyes had lens opacities localized to the posterior pole, and 12 eyes presented with total opacity of the lens. Preexisting posterior capsule defect was identified intraoperatively in 11 eyes with total lens opacity. Eyes with preexisting posterior capsule defects more frequently required ciliary sulcus fixation of the IOL (P=.01). The mean follow-up after cataract extraction was 66.9 months ± 35.9 (SD). The mean final corrected distance visual acuity of patients with total opacity (0.37 ± 0.57 logMAR) was better than that of patients with posterior polar opacity (0.56 ± 0.50 logMAR), with borderline significance (P=.05).

CONCLUSIONS

A preexisting posterior capsule defect, found most often in eyes that presented with total lens opacity, could be an obstacle to capsular bag fixation of the IOL. Posterior lenticonus patients with total lens opacity had marginally significantly better visual outcomes than patients with posterior polar opacity.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Anti-apoptotic effect of clusterin on cisplatin-induced cell death of retinoblastoma cells

Clusterin is a cytoprotective chaperone protein that is known to protect various retinal cells. It was also reported to be overexpressed in several types of malignant tumors, whose chemoresistance correlates with the expression of clusterin. Herein, we investigated the effect of clusterin on cisplatin-induced cell death of retinoblastoma cells. Firstly, evaluation of clusterin expression demonstrated that it was highly expressed in human retinoblastoma tissues and cell lines (SNUOT-Rb1 and Y79) particularly in the area between viable cells around vessels and necrotic zones in the relatively avascular area in human retinoblastoma tissues. Furthermore, the effects of cisplatin on retinoblastoma cells were evaluated. Cisplatin (1 µg/ml) significantly affected cell viability of SNUOT-Rb1 cells by inducing caspase-3-dependent apoptosis. Notably, the cell death due to cisplatin was prevented by 5 µg/ml of clusterin administered 4 h prior to cisplatin treatment by inhibiting cisplatin-induced apoptosis. Furthermore, overexpression of clusterin exerted its anti-apoptotic effect on cisplatin-induced apoptosis, and effectively prevented cisplatin-induced cell death. These data suggest that clusterin, found to be expressed in human retinoblastoma, may exert anti-apoptotic effects on cisplatin-induced apoptosis and prevent cell death. Therefore, clusterin can contribute to cisplatin resistance of retinoblastoma.

Systemic steroid-induced cataracts in children: long-term changes in morphology and visual acuity

PURPOSE

To report the long-term visual prognosis and surgical rates of steroid-induced cataracts in children.

METHODS

The medical records of children diagnosed with steroid-induced cataracts who were followed up for more than 5 years were retrospectively reviewed. Children over 3 years of age who cooperated with the initial visual acuity test (Snellen chart) were included. The following data were evaluated: best-corrected visual acuity at the time of diagnosis and at final follow-up, morphologic changes in the cataract, and surgical outcomes and associated systemic diseases that required steroid treatment.

RESULTS

A total of 59 eyes of 30 patients with posterior subcapsular cataracts were included. The mean follow-up period after diagnosis was 7.6 ± 2.9 years (range, 5-14.5 years). Cataracts were graded on the basis of the size of lens opacity. Cataract progression was defined as widening of the lens opacity. Cataracts progressed in 20 eyes (34%) and remained unchanged in 39 eyes (66%). Three patients underwent bilateral cataract surgery because of cataract progression and significant loss of visual acuity. Of the 53 eyes of 27 children (90%) who did not undergo surgery, best-corrected visual acuity did not change significantly during the follow-up period.

CONCLUSIONS

In this study cohort, cataract progressed in 34% of the eyes with steroid-induced cataract; however, surgery was required in only 10% of the children, and in these patients the postoperative visual outcome was favorable.

Rk1, a ginsenoside, is a new blocker of vascular leakage acting through actin structure remodeling

Endothelial barrier integrity is essential for vascular homeostasis and increased vascular permeability and has been implicated in many pathological processes, including diabetic retinopathy. Here, we investigated the effect of Rk1, a ginsenoside extracted from sun ginseng, on regulation of endothelial barrier function. In human retinal endothelial cells, Rk1 strongly inhibited permeability induced by VEGF, advanced glycation end-product, thrombin, or histamine. Furthermore, Rk1 significantly reduced the vessel leakiness of retina in a diabetic mouse model. This anti-permeability activity of Rk1 is correlated with enhanced stability and positioning of tight junction proteins at the boundary between cells. Signaling experiments revealed that Rk1 induces phosphorylation of myosin light chain and cortactin, which are critical regulators for the formation of the cortical actin ring structure and endothelial barrier. These findings raise the possibility that ginsenoside Rk1 could be exploited as a novel prototype compound for the prevention of human diseases that are characterized by vascular leakage.

Orthotopic transplantation of retinoblastoma cells into vitreous cavity of zebrafish for screening of anticancer drugs

BACKGROUND

With high throughput screening, novel therapeutic agents can be efficiently identified. Unfortunately, researchers only resort to in vitro cell viability assays for screening of anticancer drugs for retinoblastoma, the most common intraocular cancer in the childhood. Current available animal models of retinoblastoma require more than 2 weeks for tumour formation and the investigation of the efficacy of therapeutic agents. In this study, we established a novel orthotopic transplantation model of retinoblastoma in zebrafish as an in vivo animal model for screening of anticancer drugs.

