Occult retinal neovascularization following intravitreal bevacizumab and laser treatment for retinopathy of prematurity

BACKGROUND

We present a patient with retinopathy of prematurity (ROP) who developed worsening plus disease after complete regression of stage 3 ROP. The use of fundus fluorescein angiography (FFA) aided the visualization of occult neovascularization that caused the disease progression.

CASE PRESENTATION

The patient was at high risk for ROP due to low birth weight of 690 g and gestational age of 25 weeks. After the diagnosis of stage 3 ROP in zone I without plus disease, she was treated initially with bilateral intravitreal bevacizumab (IVB) and followed by laser photocoagulation 5 weeks later. Despite the resolution of ROP stage, the plus disease worsened. Neither systemic risk factors nor skip laser areas were observed. Hence, FFA was performed and subsequently identified occult neovascularization with active leakage. Additional IVB and laser treatment in the capillary dropout area inside vascularized retina were added. The plus disease improved but mild arteriolar tortuosity persisted.

CONCLUSIONS

Worsening of plus disease after completion of laser ablation and IVB with complete regression of stage 3 ROP is rare. Systemic risk factors such as continuous oxygen therapy and cardiovascular disease should be ruled out. FFA aided in identifying occult neovascularization and prompted further treatment.

Risk factor-based models to predict severe retinopathy of prematurity in preterm Thai infants

PURPOSE

To develop prediction models for severe retinopathy of prematurity (ROP) based on risk factors in preterm Thai infants to reduce unnecessary eye examinations in low-risk infants.

METHODS

This retrospective cohort study included preterm infants screened for ROP in a tertiary hospital in Bangkok, Thailand, between September 2009 and December 2020. A predictive score model and a risk factor-based algorithm were developed based on the risk factors identified by a multivariate logistic regression analysis. Validity scores, and corresponding 95% confidence intervals (CIs), were reported.

RESULTS

The mean gestational age and birth weight (standard deviation) of 845 enrolled infants were 30.3 (2.6) weeks and 1264.9 (398.1) g, respectively. The prevalence of ROP was 26.2%. Independent risk factors across models included gestational age, birth weight, no antenatal steroid use, postnatal steroid use, duration of oxygen supplementation, and weight gain during the first 4 weeks of life. The predictive score had a sensitivity (95% CI) of 92.2% (83.0, 96.6), negative predictive value (NPV) of 99.2% (98.1, 99.6), and negative likelihood ratio (NLR) of 0.1. The risk factor-based algorithm revealed a sensitivity of 100% (94, 100), NPV of 100% (99, 100), and NLR of 0. Similar validity was observed when "any oxygen supplementation" replaced "duration of oxygen supplementation." Predictive score, unmodified, and modified algorithms reduced eye examinations by 71%, 43%, and 16%, respectively.

CONCLUSIONS

Our risk factor-based algorithm offered an efficient approach to reducing unnecessary eye examinations while maintaining the safety of infants at risk of severe ROP. Prospective validation of the model is required.

Validation of the postnatal growth and retinopathy of prematurity (G-ROP) screening criteria in a Thai cohort

PURPOSE

To validate Postnatal Growth and Retinopathy of Prematurity (G-ROP) criteria for Thai infants.

STUDY DESIGN

A retrospective review of infants receiving ROP screening during 2009-2020.

METHODS

Baseline characteristics, clinical progression and final ROP outcomes were collected. G-ROP was applied to infants who met at least one of the following 6 criteria: birth weight (BW) below 1051 g, gestational age (GA) under 28 weeks, weight gain (WG) less than 120 g during postnatal day 10-19, WG less than 180 g during day 20-29, WG less than 170 g during day 30-39 and hydrocephalus.

RESULTS

A total of 684 infants (boys, 53.4%) were included. Median (IQR) BW was 1200 (960-1470) grams and median GA was 30 (28-32) weeks. Prevalence of ROP was 26.6%, with 28 (4.1%) having type 1, 19 (2.8%) type 2 and, 135 (19.7%) having other ROP. Treatment was performed in 26 infants (3.8%). Sensitivity of G-ROP to include type 1, 2 or treatment-requiring ROP cases was 100% with 36.9% specificity, excluding 235 (34.4%) cases of unnecessary screening. To adjust for our setting of initial eye examination at 4 weeks' postnatal date, the last 2 criteria of G-ROP were replaced by the occurrence of grade 3 or 4 intraventricular hemorrhage (IVH). This modified G-ROP criteria yielded 100% sensitivity, 42.5% specificity and excluded 271 (39.6%) cases of unnecessary screening.

