Radiation Dose Responses, Thresholds, and False Negative Rates in a Series of Cataract Surgery Prevalence Studies among Atomic Bomb Survivors

In order to find imperfect sensitivity or the false-negative rate of cataract surgery due to latent clinically significant or severe cataract and a dose-response threshold, cataract surgery prevalence data analysis was made for each of the two-year periods from 1986 through 2005 among atomic bomb survivors. Using the latent variable regression model published earlier, cataract prevalence studies allowing for false-negative and/or false-positive rates were conducted in each of the 10 two-year periods during 1986 to 2005. As the best statistical model for prevalence data, a logistic model with a non-negligible false negative rate was selected for analysis. The commonly used naïve logistic analysis resulted in an average odds ratio (OR) at 1 Gy of 1.33 (95%CI: 1.28, 1.38) for cataract surgery with no linear time trend (p = 0.334), and the OR at 1 Gy with the model allowing for sensitivity was 1.48 (95%CI: 1.40, 1.56) for clinically significant or severe cataract with no linear time trend (p = 0.263). Cataract surgery is an imperfect surrogate for clinically significant cataract, and the sensitivity increased from 0.15 to 0.50 during the 20 y with increasing rate of sensitivity per 2-y period of approximately 22%. The dose-response threshold based on a naïve logistic model for cataract surgery ranged from 0.04-1.03 Gy (simple average of 0.41 Gy) with no linear time trend (p = 0.620) in the 10 2-y periods compatible with the no dose response threshold model in all periods.

Radiation-induced eye lens changes and risk for cataract in interventional cardiology

BACKGROUND

Recent studies have reported a significant increase in eye lens opacities among staff in the cardiac catheterization laboratory but indicated further studies are needed to confirm the findings.

OBJECTIVE

To evaluate the prevalence of opacities in eyes of cardiologists, radiographers and nurses working in interventional cardiology.

METHODS

The eyes of 52 staff in interventional cardiology facilities and 34 age- and sex-matched unexposed controls were screened in a cardiology conference held in Kuala Lumpur by dilated slit-lamp examination, and posterior lens changes were graded. Individual cumulative lens X-ray exposures were calculated from responses to a questionnaire in terms of workload and working practice.

RESULTS

The prevalence of posterior lens opacities among interventional cardiologists was 53%, while in nurses and radiographers it was 45%. Corresponding relative risks were 2.6 (95% CI: 1.2-5.4) and 2.2 (95% CI: 0.98-4.9), for interventional cardiologists and support staff, respectively.

CONCLUSIONS

This study confirms a statistically significant increase in radiation-associated posterior lens changes in the eyes of interventional cardiology staff.

Radiation dose and cataract surgery incidence in atomic bomb survivors, 1986-2005

PURPOSE

To examine the incidence of clinically important cataracts in relation to lens radiation doses between 0 and approximately 3 Gy to address risks at relatively low brief doses.

MATERIALS AND METHODS

Informed consent was obtained, and human subjects procedures were approved by the ethical committee at the Radiation Effects Research Foundation. Cataract surgery incidence was documented for 6066 atomic bomb survivors during 1986-2005. Sixteen risk factors for cataract, such as smoking, hypertension, and corticosteroid use, were not confounders of the radiation effect on the basis of Cox regression analysis. Radiation dose-response analyses were performed for cataract surgery incidence by using Poisson regression analysis, adjusting for demographic variables and diabetes mellitus, and results were expressed as the excess relative risk (ERR) and the excess absolute risk (EAR) (ie, measures of how much radiation multiplies [ERR] or adds to [EAR] the risk in the unexposed group).

RESULTS

Of 6066 atomic bomb survivors, 1028 underwent a first cataract surgery during 1986-2005. The estimated threshold dose was 0.50 Gy (95% confidence interval [CI]: 0.10 Gy, 0.95 Gy) for the ERR model and 0.45 Gy (95% CI: 0.10 Gy, 1.05 Gy) for the EAR model. A linear-quadratic test for upward curvature did not show a significant quadratic effect for either the ERR or EAR model. The linear ERR model for a 70-year-old individual, exposed at age 20 years, showed a 0.32 (95% CI: 0.09, 0.53) [corrected] excess risk at 1 Gy. The ERR was highest for those who were young at exposure.

CONCLUSION

These data indicate a radiation effect for vision-impairing cataracts at doses less than 1 Gy. The evidence suggests that dose standards for protection of the eye from brief radiation exposures should be 0.5 Gy or less.

Cataract in atomic bomb survivors

PURPOSE

Ophthalmologic examinations were conducted on atomic bomb (A-bomb) survivors 55 years after exposure.

