RAPID ONSET HYDROXYCHLOROQUINE TOXICITY

PURPOSE

Hydroxychloroquine (HCQ) can cause irreversible damage to the retina, especially when taken over longer periods. The American Academy of Ophthalmology recommends a regimen for dosing, screening, and monitoring of patients treated with HCQ. We present an unusual case of a rapid development of severe HCQ-associated retinopathy already after 2 years after commencing HCQ treatment.

METHODS

Observational case report. Clinical examination, optical coherence tomography, fundus autofluorescence imaging, perimetry, and full-field and multifocal electroretinography were performed. Ancillary tests included neoplastic and paraneoplastic work-up, vitamin levels, and whole-exome sequencing, to rule out other potential causes of a panretinal degeneration.

RESULTS

We report on a 58-year-old woman with rheumatoid arthritis, treated initially with 200 mg HCQ daily for 1 year (daily dose 3.6 mg/kg), then 400 mg daily for 1 year (daily dose 7.2 mg/kg), and a cumulative dose of 216 g. Her medical history was otherwise unremarkable. No family history for inherited retinal conditions. She was referred due to a rapid and sudden progressive and severe concentric visual field constriction, 2 years after commencing HCQ treatment.

CONCLUSION

This case of a rapid-onset, severe panretinal degeneration shortly after start of HCQ treatment suggests underlying mechanisms and risk factors for HCQ toxicity in addition to those previously reported and a potential need for supplementary screening tests to prevent HCQ toxicity. American Academy of Ophthalmology dosing guidelines of 5 mg/kg should be strictly adhered to in patients receiving HCQ therapy.

Visual Field Sensitivity Prediction Using Optical Coherence Tomography Analysis in Hydroxychloroquine Toxicity

Purpose

This study investigates the association between local retina structure and visual function in a cohort with long-term hydroxychloroquine (HCQ) use.

Methods

The study included 84 participants (54 participants without toxicity and 30 participants with toxicity) with history of chronic HCQ use (14.5 ± 7.4 years) who had testing with spectral-domain optical coherence tomography (SD-OCT) imaging and Humphrey 10-2 visual fields. Optical coherence tomography (OCT) metrics (total and outer retina thickness [TRT and ORT], minimum intensity [MinI], and ellipsoid zone [EZ] loss) were sampled in regions corresponding to visual field test locations. Univariate linear correlations were investigated and a multivariate random forest regression using a combination of OCT metrics was used to predict visual field sensitivity by locus using a leave-one-out cross-validation strategy.

Results

In univariate linear regression, EZ loss demonstrated the strongest relationship with visual field sensitivities in the parafoveal ring with R2 = 0.58. TRT and ORT revealed positive correlations with visual field sensitivity (R2 = 0.57 and 0.40, respectively), whereas total and outer retinal MinI yielded negative correlations (R2 = 0.10 and 0.22). The multivariate model improved correlations (R2 = 0.66) yielding a root mean squared error of 3.8 decibel (dB). Feature importance analysis identified EZ loss as the most relevant predictor of function.

Conclusions

Multiple OCT-derived quantitative metrics used in combination can provide information to predict local sensitivities. The results indicate a strong relationship between retinal function and OCT measures, which contribute to the understanding of the retinal toxicity caused by HCQ as well as being applicable to outcome development for other degenerative diseases of the outer retina.

ASYMMETRIC HYDROXYCHLOROQUINE MACULAR TOXICITY WITH APHAKIC FELLOW EYE

BACKGROUND/PURPOSE

Retinal toxicity associated with antimalarial drug use in inflammatory conditions is well described and may be more common than previously recognized. Antimalarial drugs bind to melanin in ocular tissues, particularly the retinal pigment epithelium, but the mechanism of toxicity and its relation to light is unclear.

METHODS

Case report.

RESULTS

A 62-year-old white woman with erosive rheumatoid arthritis developed hydroxychloroquine toxicity in her phakic eye, with her aphakic fellow eye only mildly affected.

CONCLUSION

We report the clinical evaluation of this rare case of asymmetrical hydroxychloroquine retinopathy and present a hypothesis regarding the mechanism of drug toxicity.

Quantitative Fundus Autofluorescence in HCQ Retinopathy

Purpose

To increase our understanding of the mechanisms underlying hydroxychloroquine (HCQ) retinopathy, analyses by quantitative fundus autofluorescence (qAF) and near-infrared fundus autofluorescence (NIR-AF) were compared to results obtained by recommended screening tests.

Methods

Thirty-one patients (28 females, 3 males) were evaluated with standard automated perimetry and spectral domain optical coherence tomography (SD-OCT); 28 also had multifocal electroretinography (mfERG). Measurement of short-wavelength fundus autofluorescence (SW-AF) by qAF involved the use of an internal fluorescent reference and intensity measurements in eight concentric segments at 7° to 9° eccentricity. For semiquantitative analysis of NIR-AF, intensities were acquired along a vertical axis through the fovea.

Results

Four of 15 high-dose (total dose >1000 g, daily dose >5.0 mg/kg) patients and one of 16 low-dose (total dose <1000 g, daily dose 4.4 mg/kg) patients were diagnosed with HCQ-associated retinopathy based on abnormal 10-2 visual fields, SD-OCT, and SW-AF imaging. Three of the high-dose patients also had abnormal mfERG results. Of the five patients exhibiting retinopathy, two had qAF color-coded images revealing higher intensities inferior, nasal, and lateral to the fovea. The abnormal visual fields also exhibited superior-inferior differences. Mean NIR-AF gray-level intensities were increased in four high-dose patients with no evidence of retinopathy. In two patients with retinopathy, NIR-AF intensity within the parafovea was below the normal range. One high-dose patient (6.25 mg/kg) had only abnormal mfERG results.

Conclusions

These findings indicate that screening for HCQ retinopathy should take into consideration superior-inferior differences in susceptibility to HCQ retinopathy.