CONCLUSION

G-ROP criteria can be applied to our hospital setting. Occurrence of IVH grade 3 or 4 was proposed as an alternative in modified G-ROP criteria.

A generation of human-induced pluripotent stem cell line (MUi032-A) from a Choroideremia disease patient carrying a hemizygous mutation on the CHM gene

Choroideremia (CHM) is a monogenic, X-linked inherited retinal disease caused by mutations in the CHM gene. CHM patients develop progressive loss of vision due to degeneration of cell layers in the retina. In this report, the human-induced pluripotent stem cell, MUi032-A, was generated from CD34+ hematopoietic stem/progenitor cells of a male CHM patient by co-electroporation of non-integration episomal vectors containing OCT4/shp53, Sox-2/KLF4, and L-MYC/LIN-28. The MUi032-A showed normal karyotype and a hemizygous c.715C > T mutation. They expressed pluripotency markers and differentiated into cells derived from three germ layers. This cell line may be useful for disease mechanisms and gene therapy studies.

Effect of surgical simulation training on the complication rate of resident-performed phacoemulsification

Objective

To study the effect of additional training with ophthalmic surgical simulation on the intraoperative complication rates of phacoemulsification performed by residents.

Methods and materials

This was a retrospective study of phacoemulsification surgeries performed by third-year residents at Siriraj Hospital. The operations were classified into two groups according to the experience of the surgeon in simulation training, that is, trained vs untrained. The main outcome was the total rate of complications. Other outcomes, including posterior capsule rupture, anterior capsulorhexis tearing, zonular dehiscence, retaining of lens material and intraocular lens (IOL) implantation methods, were also analysed.

Results

In total, 2971 operations were performed, comprising 1656 operations by 21 residents in the trained group, and 1315 by 20 residents in the untrained group. The total rate of complications in the simulator-trained group was lower than in the untrained group (13.6% vs 17.3%, p=0.005). Only the rate of retaining lens material showed a statistically significantly reduction (p<0.001); however, the rates of posterior capsule rupture, anterior capsulorhexis tearing and zonular dehiscence were not significantly different (p=0.08, 0.17, 0.23, respectively). The IOL implantation methods and surgical aphakia rate between the two groups were similar (p=0.44). In the subgroup analysis, the posterior capsule rupture rate in the first half of all cases performed by the residents was lower in the trained group (8.8% vs 12.4%, p=0.02).

Conclusion

Ophthalmic simulation training reduces the total rate of complications of resident-performed phacoemulsification. It also shortens the learning curve for cataract surgery training, as indicated by the decreased posterior capsule rupture rate in the initial cases of cataract surgery.

Epidemiology of Pediatric Open Globe Injuries in a University Hospital in Thailand

Objective: To describe the epidemiology, clinical characteristics, and clinical outcomes of pediatric traumatic open globe injuries and to determine the risk factors for poor visual outcome.

Methods: The medical records of patients aged younger than 15 years of age who were diagnosed with open globe injuries from January 2005 to December 2015 were retrospectively reviewed. The patients’ demographic data were collected, including age, sex, injury date, place of injury, mechanism of injury, cause of injury, and the activity related to the injury. Clinical data were recorded, including initial visual acuity (VA), wound size, wound location, associated ocular findings at presentation, and complications. The prognostic factors for a poor visual outcome were assessed.

Results: In total, 46 pediatric patients were included in this study. The mean age was 6.8 years old. Most patients were male (65.2%). The most common type of injury was penetrating injury (60.9%) and mostly occurred during playing (60.9%). Household appliances/furniture and scissors/knives were common causes of injuries (17.4%, 15.2%, respectively). Poor final VA worse than 6/60 was found in 17 patients (37%). Wound location and retinal detachment (RD) at the time of presentation were significant prognostic factors for a poor visual outcome according to the univariate analysis (p = 0.008, <0.001). Only wound location at zone II and III was found to be significantly correlated with poor final VA in the multivariate analysis (adjusted risk ratio (RR) = 2.87, 95% confidence interval (CI), 1.26-6.55, p = 0.012). Traumatic cataract was the most common associated injury (45.7%).

Conclusions: One-third of pediatric patients with open globe injuries had a poor visual outcome. Wound location at zone II and III significantly correlated with a poor visual outcome in pediatric open globe injuries. The parents and caregivers should be made aware of the seriousness of open globe injuries in order to prevent children from possible injuries.