MATERIALS AND METHODS

A-bomb survivors who had been exposed before 13 years of age at the time of the bombings in 1945 or who had been examined in a previous study between 1978 and 1980. The examinations, conducted between June 2000 and September 2002, included slit-lamp examination, digital photography and a cataract grading system for three parts of the lens (nucleus, cortex and posterior subcapsule) as an outcome variable. Proportional odds logistic regression analysis was conducted using the lowest grading class as a reference and included explanatory variables such as age, sex, city, dose and various cataract-related risk factors. When the grades in an individual differed, the worst grade was used.

RESULTS

Results indicate that odds ratios (ORs) at 1 Sv were 1.07 (95% confidence intervals [CI] 0.90, 1.27) in nuclear colour, 1.12 (95% CI 0.94, 1.30) in nuclear cataract, 1.29 (95% CI 1.12, 1.49) in cortical cataract and 1.41 (95% CI 1.21, 1.64) in posterior subcapsular cataract. The same was true after excluding 13 people whose posterior subcapsular cataracts had been previously detected.

CONCLUSION

Significant radiation effects were observed in two types of cataracts in A-bomb survivors.

Postoperative cataract cases among atomic bomb survivors: radiation dose response and threshold

Recent evidence argues against a high threshold dose for vision-impairing radiation-induced cataractogenesis. We conducted logistic regression analysis to estimate the dose response and used a likelihood profile procedure to determine the best-fitting threshold model among 3761 A-bomb survivors who underwent medical examinations during 2000-2002 for whom radiation dose estimates were available, including 479 postoperative cataract cases. The analyses indicated a statistically significant dose-response increase in the prevalence of postoperative cataracts [odds ratio (OR), 1.39; 95% confidence interval (CI), 1.24-1.55] at 1 Gy, with no indication of upward curvature in the dose response. The dose response was suggestive when the restricted dose range of 0 to 1 Gy was examined. A nonsignificant dose threshold of 0.1 Gy (95% CI, <0-0.8) was found. The prevalence of postoperative cataracts in A-bomb survivors increased significantly with A-bomb radiation dose. The estimate (0.1 Gy) and upper bound (0.8 Gy) of the dose threshold for operative cataract prevalence was much lower than the threshold of 2-5 Gy usually assumed by the radiation protection community and was statistically compatible with no threshold at all.

No association of complement factor H gene polymorphism and age-related macular degeneration in the Japanese population

PURPOSE

The aim of this study was to determine whether genetic polymorphism of complement factor H (CFH) is associated with age-related macular degeneration (AMD) in the Japanese population.

METHODS

Genomic DNA was examined in a cohort of 67 Japanese patients with AMD and 107 controls. TT/TC/CC genotypes on exon 9 were screened for sequence alternation by polymerase chain reaction analysis and through sequencing.

RESULTS

The mean ages +/- SD of AMD patients and control subjects were 73 +/- 8.5 years and 72 +/- 8.7 years, respectively. There was no significant difference between CFH genotypes in the AMD group (TT, 76%; TC, 19%; CC, 5%) and the control group (TT, 80%; TC, 17%; CC, 3%). The frequencies of T and C alleles were 86% and 14%, respectively, in the AMD group and 89% and 11%, respectively, in the control group.

CONCLUSION

CFH gene polymorphism is not associated with AMD in the Japanese population. Moreover, the frequency of the C allele is low among the Japanese population.

Triamcinolone acetonide inhibits IL-6- and VEGF-induced angiogenesis downstream of the IL-6 and VEGF receptors

PURPOSE

To test whether triamcinolone acetonide (TA) inhibits angiogenesis induced by IL-6 or VEGF and whether this inhibition is through antagonism of the IL-6 or the VEGF receptor 2.

METHODS

A rat cornea micropocket assay was used to initiate IL-6- and VEGF-mediated angiogenesis. The ability of TA or neutralizing VEGF antibody to inhibit IL-6- or VEGF-mediated neovascularization was analyzed by measuring vessel length, vessel extension, and vessel area. The phosphorylation of signal transduction activator 3 (STAT3), VEGF receptor, and extracellular signal-regulated kinase 1/2 (ERK1/2) was determined by Western blot in human umbilical vein endothelial cell (HUVEC) lysates after stimulus with IL-6 or VEGF, with and without TA pretreatment. The effect of IL-6 or TA on STAT3 expression in cornea was determined by Western blot.

RESULTS

IL-6 induced corneal angiogenesis in a dose-dependent manner, with 350 ng producing a peak at day 6. VEGF antibodies and TA blocked IL-6-mediated limbal neovascularization. TA also directly inhibited angiogenesis stimulated by a VEGF pellet; the glucocorticoid receptor antagonist mifepristone neutralized TA inhibition of angiogenesis. TA did not inhibit IL-6-induced STAT3 phosphorylation and did not inhibit VEGF-induced phosphorylation of the VEGF receptor 2 or of ERK1/2 in endothelial cells, but TA decreased IL-6-induced STAT3 expression in cornea.