The effect of Bushen Huoxue method in treating glaucoma: A protocol for systematic review and meta-analysis

BACKGROUND

Glaucoma is a common ophthalmic neurodegenerative disease and the main cause of blindness, which seriously affects the life and work of patients, without more effective treatment for optic nerve damage. Bushen Huoxue (BSHX) method is a traditional Chinese medicine (TCM) therapy that has been widely used as an alternative therapy to treat optic nerve damage in glaucoma patients with growing beneficial effect evidence, however, there is no current systematic review has addressed its effect for glaucoma. This study will conduct a systematic review and meta-analysis of the currently published randomized controlled trials (RCTs) of BSHX method for the treatment of glaucoma, aim to assess the efficacy and safety of BSHX method for patients with glaucoma.

METHODS

We will thoroughly search literatures of RCTs related to BSHX method for glaucoma in PubMed, Medline, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP and Wanfang database and other databases from the establishment of the database to November 2019, with no language restriction. After reviewing the title, abstract and full text, 2 reviewers will independently select the study, extract the data, after assess the risk of bias, we will conduct a meta-analysis of the data extracted from the included RCTs, including total effective rate, intraocular pressure (IOP), visual acuity, visual field, TCM syndrome score, and adverse events. The meta-analysis will be performed using Review Manager 5.3 software and the results will be based on either random effects or fixed effects models, depending on the heterogeneity. Trial sequential analysis (TSA) and Grading of Recommendations, Development and Evaluate system (GRADE) will be conduct to evaluate the reliability and quality of evidence.

RESULTS

The results of the study will be published in a peer-reviewed journal, and provide a reasonable and high-quality evidence for the efficacy and safety of BSHX method for glaucoma.

CONCLUSION

This study will be the first meta-analysis to evaluate the efficacy of BSHX method in the treatment of glaucoma comprehensively, and will to provide helpful evidence for the clinical treatment of this disease.

REGISTRATION

PROSPERO CRD42020159897.

The Use of Vitamins and Coenzyme Q10 for the Treatment of Vascular Occlusion Diseases Affecting the Retina

Nutritional supplementation with antioxidants and vitamins is widely recommended in the treatment of vascular disorders affecting the retina, although there is insufficient evidence on its effectiveness. The vitamin-like compound coenzyme Q10 (CoQ10) is a nutritional supplement of current interest to treat neurodegenerative diseases. Here, we report a retrospective clinical case series study of 48 patients diagnosed with retinal vascular diseases, including non-arteritic ischemic optic neuropathy (NAION), retinal artery occlusion (RAO), and homonymous hemianopia or quadrantanopia following stroke, treated with oral supplementation with CoQ10 (100 mg per day) and vitamins. Patient follow-up was performed using the Humphrey field analyzer and 30-2 testing algorithm to determine the visual field index (VFI) and progression rates. All treated patients showed positive VFI progression rates per year: +11.5 ± 15% for NAION patients (n = 18), +22 ± 17% for RAO patients (n = 7), +9.3 ± 10.5% for hemianopia/quadrantanopia patients (n = 10), and +11 ± 21% for patients with other conditions (n = 13). The interruption of CoQ10 supplementation in one patient resulted in a pronounced decrease of the VFI, which was partially recovered when treatment was restored. This study supports the role of CoQ10 as a nutritional therapeutic agent for vascular diseases affecting the retina. Owing to decreased VFI after interruption of CoQ10, its beneficial effects may be reversible.

Evaluation of Hydroxychloroquine Retinopathy Using Ultra-Widefield Fundus Autofluorescence: Peripheral Findings in the Retinopathy

OBJECTIVES

To investigate the application of ultra-widefield fundus autofluorescence (UWF-FAF) imaging in evaluating hydroxychloroquine (HCQ) retinopathy and to report peripheral autofluorescence findings in Asian patients with this condition.

DESIGN

Retrospective case series.

METHODS

Setting: institutional.

PATIENT POPULATION

58 eyes of 29 patients with HCQ retinopathy.

OBSERVATION PROCEDURES

UWF-FAF imaging was performed, and the images were compared to conventional FAF images obtained using a confocal digital ophthalmoscope. The sensitivities of detecting retinopathy using the 2 modalities were compared. Peripheral autofluorescence findings in the eyes with HCQ retinopathy were assessed, and their association with the Humphrey visual field test results obtained using the 30-2 and full-field 120 (FF-120) protocols was analyzed. Main outcome measurements were abnormal FAF findings.

RESULTS

In 41 of 58 eyes (70.7%) with HCQ retinopathy, abnormal FAF findings were noted in the retinal periphery outside the field of view of conventional FAF as hypoautofluorescent (23 eyes, 39.7%) and hyperautofluorescent (38 eyes, 65.5%) lesions. In 5 eyes (8.6%), differences were revealed between conventional FAF and UWF-FAF in detecting retinopathy. Most of the eyes with severe retinopathy showed the most extensive hypoautofluorescence in the nasal peripheral retina. The areas with abnormal FAF findings were significantly correlated with the number of unseen spots on FF-120 results and mean deviation and pattern standard deviation of the 30-2 test results (all P < .001).

CONCLUSIONS

Peripheral autofluorescence findings varied in eyes with HCQ retinopathy according to the severity of the retinopathy. The retinal findings with UWF-FAF were functionally correlated to visual field results. UWF-FAF may be useful for evaluating HCQ retinopathy, particularly in Asian patients.

The Diagnostic Utility of Multifocal Electroretinography in Detecting Chloroquine and Hydroxychloroquine Retinal Toxicity

PURPOSE

To evaluate multifocal electroretinography (mfERG) as a screening test for detecting hydroxychloroquine and chloroquine toxicity.

DESIGN

Diagnostic accuracy study.