Rare Co-Occurrence of Visual Snow in a Female Carrier With RPGRORF15-Associated Retinal Disorder

X-linked retinitis pigmentosa (XLRP), a rare form of retinitis pigmentosa (RP), is predominantly caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene. Affected males often present with severe phenotypes and early disease onset. In contrast, female carriers are usually asymptomatic or show stationary phenotypes. Herein, we reported an 8-year-old female carrier, a daughter of a confirmed RP father with RPGR mutation, with an early onset of progressive cone-rod pattern retinal dystrophy. Additionally, the carrier experienced visual snow-like symptom as long as she recalled. Ophthalmological examination showed the reduction of visual acuity and attenuation of photoreceptor functions since the age of 5 years. Further analysis revealed a heterozygous pathogenic variant of the RPGR gene and a random X-inactivation pattern. Although she harboured an identical RPGR variant as the father, there were phenotypic intrafamilial variations. The information on the variety of genotypic and phenotypic presentations in XLRP carriers is essential for further diagnosis, management, and monitoring of these cases, including the design of future gene therapy trials.

Autoantibody profiles and clinical association in Thai patients with autoimmune retinopathy

Autoimmune retinopathy (AIR) is a rare immune-mediated inflammation of the retina. The autoantibodies against retinal proteins and glycolytic enzymes were reported to be involved in the pathogenesis. This retrospective cohort study assessed the antiretinal autoantibody profiles and their association with clinical outcomes of AIR patients in Thailand. We included 44 patients, 75% were females, with the overall median age of onset of 48 (17-74, IQR 40-55.5) years. Common clinical presentations were nyctalopia (65.9%), blurred vision (52.3%), constricted visual field (43.2%), and nonrecordable electroretinography (65.9%). Underlying malignancy and autoimmune diseases were found in 2 and 12 female patients, respectively. We found 41 autoantibodies, with anti-α-enolase (65.9%) showing the highest prevalence, followed by anti-CAII (43.2%), anti-aldolase (40.9%), and anti-GAPDH (36.4%). Anti-aldolase was associated with male gender (P = 0.012, OR 7.11, 95% CI 1.54-32.91). Anti-CAII showed significant association with age of onset (P = 0.025, 95% CI - 17.28 to - 1.24), while anti-α-enolase (P = 0.002, OR 4.37, 95% CI 1.83-10.37) and anti-GAPDH (P = 0.001, OR 1.87, 95% CI 1.32-2.64) were significantly associated with nonrecordable electroretinography. Association between the antibody profiles and clinical outcomes may be used to direct and adjust the treatment plans and provide insights in the pathogenesis of AIR.

Clinical outcomes and prognosis of Thai retinoblastoma patients

BACKGROUND

Retinoblastoma (RB) outcomes in Thailand are unfavorable compared to those of developed countries. This study aims to determine whether the clinical outcomes of patients with RB significantly improved after the implementation of new therapeutic approaches and which clinical factors affect survival and globe-saving outcomes.

METHODS

The medical records of patients newly diagnosed with RB and treated at Siriraj Hospital between January 2005 and December 2018 were reviewed retrospectively. Clinical data, treatments, and outcomes were collected and analyzed.

RESULTS

In 194 eyes (144 patients), leukocoria was the most common presenting feature (76.8%); 129 (66.5%) eyes were staged in group E of the International Classification of Intraocular Retinoblastoma. Of the 149 enucleated eyes, 35 had high-risk histopathological features, mostly choroidal invasion; 45 eyes (23.2%) could be salvaged. The 5-year overall survival rate was 90.3%, an improvement compared to the previous study. The 5-year enucleation-free survival rates of Groups A and B, C, D and E were 100%, 83.1%, 36.7% and 16.6% respectively. Factors associated with a lower survival rate were interval from symptom onset to diagnosis >3 months (hazard ratio (HR): 5.8: 95% confidence interval (CI): 1.637, 20.579) and buphthalmos (HR: 12.57: 95% CI: 3.936, 40.153). Factors associated with high-risk features were secondary glaucoma (HR: 11.016: 95% CI: 1.24, 98.10) and pseudohypopyon (HR: 14.110: 95% CI: 2.16, 92.05).

CONCLUSIONS

Survival rates and globe-saving rates appear to have improved; however, advanced-stage presentation remains the major hindrance. Further studies with a larger cohort and longer follow-up are warranted.

