Colour vision restrictions for driving: an evidence-based perspective on regulations in ASEAN countries compared to other countries.

Colour vision deficiency is an impairment in discriminating colours. Beyond occupational opportunities, colour vision-based restrictions may limit driving, which is a daily task for many people. This review aims to compare existing colour vision requirements for obtaining a driving license in southeast Asian countries to the rest of the world. Subsequently, to review existing published literature and provide evidence-based recommendations for future guidelines for colour-deficient drivers. Color vision requirements for obtaining a driving license vary widely amongst countries. While colour-deficient drivers may face mild challenges in driving, increased awareness and developing effective compensatory strategies could enable them to drive safely. The current evidence does not support a strict exclusion of all colour-deficient individuals from driving. Instead, emphasis is needed on screening to increase awareness and insight into their disability. Future studies should consider compensatory adaptive strategies that are specific for high-risk situations such as challenging driving conditions.

A real-world study of effectiveness of intravitreal bevacizumab and ranibizumab injection for treating retinal diseases in Thailand.

BACKGROUND: To evaluate the effectiveness of intravitreal bevacizumab (IVB) and intravitreal ranibizumab (IVR) in actual practice for treating patients with retinal diseases in Thailand. METHODS: A prospective, multi-centre, observational study was conducted among eight hospitals in their ophthalmology outpatient departments. Participants consisted of patients who had previously not received any IVB or IVR treatment between 2013 and 2014. The primary outcome measurement was the change in best-corrected visual acuity (BCVA) at the end of the follow-up period compared to baseline. RESULTS: There were 1629 treatment-naïve patients for the pro re nata (PRN) treatment pattern and 226 treatment-naive patients for the three-injections (3Inj) treatment pattern. BCVA improvements were found in 35% of the PRN group and 47% of the 3Inj group; however, it was not clinically meaningful between the IVB and IVR groups (P-value = 0.568 for PRN, P-value = 0.103 for 3Inj). A multivariable logistic regression (using the propensity score) showed that positive factors associated with vision improvement for the PRN pattern were the number of drug injections, having retinal vein occlusion, and under 60 years of age, while good BCVA at baseline was a negative predictive factor. For the 3Inj pattern, under 60 years of age and baseline BCVA were statistically significant predictors. Nonetheless, diabetes mellitus (DM) without other comorbidities was a statistically significant predictor of low response to vision improvement compared to DM with other comorbidities. CONCLUSIONS: This study was the first observational, prospective study to evaluate the real-life effectiveness of IVB and IVR in Thailand. The majority of participants who used IVB or IVR showed improvements in BCVA after treatment. Further evaluation such as long-term follow-ups and subsequent comparison of effectiveness between IVB and IVR should be investigated due to the limited sample of IVR patients. TRIAL REGISTRATION: Thai Clinical Trial Registry TCTR20141002001 . Registered 02 October 2014 (retrospectively registered).

Correction to: Real-World Safety of Intravitreal Bevacizumab and Ranibizumab Treatments for Retinal Diseases in Thailand: A Prospective Observational Study.

The Open Access license, which previously read.

Real-World Safety of Intravitreal Bevacizumab and Ranibizumab Treatments for Retinal Diseases in Thailand: A Prospective Observational Study.

BACKGROUND: There is very limited evidence examining serious systemic adverse events (SSAEs) and post-injection endophthalmitis of intravitreal bevacizumab (IVB) and intravitreal ranibizumab (IVR) treatments in Thailand and low- and middle-income countries. Moreover, findings from the existing trials might have limited generalizability to certain populations and rare SSAEs. OBJECTIVES: This prospective observational study aimed to assess and compare the safety profiles of IVB and IVR in patients with retinal diseases in Thailand. METHODS: Between 2013 and 2015, 6354 patients eligible for IVB or IVR were recruited from eight hospitals. Main outcomes measures were prevalence and risk of SSAEs, mortality, and endophthalmitis during the 6-month follow-up period. RESULTS: In the IVB and IVR groups, 94 and 6% of patients participated, respectively. The rates of outcomes in the IVB group were slightly greater than in the IVR group. All-cause mortality rates in the IVB and IVR groups were 1.10 and 0.53%, respectively. Prevalence rates of endophthalmitis and non-fatal strokes in the IVB group were 0.04% of 16,421 injections and 0.27% of 5975 patients, respectively, whereas none of these events were identified in the IVR group. There were no differences between the two groups in the risks of mortality, arteriothrombotic events (ATE), and non-fatal heart failure (HF). Adjustment for potential confounding factors and selection bias using multivariable models for time-to-event outcomes and propensity scores did not alter the results. CONCLUSIONS: The rates of SAEs in both groups were low. The IVB and IVR treatments were not associated with significant risks of mortality, ATE, and non-fatal HF. TRIAL REGISTRATION: Thai Clinical Trial Registry identifier TCTR20141002001.

Localized RPE Removal with a Novel Instrument Aided by Viscoelastics in Rabbits.