METHODS

Patients referred to the University of Ottawa for hydroxychloroquine or chloroquine retinopathy screening during 2011-2014 underwent 10-2 automated visual field, spectral domain optical coherence tomography, and mfERG testing. Patients with amblyopia, high myopia or hyperopia, coexisting retinal disease, or prior surgery were excluded. Abnormalities in parafoveal ring amplitudes or ring ratios were considered a positive mfERG result. We used the definition for hydroxychloroquine and chloroquine toxicity provided by the 2016 American Academy of Ophthalmology recommendations. Area under the curve (AUC) for each mfERG parameter and the sensitivity and specificity of mfERG were calculated. Logistic regression was used to model the effect of covariates in receiver operating characteristic (ROC) analyses.

RESULTS

In total, 63 patients (47 female, 16 male) were included. Of 120 eyes, 16 (13.3%) had toxicity according to the American Academy of Ophthalmology guidelines, and 39 (32.5%) had positive mfERG findings. mfERG was found to have a sensitivity of 1.00 (95% CI 0.79-1.00) and a specificity of 0.78 (95% CI 0.69-0.85). Ring 2 amplitude had the best performance among all parameters (AUC 0.97, 95% CI 0.94-1.00). Ring 2 amplitude decreased linearly with increasing cumulative dose and daily dose.

CONCLUSIONS

The high sensitivity of parafoveal depression on mfERG and its relationship to cumulative and daily dose illustrates an important role for objective functional testing. The high false-positive rate suggests a potential period where physiologic dysfunction is detected objectively on mfERG before structural change on spectral domain optical coherence tomography.

Preclinical tissue distribution and metabolic correlations of vigabatrin, an antiepileptic drug associated with potential use-limiting visual field defects

Vigabatrin (VGB; (S)-(+)/(R)-(-) 4-aminohex-5-enoic acid), an antiepileptic irreversibly inactivating GABA transaminase (GABA-T), manifests use-limiting ocular toxicity. Hypothesizing that the active S enantiomer of VGB would preferentially accumulate in eye and visual cortex (VC) as one potential mechanism for ocular toxicity, we infused racemic VGB into mice via subcutaneous minipump at 35, 70, and 140 mg/kg/d (n = 6-8 animals/dose) for 12 days. VGB enantiomers, total GABA and β-alanine (BALA), 4-guanidinobutyrate (4-GBA), and creatine were quantified by mass spectrometry in eye, brain, liver, prefrontal cortex (PFC), and VC. Plasma VGB concentrations increased linearly by dose (3 ± 0.76 (35 mg/kg/d); 15.1 ± 1.4 (70 mg/kg/d); 34.6 ± 3.2 μmol/L (140 mg/kg/d); mean ± SEM) with an S/R ratio of 0.74 ± 0.02 (n = 14). Steady state S/R ratios (35, 70 mg/kg/d doses) were highest in eye (5.5 ± 0.2; P < 0.0001), followed by VC (3.9 ± 0.4), PFC (3.6 ± 0.3), liver (2.9 ± 0.1), and brain (1.5 ± 0.1; n = 13-14 each). Total VGB content of eye exceeded that of brain, PFC and VC at all doses. High-dose VGB diminished endogenous metabolite production, especially in PFC and VC. GABA significantly increased in all tissues (all doses) except brain; BALA increases were confined to liver and VC; and 4-GBA was prominently increased in brain, PFC and VC (and eye at high dose). Linear correlations between enantiomers and GABA were observed in all tissues, but only in PFC/VC for BALA, 4-GBA, and creatine. Preferential accumulation of the VGB S isomer in eye and VC may provide new insight into VGB ocular toxicity.

Influence of Carteolol and Timolol on IOP and Visual Fields in Glaucoma: A Multi-Center, Double-Masked, Prospective Study

The influences of Carteolol and Timolol eye drops on intraocular pressure (IOP) and visual fields were compared in a multi-center, double-masked, prospective study. Two-hundred and forty eyes of 120 patients were initially included in the study, and 142 eyes of 72 patients fulfilled all the criteria for final statistical analysis. Both drugs significantly reduced IOP. The visual fields in both treatment groups did not change during one year of treatment. In both groups some patients improved slightly, and others deteriorated slightly. This indicates that locally applied beta-blockers may efficiently stop further progression of visual field defects in cases with increased IOP and early visual field damage. There was no difference between Carteolol and Timolol in this regard. The side effects were minimal, and there were no differences in their frequency or intensity in the two treatment groups.

Influence of Nifedipine on the Visual Fields of Patients with Optic-Nerve-Head Diseases

Calcium-channel blockers have long been employed in coronary disease, and recent investigations have indicated their efficacy in improving the visual field in low-tension glaucoma or presumed vasospasm, possibly by enhancing ocular circulation. We evaluated the short-term influence of a typical calcium-channel blocker, nifedipine, on 59 patients with visual-field defects, some with optic-nerve-head pathology (n = 38) and some with normal-appearing optic nerve heads (n = 21). On the average, a statistically significant improvement of 1.2 dB was observed. Different types of patients, however, behaved quite differently. The younger the patient, the greater the improvement. Patients with normal optic nerve heads improved by 1.54 dB, whereas patients with optic-nerve-head excavation improved by only 0.66 dB. No response was observed in patients with anterior ischemic neuropathy. Marked deterioration was noted in one glaucoma patient with low systemic blood pressure. The visual-field changes were observed in the scotomatous and non-scotomatous areas. Thus, the calcium-channel blocker nifedipine can be effective in some selected diseases whose pathogenesis probably involves vascular dysregulation though it may even be contraindicated in others

The Effect of Betaxolol on Ocular Blood Flow and Visual Fields in Patients with Normotension Glaucoma

Purpose

This study investigated the effect of ophthalmic betaxolol, a ß, selective adrenoceptor antagonist, on ocular blood flow and visual function in patients with normotension glaucoma (NTG).

Methods

Thirty-six eyes of eighteen patients with NTG, but otherwise free of systemic disease, were included. Blood fibrinogen, sedimentation rates, Goldmann intraocular pressure, Humphrey automated perimetry, and color Doppler imaging were done at baseline and after one year of twice-daily bilateral topical ocular dosing with 0.5% betaxolol HCl.