GD2-specific chimeric antigen receptor-modified T cells targeting retinoblastoma - assessing tumor and T cell interaction

A novel disialoganglioside 2 (GD2)-specific chimeric antigen receptor (CAR)-modified T cell therapy against retinoblastoma (RB) were generated. GD2-CAR consists of a single-chain variable fragment (scFv) derived from a monoclonal antibody, hu3F8, that is linked with the cytoplasmic signaling domains of CD28, 41BB, a CD3ζ, and an inducible caspase 9 death fusion partner. GD2 antigen is highly expressed in Y79RB cell line and in several surgical RB tumor specimens. In vitro co-culture experiments revealed the effective killing of Y79RB cells by GD2-CAR T cells, but not by control CD19-CAR T cells. The killing activities of GD2-CAR T cells were diminished when repeatedly exposed to the tumor, due to an attenuated expression of GD2 antigen on tumor cells and upregulation of inhibitory molecules of the PD1 and PD-L1 axis in the CAR T cells and RB tumor cells respectively. This is the first report to describe the potential of GD2-CAR T cells as a promising therapeutic strategy for RB with the indication of potential benefit of combination therapy with immune checkpoint inhibitors.

Intravitreal autologous mesenchymal stem cell transplantation: a non-randomized phase I clinical trial in patients with retinitis pigmentosa

Background

Retinitis pigmentosa (RP) is a progressive inherited retinal disease with great interest for finding effective treatment modalities. Stem cell-based therapy is one of the promising candidates. We aimed to investigate the safety, feasibility, and short-term efficacy of intravitreal injection of bone marrow-derived mesenchymal stem cells (BM-MSCs) in participants with advanced stage RP.

Methods

This non-randomized phase I clinical trial enrolled 14 participants, categorized into three groups based on a single dose intravitreal BM-MSC injection of 1 × 10⁶, 5 × 10⁶, or 1 × 10⁷ cells. We evaluated signs of inflammation and other adverse events (AEs). We also assessed the best corrected visual acuity (BCVA), visual field (VF), central subfield thickness (CST), and subjective experiences.

Results

During the 12-month period, we noticed several mild and transient AEs. Interestingly, we found statistically significant improvements in the BCVA compared to baseline, although they returned to the baseline at 12 months. The VF and CST were stable, indicating no remarkable disease progression. We followed 12 participants beyond the study period, ranging from 1.5 to 7 years, and observed one severe but manageable AE at year 3.

Conclusion

Intravitreal injection of BM-MSCs appears to be safe and potentially effective. All adverse events during the 12-month period required observation without any intervention. For the long-term follow-up, only one participant needed surgical treatment for a serious adverse event and the vision was restored. An enrollment of larger number of participants with less advanced RP and long-term follow-up is required to evaluate the safety and efficacy of this intervention.

Trial registration

ClinicalTrials.gov, NCT01531348. Registered on February 10, 2012

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-020-02122-7.

Molecular and clinical characterization of Thai patients with achromatopsia: identification of three novel disease-associated variants in the CNGA3 and CNGB3 genes

PURPOSE

Achromatopsia (ACHM) is an autosomal recessive cone disorder characterized by pendular nystagmus, photophobia, reduced visual acuity, and partial or total absence of color vision. Mutations in six genes (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6) have been reported in ACHM. There is no information on these disease-associated genes in Thai population. This study aimed to investigate the molecular and clinical characteristics in Thai patients with ACHM.

METHODS

Seven unrelated Thai patients with ACHM were recruited. Detailed ophthalmologic examination was performed. Polymerase chain reaction (PCR)-coupled single-strand conformation polymorphism (SSCP) screening followed by Sanger sequencing was used to identify sequence variants in all exons and splice junctions of three genes (CNGA3, CNGB3, and GNAT2). The pathogenicity of the detected variants was interpreted. Segregation analysis was performed to determine variant sharing in available family members.

RESULTS

Four patients displayed different SSCP migration patterns. Sequence analysis revealed a reported pathogenic and a novel disease-associated variant in the CNGA3 gene. For the CNGB3 gene, we found two novel disease-associated variants and a reported variant of uncertain significance (VUS). Segregation analysis confirmed that the variants identified in each patient were present in the heterozygous state in their corresponding family members, which was consistent with an autosomal recessive mode of inheritance.

CONCLUSIONS

This study demonstrated the first molecular and clinical characterization of ACHM in Thai patients. The identification of disease-associated genes in a specific population leads to a personalized gene therapy benefiting those affected patients.

Global Retinoblastoma Presentation and Analysis by National Income Level

Importance

Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale.

Objectives

To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis.

Design, Setting, and Participants

A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017.

Main Outcomes and Measures

Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis.

Results

The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]).

Conclusions and Relevance

This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs.