CONCLUSIONS

IL-6- and VEGF-mediated corneal neovascularization are blocked by TA through the mifepristone-sensitive steroid receptor. TA inhibits IL-6-induced STAT3 expression in cornea, but it does not inhibit activation of the IL-6 or the VEGF receptor in cultured human endothelial cells. This finding has two implications. The fact that TA directly inhibits VEGF action implies that other factors may be critical to angiogenesis and sensitive to glucocorticoids.

Aqueous humour levels of cytokines are correlated to vitreous levels and severity of macular oedema in branch retinal vein occlusion

AIM

To investigate whether the aqueous levels of vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) are correlated to the vitreous levels of these substances and to the severity of macular oedema in branch retinal vein occlusion (BRVO).

METHODS

Aqueous and vitreous samples were obtained during cataract and vitreous surgery from 24 patients (24 eyes) with macular oedema in BRVO. The VEGF and IL-6 levels in aqueous humour, vitreous fluid, and plasma were determined by enzyme-linked immunosorbent assay. The degree of retinal ischaemia was evaluated in terms of the area of capillary nonperfusion using the Scion Image. The severity of macular oedema was evaluated using the OCT.

RESULTS

The aqueous level of VEGF was significantly correlated with the vitreous level of VEGF (P<0.0001). Vitreous levels of VEGF and IL-6 were significantly correlated with the nonperfusion area of BRVO (P<0.0001, P=0.0061, respectively), as were the aqueous levels of VEGF and IL-6 (P<0.0001, P=0.0267, respectively). Furthermore, the vitreous levels of VEGF and IL-6 and the aqueous level of VEGF were significantly correlated with the severity of macular oedema of BRVO (P=0.0001, P=0.0331, P=0.0272, respectively).

CONCLUSION

Our results suggest that the aqueous level of VEGF may reflect its vitreous level. Measurement of the aqueous level of VEGF may be clinically useful to indicate the severity of macular oedema with BRVO.

High glucose concentration induces elevated expression of anti-oxidant and proteolytic enzymes in cultured human retinal pigment epithelial cells

We investigated the differential protein expression patterns of retinal pigment epithelial (RPE) cells exposed to increased glucose concentrations. Cultured human RPE cells (ARPE-19) were exposed for 4 days with normal blood glucose concentration (5.5 mM D-glucose), followed by exposure to either normal (5.5 mM) or high (33 mM) concentrations of D-glucose for 48h. Protein extracts of glucose-treated RPE cells were then subjected to comparative proteome analysis based on 2-D gel electrophoresis. Protein spots were visualized by silver staining. The differentially expressed proteins were excised and digested in-gel with trypsin, then analysed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The expression levels of cathepsin B, glutathione peroxidase and heat shock protein 27 were increased, and that of protein disulfide isomerase decreased in high glucose treated RPE compared to normal glucose. The isoelectric point of copper/zinc-containing superoxide dismutase (Cu/Zn-SOD) shifted toward acidic region in response to high glucose. Cu/Zn-SOD activity in high glucose group was significantly lower than that in normal glucose group (P<0.05, Mann-Whitney U-test). Systematic survey of protein expression has revealed that RPE cells respond to acute, pathologically high glucose levels by the elevated expression of anti-oxidant and proteolytic enzymes.

A reanalysis of atomic-bomb cataract data, 2000-2002: a threshold analysis

To obtain the best statistical model for a previous study of cataract prevalence in atomic-bomb survivors, we tested the fitness of the threshold model in an updated dataset of the study, utilizing re-diagnosis by a single ophthalmologist, use of the DS02 dosimetry system, and separation of the in utero group. The results suggest that, in 730 atomic-bomb survivors, we cannot conclude thresholds are greater than 0 Sv in cortical cataract and posterior sub-capsular opacity since the lower 90% confidence limits of the thresholds were 0 Sv. Threshold dose point estimates were 0.6 Sv (90% CI, <0.0-1.2 Sv) and 0.7 Sv (90% CI, <0.0-2.8 Sv) for cortical cataract and posterior sub-capsular opacity, respectively. Detailed regression analyses with no threshold model showed that nuclear color and nuclear opacity have no dose responses (p > 0.40). Cortical cataract showed a significant dose effect (p = 0.002), with an odds ratio (OR)/Sv of 1.30 (95% CI, 1.10-1.53) and no dose-effect modifiers. Posterior sub-capsular opacity showed a significant dose effect (p < 0.001), with an OR/Sv of 1.44 at age of exposure of 10 y (95% CI, 1.19-1.73). The dose effect decreased significantly with increasing age at exposure (p = 0.022). No dose response was observed for in utero survivors (p > 0.20).