Results

After treatment, the resistivity index of the ophthalmic artery was significantly reduced, and visual fields were significantly improved. The resistivity indexes of the central retinal artery and posterior ciliary artery were also reduced but did not achieve statistical significance. Intraocular pressure was significantly reduced. There was no change in blood fibrinogen and sedimentation rates.

Conclusions

These findings indicate that long-term treatment with ophthalmic betaxolol improves ocular hemodynamics by lowering the resistivity index of the ophthalmic artery and results in an improvement in the visual fields of patients with NTG. In view of this positive effect on blood flow and visual function, betaxolol is recommended in the management of patients with NTG.

Multichannel perimetric alterations in systemic lupus erythematosus treated with hydroxychloroquine

Systemic lupus erythematosus (SLE) is a multiorgan autoimmune disease of unknown etiology with many clinical manifestations. We report the first case of SLE in which visual alterations were evaluated with multichannel perimetry. Some achromatic and color vision alterations may be present in SLE, especially when treated with hydroxychloroquine. The sensitivity losses detected in the chromatic channels in the central zone of the visual field were consistent with the results of the FM 100 Hue color test. Likewise, the multichannel perimetry detected sensitivity losses in the parafoveal area for both chromatic channels, especially for the blue-yellow.

mTOR Inhibition Mitigates Molecular and Biochemical Alterations of Vigabatrin-Induced Visual Field Toxicity in Mice

BACKGROUND

Gamma-vinyl-γ-aminobutyric acid (GABA) (vigabatrin) is an antiepileptic drug and irreversible GABA transaminase inhibitor associated with visual field impairment, which limits its clinical utility. We sought to relate altered visual evoked potentials associated with vigabatrin intake to transcriptional changes in the mechanistic target of rapamycin (mTOR) pathway and GABA receptors to expose further mechanisms of vigabatrin-induced visual field loss.

METHODS

Vigabatrin was administered to mice via an osmotic pump for two weeks to increase GABA levels. Visual evoked potentials were examined, eye samples were collected, and gene expression was measured by quantitative reverse transcription-polymerase chain reaction. Similarly, human retinal pigment epithelial cells (ARPE19) were exposed to vigabatrin and treated with mTOR inhibitors for mTOR pathway analysis and to assess alterations in organelle accumulation by microscopy.

RESULTS

Dysregulated expression of transcripts in the mTOR pathway, GABA_A/B receptors, metabotropic glutamate (Glu) receptors 1/6, and GABA/glutamate transporters in the eye were found in association with visual evoked potential changes during vigabatrin administration. Rrag genes were upregulated in both mouse eye and ARPE19 cells. Immunoblot of whole eye revealed greater than three fold upregulation of a 200 kDa band when immunoblotted for ras-related guanosine triphosphate binding D. Microscopy of ARPE19 cells revealed selective reversal of vigabatrin-induced organelle accumulation by autophagy-inducing drugs, notably Torin 2. Changes in the mTOR pathway gene expression, including Rrag genes, were corrected by Torin 2 in ARPE19 cells.

CONCLUSIONS

Our studies, indicating GABA-associated augmentation of RRAG and mTOR signaling, support further preclinical evaluation of mTOR inhibitors as a therapeutic strategy to potentially mitigate vigabatrin-induced ocular toxicity.

Optic Neuritis with Visual Field Defect—Possible Ibuprofen-Related Toxicity

Objective:

To report a case of optic neuritis with visual field defect associated with ibuprofen.

Case Summary:

A 41-year-old white man developed blurred vision in his right eye and pain with eye and head movements that lasted 2 days after use of ibuprofen 400 mg 3 times daily during the preceding 3 weeks. Medical and family histories were negative for significant related disease. Ophthalmologic examination revealed a marked decrease in visual acuity to 20/200 in the right eye with quadrant visual field loss and absent responses in visual evoked potential (VEP). After discontinuation of the drug and treatment with high-dose intravenous methylprednisolone and subcutaneous low-molecular-weight heparin, the patient's vision improved to 20/70, the visual field defect vanished, and the VEP returned to almost normal values during a 1 year follow-up period. An objective causality assessment revealed that the adverse reaction was possibly related to ibuprofen.

Discussion:

Ocular toxicity with blurred vision and centrocecal visual field defects have been rarely associated with long-term ibuprofen intake. We report a case of retrobulbar optic neuritis with quadrant visual field defect following short-term but regular ibuprofen intake. Although idiopathic optic neuritis cannot be completely ruled out, the absence of other risk factors and additional findings plus the improvement after discontinuation of the drug speak for isolated toxic optic neuritis of the right eye.

Conclusions:

Drug toxicity is an important differential diagnosis in retrobulbar optic neuritis. Clinicians should be aware of the potential optic toxicity, even with short-term use of a drug, and perform a thorough medication history in every patient with visual disturbances without a clear cause.

Can subtenon methylprednisolone acetate be a choice for the acute non-arteritic ischemic optic neuropathy treatment?

Nonarteritic ischemic optic neuropathy is characterized by sudden, painless, unilateral vision loss. A case of an acute NAION patient who was treated with subtenon methyl prednisolone acetate was presented. The patient, a 65-year-old male, presented vision loss for two days. The total ophthalmologic examination, fundus photography, and automated perimetry were applied to the patient before and after 1, 3, and 6 months from injection. The visual acuity increased from 0,1 to 0,3 in the first month and to 0,7 at the last visit, the visual field defect being mostly improved. This case showed that 40 mg of subtenon methyl prednisolone acetate injection was an effective and safe treatment method for acute NAION. However, a large randomized controlled trial is needed to assess the efficacy of subtenon methyl prednisolone acetate as a treatment for NAION.