Outcomes of pediatric retinoblastoma treated with ICEV regimen: A single-center study

Retinoblastoma is the most common intraocular malignancy in children. The aim of this study was to investigate the efficacy and toxicity of combination ifosfamide, carboplatin, etoposide, and vincristine (ICEV) in advanced-stage pediatric retinoblastoma [International Classification of Retinoblastoma (ICRB) group D or E], and in ICRB group C in the second eye in simultaneously treated bilateral retinoblastoma. The medical records of retinoblastoma patients treated with concurrent ICEV regimen and focal therapy were retrospectively reviewed. The ICEV treatment protocol was, as follows: ifosfamide 1800 mg/m² on Days 1-3; MESNA 600 mg/m² on Days 1-3; carboplatin 560 mg/m² on Day 1; etoposide 150 mg/m² on Days 1-3; and vincristine 1.5 mg/m² on Day 1. Of 16 retinoblastoma patients, 13 had bilateral disease. Seven first eyes in bilateral disease that were enucleated prior to ICEV therapy were excluded. Twenty-two eyes were finally included (six group C, six group D, and ten group E). Median follow-up was 3.4 years, and the median number of ICEV courses was 7. Fifteen globes could be salvaged, 12 responded to ICEV (six group C, five group D, and one group E), and three unresponsive eyes could be salvaged with external beam radiation therapy (EBRT). Enucleation-free and relapse-free survival was 68.2 and 54.5%, respectively. The results of this study suggest ICEV as an alternative therapeutic approach for globe salvage in pediatric retinoblastoma, especially in ICRB groups C and D with manageable acute toxicity. Further study in larger cohort is needed to confirm the effectiveness of treatment.

Whole Exome Sequencing in Eight Thai Patients With Leber Congenital Amaurosis Reveals Mutations in the CTNNA1 and CYP4V2 Genes

Purpose

Our goal was to describe the clinical and molecular genetic findings in Thai patients with Leber congenital amaurosis (LCA).

Methods

Whole exome sequencing (WES) was performed in eight unrelated patients. All genes responsible for inherited retinal diseases (IRDs) based on RetNet were selected for analysis. Potentially causative variants were filtered through a bioinformatics pipeline and validated using Sanger sequencing. Segregation analysis of the causative genes was performed in family members when available.

Results

Eleven deleterious variants, six nonsense and five missense, were identified in seven genes: four LCA-associated genes (CEP290, IQCB1, NMNAT1, and RPGRIP1), one gene responsible for syndromic LCA (ALMS1), and two IRDs-related genes (CTNNA1 and CYP4V2). Clinical reassessment supported the diagnosis of syndromic LCA in those patients harboring potentially pathogenic variants in the ALMS1. Interestingly, two causative genes, CTNNA1 and CYP4V2, previously reported to cause butterfly-shaped pigment dystrophy (BSPD) and Bietti's crystalline dystrophy (BCD), respectively, were detected in two other patients. These two patients developed rapid and severe visual loss in contrast to BSPD and BCD patients in previous studies. The results of this study demonstrate that causative variants identified in the CTNNA1 and CYP4V2 genes are also associated with LCA.

Conclusions

This is the first report describing the molecular genetics and clinical manifestations of Thai patients with LCA. The present study expands the spectrum of LCA-associated genes, which is a benefit for molecular diagnosis. The identification of mutations in the CTNNA1 and CYP4V2 genes requires further elucidation in larger cohorts with LCA.

Treatment of epidemic keratoconjunctivitis with 2% povidone-iodine: a pilot study

PURPOSE

The purpose of this study was to analyze the outcome of treating epidemic keratoconjunctivitis (EKC) with 2% povidone-iodine (PVP-I) solution.

METHODS

A prospective, interventional, uncontrolled study was performed in participants diagnosed with EKC. PVP-I was applied to the affected eyes 4 times a day for a week. Participants were informed about transient eye stinging and discoloration after application. Drug discontinuation was allowed for early recovery or encountering any adverse effects. Data collection included history, symptoms, and signs at the initial presentation and at 1 week. Main outcomes were the recovery rate within a week of treatment and drug tolerability.

RESULTS

Of 172 enrolled, 61 participants completed the study. EKC occurred bilaterally in 40 participants (66%). Single eye from each participant was included for analysis. The mean (standard deviation) time elapsed before treatment was 2.1 (1.46) days. The recovery rate within a week of treatment was 77% (95% confidence interval, 65.1-85.8). Twenty-eight participants (45.9%) recovered within a week after the onset. Application of PVP-I was sustained until recovery or completing a 7-day trial in 78.7%. No severe ocular or systemic adverse effects have been reported related to this treatment.

CONCLUSIONS

Ocular application of 2% PVP-I was tolerable. This measure successfully relieved ocular discomfort from EKC in 3 quarters of the study group within a week. A randomized, controlled trial is required to verify the benefit of this measure.