Subretinal neovascularization associated with retinochoroidal coloboma

PURPOSE

To report a case of subretinal neovascularization associated with retinochoroidal coloboma.

METHODS AND RESULTS

A 44-year-old female presented with metamorphopsia in her right eye for 4 weeks. Funduscopic examination revealed bilateral inferior retinochoroidal coloboma. Fluorescein angiography disclosed foci of subretinal neovascularization at the margin between the colobomatous defect and the normal-appearing retina. Five month later, multiple small areas of subretinal hemorrhages were noted. The hemorrhage was gradually absorbed. Six years after initial presentation, subretinal hemorrhage did not recur and her right VA was 0.2.

CONCLUSIONS

Ophthalmologists should be aware of this rare but important complication of retinochoroidal coloboma.

Neuroprotective effects of erythropoietin on glutamate and nitric oxide toxicity in primary cultured retinal ganglion cells

Erythropoietin receptor (EpoR) is expressed in the central nervous system (CNS), however, no clear consensus has been obtained whether Epo acts as a prosurvival factor in neurons. Because retinal ganglion cell (RGC) death is a common cause of reduced visual function in several ocular diseases, we explored whether Epo might potentially be beneficial in protecting RGCs from glutamate and nitric oxide (NO)-induced cytotoxicity, using isolated RGCs by a two-step panning method. Brain-derived neurotrophic factor (BDNF) was used as a positive control. EpoR mRNA was expressed in isolated RGCs, and EpoR protein was expressed on the RGCs in the normal and ischemic retinas. Epo had less potential to improve the survival of primary RGCs in serum-free medium than BDNF. In these cells, BDNF, but not Epo, downregulated the expression of Bim, a proapoptotic Bcl-2 family member that plays a key role in cytokine-mediated cell survival, suggesting a possible mechanism for this difference. When RGCs were cultured with glutamate or an NO-generating reagent, the survival of RGCs was compromised, and Bcl-2 expression was decreased in these cells. Both Epo and BDNF significantly reduced RGC death induced by glutamate and NO. In agreement with this, these factors reversed the Bcl-2 expression. These findings suggest that Epo may be a potent neuroprotective therapeutic agent for the treatment of ocular diseases that are characterized by RGC death.

Intravitreal levels of vascular endothelial growth factor and interleukin-6 are correlated with macular edema in branch retinal vein occlusion

BACKGROUND

To investigate whether vascular endothelial growth factor (VEGF) or interleukin-6 (IL-6) contributes to the pathogenesis of macular edema in eyes with branch retinal vein occlusion (BRVO), the correlations between these factors were investigated.

METHODS

We studied 25 patients suffering from macular edema with BRVO and 14 patients with nonischemic ocular disease (control group). The degree of retinal ischemia was evaluated in terms of the area of capillary nonperfusion using Scion Images, and the severity of macular edema was examined using optical coherence tomography. Vitreous fluid samples were obtained at the time of vitreoretinal surgery, and VEGF and IL-6 levels in the vitreous fluid and plasma were determined by means of enzyme-linked immunosorbent assays.

RESULTS

Vitreous fluid levels of VEGF and IL-6 were significantly elevated in patients with BRVO compared with control patients (P = 0.0011 and P < 0.0001, respectively). Also, the vitreous level of VEGF was significantly correlated with that of IL-6 (P = 0.0012), and vitreous levels of VEGF and IL-6 were correlated with the size of the BRVO nonperfusion area (P < 0.0001 and P = 0.0033, respectively). Furthermore, vitreous levels of VEGF and IL-6 were correlated with the severity of macular edema (P = 0.0008 and P = 0.0191, respectively) and the severity of macular edema of BRVO was significantly correlated with the size of the BRVO nonperfusion area (P=0.0044).

CONCLUSIONS

The levels of VEGF and IL-6 are increased in patients with macular edema with BRVO and are significantly correlated with the size of the nonperfusion area and the severity of macular edema. Therefore, they may play a role in macular edema with BRVO.

Pathogenesis of macular edema with branch retinal vein occlusion and intraocular levels of vascular endothelial growth factor and interleukin-6

PURPOSE

To determine whether correlations between vascular endothelial growth factor (VEGF) or interleukin-6 (IL-6) contribute to the pathogenesis of macular edema in eyes of patients with branch retinal vein occlusion (BRVO).

DESIGN

Retrospective case-control study.

METHODS

Nineteen patients with macular edema with BRVO and seven patients with non-ischemic ocular disease (control group) were studied. The degree of retinal ischemia was evaluated in terms of the area of capillary non-perfusion, and the severity of macular edema was examined by optical coherence tomography. Aqueous humor samples were obtained at the time of combined vitrectomy and cataract surgery, and VEGF and IL-6 levels in aqueous humor and plasma were determined by enzyme-linked immunosorbent assay.