Topiramate associated non-glaucomatous visual field defects

We report a 34-years-old woman who presented with bilateral incongruous inferior visual field defects after the commencement of topiramate for management of migraine. Investigations did not reveal any underlying angle closure glaucoma, reported in current literature to be associated commonly with topiramate associated visual field defects. The changes in the peripheral visual fields gradually improved over several months after the medication was withdrawn. There were only minor changes persistent on the left side on a background of pre-existing myopia and keratoconus. Visual field deficits secondary to topiramate are more commonly attributed to angle closure glaucoma due to ciliochoroidal effusion syndrome. In such instance, the visual field defects are associated with considerable pain due to raised intra-ocular pressure. There have also been reports of visual scotomas due to retinal damage and maculopathy in patients taking topiramate. It is worthwhile to obtain a baseline perimetry in patients being considered for topiramate therapy in order to gauge any changes in their peripheral field of vision during the treatment. Changes in visual fields during the course of medication use and after cessation can be easily compared especially if there are other possible confounders such as refractive errors or a history of migraine.

Peripheral refraction and higher-order aberrations with cycloplegia and fogging lenses using the BHVI-EyeMapper

PURPOSE

To determine if a fogging lens ameliorates accommodative effects driven by the closed-view design of the BHVI-EyeMapper (EM) instrument. We compared cycloplegic refraction and higher-order aberration measurements of the EM with those obtained with a fogging lens.

METHODS

Twenty-six, young, participants (15F, 25±5 years, range: 18-35 years, SE: +0.25 D and -3.50 D) with good ocular health were recruited. Five independent measurements of on- and off-axis refraction and higher-order aberrations were recorded across the horizontal visual field, under two conditions: non-cycloplegic measurements with +1.00 D fogging lens and cycloplegia, always in the same sequence. The contralateral eye was occluded during the measurements. Two drops of 1% Tropicamide delivered within 5 min facilitated cycloplegic measurements. All participants were refracted 30 min after installation of the second drop.

RESULTS

Mean spherical equivalent measures of the non-cycloplegic condition were significantly more myopic than their cycloplegic counterparts (p<0.05); approximately by 0.50 D centrally, increasing to 1.00 D towards the periphery. The horizontal astigmatic component, J180, demonstrated small but statistically significant differences between the test conditions. Differences were predominant for eccentricities greater than 30°, in both nasal and temporal meridians. The oblique astigmatic component, J45, was not significantly different between the test conditions. The primary spherical aberration coefficient C(4, 0) was significantly less positive for the non-cycloplegic state than its cycloplegic counterpart. This result held true across the entire horizontal visual field. The horizontal coma and trefoil coefficients C(3, 1) and C(3, 3) were not significantly different between the two conditions.

CONCLUSIONS

The use of +1.00 D fogging lens without cycloplegia did not provide complete relaxation of accommodation. The discrepancies between cycloplegic and non-cycloplegic EM measurements were found to be more pronounced for peripheral field angles than central measures, for both M and J180 components.

Safety and Proof-of-Concept Study of Oral QLT091001 in Retinitis Pigmentosa Due to Inherited Deficiencies of Retinal Pigment Epithelial 65 Protein (RPE65) or Lecithin:Retinol Acyltransferase (LRAT)

Restoring vision in inherited retinal degenerations remains an unmet medical need. In mice exhibiting a genetically engineered block of the visual cycle, vision was recently successfully restored by oral administration of 9-cis-retinyl acetate (QLT091001). Safety and visual outcomes of a once-daily oral dose of 40 mg/m²/day QLT091001 for 7 consecutive days was investigated in an international, multi-center, open-label, proof-of-concept study in 18 patients with RPE65- or LRAT-related retinitis pigmentosa. Eight of 18 patients (44%) showed a ≥20% increase and 4 of 18 (22%) showed a ≥40% increase in functional retinal area determined from Goldmann visual fields; 12 (67%) and 5 (28%) of 18 patients showed a ≥5 and ≥10 ETDRS letter score increase of visual acuity, respectively, in one or both eyes at two or more visits within 2 months of treatment. In two patients who underwent fMRI, a significant positive response was measured to stimuli of medium contrast, moving, pattern targets in both left and right hemispheres of the occipital cortex. There were no serious adverse events. Treatment-related adverse events were transient and the most common included headache, photophobia, nausea, vomiting, and minor biochemical abnormalities. Measuring the outer segment length of the photoreceptor layer with high-definition optical coherence tomography was highly predictive of treatment responses with responders having a significantly larger baseline outer segment thickness (11.7 ± 4.8 μm, mean ± 95% CI) than non-responders (3.5 ± 1.2 μm). This structure-function relationship suggests that treatment with QLT091001 is more likely to be efficacious if there is sufficient photoreceptor integrity.

Systemic and Ocular Hemodynamic Risk Factors in Glaucoma

Primary open angle glaucoma (POAG) is a multifactorial disease characterized by progressive retinal ganglion cell death and visual field loss. It is known that alterations in intraocular pressure (IOP), blood pressure (BP), and ocular perfusion pressure (OPP) can play a significant role in the pathogenesis of the disease. Impaired autoregulatory capacity of ocular blood vessels may render tissues vulnerable to OPP changes and potentially harmful tissue ischemia-reperfusion damage. Vascular risk factors should be considered more important in a subgroup of patients with POAG, and especially in patients with normal tension glaucoma (NTG) with evidence of unphysiological BP response. For example, reduction of BP during the nighttime has an influence on OPP, and increased circadian OPP fluctuation, which might stand for unstable ocular blood flow, has been found to be the consistent risk factor for NTG development and progression. Central visual field may be affected more severely than peripheral visual field in NTG patients with higher 24-hour fluctuation of OPP. This review will discuss the current understanding of allegedly major systemic and ocular hemodynamic risk factors for glaucoma including systemic hypertension, arterial stiffness, antihypertensive medication, exaggerated nocturnal hypotension, OPP, and autonomic dysregulation.

[CANNABIS AND GLAUCOMA: AN ANCIENT LEGEND OR A NOVEL THERAPEUTIC HORIZON?]