METHODS

We injected retinoblastoma cells into the vitreous cavity of zebrafish at 48 hours after fertilization. Eyeballs of zebrafish were scanned daily under the confocal laser microscope, and the tumor population was quantitatively analyzed by measuring the mean intensity of green fluorescent protein (GFP). Transplanted retinoblastoma cells were isolated to perform further analyses including Western blotting and reverse transcriptase-polymerase chain reaction to confirm that retinoblastoma cells maintained their characteristics as tumor cells even after transplantation and further isolation. To figure out the potential of this model for screening of anticancer drugs, zebrafish were cultured in Ringer's solution containing carboplatin and melphalan after the injection of retinoblastoma cells.

RESULTS

The degree of the tumor population was dependent on the number of retinoblastoma cells injected and maintained stably for at least 4 days. Transplanted retinoblastoma cells maintain their proliferative potential and characteristics as retinoblastoma cells after isolation. Interestingly, systemic application of carboplatin and melphalan demonstrated significant reduction in the tumor population, which could be quantitatively analyzed by the estimation of the mean intensity of GFP.

CONCLUSIONS

This orthotopic retinoblastoma model in zebrafish is expected to be utilized for the screening of anticancer drugs for the treatment of retinoblastoma.

Capillary-free vascularized retina in patients with aggressive posterior retinopathy of prematurity and late retinal capillary formation

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.

Prognostic factors for visual recovery after transsphenoidal pituitary adenectomy

OBJECTIVES

Pituitary adenomas often cause deficits in visual acuity (VA) and visual field (VF) due to compression of the optic chiasm. This study is to identify factors most likely to predict the prognosis of VA and VF after transsphenoidal pituitary adenectomy.

MATERIALS AND METHODS

Clinical records of patients who underwent transsphenoidal pituitary adenectomy were retrospectively reviewed. Data analysed included systemic and visual symptom duration, tumour size, presence of suprasellar tumour extension, histological classification of tumour, VA, and VF. VFs were determined using the Goldmann VF test and quantified according to methods outlined by the American Medical Association.

RESULTS

One-hundred and seventy eyes from 85 patients were included. Systemic and visual symptom duration, pre- and postoperative tumour size, and age did not correlate with postoperative VA or VF score. Patients with normal preoperative VA had a better postoperative VA than that of patients with preoperative VA of 20/30 or worse. Patients with normal preoperative VA had better postoperative VF score than that of patients with preoperative VA of 20/70 or worse. Postoperative VF score was lower in the preoperative ≥ 2 quadrant field loss group than in the ≤ 1 quadrant field loss group. Postoperative VA was worse in the ≥ 2 quadrant loss group than in the normal field group. Preoperative VA correlated with postoperative VA and VF score, and preoperative VF score correlated with postoperative VF score but not with VA.

CONCLUSIONS

Preoperative VA is a prognostic factor for postoperative VA and VF. Preoperative VF is predictive of postoperative VF and postoperative VA in cases with severe VF loss.

Pathogenic mutations in two families with congenital cataract identified with whole-exome sequencing

PURPOSE

Congenital cataract is one of the most frequent causes of visual impairment and childhood blindness. Approximately one quarter to one third of congenital cataract cases may have a genetic cause. However, phenotypic variability and genetic heterogeneity hamper correct genetic diagnosis. In this study, we used whole-exome sequencing (WES) to identify pathogenic mutations in two Korean families with congenital cataract.

METHODS

Two affected members from each family were pooled and processed for WES. The detected variants were confirmed with direct sequencing.

RESULTS

WES readily identified a CRYAA mutation in family A and a CRYGC mutation in family B. The c.61C>T (p.R21W) mutation in CRYAA has been previously reported in a family with congenital cataract and microcornea. The novel mutation, c.124delT, in CRYGC may lead to a premature stop codon (p.C42Afs*60).

CONCLUSIONS

This study clearly shows the efficacy of WES for rapid genetic diagnosis of congenital cataract with an unknown cause. WES will be the first choice for clinical services in the near future, providing useful information for genetic counseling and family planning.

NK cell-associated antigen expression in retinoblastoma animal model

Natural killer (NK) cells are critical components of our immune system. Herein, we for the first time analyzed the expression and localization of the activating receptor NK cell lectin-like receptor gene 2D (NKG2D) ligands, HLA-G, MICA, MICA/B, and ULBP-2 in orthotopic transplantation models of retinoblastoma. Interestingly, HLA-G and MICA/B were expressed in retinoblastoma cell, whereas MICA and ULBP-2 were not detected. Moreover, HLA-G and MICA/B were primarily detected in proliferative area of the tumor periphery with high Ki-67 immunostaining. Our results suggest that NKG2D ligands are differentially expressed in retinoblastoma, which would play a crucial role in immunomodulation in retinoblastoma.

Long-term visual outcomes of penetrating keratoplasty for Peters anomaly

BACKGROUND

To investigate the long-term results and visual outcomes of penetrating keratoplasty (PKP) in Peters anomaly.

METHODS

Twenty-three eyes from 22 patients with Peters anomaly who underwent PKP from 1998 to 2008 were reviewed retrospectively. Patients who were followed for more than 3 years after the first PKP were included in this study. The systemic and ophthalmic features of the recipients were assessed, and the various prognostic factors for graft survival were evaluated. Disease severity was determined according to other accompanying eye anomalies in mild or severe form. The final visual outcomes were presented with respect to graft clarity.