RESULTS

Aqueous levels of VEGF (351 +/- 273 pg/ml) and IL-6 (7.10 +/- 6.51 pg/ml) were significantly elevated in patients with BRVO compared with the control patients (119 +/- 38.7 pg/ml and 2.27 +/- 1.11 pg/ml, respectively) (P = .0017 and P = .0052, respectively). Aqueous level of VEGF was significantly correlated with that of IL-6 (P = .0396), and aqueous levels of VEGF and IL-6 were correlated with the size of the BRVO non-perfused area (P < .0001 and P = .0331, respectively). Aqueous level of VEGF was correlated with the severity of macular edema (P = .0306).

CONCLUSIONS

VEGF and IL-6 may be involved in the pathogenesis of macular edema with BRVO. The increase in these cytokines might be used as a unique index of BRVO, through which we can determine the severity of the ischemic condition as being in a quiescent state or an exacerbation of macular edema.

A five-year review of patients admitted with the diagnosis of bacterial endophthalmitis

We conducted a retrospective, hospital-based study of patients who were diagnosed with bacterial endophthalmitis on admission to the Department of Ophthalmology, Hiroshima University Hospital, between January 1999 and December 2003. Thirty eyes of 30 patients were identified. Of these patients, 19 eyes had postoperative endophthalmitis, 8 eyes had penetrating trauma and 3 eyes were infected from an endogenous source. All of the patients underwent immediate three-port pars plana vitrectomy. Vitreous specimens of diabetic patients demonstrated a significantly higher incidence of positive bacterial culture. Diabetic vitreous appeared to be a good medium for culture. Visual acuity of hand motion or less at the latest follow-up visit was associated with the presence of diabetes. Prompt treatment with vitrectomy and intra-vitreal antibiotics is crucial for patients with bacterial endophthalmitis, especially if they are diabetic.

Characteristics and surgical outcomes of paediatric retinal detachment

PURPOSE

To report the clinical features and surgical and visual outcomes of rhegmatogenous retinal detachment (RRD) in the paediatric population.

METHODS

A retrospective review of children (aged 0-15 years) who underwent primary surgical repair for RRD at the Hiroshima University Hospital between 1988 and 2001.

RESULTS

In all 53 eyes of 49 patients were identified; paediatric RRD accounted for 3.1% of 1779 eyes with RRD operated on during this period. The causes of RRD included blunt trauma (27%), myopia (25%), idiopathic (20%), familial exudative vitreoretinopathy (13%), and others. Among 55 eyes, 12 (22%) already had proliferative vitreoretinopathy (PVR) of grade C or D preoperatively. The median initial visual acuity (VA) was 0.3. Retinal reattachment was achieved with a single operation in 78%. Final retinal reattachment was achieved in 87%. Retinal reattachment rates with and without PVR were 42% and 100%, respectively (P<0.01). Median final VA was 0.7. Final VA was > or =0.1 in 73% and > or =0.5 in 53%; four eyes had a final VA of no light perception. The presence of preoperative PVR (P=0.03) and the initial VA (P<0.0001) significantly affected final VA.

CONCLUSIONS

Paediatric RRD is characterised by a delay in diagnosis, as evidenced by the high rate of PVR at presentation. Retinal reattachment was adversely affected by the presence of PVR. Final VA correlated with the initial VA and was significantly affected by preoperative PVR. Early diagnosis may improve the visual prognosis of paediatric retinal detachment.

Eyelid lengthening combined with penetrating keratoplasty for exposure keratopathy in Graves' ophthalmopathy--a case report

Upper eyelid retraction is a well-known component of Graves' disease. With greater degrees of retraction, corneal exposure is usually increased. We report here on a patient with corneal perforation following exposure keratopathy due to upper eyelid retraction. The patient was treated with penetrating keratoplasty and an upper eyelid lengthening procedure using Goretex dura substitute as an interpositional graft material. The exposure keratopathy resolved postoperatively and this condition has been maintained for 45 months since the operation, with a good cosmetic outcome and symmetry of the palpebral fissures.

Improvement in cognitive impairment after cataract surgery in elderly patients

PURPOSE

To evaluate whether cognitive impairment improves in elderly patients who have cataract surgery with intraocular lens (IOL) implantation.

SETTING

Kouki Hospital, Yamaguchi, Japan.

METHODS

A prospective observational study evaluated patients' scores on the Revised Hasegawa Dementia Scale (HDS-R) and the HDS-R minus 1 item regarding immediate regeneration (ie, function of vision and memory). Twenty patients (6 men, 14 women) with cognitive impairment had cataract surgery in 1 eye between March 1996 and July 2001 at Kouki Hospital, Japan. The mean age of the patients was 81.8 years (range 61 to 90 years). Twenty patients (4 men, 16 women) with cognitive impairment who did not have cataract surgery were selected as a control. The mean age in the control group was 84.3 years (range 70 to 93 years). The HDS-R was administered twice between March 1996 and July 2001.