Glaucoma causes damage to the optic nerve and compromises the visual field. The main risk factor of the disease is the level of the intra-ocular pressure. Therapeutic options include medical and surgical treatment, aimed to lower the intra-ocular pressure. Consumption of the cannabis plant (Cannabis Satival has been known since ancient times. It can be consumed orally, topically, intra-venous or by inhalation. The main active ingredient of cannabis is THC (Tetra-Hydro-Cannabinol). One of THC's reported effects is the reduction of intra-ocular pressure. Several studies have demonstrated temporary intra-ocular pressure decrease in both healthy subjects and glaucoma patients following topical application or systemic consumption. The effect was a short term one. It was followed by the development of resistance to the drug after prolonged intake and it was also accompanied by topical and systemic side effects. Cannabis may be considered as a therapeutic option in glaucoma. Its limited effect, development of resistance, acquired side effects and the accompanying psycho-active influence limit its advantage and cause its efficacy to be dubious. Therefore, cannabis treatment for glaucoma currently seems impractical and is not recommended by either the Israeli or the American glaucoma societies.

Latanoprost for open-angle glaucoma (UKGTS): a randomised, multicentre, placebo-controlled trial

BACKGROUND

Treatments for open-angle glaucoma aim to prevent vision loss through lowering of intraocular pressure, but to our knowledge no placebo-controlled trials have assessed visual function preservation, and the observation periods of previous (unmasked) trials have typically been at least 5 years. We assessed vision preservation in patients given latanoprost compared with those given placebo.

METHODS

In this randomised, triple-masked, placebo-controlled trial, we enrolled patients with newly diagnosed open-angle glaucoma at ten UK centres (tertiary referral centres, teaching hospitals, and district general hospitals). Eligible patients were randomly allocated (1:1) with a website-generated randomisation schedule, stratified by centre and with a permuted block design, to receive either latanoprost 0·005% (intervention group) or placebo (control group) eye drops. Drops were administered from identical bottles, once a day, to both eyes. The primary outcome was time to visual field deterioration within 24 months. Analyses were done in all individuals with follow-up data. The Data and Safety Monitoring Committee (DSMC) recommended stopping the trial on Jan 6, 2011 (last patient visit July, 2011), after an interim analysis, and suggested a change in primary outcome from the difference in proportions of patients with incident progression between groups to time to visual field deterioration within 24 months. This trial is registered, number ISRCTN96423140.

FINDINGS

We enrolled 516 individuals between Dec 1, 2006, and March 16, 2010. Baseline mean intraocular pressure was 19·6 mm Hg (SD 4·6) in 258 patients in the latanoprost group and 20·1 mm Hg (4·8) in 258 controls. At 24 months, mean reduction in intraocular pressure was 3·8 mm Hg (4·0) in 231 patients assessed in the latanoprost group and 0·9 mm Hg (3·8) in 230 patients assessed in the placebo group. Visual field preservation was significantly longer in the latanoprost group than in the placebo group: adjusted hazard ratio (HR) 0·44 (95% CI 0·28-0·69; p=0·0003). We noted 18 serious adverse events, none attributable to the study drug.

INTERPRETATION

This is the first randomised placebo-controlled trial to show preservation of the visual field with an intraocular-pressure-lowering drug in patients with open-angle glaucoma. The study design enabled significant differences in vision to be assessed in a relatively short observation period.

FUNDING

Pfizer, UK National Institute for Health Research Biomedical Research Centre.

Brain and optic chiasmal herniation following cabergoline treatment for a giant prolactinoma: wait or intervene?

OBJECTIVE

Dopamine agonists (DA) are the treatment of choice in patients with macroprolactinomas. Brain and optic chiasm herniation are unusual complications following treatment with DA.

REPORT

We present a case of a giant prolactinoma complicated by visual deterioration following cabergoline treatment. A 42-year-old man was admitted with seizures, right visual loss and visual defect in the upper left temporal quadrant. Magnetic resonance imaging (MRI) identified a giant adenoma, which proved to be a prolactinoma, compressing the optic chiasm and extending into the suprasellar region. Treatment with cabergoline was initiated resulting in improvement in visual fields, tumor shrinkage and prolactin level decrease. Five months later and despite tumor reduction, a deterioration of his visual fields was observed. The second MRI revealed brain and optic chiasmal herniation into the pituitary sella. Cabergoline dose was reduced and surgical resection of the adenoma along with untethering of the optic nerve was performed leading to improvement of the visual defects.

CONCLUSIONS

This report describes a rare case of brain and optic chiasmal herniation attributed to DA therapy for a macroprolactinoma. It is important for clinicians to examine visual fields and promptly identify any visual deterioration in patients with macroprolactinomas receiving DA treatment.

Attenuation of the retinal nerve fibre layer and reduced retinal function assessed by optical coherence tomography and full-field electroretinography in patients exposed to vigabatrin medication

PURPOSE

To investigate the clinical value of assessment of peripapillary retinal nerve fibre layer (RNFL) thickness with OCT in addition to the evaluation of retinal function measured by full-field electroretinography (ff-ERG) in patients with suspected vigabatrin (VGB)-attributed visual field defects.

METHODS

Visual fields from adult patients in our clinical follow-up program for VGB medication were analysed. Twelve patients with suspected VGB-attributed visual field defects were selected for the study. They were re-examined with computerized kinetic perimetry, ff-ERG and OCT (2D circle scan).

RESULTS

Constricted visual fields were found in all patients. Comparative analysis of ff-ERG parameters showed reduced b-wave amplitudes for the isolated and the combined rod and cone responses (p < 0.0001). The a-wave, reflecting photoreceptor activity, was reduced (p = 0.001), as well as the summed amplitude of oscillatory potentials (p = 0.029), corresponding to inner retinal function. OCT measurements demonstrated attenuation of the RNFL in nine of 12 patients, most frequently superiorly and/or inferiorly. No temporal attenuation was found. Significant positive correlations were found between the total averaged RNFL thickness, superior and inferior RNFL thickness and reduced ff-ERG parameters. Positive correlations were also found between RNFL thickness and isopter areas.