RESULTS

Among the 22 patients, 14 patients had unilateral disease, and eight patients had bilateral disease. Associated systemic anomalies were observed in six patients. The mean age at the first PKP was 42.4 months. Nineteen eyes (83 %) underwent PKP after 12 months of age. The graft failure rates at 1 year, 3 years, 5 years, and 10 years after PKP were 30 %, 39 %, 70 %, and 77 % respectively. Graft rejection within 1 month after PKP and severe disease were significant risk factors for graft failure. The mean final VAs in the clear-graft group and the failed-graft group were 1.883 logMAR and 2.767 logMAR (P < 0.001).

CONCLUSION

The results of delayed PKP in Peters anomaly were not inferior compared to the results of PKP performed at an earlier period in previous studies. If other congenital ophthalmic anomalies were present or graft rejection occurred within 1 month after PKP, the chance of graft failure was significantly increased.

Tissue factor regulates tumor angiogenesis of retinoblastoma via the extracellular signal-regulated kinase pathway

Retinoblastoma, a well-vascularized tumor that is dependent on a very robust angiogenic response, is the most common intraocular malignancy in children. Tissue factor (TF) is known to regulate tumor progression and in the present study we demonstrated that TF regulates tumor angiogenesis of retinoblastoma. In an orthotopic transplantation model of retinoblastoma, TF was selectively expressed in the proliferative area of retinoblastoma including tumor vessels as well as tumor cells, where TF expression was co-localized with endothelial cells of tumor vessels. TF expression progressively increased with fibroblast growth factor-2 (FGF-2)-induced proliferation of human umbilical vein endothelial cells (HUVECs), which was effectively inhibited by blockade of the TF pathway by TF pathway inhibitor (TFPI). In addition, FGF-2-induced angiogenic processes of migration and tube formation of vascular endothelial cells were also effectively suppressed by TFPI, which would be mediated by inhibition of extracellular signal-regulated kinase activation. Therefore, further to our previous report that TF is involved in tumor cell proliferation of retinoblastoma, our current data suggest that blockade of the TF pathway by TFPI could effectively inhibit tumor growth by suppressing tumor cell proliferation and tumor angiogenesis at the same time.

Long-term results of lens-sparing vitrectomy for progressive posterior-type stage 4A retinopathy of prematurity

Purpose

To assess the long-term anatomic and visual outcomes and associated complications of lens-sparing vitrectomy (LSV) in infants with progressive posterior-type tractional retinal detachment (TRD) associated with stage 4A retinopathy of prematurity (ROP).

Methods

In a retrospective case series, the medical records of consecutive patients who presented with progressive posterior-type stage 4A ROP and underwent LSV between 1999 and 2007 were reviewed. Retinal attachment status, visual acuity, and development of postoperative complications were assessed.

Results

Eleven eyes of 9 patients were included. The mean follow-up period was 4.6 years. In 8 eyes (73%), plus disease was present at the time of LSV. In 3 eyes (27%), 2 (66%) without plus disease and 1 (13%) with plus disease, the retina remained reattached in the end, while 8 eyes (73%) had TRD on final examination. Two eyes with reattached retinas showed favorable visual acuity. In those eyes with detached retinas, 5 (68%) showed no light perception. When surgery for ROP was unsuccessful, development of cataract, corneal opacity, or glaucoma was common.

Conclusions

The long-term anatomic success rate of LSV for progressive posterior-type stage 4A ROP was low, especially in the presence of plus disease at the time of LSV. Anatomical reattachment is very important for preventing complications and gaining better visual outcomes.

Superior rectus muscle recession for residual head tilt after inferior oblique muscle weakening in superior oblique palsy

Purpose

Residual head tilt has been reported in patients with superior oblique muscle palsy (SOP) after surgery to weaken the inferior oblique (IO) muscle. The treatments for these patients have not received appropriate attention. In this study, we evaluated the superior rectus (SR) muscle recession as a surgical treatment.

Methods

The medical records of 12 patients with SOP were retrospectively reviewed. Each of these patients had unilateral SR muscle recession for residual head tilt after IO muscle weakening due to SOP. The residual torticollis was classified into three groups on the basis of severity: mild, moderate, or severe. Both IO muscle overaction and vertical deviation, features of SOP, were evaluated in all patients. The severity of the preoperative and postoperative torticollis and vertical deviation were compared using a paired t-test and Fisher's exact test.

Results

The torticollis improved in nine of 12 (75%) patients after SR muscle recession. The difference between the preoperative and postoperative severity of torticollis was statistically significant (p = 0.0008). After surgery, the mean vertical deviation was significantly reduced from 12.4 prism diopters to 1.3 prism diopters (p = 0.0003).

Conclusions

Unilateral SR muscle recession is an effective method to correct residual head tilt after IO muscle weakening in patients with SOP. This surgical procedure is believed to decrease head tilt by reducing the vertical deviation and thereby the compensatory head tilt.

The validity of routine brain MRI in detecting post-laminar optic nerve involvement in retinoblastoma

OBJECTIVE

To describe the diagnostic validity of a gadolinium-enhanced routine brain MRI scan with 5 mm section thickness for the detection of optic nerve involvement in patients with retinoblastoma.

METHODS

Medical records of primarily enucleated retinoblastoma patients who underwent routine preoperative brain MRI scan with section thickness of 5 mm were retrospectively reviewed. Preoperative magnetic resonance images were independently reviewed in a masked fashion by two radiologists and compared with histological findings.