RESULTS

The mean HDS-R scores in the cataract surgery group improved from 12.5 points +/- 5.3 (SD) preoperatively to 16.6 +/- 6.2 points postoperatively; the improvement was significant (t = -5.02; P<.0001). After cataract surgery, the grade of cognitive impairment improved in 12 patients (60%), was unchanged in 7 (35%), and was worse in 1 (5%).

CONCLUSION

Cataract surgery improved cognitive impairment in elderly Japanese patients.

Proteome analysis of human vitreous proteins

PURPOSE

Various protein contents such as enzymes, growth factors, and structural components are responsible for biological activities in organs. We have created a map of vitreous proteins and developed a proteome analysis of human vitreous samples to understand the underlying molecular mechanism and to provide clues to new therapeutic approaches in eyes with proliferative diabetic retinopathy (PDR).

METHODS

Vitreous and serum samples were obtained from subjects with idiopathic macular hole (MH, 26 cases) and PDR (33 cases). The expressed proteins in the samples were separated by two-dimensional (2-D) polyacrylamide gel electrophoresis. Protein spots were visualized by silver staining, and their expression patterns were analyzed. Some protein spots of concern were excised from the 2-D gels, digested in situ with trypsin, and analyzed by mass spectrometry.

RESULTS

More than 400 spots were detected on 2-D gels of MH cases, of which 78 spots were successfully analyzed. The spots corresponded to peptide fragments of 18 proteins, including pigment epithelium-derived factor, prostaglandin-D2 synthase, and interphotoreceptor retinoid-binding protein. These were not identified in the corresponding serum samples. These proteins were also expressed in PDR samples, with no distinct tendency to increase or decrease compared with the MH samples. More than 600 spots were detected on 2-D gels of PDR cases, of which 141 spots were successfully analyzed. The spots corresponded to peptide fragments of 38 proteins. Enolase and catalase were identified among four detected spots. Neither was found in MH vitreous or in PDR serum samples.

CONCLUSION

A map of protein expression was made in human vitreous from eyes with MH and PDR. In the PDR eyes, the increased protein expression observed was due to barrier dysfunction and/or production in the eye. Proteome analysis was useful in systematic screening of various protein expression in human vitreous samples.

Retinal pigment epithelial tear involving the fovea with preserved visual function

Tears of the retinal pigment epithelium are known to occur either spontaneously or after laser photocoagulation in eyes with retinal pigment epithelium detachment. A 65-year-old man with preexisting retinal pigment epithelium detachment developed a retinal pigment epithelium tear after dye laser retinal photocoagulation. The tear gradually expanded to involve the fovea, but his best-corrected visual acuity remained 0.7 in the left eye during 20 months. Optical coherence tomography showed a defect of the retinal pigment epithelium with absence of regeneration. Scanning laser ophthalmoscopy revealed his fixation approached intact retinal pigment epithelium, but was still beneath the fovea. This case may indicate that the retinal pigment epithelium directly beneath the central macula is not essential for maintenance of the overlying foveal function under some conditions.

Retinal detachment in the mentally retarded

PURPOSE

To report the clinical features and surgical outcomes of retinal detachment in mentally retarded patients.

METHODS

Retrospective review of records of mentally retarded patients who had retinal reattachment surgery at the authors' institutions between February 1994 and February 2000. There were 8 patients with 13 surgically treated eyes. Demographic and clinical data were abstracted from the patients' medical records.

RESULTS

The retina of 12/13 (92%) eyes remained reattached after a follow-up ranging from 9 to 78 months. In 6 eyes of the 4 patients whose visual acuity (VA) could be determined, VA improved in 5 eyes of 3 patients. In the remaining 4 patients whose VA could not be determined, improved behavioral patterns suggesting a successful surgical outcome were observed in 3 patients with bilateral retinal detachment, although in one of these patients only unilateral retinal reattachment was achieved. The findings in the eyes in this study agree with the findings in reports on patients with traumatic retinal detachment.

CONCLUSIONS

The retinal reattachment rate is fair in the mentally retarded compared with the rate in other segments of the population. Ophthalmological examinations should be provided regularly for mentally retarded persons to keep open the possibility for early sight-improving surgery.

