Visual function and inner retinal structure correlations in aquaporin-4 antibody-positive optic neuritis

Purpose

To investigate the correlation between visual function and thinning of the retinal nerve fiber layer (RNFL) and the macular ganglion cell-inner plexiform layer (GCIPL) as measured by optical coherence tomography (OCT) in eyes with aquaporin-4 IgG-positive optic neuritis (AQP4-IgG-positive ON).

Study design

Prospective study.

Methods

Patients with a history of ON were categorized into 2 groups: the AQP4-IgG-positive group and the AQP4-IgG-negative group. Patients with multiple sclerosis were excluded. All patients underwent ophthalmologic examination and OCT imaging at least 6 months after the last episode of acute ON. Visual function and inner retinal structure correlations were analyzed using Pearson correlation and regression analyses.

Results

Thirty-one previous ON eyes of 17 AQP4-IgG-positive patients and 21 previous ON eyes of 15 AQP4-IgG-negative patients were registered. Visual function, especially the visual field, was better correlated with RNFL than with macular GCIPL. The best correlation between visual function and RNFL was the linear model, whereas the best correlation between visual function and GCIPL was the nonlinear model (inverse regression). Regression models revealed worse visual function in AQP4-IgG-positive ON than in AQP4-IgG-negative ON, whereas no differences in RNFL and GCIPL were found between the 2 groups.

Conclusions

RNFL measured by OCT can be a useful retinal structure for estimating and monitoring visual field loss in AQP4-IgG-positive ON patients, particularly in patients whose visual field cannot be quantitated. The correlation between visual function and the inner retinal structure of eyes with AQP4-IgG is unique and differs from that of eyes without AQP4-IgG.

     

Neuropsychiatric symptoms, functional impairment and executive ability in Thai patients with Alzheimer's disease

BACKGROUND: Instrumental activities of daily living (IADL) depend on executive planning and procedural memory mediated by the frontal lobes. Planning and judgment are involved in clock drawing. Neuropsychiatric symptoms are also mediated by frontal lobes, and a relationship between ADL, clock drawing and neuropsychiatric symptoms was hypothesized. OBJECTIVE: To investigate the relationship between behavioral disturbances, ADL, and executive function. METHODS: Seventy-three Thai patients with Alzheimer's disease (AD) were evaluated. Neuropsychiatric symptoms and behaviors were assessed with the Nevropsychiatric Inventory (NPI). The Thai version of the Mini-mental State Examination (TMSE) was utilized as a global cognitive assessment. A clock-drawing test (CDT) and both category (animals) and letter (ko, so in Thai) verbal fluency were used as executive measures. Thai ADL scale, Barthel Index (BI), and Functional Assessment Questionnaire (FAQ) were ADL measures used in this study. RESULTS: There were statistically significant correlations between CDT and the frontally-mediated behaviors of agitation (r = -0.367), apathy (r = -0.273) and disinhibition (r = -0.247). Verbal fluency correlated with agitation (r = -0.341). There were significant correlations between Thai ADL scores and agitation (r = 0.350), apathy (r = 0.441), and disinhibition (r = 0.417). FAQ correlated with the same three behaviors. After controlling for TMSE, a significant correlation remained between Thai ADL scores and agitation (r = 0.291) and apathy (r = 0.342). CONCLUSIONS: We demonstrated correlations between ADL and behavioral changes in Thai elderly with AD. Our results emphasize the important relationships among behavioral changes and impaired ADL.     

A new measurement of activities of daily living for Thai elderly with dementia

BACKGROUND: Activities of daily living (ADL) vary across cultures, and measure of ADL needs to be specific to the population under study. We developed an ADL measure for Thai elderly with dementia and investigated the reliability and validity of this instrument. MATERIALS AND METHODS: Item construction was accomplished with a panel of neurologists and a rehabilitation medicine physician. One hundred eighty-one subjects were interviewed using the Thai ADL measure. Of this sample, one hundred fifty-nine had dementia according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria. These data were analyzed for internal consistency; concurrent validity was determined by comparison with the Barthel Index, Functional Assessment Questionnaire (FAQ), Thai Mental State Exam (TMSE), and Clinical Dementia Rating (CDR) scale; and discriminant validity was determined by comparison with the Neuropsychiatric Inventory (NPI). Thirty subjects were tested to determine interrater and test-retest reliability. RESULTS: Thai ADL measure was composed of six basic ADL and seven instrumental ADL. It had high correlation with TMSE scores (r = -.69), CDR scores (r = .81), Barthel Index scores (r = -.80), and FAQ scores (r = .88), and moderate correlation with NPI scores (r = .46). The instrument had high test-retest reliability (intraclass correlation coefficient [ICC] = .92, .89) and high interrater reliability (ICC = .96, .93). CONCLUSION: The Thai ADL scale is easy to use and it has high reliability. It had high concurrent validity with previously published ADL scales. The methodology used to develop the Thai ADL scale can provide a model for creating culturally competent ADL scales.     