RESULTS

41 eyes of 41 patients were included and the mean age at enucleation was 23.1 months. Among 41 eyes, 14 eyes were diagnosed to have post-laminar optic nerve invasion on histopathology. The accuracy, sensitivity and specificity of MRI for the diagnosis of post-laminar invasion were 73.2%, 35.7% and 92.6%, respectively, by the first radiologist and 78.0%, 42.9% and 96.3%, respectively, by the second radiologist. Moderate agreement was found between two radiologists (κ =0.48, p<0.01).

CONCLUSIONS

Compared with the results of previous studies using orbital MRI with less than 3 mm section thickness, routine brain MRI with section thickness of 5 mm showed comparable specificity but inferior sensitivity in detecting optic nerve involvement of retinoblastoma.

Human apolipoprotein(a) kringle V inhibits ischemia-induced retinal neovascularization via suppression of fibronectin-mediated angiogenesis

Retinal neovascularization is observed in progression of diabetic retinopathy. New vessels grow into the vitreous cavity in proliferative diabetic retinopathy, resulting in traction retinal detachment and vitreous hemorrhage. To overcome the catastrophic visual loss due to these complications, efforts have been focused on the treatment of retinal neovascularization. In this study, we demonstrated the inhibitory effect of recombinant human apolipoprotein(a) kringle V (rhLK8) in an animal model of ischemia-induced retinal neovascularization. rhLK8 induced no definite toxicity on endothelial cells and retinal tissues at the therapeutic dosage. Interestingly, rhLK8 showed antiangiogenic effect, particularly on fibronectin-mediated migration of endothelial cells. Further experiments demonstrated high binding affinity of rhLK8 to α3β1 integrin, and suppression of it might be the mechanism of antiangiogenic effect of rhLK8. Furthermore, rhLK8 inhibited phosphorylation of focal adhesion kinase, resulting in suppression of activation of consequent p130CAS-Jun NH(2)-terminal kinase. Taken together, our data suggested the possible application of rhLK8 in the treatment of retinal neovascularization by suppression of fibronectin-mediated angiogenesis.

Long-term results of bilateral congenital cataract treated with early cataract surgery, aphakic glasses and secondary IOL implantation

PURPOSE

To evaluate the long-term visual outcome after early surgery of bilateral dense congenital cataracts, aphakic correction with glasses and secondary intraocular lens (IOL) implantation around 2 years of age.

METHODS

The medical records of paediatric patients who underwent cataract extraction, aphakic correction and secondary IOL implantation from 1993 to 2004 at Seoul National University Children's Hospital were reviewed retrospectively. Age at secondary IOL implantation, axial length (AL), best corrected visual acuity (BCVA), refractive error, ocular alignment, stereopsis, and postoperative ocular complications were recorded.

RESULTS

Thirty-seven paediatric bilateral pseudophakic patients were identified with a mean follow-up period of 81.4 months. Best corrected visual acuity of 20/40 or better were attained in 44.0% of eyes, and the median BCVA was 20/50. Preoperative factors associated with poor visual prognosis included cataract surgery after 8 weeks of age, interocular AL difference of 0.5 mm or more, and glaucoma. Amblyopic eyes showed more myopic change compared to fellow eyes. Good or moderate binocular function was achieved in 18.9% of all patients. Incidences of strabismus, glaucoma, posterior capsular opacity formation were 46.0%, 32.4% and 4.0%, respectively.

CONCLUSION

Good postoperative BCVA and binocular function were achieved in most healthy children with bilateral dense congenital cataract and no posterior segment pathology. Early cataract surgery, aphakic correction with glasses and secondary IOL implantation around 2 years of age appears to be appropriate methods.

Clinical characteristics, course, and visual prognosis of partial cataracts that seem to be visually insignificant in children

PURPOSE

To report the clinical characteristics and visual prognosis of pediatric partial cataracts that seem to be visually insignificant.

METHODS

In this retrospective case series, the morphologic type and etiology, laterality, best-corrected visual acuity (BCVA), progression, and visual prognosis of partial cataracts in children with more than 1 year of follow-up were evaluated.

RESULTS

Of 110 children (184 eyes), 74 (67%) had bilateral and 36 (33%) had unilateral cataracts. The most common type of cataract was posterior subcapsular (36%), followed by nuclear (18%) cataracts. The most common etiology was idiopathic (51%), followed by steroid-induced (28%). Cataracts progressed to surgery in 21 eyes (11%). Among these patients, BCVA was 20/38 at final examination (average follow-up 5.1 years). Among those in whom cataracts did not progress, BCVA was 20/28 at final examination (average follow-up 6.1 years). Initial BCVA was better in the nonprogression group than in the progression group (P = 0.04), but final BCVA did not differ between the groups (P = 0.96).

CONCLUSIONS

Most patients with partial cataracts that seemed to be visually insignificant and were treated without surgery did not progress and showed favorable visual outcomes. In children who had progressive vision loss, surgery was necessary: these patients also had favorable visual outcomes.

Clinical characteristics of optic neuritis in Koreans greater than 50 years of age

Purpose

To report clinical characteristics of optic neuritis (ON) in Koreans >50 years of age.

Methods

A retrospective chart review was performed on patients with ON between January 2000 and December 2009. We obtained the best-corrected visual acuity (BCVA), Goldmann perimetry, relative afferent pupillary defect (RAPD), and color function tests as well as brain magnetic resonance imaging (MRI) findings in patients who were in the acute stage of the disorder.