Novel and De-novo TruncatingPAX6Mutations and Ocular Phenotypes in Thai Aniridia Patients

PURPOSE

To describe the ophthalmic findings and mutation analyses of the PAX6 gene in Thai aniridia patients.

METHODS

Ten patients from six unrelated families underwent a comprehensive ophthalmic examination. Mutations in the PAX6 gene were screened by single-strand conformational polymorphism (SSCP) and direct DNA sequencing of the SSCP variants.

RESULTS

Seven patients developed cataracts and six developed glaucoma. Mutation analysis demonstrated four different truncating mutations, two of which were de novo. These included one novel insertion/deletion mutation (c.474del12insGA in exon 5) and three nonsense mutations. R203X and R240X are common recurrent mutations, while Q277X in exon 10 is novel. All mutations resulted in loss of function of the PAX6 protein.

CONCLUSION

Our data confirm inter- and intrafamilial variable phenotypic manifestations of which the underlying mechanisms may be haploinsufficiency or dominant-negative mutation.

A novel H572R mutation in the transforming growth factor-beta-induced gene in a Thai family with lattice corneal dystrophy type I

PURPOSE

To describe a large Thai family with lattice corneal dystrophy (LCD) type I and to determine whether this LCD is associated with mutations within the transforming growth factor-beta-induced (TGFBI) gene.

METHODS

A six-generation family with LCD type I was identified and diagnosed on the basis of clinical and/or histopathologic evaluation. Visual acuity testing and slit-lamp biomicroscopic evaluation were carried out and corneal photography was documented. All 17 exons and flanking intron sequences of the TGFBI gene were sequenced.

RESULTS

Thirty-three participants demonstrated LCD in both eyes, most of which was symmetrical. Age at onset of decreased vision was the mid- to late twenties. Visual acuity varied from 6/6 to no light perception. Two patients, 74 and 42 years of age, demonstrated a thick yellowish plaque covering the corneal surfaces. DNA sequencing revealed a heterozygous mutation in exon 13 (A1762G), changing histidine to arginine at codon 572 (H572R). Ten of 42 clinically unaffected family members, all under 25 years of age, exhibited the same mutation.

CONCLUSIONS

This is the first report of a molecular analysis of LCD type I in Thai patients. The novel mutation identified is associated with distinct phenotypes and later onset of the disease compared with the more common R124C mutation.

The unique characteristics of Thai Leber hereditary optic neuropathy: analysis of 30 G11778A pedigrees

Leber hereditary optic neuropathy (LHON) is characterized by acute or subacute bilateral visual loss, and affects mostly young males. The most common mitochondrial DNA mutation responsible for LHON worldwide is G11778A. Despite different genetic backgrounds, which are believed to influence the disease expression, most features of LHON are quite common in different populations. However, there seem to be a few ethnic-specific differences. Analyses of our 30 G11778A LHON pedigrees in Thailand showed some characteristics different from those of Caucasians and Japanese. In particular, our pedigrees showed a lower male to female ratio of affected persons (2.6:1) and much higher prevalence of G11778A blood heteroplasmy (37% of the pedigrees contained at least one heteroplasmic G11778A individual). Heteroplasmicity seemed to influence disease manifestation in our patients but did not appear to alter the onset of the disease. The estimated overall penetrance of our G11778A LHON population was 37% for males and 13% for females. When each of our large pedigrees were considered separately, disease penetration varied from 9 to 45% between the pedigrees, and also varied between different branches of the same large pedigree. Survival analysis showed that the secondary LHON mutations G3316A and C3497T had a synergistic deleterious effect with the G11778A mutation, accelerating the onset of the disease in our patients.

Anticardiolipin IgG antibody and homocysteine as possible risk factors for retinal vascular occlusive disease in thai patients

PURPOSE

To assess the role of serum anticardiolipin IgG antibody and fasting plasma homocysteine levels as risk factors for retinal vascular occlusive disease in Thai patients.

METHODS

This is a retrospective, case-control study. Forty-one consecutive patients with recent onset of retinal vascular occlusive diseases were enrolled. In conjunction with a routine laboratory work up, serum anticardiolipin IgG antibody and plasma homocysteine were evaluated. Ninety volunteers without a history of retinal vascular occlusive disease were chosen as controls.

RESULTS

In general, mean levels of anticardiolipin IgG antibody and homocysteine did not differ between the patients and controls. However, when the groups without a history of underlying systemic diseases were compared, there were statistically significant differences in the anticardiolipin IgG antibody level between patients and controls (mean 12.24 +/- 8.66 and 7.70 +/- 6.69 GPL units/ml, respectively) with a P value of 0.024.