CONCLUSION

OCT measurements can detect attenuation of the RNFL in patients exposed to VGB medication. RNFL thickness correlates with reduced ff-ERG parameters and isopter areas of constricted visual fields, indicating that VGB is retino-toxic on several levels, from photoreceptors to ganglion cells. The study also supports previous studies, suggesting that OCT measurement of the RNFL thickness may be of clinical value in monitoring patients on vigabatrin therapy.

Chlorogenic acid supplementation improves multifocal electroretinography in patients with retinitis pigmentosa

To evaluate the effect of chlorogenic acid supplementation in patients with retinitis pigmentosa, we evaluated objective change in visual function with multifocal electroretinography, along with visual acuity, visual field, standard electroretinography, and contrast sensitivity. Eighteen patients diagnosed with retinitis pigmentosa were enrolled in this prospective, non-comparative, single-arm study. Multifocal electroretinography, best-corrected visual acuity in Early Treatment Diabetic Retinopathy Study letters, total point score on visual field examination with Humphrey Field Analyzer II, electroretinography, and contrast sensitivity were measured and repeated after 3 months supplementation with chlorogenic acid. The amplitude of ring 5 was significantly higher on multifocal electroretinography after 3 months of chlorogenic acid supplementation (7.2 ± 9.5 vs 8.3 ± 10.8 nV/deg(2), mean ± standard deviation, P = 0.022). There were no significant changes in the best-corrected visual acuity, total point score on Humphrey Field Analyzer, 30 Hz flicker amplitude on standard electroretinography, or contrast sensitivity. Chlorogenic acid may have a beneficial effect on the peripheral area at the margins of retinal degeneration, and should be considered as an anti-oxidant for the management of retinitis pigmentosa.

[Enhanced ocular staining score in patients with primary Sjögren's syndrome]

The authors focus on the assessment of ocular manifestation in patients with primary Sjögren's syndrome using the Ocular Staining Score. The method offers the possibility to stain different ocular structures separately: cornea with fluorescein and conjunctiva with lissamine green dye and provides for separate evaluation of abnormalities, unlike the current system assessing ocular damage where ocular tissues are stained either with bengal rose or lissamine green dye. The paper presents new criteria for the diagnosis of dry eye secondary to the autoimmune Sjögren's syndrome and their high specificity (94.7% and 93.3%)ö based on the results of clinical trials in 1618 patients, conducted by an international research team.

Modelling the risk of visual field loss arising from long-term exposure to the antiepileptic drug vigabatrin: a cross-sectional approach

BACKGROUND

The antiepileptic drug vigabatrin has been used widely since 1989, but has only been approved for use in the US since 2009. The risk:benefit of vigabatrin is generally predicated upon an assumed frequency of associated visual field loss (VAVFL) of approximately 31 %. This estimate is based upon relatively short-term usage (up to 4-5 years) and it is essential to determine whether the frequency of VAVFL increases with longer-term usage.

OBJECTIVE

The aim of this study was to model, from cross-sectional evidence, over greater ranges of treatment duration and cumulative dose than previously evaluated, the risk (frequency) of VAVFL with increasing exposure to vigabatrin.

STUDY DESIGN AND SETTING

This was a retrospective cohort study undertaken in a regional hospital epilepsy clinic.

PATIENTS

The cohort comprised 147 consecutive patients treated with vigabatrin for refractory complex partial (focal) seizures, who had all undergone ophthalmological examination and who had undertaken perimetry, reliably, according to a standard and robust protocol. The visual field plots were evaluated masked to treatment duration and dose.

MAIN OUTCOME MEASURE

The risk (frequency) of VAVFL with increasing exposure to vigabatrin was modelled, from the cross-sectional evidence, by standard and plateau logistic regression.

RESULTS

The cohort comprised 80 females and 67 males (mean age 40.3 years, standard deviation 13.7). The median duration of vigabatrin exposure was 7.9 years (interquartile range 3.6-11.0, range 0.2-16.1 years); 46 patients (31 %) had received vigabatrin for over 10 years. Eighty-seven patients (59 %) exhibited VAVFL; the proportion with VAVFL was higher in males (66 %) than females (54 %). The plateau model for duration and for cumulative dose exhibited a better fit than the standard model (both p < 0.001). The modelled frequency of VAVFL increased with increasing exposure up to approximately 6 years duration and 5 kg cumulative dose, and plateaued at approximately 76 % (95 % CI 67-85) and 79 % (95 % CI 70-87), respectively. Severity of VAVFL, classified in terms of the visual field index Mean Deviation, was not significantly associated with either duration or cumulative dose of therapy.

CONCLUSION

Clinicians and patients, in enabling informed choice, should be alert to the possible substantial increased risk:benefit for VAVFL with increasing long-term exposure to vigabatrin and the ensuing increased cost:benefit resulting from the necessary additional visual assessments.

Rapid and efficient directed differentiation of human pluripotent stem cells into retinal pigmented epithelium

Controlling the differentiation of human pluripotent stem cells is the goal of many laboratories, both to study normal human development and to generate cells for transplantation. One important cell type under investigation is the retinal pigmented epithelium (RPE). Age-related macular degeneration (AMD), the leading cause of blindness in the Western world, is caused by dysfunction and death of the RPE. Currently, RPE derived from human embryonic stem cells are in clinical trials for the treatment of AMD. Although protocols to generate RPE from human pluripotent stem cells have become more efficient since the first report in 2004, they are still time-consuming and relatively inefficient. We have found that the addition of defined factors at specific times leads to conversion of approximately 80% of the cells to an RPE phenotype in only 14 days. This protocol should be useful for rapidly generating RPE for transplantation as well as for studying RPE development in vitro.