Results

Nine eyes in eight patients were included. The mean age of patients at presentation was 60.5 years (range, 53 to 71 years). Six patients were female, and two were male. There was one patient with bilateral ON. The mean BCVA at presentation was 20 / 400 (no light perception-20 / 70). Eight eyes (89%) complained of pain with eye movement. Six eyes (66%) had disc edema. Central scotoma was the most common field defect. All eyes had color abnormalities. Five eyes in four patients showed abnormalities of the involved optic nerves on MRI. The patients were followed for a mean of 11.3 months (range, 2 to 34 months). All of the patients recovered to a BCVA of 20 / 40 or better within 2 months. On the last follow-up, the mean BCVA was 20 / 20 (20 / 40 to 20 / 16). Four eyes showed remnant central scotoma. One eye had remnant RAPD, and two eyes had mild color abnormalities.

Conclusions

Although ON is uncommon in elderly patients, it can develop in patients >50 years of age, and clinical features of optic neuritis in elderly patients are similar to those of younger patients.

Inhibitory activity of bevacizumab to differentiation of retinoblastoma cells

Vascular endothelial growth factor (VEGF) is a major regulator in retinal and choroidal angiogenesis, which are common causes of blindness in all age groups. Recently anti-VEGF treatment using anti-VEGF antibody has revolutionarily improved the visual outcome in patients with vaso-proliferative retinopathies. Herein, we demonstrated that bevacizumab as an anti-VEGF antibody could inhibit differentiation of retinoblastoma cells without affection to cellular viability, which would be mediated via blockade of extracellular signal-regulated kinase (ERK) 1/2 activation. The retinoblastoma cells expressed VEGFR-2 as well as TrkA which is a neurotrophin receptor associated with differentiation of retinoblastoma cells. TrkA in retinoblastoma cells was activated with VEGF treatment. Interestingly even in the concentration of no cellular death, bevascizumab significantly attenuated the neurite formation of differentiated retinoblastoma cells, which was accompanied by inhibition of neurofilament and shank2 expression. Furthermore, bevacizumab inhibited differentiation of retinoblastoma cells by blockade of ERK 1/2 activation. Therefore, based on that the differentiated retinoblastoma cells are mostly photoreceptors, our results suggest that anti-VEGF therapies would affect to the maintenance or function of photoreceptors in mature retina.

The long-term survival analysis of bilateral lateral rectus recession versus unilateral recession-resection for intermittent exotropia

PURPOSE

To conduct a comparison of the long-term surgical outcomes of bilateral lateral rectus recession (BLR) vs unilateral lateral rectus recession-medial rectus resection (RR) in treatment of intermittent exotropia.

DESIGN

Nonrandomized, retrospective case series.

METHODS

Consecutive patients who underwent BLR or RR for treatment of intermittent exotropia between 2002 and 2006 and had ≥2 years' follow-up were recruited. Surgical outcomes were grouped according to postoperative angle of deviation as overcorrection (esophoria/tropia >5 Δ), success (esophoria/tropia ≤5 Δ to exophoria/tropia ≤10 Δ), or undercorrection/recurrence (exophoria/tropia >10 Δ), and were compared between the BLR group and the RR group at postoperative 1 day, 1 month, 6 months, 1 year, and 2 years, and at the final examination.

RESULTS

Of 128 patients, 55 underwent BLR and 73 underwent RR. The mean follow-up period was 44.2 months in the BLR group and 47.8 months in the RR group. At 1 day, 1 month, 6 months, 1 year, and 2 years after surgery, surgical outcomes in each group were not different (P > .05) However, the final outcome at a mean of 3.8 years was significantly different between the groups, demonstrating a higher success rate in the BLR group than in the RR group (58.2% vs 27.4%, P < .01). Cumulative probability of survival from recurrence was higher in the BLR group than in the RR group (P = .01, log-rank test). Recurrences were most common within 6 months from surgery; however, after that, recurrences occurred continuously in the RR group and rarely in the BLR group.

CONCLUSION

Surgical outcomes by 2 years after surgery for intermittent exotropia were not different between the BLR and RR groups. However, final outcomes were better in the BLR group than in the RR group. This may be caused by the difference of recurrence rate over time: continuous recurrence of exotropia occurred in the RR group, while recurrence was low in the BLR group after postoperative 6 months.

The clinical outcomes of proton beam radiation therapy for retinoblastomas that were resistant to chemotherapy and focal treatment

Purpose

To evaluate the clinical results of proton beam radiation therapy (PBRT) for treatment of retinoblastoma.

Methods

Children with retinoblastoma who were treated with chemotherapy and focal treatment such as brachytherapy and thermotherapy but showed no response or developed recurrences later received PBRT. The PBRT strategy was designed to concentrate the radiation energy to the retinoblastoma and spare the surrounding healthy tissue or organs.

Results

There were three patients who received PBRT. The first patient received PBRT because of an initial lack of tumor regression with chemotherapy and brachytherapy. This patient showed regression after PBRT. The second patient who developed recurrence of retinoblastoma as diffuse infiltrating subretinal seeding was taken PBRT. After complete regression, there was recurrence of tumor and the eye was enucleated. The third patient had unilateral extensively advanced retinoblastoma. Initial chemotherapy failed and tumor recurred. The tumor responded to PBRT and regressed significantly. However, the eye developed sudden multiple recurrences, so we had to perform enucleation.