PURPOSE: We developed a surgical method for localized and atraumatic removal of the retinal pigment epithelium (RPE) with a novel instrument. METHODS: Bleb retinal detachments (bRD) were raised with balanced salt solution (BSS) following vitrectomy in 27 rabbits. The RPE was scraped with 3 loop variants (polypropylene [PP], 0.1 mm; PP, 0.06 mm; metal, 0.1 mm) of a custom-made instrument. Stabilization of bRDs with BSS or various concentrations (0.1%-0.5%) of hyaluronic acid (HA) was video analyzed. Perfusion-fixed samples of scraped areas and controls were studied by light and transmission electron microscopy. RESULTS: The bRDs were sufficiently stabilized by ≥0.25% HA. Using the PP 0.1 mm loop with a single forward/backward stroke, an area of ca. 2.5 × 1.5 mm was nearly devoid of RPE, yet did show occasional Bruch's membrane (BM) defects combined with choriocapillaris hemorrhages in 13% of the bRDs. A single scrape with PP 0.06 mm resulted in unsatisfactory RPE denudement, while repeated scraping maneuvers caused more BM defects and hemorrhages. The metal loop resulted in incomplete RPE removal and massive intraoperative subretinal hemorrhages. Histologically, intact photoreceptor outer segments (POS) were observed above the RPE wounds in bRDs. Controls with bRDs alone showed an intact RPE monolayer with microvilli, with few engulfed remains of POS. CONCLUSIONS: Localized removal of RPE in HA stabilized bRD can be achieved by a PP 0.1 mm loop instrument. TRANSLATIONAL RELEVANCE: Removal of degenerated RPE may aid RPE cell replacement strategies.

The first rapid assessment of avoidable blindness (RAAB) in Thailand.

BACKGROUND: The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB) study in Thailand. METHODS: A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. RESULTS: The age and sex adjusted prevalence of blindness (presenting visual acuity (VA) <20/400), severe visual impairment (VA <20/200 but ≥20/400), and moderate visual impairment (VA <20/70 but ≥20/200) were 0.6% (95% CI: 0.5-0.8), 1.3% (95% CI: 1.0-1.6), 12.6% (95% CI: 10.8-14.5). There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. CONCLUSION: Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system.

Human RPE stem cells grown into polarized RPE monolayers on a polyester matrix are maintained after grafting into rabbit subretinal space.

Transplantation of the retinal pigment epithelium (RPE) is being developed as a cell-replacement therapy for age-related macular degeneration. Human embryonic stem cell (hESC) and induced pluripotent stem cell (iPSC)-derived RPE are currently translating toward clinic. We introduce the adult human RPE stem cell (hRPESC) as an alternative RPE source. Polarized monolayers of adult hRPESC-derived RPE grown on polyester (PET) membranes had near-native characteristics. Trephined pieces of RPE monolayers on PET were transplanted subretinally in the rabbit, a large-eyed animal model. After 4 days, retinal edema was observed above the implant, detected by spectral domain optical coherence tomography (SD-OCT) and fundoscopy. At 1 week, retinal atrophy overlying the fetal or adult transplant was observed, remaining stable thereafter. Histology obtained 4 weeks after implantation confirmed a continuous polarized human RPE monolayer on PET. Taken together, the xeno-RPE survived with retained characteristics in the subretinal space. These experiments support that adult hRPESC-derived RPE are a potential source for transplantation therapies.

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.

Vernal keratoconjunctivitis in Thailand.

A prospective, cross-sectional and randomized cross-over study was conducted to study the clinical features and treatment outcome among Thai patients with vernal keratoconjunctivitis (VKC). History-taking and eye examinations were performed. Mild cases of VKC were given topical antihistamine four times daily. Moderate and severe cases of VKC were treated with topical lodoxamide four times a day. Severe cases of VKC were given topical corticosteroids. Moderate and severe cases of VKC, which were refractory to treatment with either corticosteroids or a mast cell stabilizer had topical cyclosporine 0.5% instilled four times daily. Five patients were exposed to two different treatment regimens in sequence. As main outcome measures, itching, foreign body sensation, photophobia, conjunctival injection, papillae and chemosis were evaluated weekly. The patients with the palpebral type of VKC had daily symptoms, which were more severe and triggered by house-dust with a significant difference among the groups. Limbal VKC was associated with allergic rhinitis more commonly than palpebral VKC. Positive results of skin prick testing to acacia, careless weed, mold, Johnson grass and cow's milk were significantly more common in patients with palpebral VKC. The most common symptoms and signs were found in the mixed type of VKC. Purulent discharge, pannus and lid erythema were found in the palpebral type. Levocabastine hydrochloride was sufficient for mild cases of limbal VKC; lodoxamide for the limbal and mixed types. Prednisolone acetate was the drug of choice in severe cases of any type but only for a short period of time. The success rate of topical cyclosporine in the palpebral type was lower than in the limbal type due to an intolerable burning sensation. Topical cyclosporine used in 4 patients with limbal and palpebral type had a success rate of 100% which was greater than in the lodoxamide group (66.7%, 0%). Compared with topical corticosteroid-treated eyes in one patient, the success rate in topical cyclosporine-treated eyes was not success. Grading the severity of each type of VKC is crucial to obtain good response of any medication and compliance. Topical cyclosporine 0.5% can be an alternative drug to relieve symptoms and signs of VKC in order to avoid steroid-induced glaucoma.