Severe ocular and orbital toxicity after intracarotid injection of carboplatin for recurrent glioblastomas

BACKGROUND

Glioblastoma is a malignant tumor that occurs in the cerebrum during adulthood. With current treatment regimens including combined surgery, radiation and chemotherapy, the average life expectancy of the patients is limited to approximately 1 year. Therefore, patients with glioblastoma sometimes have intracarotid injection of carcinostatics added to the treatment regimen. Generally, carboplatin is said to have milder side effects than cisplatin, whose ocular and orbital toxicity are well known. However, we experienced a case of severe ocular and orbital toxicity after intracarotid injection of carboplatin, which is infrequently reported.

CASE

A 58-year-old man received an intracarotid injection of carboplatin for recurrent glioblastomas in his left temporal lobe. He complained of pain and visual disturbance in the ipsilateral eye 30 h after the injection. Various ocular symptoms and findings caused by carboplatin toxicity were seen.

RESULTS

He was treated with intravenous administration of corticosteroids and glycerin for 6 days after the injection. Although the intraocular pressure elevation caused by secondary acute angle-closure glaucoma decreased and ocular pain diminished, inexorable papilledema and exudative retinal detachment continued for 3 weeks. Finally, 6 weeks later, diffuse chorioretinal atrophy with optic atrophy occurred and the vision in his left eye was lost.

CONCLUSION

When performing intracarotid injection of carboplatin, we must be aware of its potentially blinding ocular toxicity. It is recommended that further studies and investigations are undertaken in the effort to minimize such severe side effects.

[Effect of ultraviolet-B irradiation pretreatment on a second-set rejection model of orthotopic corneal grafts]

PURPOSE

To investigate the effect of ultraviolet-B irradiation (UV-B) on the donor cornea in a second-set rejection model of rat orthotopic corneal transplantation.

MATERIALS AND METHODS

Three patterns of fully mismatched allogeneic bilateral orthotopic corneal transplantations (DA to AO) after 10-week interval were studied: Untreated primary corneal grafts into the right eyes followed by untreated secondary grafts into the left eyes, UV-B treated primary corneal grafts into the right eyes followed by untreated secondary grafts into the left eyes, and untreated primary corneal grafts into the right eyes followed by UV-B treated secondary grafts into the left eyes.

RESULTS

The rejection of untreated secondary grafts was hastened in recipients who had previously rejected untreated primary grafts (p = 0.00507). Recipients bearing long-surviving UV-B pretreated corneal grafts rejected secondary untreated corneal grafts at the first-set tempo. Recipients who had previously rejected untreated primary grafts rejected UV-B pretreated secondary grafts at the first-set tempo.

CONCLUSIONS

The UV-B pretreatment to donor corneas may induce dysfunction of antigen presentation so that the recipients' immune system fails to be sensitized in second-set phenomena.

Growth regulation of bovine retinal pericytes by transforming growth factor-beta2 and plasmin

PURPOSE

Transforming growth factor -beta2 (TGF-beta2) is a predominant isoform of TGF-betas in the eye and plasmin is a peptidase with many functions. To better understand the pathogenesis of retinal microcirculation disorders, the effects of TGF-beta2 and plasmin on cultured bovine retinal pericytes were investigated.

METHODS

Exogenous TGF-beta2 or plasmin was added to some cultures, DNA synthesis during cell cycle progression was investigated using [(3)H]thymidine incorporation. Anti-TGF-beta2 antibody was added to neutralize the effects of TGF-beta2. TGF-beta2 in the culture medium was measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Exogenous TGF-beta2 (10 pg to 100 ng/mL) suppressed DNA synthesis. Pericytes produced TGF-beta2. Anti-TGF-beta2 antibody neutralized TGF-beta2 and accelerated DNA synthesis, which shows that pericytes regulate their own cell cycle by action of the autocrine and/or paracrine system of TGF-beta2. Plasmin (0.2 to 0.5 U/mL) accelerated DNA synthesis in a dose-dependent manner, while addition of aprotinin, a protease inhibitor, counteracted this effect of plasmin. The concentration of TGF-beta2 in the culture medium decreased with the addition of plasmin. Simultaneous addition of both plasmin and anti-TGF-beta2 antibody accelerated DNA synthesis. High and low glucose concentrations of the culture medium did not affect DNA synthesis.

CONCLUSIONS

Our results suggest that TGF-beta2 and plasmin respectively decrease and increase DNA synthesis. In a retinal microcirculation disorder, they may play competitive roles in the cell cycle of pericytes.