Conclusions

PBRT for retinoblastoma was effective in cases of showing no response to other treatment modalities. However, it should be carefully applied when there was recurrence of diffuse infiltrating subretinal seeding or extensively advanced retinoblastoma initially.

Hypoxia-induced insulin-like growth factor II contributes to retinal vascularization in ocular development

In ocular development, retinal physiological hypoxia in response to the retinal metabolic activity controls retinal vascular development, which is regulated by variable angiogenic factors. Herein, we demonstrated that hypoxia-induced IGF-II could contribute to retinal vascularization in ocular development. In the developing retina, IGF-II expression appears to be predominant on retinal vessels, which was chronologically increased and peaked during active retinal angiogenesis similar to VEGF expression. Under hypoxic condition, IGF-II as well as VEGF was significantly up-regulated in retinal vascular endothelial cells. In addition, IGF-II treatment could also increase VEGF expression in retinal vascular endothelial cells. The VEGF expression induced by IGF-II was mediated by ERK-1/2 activation. Moreover, IGF-II strongly promoted angiogenic processes of migration and tube formation of retinal microvascular endothelial cells. In conclusion, our results provided that hypoxia-induced IGF-II may regulate retinal vascular development not only directly by IGF-II-mediated angiogenic activity, but also indirectly by IGF-II-induced VEGF expression. Therefore, the potential contribution of IGF-II to pathological retinal angiogenesis should be furthermore explored for the development of novel treatments to vaso-proliferative retinopathies.

Antiangiogenic effect of silicate nanoparticle on retinal neovascularization induced by vascular endothelial growth factor

Angiogenesis-related blindness indicates the spectrum of retinal diseases that are caused by pathological angiogenesis, resulting in catastrophic vision loss. We aimed to demonstrate the antiangiogenic effect of silicate nanoparticles (SiNPs) on the retinal neovascularization. No direct toxicity of SiNPs was observed on retinal neuronal or endothelial cells, nor on the retinal tissue. Furthermore, intravitreal injection of SiNPs effectively reduced anomalous retinal angiogenesis in oxygen-induced retinopathy mice. SiNPs also effectively inhibited in vitro vascular endothelial growth factor (VEGF)-induced angiogenesis. Via suppression of VEGF receptor-2 phosphorylation induced by VEGF, SiNPs blocked ERK 1/2 activation. SiNPs could be an inhibitor of the potency and safety of retinal neovascularization that is mediated by VEGF and utilized in the treatment of angiogenesis-related blindness.

FROM THE CLINICAL EDITOR

In this important preclinical study, silicate NP-s are studied to address retinal neovascularization, an important pathomechanism of different retinal diseases that could lead to catastrophic vision loss. The authors conclude that SiNP-s could be utilized as inhibitors of retinal neovascularization mediated by VEGF and propose future applications in the treatment of angiogenesis-related blindness.

Long-term results of lens-sparing vitrectomy for stages 4B and 5 retinopathy of prematurity

PURPOSE

To assess long-term anatomic and visual outcomes and associated complications of lens-sparing vitrectomy (LSV) for treatment of tractional retinal detachments (TRDs) associated with stages 4B and 5 retinopathy of prematurity (ROP).

METHODS

We performed a retrospective review of medical records and data analyses of consecutive patients who presented with stages 4B and 5 ROP and underwent LSV from 1999 to 2007. Retinal reattachment status, visual acuity and postoperative complications were evaluated.

RESULTS

Twenty-one eyes of 20 patients, including 13 eyes with stage 4B ROP and 8 eyes with stage 5 ROP, were examined. The mean follow-up period was 5.6 years. In 9 (43%) out of 21 eyes, retinas were eventually reattached. The anatomic success rates were 62% in stage 4B and 13% in stage 5 ROP. In eyes with reattached retinas, visual acuity better than form vision was shown in 7 eyes (78%), whereas no light perception was present in 10 eyes (83%) among eyes with TRD on final examination. Postoperative intraocular hemorrhage occurred in nine eyes (43%). Long-term complications of cataract, corneal opacity, glaucoma and strabismus developed in 4 (19%), 6 (29%), 7 (33%) and 8 (38%) eyes, respectively, and were more common in eyes with TRD.

CONCLUSIONS

After following-up for a mean of 5.6 years, the anatomical success rate of LSV was encouraging for the correction of TRD associated with stage 4B ROP but not for stage 5 ROP. Retinal reattachment is important for obtaining better visual outcomes and preventing the development of late complications.

Dermis-fat graft for treatment of exposed porous polyethylene implants in pediatric postenucleation retinoblastoma patients

PURPOSE

To demonstrate the use of the autogenous dermis-fat graft for the treatment of porous polyethylene implant exposure and volume augmentation in postenucleation retinoblastoma children.

DESIGN

Retrospective, interventional case series.

METHODS

Ten children who received a dermis-fat graft at Seoul National University Hospital between July 1, 2005 and January 31, 2010 were included in this study. The patients had undergone unilateral enucleation for retinoblastoma, and received a subconjunctival dermis-fat graft to repair implant exposure and simultaneously correct enophthalmos. The clinical characteristics of the patients, rate of graft survival, and complications were analyzed. The cosmetic outcome was assessed using a grading system.

RESULTS

All patients had enucleation using porous polyethylene implant as a primary orbital implant. The average time to exposure was 89.1 ± 22.4 months and the median size of defect was 2 × 3 mm. With a mean follow-up of 28 months, 9 of 10 patients showed well-survived graft without re-exposure. One patient who experienced a graft failure managed with implant rotation and a scleral graft. Seven patients showed significant improvement of enophthalmos.