Accuracy of Holladay 2 formula using IOLMaster parameters in the absence of lens thickness value

Background

The accuracy of the Holladay 2 (H2) formula is well-documented. This formula requires seven variables to estimate effective lens position (ELP) for the IOL power calculation. The lens thickness (LT) value is one of the required variables. Interestingly, the IOLMaster, which is one of the most commonly used optical biometers, can provide all the required ocular variables except LT value. It has become a pertinent issue to evaluate the accuracy of theH2 formula when it is used without the LT value. The purpose of this study was to evaluate the results when using the H2 formula, without the LT value, and compare such results to those obtained using the Haigis formula and the Hoffer Q formula.

Methods

The Institutional review board (IRB) gave their approval for the conduct of this prospective comparative study. One hundred and sixty-three eyes of 143 cataract patients from the Ophthalmology Department, Siriraj Hospital, Thailand were recruited. All eyes were measured using the IOLMaster (Carl Zeiss Meditec, Jena, Germany) for keratometry (K), axial length (AL), anterior chamber depth (ACD), and horizontal white-to-white (WTW) corneal diameter. Then, the LT measurement was obtained by A-scan ultrasonography (Quantel Axis-II, Quantel Medical, USA). Every patient underwent uncomplicated phacoemulsification by a single surgeon (NC) with a single technique using a single IOL model. Post-operative refraction was obtained at 3 months. The mean absolute errors (MAEs), median absolute errors (MedAEs) and percentage of the eyes within ±0.25, ±0.50, and ±1.00 D of predicted refraction was calculated for H2 formula both with and without LT input, Haigis, and Hoffer Q formula. The results were also classified into a group of short AL (<22.0 mm), average AL (22.0 to 24.5 mm) and long AL (>24.5 mm).

Results

There was no statistically significant difference in either MAEs or MedAEs of all formulas in all AL groups including the H2 with and without LT. There was a trend toward lower MAEs and MedAEs for H2 in the long AL group. Percentage of the eyes within ±0.25, ±0.50, and ±1.00 D of predicted refraction were similar in all AL groups.

Conclusion

The preliminary results of this study showed that the H2 formula performed well even without the LT value. It was comparable to the Haigis and Hoffer Q formulas.     

Randomized, controlled, double-blind trial of daily oral azithromycin in adults for the prophylaxis of Plasmodium vivax malaria in Western Thailand

We assessed the prophylactic efficacy of azithromycin (250 mg/day) against malaria in 276 adults in western Thailand in a randomized, double-blind, placebo-controlled trial. After antimalarial suppressive treatment, volunteers were randomized in a 2:1 ratio to either the azithromycin or placebo, respectively. Study medication was given for an average of 74 days. The azithromycin group (n = 179) had five endpoint parasitemias (1 Plasmodium vivax and 4 P. falciparum), and the placebo group (n = 97) had 28 endpoint parasitemias (21 P. vivax, 5 P. falciparum, and 2 mixed infections). Adverse events and compliance and withdrawal rates were similar in both groups. The protective efficacy (PE) of azithromycin was 98% for P. vivax (95% confidence interval [CI] = 88-100%). There were too few cases to reliably estimate the efficacy of azithromycin for P. falciparum (PE =71%, 95% C =-14-94%). We conclude that daily azithromycin was safe, well-tolerated, and had a high efficacy for the prevention of P. vivax malaria.     

Factors associated with family planing acceptance in Bangkok metropolis health clinic areas (MHCs)

To study contraceptive use in Bangkok, 6,809 eligible women were interviewed in a community survey of 5 Metropolis areas. 34.7% were current users of interval contraception and the pill was the most common method. 29.9% were not currently in need of family planning. 18.3% of women were not using contraception, but only 6.2% were in need of family planning (FP) and not currently practising contraception. Non-acceptors who were in need of FP, had a lower educational level; 13.4% did not know about contraception but 52.4% previously used contraception. The most common reason for not currently practising FP was fears about contraceptive safety (37.5%). The prevalence of pregnancy in the community was 10.4%.The fact that only 6.2% of women were not practising FP and were in need of contraception suggests that the services in Bangkok are adequate to meet the needs of most women. However, the subgroup of non-acceptors in need of FP who were from a low socio-economic group require special motivation and services. 1,835 women attending Metropolis Health Centres in the same areas were interviewed to determine their choice of contraception; 57.4% chose the pill.