Involvement of CD8+ RT1.B+ and CD4+ RT1.B+ cells of cervical lymph nodes in the immune response after corneal transplantation in the rat

Graft rejection reactions have been observed with concomitant lymphocyte infiltrations after allogenic corneal transplantation, although the cornea is considered to be relatively protected from the systemic immune response. In order to characterize the lymphocytes that accumulate in cervical lymph nodes following transplantation, we used a model of orthotopic penetrating keratoplasty in inbred rats. After grafting, the time course of the pathological scoring was monitored, and subpopulations of CD4+ RT1.5+ and CD8+ RT1.B+ cells were analyzed in the cells harvested from the cervical lymph nodes. The number of CD8+RT1.B+ cells increased 1 week after grafting, reaching the maximum at 3 weeks; whereas CD4+ RT1.B+ cells were induced 1 week after the grafting and remained constant during the next 3 weeks. There were four times as many CD4+ RT1.B+ cells as CD8+ RT1.B+ cells 1 week after grafting when there was no rejection. Therefore, it appears that CD8+RT1.B+ and CD4+RT1.B+ cells in the cervical lymph nodes do participate in ocular immunologic responses.

Ultrasound biomicroscopy in the diagnosis of persistent hypotony after vitrectomy

PURPOSE

To describe a case of persistent hypotony after an otherwise successful vitreous surgery for epiretinal membrane, in which ciliochoroidal detachment was detected by ultrasound biomicroscopy but not by ophthalmoscopy.

METHOD

We used ultrasound biomicroscopy to determine the cause of persistent postoperative hypotony.

RESULTS

Ultrasound biomicroscopy clearly disclosed ciliochoroidal detachment. In an attempt to resolve ciliochoroidal detachment, we performed vitrectomy and fluid-gas exchange combined with diathermy around the sites of sclerotomy. Postoperatively, the regression of ciliochoroidal detachment was confirmed by ultrasound biomicroscopy.

CONCLUSIONS

Using ultrasound biomicroscopy, we were able to visualize ciliochoroidal detachment and its regression clearly, which we had not observed during ophthalmoscopy.

Postoperative posterior retinal holes after pars plana vitrectomy for primary retinal detachment

BACKGROUND

Although retinal breaks occur frequently during vitrectomy, the postoperative occurrence of new retinal holes close to the vascular arcade after vitrectomy for rhegmatogenous retinal detachment rarely has been reported.

METHODS

Three patients with rhegmatogenous, retinal detachment were treated by vitrectomy. More than 49 days after vitrectomy, posterior retinal holes with no retinal detachment occurred halfway between the vascular arcade and the chorioretinal scar around the extrusion hole or the primary retinal tear.

RESULTS

These new holes were effectively managed with photocoagulation.

CONCLUSION

New hole formation could be caused by the technique of the internal drainage, the contraction of the photocoagulation scar, or epiretinal membrane contraction. Another possibility is that new holes occur through two opposite tangential traction contractile forces: one induced by the contraction of the photocoagulation scar, the other caused by the contraction of the premacular cortical vitreous attached to the vascular arcade.

Effect of FK 506 administered topically versus intramuscularly on suppression of the corneal immune reaction in rats

The immunosuppressive effect of FK 506 on penetrating keratoplasty in rats was evaluated following intramuscular and topical administration. Implanted corneal grafts were inspected weekly by clinical evaluation for 3 weeks. Cytotoxic T lymphocyte (CTL) activity was measured in the spleen on postoperative day 21, and the grafts were examined histologically. A dose of FK 506, 0.1 mg/kg given intramuscularly, only moderately suppressed CTL activity and the graft failed. In contrast, doses of either 0.024 mg/day topically or 0.3 mg/kg intramuscularly suppressed CTL activity and the grafts remained intact. Results suggest that FK 506 administered topically would be effective in preventing failure of human corneal grafts.

Computerized tomography of two patients with morning glory syndrome

Morning glory syndrome (MGS), an uncommon optic disc anomaly, is characterized by a funnel-shaped, excavated optic disc surrounded by chorioretinal pigmentary disturbance. Generally, it is an isolated ocular abnormality. The authors describe two patients in whom MGS developed in association with brain abnormalities. In both cases, there was enlargement of the optic nerve that showed increased radiodensity similar to that of sclera and cavum vergae in the brain cavity present in computerized tomography (CT). To our knowledge, the coexistence of MGS, cavum vergae and an enlarged retrobulbar optic nerve showing increased radiodensity have not been previously reported. The findings suggest that MGS may be based on a developmental anomaly involving the brain, and the enlarged optic nerve may be associated with sclera because of the isodensity in CT.

Induction of cytotoxic T lymphocytes from splenocytes after orthotopic penetrating keratoplasty in the rat

We used a rat model of orthotopic penetrating keratoplasty to study splenic cell cytotoxicity in the host. DA (RT1avl) rats received grafts of Fischer (F344, RT1lv1) rat corneas. Cytotoxic T lymphocyte (CTL) activity was measured by the cell-mediated lymphocytotoxicity assay using 4/4R.M.-4 cells as target cells. CTL activity became detectable in vitro 2 weeks after grafting and peaked at 3 weeks. This simple method of quantifying CTL activity in the orthotopic penetrating keratoplasty model should provide a reliable tool for studying the CTL response in corneal transplantation.