Ngamkae Ruangvaravate

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

AbstractLeber 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.

Potassium iodate toxic retinopathy: a report of five cases.

Background: Potassium iodate (KIO3) is an iodized salt used for iodine supplementation in areas endemic for goiter. KIO3 overdose in humans is rare. The authors report unusual cases of retinal toxicity from KIO3 overdose that caused acute vision loss. Methods: The clinical manifestations, toxic dosage of iodate, and ocular changes in five patients who had taken a KIO3 overdose were analyzed. Electroretinography, visual evoked potential (VEP), and fundus fluorescein angiography (FA) were performed to study retinal function and changes. Results: Two men and three women (age 22‐65 years) ingested KIO3 solution at a concentration between 187 and 470 mg/kg body weight. Visual acuity ranged from light perception with projection to counting fingers and decreased from 2 to 12 hours after ingestion. Fundus FA showed bilateral extensive areas of retinal pigment epithelial (RPE) window defects, and electroretinography and VEP showed marked impairment of retinal function. Visual acuity improved from counting fingers to 20/80 in 3 months. Conclusion: Potassium iodate can produce retinal toxicity that damages RPE and photoreceptor cells. The recovery of retinal function depends on the amount of chemical absorption, the regeneration of RPE, and the recovery function of photoreceptor cells. RETINA 20:378‐383, 2000

Effect of 0.3% Hydroxypropyl Methylcellulose/Dextran Versus 0.18% Sodium Hyaluronate in the Treatment of Ocular Surface Disease in Glaucoma Patients: A Randomized, Double-Blind, and Controlled Study.

Abstract Purpose: To compare the efficacy and safety of 0.3% hydroxypropyl methylcellulose/dextran (HPMC/dextran) and 0.18% sodium hyaluronate (SH) in the treatment of ocular surface disease in patients using antiglaucoma drugs containing preservatives. Methods: This was a double-blind, randomized, parallel-group study in 70 glaucoma patients with Ocular Surface Disease Index (OSDI) score greater than 20 points and/or presence of ocular signs. Patients were randomized to receive either preservative-free 0.3% HPMC/dextran (n=35) or preservative-free 0.18% SH (n=35). Treatment was 1 drop in each eye, 4 times a day. Data were collected at baseline, at day 7 and day 28. Results: The groups were homogeneous at baseline. At day 28, both treatments showed significant improvements (P<0.05) in the mean OSDI score, lid skin and lid margin inflammation, conjunctival injection, and expressibility of meibomian glands, corneal staining score, fluorescein tear breakup time (FBUT), and Schirmer I test. However, the mean OSDI score, lid margin inflammation and conjunctival injection showed significant improvements (P<0.05) in the SH group at days 7 and 28, compared to the HPMC/dextran group. FBUT and the Schirmer I test also showed significant improvements (P<0.05) in the SH group compared to the HPMC/dextran group, at day 28. No adverse reactions were observed in either group. Conclusions: Preservative-free artificial tear, 0.3% HPMC/dextran, and 0.18% SH, caused a significant relief of the ocular surface disease in glaucoma patients. However, 0.18% SH led to a greater improvement in ocular signs and symptoms than 0.3% HPMC/dextran.

Prevalence and risk factors for chloroquine maculopathy and role of plasma chloroquine and desethylchloroquine concentrations in predicting chloroquine maculopathy.

To determine the prevalence and to identify the risk factors of chloroquine maculopathy (CM), and to evaluate the association of plasma chloroquine (CQ) and desethylchloroquine (DCQ) levels and CM.

Immediate Anterior Chamber Paracentesis with a 30-Gauge Needle for Acute Primary Angle Closure

Background: Primary angle-closure glaucoma (PACG) is more common among Asians than among Caucasians. Acute primary angle closure (APAC) is a serious associated complication in PACG patients. When conventional treatment fails, Anterior Chamber Paracentesis (ACP) can be performed to decrease IOP. Although slit knives are commonly used for performing ACP, other techniques can also be used to perform this procedure. Objective: To investigate the efficacy and safety of immediate anterior chamber paracentesis using a 30-gauge needle combined with conventional topical and systemic medications for the treatment of APAC. Materials and methods: This prospective study was conducted in 15 consecutive primary angle-closure glaucoma patients that presented with and who were treated for acute primary angle closure (APAC) at the Department of Ophthalmology, Siriraj Hospital, (Bangkok, Thailand) during the January 2015 to December 2015 study period. Patients were included if they were older than 18 years of age, if this was their first known attack of APAC, and if they had an IOP ≥ 40 mmHg. Results: Mean age of the 15 included participants (3 males, 12 females) was 61 years. Mean presenting IOP ± SD was 54.3 ± 11.6 mmHg. Twelve of 15 eyes had visual acuity worse than 6/18. Immediately after ACP, mean IOP ± SD was 7.5 ± 5.1 mmHg. None of the 15 included eyes were reactive to light prior to ACP. Mean pupil diameter was significantly reduced from baseline at 60 minutes after ACP (p=0.004) and was significantly smaller than baseline at 24 h after ACP (p=0.03). BCVA was improved to ≥ 6/18 in 11 and 12 eyes at 1 and 24 h after ACP, respectively. All patients had relief from symptoms immediately following ACP. No ACP-related complications were observed in any patient in this study. Conclusion: Immediate APC with a 30-guage needle is a safe and effective initial treatment for APAC. APC should be combined with conventional treatment with topical and/or systemic medications. APC yields rapid IOP reduction, dramatic relief of symptoms, and corneal clarity. APC may also improve response to further treatment, improve IOP control, and may reduce or eliminate the need for systemic medication.