CONCLUSIONS

Implantation of an autogenous dermis-fat graft is a procedure that can be effectively used to treat porous polyethylene implant exposure and simultaneously correct enophthalmos. Use of this procedure can be particularly advantageous for pediatric postenucleation patients.

Initial postoperative deviation as a predictor of long-term outcome after surgery for intermittent exotropia

PURPOSE

To determine the relationship between initial postoperative deviation and long-term results after surgery for intermittent exotropia.

METHODS

A nonrandomized, retrospective case series. The records of patients who underwent surgery for intermittent exotropia between 2002 and 2006 and had 2 or more years of follow-up were evaluated. Distance alignment at postoperative week 1 was used to predict long-term surgical outcomes. A successful outcome was defined as no recurrence of exodeviation (exotropia/phoria >15(Δ)) at last follow-up.

RESULTS

A total of 81 patients with mean age of 7.2 years at surgery (range, 1.3-16.9) were included. Bilateral lateral rectus recession was performed in 24 patients, unilateral recession and resection in 48, and unilateral lateral rectus recession in 9. At postoperative week 1, 41 patients had orthophoria or undercorrection (0(Δ)-18(Δ) exotropia/phoria; Group A), 28 had esotropia/phoria ≤10(Δ) (Group B), and 12 had esotropia/phoria >10(Δ) (Group C) at distance. At 2 years after surgery, 12 patients (29%) in Group A, 3 patients (11%) in Group B, and none (0%) in Group C had recurrent exotropia. The recurrence rates within 2 years of surgery significantly differed between groups (P = 0.03). The long-term recurrence rates did not significantly differ in the 3 groups after a mean of 51 ± 23 months' follow-up.

CONCLUSIONS

Although initial overcorrection after intermittent exotropia surgery may be associated with lower probability of recurrence within 2 years after surgery, it cannot predict long-term motor outcomes.

Intravenously administered anti-recoverin antibody alone does not pass through the blood-retinal barrier

PURPOSE

Cancer-associated retinopathy is a paraneoplastic retinal degeneration which may primarily result from auto-immune mediated apoptosis. It has been hypothesized that high titer of auto-antibodies are able to cross the blood-retinal barrier (BRB) and to enter retinal cells to activate apoptotic pathway which has been already well-established. However, it still remains to be elucidated whether auto-antibodies could cross BRB in the retina. Herein, we demonstrated that intravenously administrated anti-recoverin antibodies could not pass through BRB and not lead to retinal cell death.

METHODS

Anti-recoverin antibody was intravenously injected to C57BL/6 mice, which were sacrificed 1 and 7 days to obtain eye. Vascular endothelial growth factor was intravitreally injected to induce BRB breakdown, which was confirmed by fluorescein angiography and western blotting for zonula occludens (ZO)-1, ZO-2 and occludin. To investigate the location of anti-recoverin antibody in the retina, immunofluorescein was performed. The retinal toxicity of intravenous anti-recoverin antibody was evaluated by histological examination and transferase-mediated dUTP nick-end labeling. Immunofluorescein staining for glial fibrillary acidic protein was done to address glial activation as well.

RESULTS

Intravenously administrated anti-recoverin antibodies were exclusively distributed on retinal vessels which were co-localized with CD31, and led to neither increase of glial fibrillary acidic protein expression, as an indicator of retinal stress, nor apoptotic retinal cell death. Moreover, even in the condition of vascular endothelial growth factor-induced BRB breakdown, anti-recoverin antibodies could not migrate across BRB and still remained on retinal vessels without retinal cytotoxicity.

CONCLUSIONS

Our results suggest that high titer of intravascular anti-recoverin antibodies could not penetrate into the retina by themselves, and BRB breakdown mediated by dysregulation of tight junction might not be sufficient to allow anti-recoverin antibodies to pass through BRB.

Tissue factor is involved in retinoblastoma cell proliferation via both the Akt and extracellular signal-regulated kinase pathways

Tissue factor (TF) is known to play a role in tumor progression. In retinoblastoma, the expression and role of TF has not been determined yet. Herein, we demonstrated for the first time that TF is closely related to the proliferation of retinoblastoma cells, which could be therefore effectively suppressed by blockade of the TF pathway. TF was selectively expressed on the areas of highly mitogenic activity in an orthotopic transplantation mouse model of retinoblastoma. In addition, the levels of TF expression in retinoblastoma cells were elevated after FGF2 treatment, whereas the proliferative effect of FGF2 on retinoblastoma cells was significantly inhibited by blockade of the TF pathway via TF pathway inhibitor (TFPI). Interestingly, retinoblastoma cells cultured with FGF2 showed increased phosphorylation of both Akt and ERK1/2. Addition of TFPI nearly abolished the FGF2-induced phosphorylation of Akt and ERK1/2 in retinoblastoma cells. Therefore, our data suggest that TF expression in retinoblastoma cells is closely related to tumor cell proliferation and TFPI has the potential to inhibit retinoblastoma cell proliferation via the inhibition of both Akt and ERK1/2 activation.