CONCLUSIONS

No association was found between plasma homocysteine level and retinal vascular occlusion in our patient population. A high level of anticardiolipin IgG antibody is shown to be a risk factor only in patients without a history of underlying systemic diseases. The effect of anticardiolipin IgG antibody on the development of retinal vascular occlusive disease appears to be limited and may not be a major cause.

Value of electrodiagnostic assessment in nonsyndromic microcephaly

PURPOSE

To evaluate the value of electroretinogram (ERG) and visual evoked potentials (VEP) in children with nonsyndromic microcephaly.

METHODS

In this observational case series, six children with nonsyndromic microcephaly aged 8.5 to 158 months were examined. Main outcome measures included the amplitude of the flash ERG (photopic, flickering, scotopic, and dark-adapted responses), the amplitude and latency of the VEP (flash or pattern-reversal stimulus), visual acuity, slit-lamp biomicroscopy, and indirect ophthalmoscopy.

RESULTS

Three children demonstrated normal fundus appearances, ERG, and VEP responses: two in this group demonstrated poor vision and brain computed tomography in the third showed schizencephaly. The remaining three children demonstrated abnormal ERG with predominant reduction in photopic amplitudes. Retinal pigmentary granularities were detected in two children in this group, one of whom has poor vision, generalized brain atrophy, and 40% reduction in VEP amplitudes.

CONCLUSIONS

Abnormal ERG is not uncommon among children with nonsyndromic microcephaly. Although cone photoreceptors are affected more than rods, this does not anticipate poor vision. It appears that defects in posterior visual pathway or developmental malformations of the brain should be responsible for poor visual function in nonsyndromic microcephaly.

Comparison of topical prednisolone acetate, ketorolac tromethamine and fluorometholone acetate in reducing inflammation after phacoemulsification

AIMS

To compare the efficacy and ocular adverse effects of topical prednisolone acetate, ketorolac tromethamine, and fluorometholone acetate in reducing inflammation after phacoemulsification.

METHOD

One hundred and twenty eyes were enrolled in a prospective, investigator-masked, randomized controlled trial. Each drug was prescribed 4 times a day for 28 days. The following data were recorded weekly: visual acuity, intraocular pressure, slit lamp biomicroscopy, grading of cells and flare in the anterior chamber, and ocular symptoms.

RESULTS

The number of eyes with a minimal amount of cells in the anterior chamber in the ketorolac group was less than the prednisolone group on day 7 (11:20, p = 0.008) and day 14 (23:31, p = 0.015), and than fluorometholone group on day 7 (11:21, p = 0.011). Intraocular pressure in the prednisolone group was higher than the ketorolac group on day 21 (14.6:12.2 mmHg, p = 0.016). One eye in the prednisolone group had intraocular pressure of 32 mmHg. Burning sensation was reported frequently in the ketorolac group.

CONCLUSION

All 3 drugs were effective in reducing post-operative inflammation. The efficacy of prednisolone acetate and fluorometholone acetate was comparable. Ketorolac tromethamine showed less efficacy than corticosteroids, however, it did not induce ocular hypertension.

Childhood onset myasthenia gravis

The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MGS). In all cases, the diagnosis was confirmed by a combination of clinical examination and Neostigmine test. The majority (92%) had localized ocular myasthenia with median onset of symptoms at 33 months of age. About 24 per cent of them progressed to generalized MGS. A few (8%) presented with respiratory failure that required ventilatory support with onset of symptoms at about 22 months. Thymectomy was performed in 10 cases. Complete and partial remissions were achieved in about 70 per cent and 26 per cent of cases respectively with the combination of an immunosuppressant (azathioprine) and a Cholinesterase inhibitor (pyridostigmine). None experienced a myasthenic crisis with proper management and good follow-up using the above combinations.

Electronegative electroretinogram in mucolipidosis IV

OBJECTIVE

To demonstrate the progression of electroretinographic (ERG) findings in mucolipidosis IV.

METHODS

Two patients with mucolipidosis IV were examined clinically and their condition was followed up for ophthalmic manifestations of the disease. Electroretinograms were performed on both patients, and conjunctival biopsy specimens were analyzed for characteristic ultrastructural inclusion bodies using light and electron microscopy. Genomic DNA isolated from peripheral blood was screened for 2 major founder mutations in the ML4 gene using polymerase chain reaction and restriction fragment length polymorphism analyses. Haplotypes were confirmed by automated sequencing of polymerase chain reaction products.

RESULTS

In patient 1, an ERG obtained at 12 months of age showed mildly subnormal amplitude of rod-mediated and cone-mediated responses and significantly prolonged rod and cone b-wave implicit times. An ERG obtained when the patient was 6.6 years old disclosed marked progression with greater loss of b-wave than a-wave responses to rod-and-cone-mediated activity. Scotopic ERG at the highest intensity was electronegative in configuration. In patient 2, ERG showed minimal rod-mediated responses, severely subnormal cone-mediated responses, and prolonged cone b-wave implicit times. Again, electronegative configuration of the scotopic bright flash response indicated greater disturbance of b-wave generators.

CONCLUSIONS

Novel ERG findings in 2 cases of mucolipidosis IV are reported with associated clinical courses, histopathologic abnormality, and genetic studies. In both cases ERGs demonstrate an electronegative configuration, suggesting that the primary retinal disturbance in mucolipidosis IV may occur at or proximal to the photoreceptor terminals.

Uveitis in a child: masquerade syndrome revisit

We present a case of relapsing acute lymphoblastic leukemia (ALL) in the anterior chamber, uveitis masquerade syndrome, which was confirmed by anterior chamber paracentesis and aqueous fluid cytology. Three months previously, the patient developed anterior uveitis without hematologic relapse. The uveitis responded well to topical steroid. After anterior chamber paracentesis, bone marrow relapse was detected. High doses of chemotherapy were prescribed. Ocular radiation was planned but the patient developed septicemia and expired. In our opinion, paracentesis should be performed without delay when uveitis develops in ALL, regardless of systemic relapse. Ocular manifestation may be the only sign of leukemic relapse or may present several months prior to systemic relapse.

Eye findings in 8 children and a spontaneously aborted fetus with RSH/Smith-Lemli-Opitz syndrome

We evaluate the ophthalmologic findings in 8 children with RSH/Smith-Lemli-Opitz syndrome (SLOS) and document abnormal concentrations of cholesterol and cholesterol precursors in the ocular tissues in a case of SLOS. The most common ophthalmologic finding was blepharoptosis, which was found in 6 of 8 patients, with the severity ranging from mild to moderate. None of the patients in the present study demonstrated cataracts; none had amblyopia from blepharoptosis. One patient had a right hypertropia with overaction of the inferior oblique muscle. This patient also had optic atrophy and a second patient had bilateral optic nerve hypoplasia. The importance of these findings to the visual function remains to be defined. Sterol analysis from ocular tissues of an aborted fetus with SLOS showed increased 7- and 8-dehydrocholesterol and a low cholesterol concentration in the retinal pigment epithelium, lens, cornea, and sclera. Routine ophthalmologic examination is indicated in SLOS because of the high incidence of abnormalities, most likely due to the abnormal synthesis of cholesterol and cholesterol precursors in the ocular tissues of these patients, as evidenced by sterol analysis of the ocular tissues in a case of SLOS.

Microcephaly with chorioretinal degeneration

PURPOSE

To describe the ophthalmologic findings and electroretinograms in patients with microcephaly and chorioretinal degeneration.

METHODS

We reviewed the hospital records of 20 patients with microcephaly that was not part of a recognizable syndrome prior to initial referral to the institutional consultative practice of one of the authors (RGW). Twelve patients, all from separate families, were diagnosed as having microcephaly with chorioretinopathy. Ten of these patients had ISCEV-standard electroretinograms (ERG).

RESULTS

No family history of microcephaly or retinal degeneration was found in any of our patients. Three patients had another family member with mental retardation. Three of the 12 were compatible with the autosomal dominant form of microcephaly with chorioretinopathy (MIM 156590), possibly as a new mutation. Eight patients, who had fundus findings of retinitis pigmentosa, were similar to the autosomal recessive form of microcephaly with chorioretinal degeneration (MIM 251270). The ERGs were moderately to severely subnormal for responses of both rods and cones. The retinal findings varied from no pigmentary changes, pigment clumping and bone spicules, pigmentary granularity, bull's eye maculopathy, choroidal and retinal atrophy, to lacunar depigmentation. Mental retardation was mild to profound. The abnormal findings from MRI/ CT brain scans (8 patients) were cerebellar atrophy (2), agenesis of cerebellar vermis (1), cortical atrophy (1), and pachygyria (1). Dysmorphic features were present in most patients. Chromosome studies were normal, except for one patient with ring chromosome 14.

CONCLUSIONS

Although the patients reviewed in this study represent a heterogeneous group of disorders, ocular abnormalities, especially retinal degeneration, are frequent among patients with microcephaly.