Clusterin protects H9c2 cardiomyocytes from oxidative stress-induced apoptosis via Akt/GSK-3β signaling pathway

Clusterin is a secretory glycoprotein, which is highly up-regulated in a variety of normal and injury tissues undergoing apoptosis including infarct region of the myocardium. Here, we report that clusterin protects H9c2 cardiomyocytes from H2O2-induced apoptosis by triggering the activation of Akt and GSK-3β. Treatment with H2O2 induces apoptosis of H9c2 cells by promoting caspase cleavage and cytochrome c release from mitochondria. However, co-treatment with clusterin reverses the induction of apoptotic signaling by H2O2, thereby recovers cell viability. The protective effect of clusterin on H2O2-induced apoptosis is impaired by PI3K inhibitor LY294002, which effectively suppresses clusterin-induced activation of Akt and GSK-3β. In addition, the protective effect of clusterin is independent on its receptor megalin, because inhibition of megalin has no effect on clusterin-mediated Akt/GSK-3β phosphoylation and H9c2 cell viability. Collectively, these results suggest that clusterin has a role protecting cardiomyocytes from oxidative stress and the Akt/GSK-3β signaling mediates anti-apoptotic effect of clusterin.

Investigation of barrier characteristics in the hyaloid-retinal vessel of zebrafish

The blood-retinal barrier (BRB) is essential for the physiological integrity of the retinal vessels. In particular, ocular pathologies of retinal neovascularization could be causally related to the BRB breakdown. Zebrafish have emerged as an advantageous model for studying vascular development and characteristics. Here we investigated for the first time the barrier characteristics of the hyaloid-retinal vessel using fli1-EGFP transgenic zebrafish. By 7 dpf, the hyaloid-retinal vessel was formed between lens and retina, where intercellular junctional complexes were already present between endothelial cells. Interestingly, NG-2 expression, but not GFAP, was colocalized with EGFP-positive cells of the hyaloid-retinal vessel. Among endothelial tight junction proteins, claudin-5 was expressed on EGFP-positive cells of the hyaloid-retinal vessel, whereas occludin and ZO-1 were not observed on the vessel. In addition, the hyaloid-retinal vessel was so leaky that a mixture of fluorescein tracers (2,000-kDa FITC-dextran, 10-kDa rhodamine-dextran, and 350-Da DAPI) diffusely infiltrated into all retinal layers. Our results suggest that, unlike retinal vessels of higher vertebrates, the hyaloid-retinal vessel of zebrafish shows insufficient characteristics to meet a functional endothelium-based CNS barrier. Therefore, it might be not suitable to use the hyaloid-retinal vessel of zebrafish for studying BRB biogenesis.

The clinical characteristics of optic neuritis in Korean children

Purpose

To study the clinical characteristics of optic neuritis in Korean children.

Methods

A retrospective review of the medical charts of 20 patients who were diagnosed with optic neuritis before age 10 was conducted in this study. Data were collected on the demographics, clinical features, use of intravenous corticosteroids, neuroimaging, and diagnosis of multiple sclerosis.

Results

The mean age at diagnosis was 6.5 ± 1.8 years (range, 3 to 9 years). Seventeen patients (85%) were female, and 13 patients (65%) exhibited bilateral diseases. Visual acuity had decreased to ≤20 / 200 in 16 of the 20 patients, and recovered to ≥20 / 40 in 16 of the 20 patients. The mean duration between the worst visual acuity and 20 / 40 was 2.30 ± 2.91 months. Intravenous corticosteroid treatment was performed in 15 patients and exerted a beneficial effect on the visual outcomes. Disc swelling was observed in 75.8% of the affected eyes. Multiple sclerosis was diagnosed in five patients with a mean follow-up period of 21.9 ± 20.3 months. The presence of lesions in brain magnetic resonance images was identified as the most significant factor with regards to the occurrence of multiple sclerosis.

Conclusions

In children with optic neuritis, a profound decrease in initial visual acuity and rapid recovery of visual acuity were confirmed. Corticosteroid treatment resulted in a beneficial effect on visual outcomes, but had no effect on the risk of multiple sclerosis.

Presumed atypical HDR syndrome associated with Band Keratopathy and pigmentary retinopathy

This report describes presumed atypical hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome associated with unexpected ocular findings. The patient had exotropia, bilateral band keratopathy, and pigmentary retinopathy, including attenuated retinal vessels and atrophy of the retinal pigment epithelium. Even though the calcific plaques were successfully removed, visual acuity in both eyes gradually decreased and electroretinography was extinguished.

Brain imaging studies in Leber's congenital amaurosis: new radiologic findings associated with the complex trait

Purpose

To report the incidence and new findings of abnormal brain imaging studies associated with patients initially diagnosed with Leber's congenital amaurosis (LCA) without definite systemic abnormalities and to determine the need for brain imaging studies in these patients.

Methods

A retrospective review of medical records was performed in 83 patients initially diagnosed as LCA and without definite systemic abnormalities before the age of 6 months in 2 tertiary referral centers. Brain magnetic resonance imaging was performed in 31 of 83 patients (37.3%).

Results

Six of 31 patients (19%) had radiologically documented brain abnormalities. Two patients had cerebellar vermis hypoplasia, 1 patient showed an absence of septum pellucidum, 2 subjects showed mild external hydrocephalus, and 1 patient was found to have a small cerebellum.

Conclusions

Approximately one fifth of the LCA patients in whom brain imaging was performed were associated with brain abnormalities, including the absence of septum pellucidum, which has not been documented in the literature. Brain imaging is mandatory in patients primarily diagnosed with LCA, even without definite neurologic or systemic abnormalities.