[Efficacy of carotid endarterectomy in patients with stenosis of carotid arteries and acute vision impairment]

The article deals with comparing efficacy (improved function of the eye) of surgical and conservative treatment of patients presenting with atherosclerotic stenosis of carotid arteries and acute vision disorders. The surgery group (carotid endarterectomy) comprised a total of 49 patients and the conservative-treatment group consisted of 50 subjects. Methods of examination included: determining visual acuity (VA), autorefractometry, direct and reverse ophthalmoscopy under the conditions of mydriasis, contactless computed tomography, computer-assisted static perimetry, assessment of the functional state of the optic nerve (ON) with determination of the parameters of the threshold of electric sensitivity and lability of the optic nerve by phosphene, ultrasonographic scanning of ophthalmic arteries and carotid arteries. The terms of examination were as follows: at baseline, one months and one year after surgery or conservative treatment. The results (by the groups) were as follows: in amaurosis fugas - improvement of VA by 0.1 and more: 15 and 0 (p<0.001), disappearance of fits of amaurosis fugas: 16 and 3 (p<0.001), widening of the fields of vision: 16 and 0 (p<0.001), improvement of the condition of the optic nerve: 16 and 0 (p<0.001), maximal increase of systolic blood velocity in the arteries of the eye (Vs): by 30% and 0. In occlusion of the central retinal artery and its branches - improvement of VA by 0.1 and more: 8 and 1 (p=0.005), widening of the fields of vision: 6 and 2 (p = 0.112), improved condition of the optic nerve: 14 and 0 (p<0.001), increase in the Vs: 40% and 0. In acute ischaemic neuropathy - improvement of VA by 0.1 and more: 9 and 2 (p<0.001), widening of the fields of vision: 9 and 3 (p=0.004), improved condition of the optic nerve: 11 and 0 (p<0.001), increased Vs: 40% and 0. Total - improvement of VA by 0.1 and more: 32 and 2 (p<0.001), widening of the fields of vision: 31 and 8 (p<0.001), improved condition of the optic nerve: 41 and 0 (p<0.001), Vs increase: 40% and 0. Carotid endarterectomy effectively improves the functional state of the eye in patients with stenosis of carotid arteries and acute vision impairments.

Long-term occupational exposure to organic solvents affects color vision, contrast sensitivity and visual fields

The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males) and 25 controls with no history of chronic exposure to solvents (10 males). All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6±6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT). Visual field assessment consisted of white-on-white 24–2 automatic perimetry (Humphrey II-750i). Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd). Results from both groups were compared using the Mann–Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01). Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01), and their ellipse area and ellipticity were higher (p<0.01). Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01) and in MD and PSD indexes (p<0.01). Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01) except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05), indexes of the Lanthony D15d (rho = 0.52; p<0.05), perimetry results in the fovea (rho = −0.51; p<0.05) and at 3, 9 and 15 degrees of eccentricity (rho = −0.46; p<0.05). Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

[The influence of water soluble antioxidant agent (mexidol) on optic nerve and blood flow velocity in ocular and orbital arteries in patients with primary open-angle glaucoma]

The prospective single-blind placebo-controlled randomized trial is devoted to influence of mexidol (2-ethil-6-methil-3-hydroxipiridine succinate) on dynamics of optic nerve electrophysiologic profile and velocity indices of blood flow in ocular and orbital arteries in correlation with changes of retinal photosensitivity, visual acuity and visual field size during course of intravenous mexidol infusions and standard treatment of primary open-angle glaucoma. 2 weeks of intravenous infusions of 300 mg mexidol daily was found to cause depression of optic nerve electrical sensitivity threshold and widening of total visual field (16 mm2 test stimulus) after 14 days of treatment. These effects were not associated with changes of blood flow velocity in ocular and orbital arteries, were transient and came to initial indices 3 months after the end of treatment. Delayed vasotropic effect of mexidol manifested in increase of blood flow velocity in central retinal artery in 90 days after the end of infusions.

Balancing clinical benefits of vigabatrin with its associated risk of vision loss

Vigabatrin is an effective and well-tolerated antiepileptic drug (AED) for the treatment of refractory complex partial seizures (rCPS) and infantile spasms (IS), but its benefits must be evaluated in conjunction with its risk of retinopathy with the development of peripheral visual field defects (pVFDs). Vigabatrin should be considered for rCPS if a patient has failed appropriate trials of other AEDs or is not a suitable candidate for other AEDs, is not an optimal surgical candidate, and continues to experience debilitating effects from seizures. Vigabatrin is indicated as monotherapy for pediatric patients with IS. Its efficacy in achieving improved seizure control should be apparent within 12 weeks in patients with rCPS and within 2-4 weeks after attaining appropriate dosage for patients with IS. Because 12 weeks is well less than the known time of onset of visual defects, the risk of developing pVFDs may be minimized by discontinuing vigabatrin early during the course of therapy for patients with inadequate response. Appropriate vision screening is recommended at baseline, every 3 months during continued vigabatrin treatment, and at 3-6 months after discontinuation (if therapy has spanned more than a few months). If a pVFD is detected at any point and the decision is made to discontinue therapy, the pVFD is not likely to progress after discontinuation of vigabatrin. Although some patients will be at risk of retinopathy, vigabatrin is an appropriate treatment option for patients who achieve substantial clinical benefit, especially given the severe consequences of rCPS and uncontrolled IS. While retinopathy with the development of pVFDs is a serious adverse event, it is not life-threatening and its risk can be effectively managed.

Coenzyme Q10 therapy in hereditary motor sensory neuropathy type VI with novel mitofusin 2 mutation

Hereditary motor sensory neuropathy type VI (HMSN VI) is hereditary neuropathy accompanied by optic neuropathy. The feasibility of Coenzyme Q10 (CoQ10) as a treatment for subacute visual impairment of HMSN VI was examined. A 37-year-old patient with HMSN VI with a novel mitofusin 2 mutation was treated with high dose of CoQ10 (200 mg/day) for eight months. Visual impairment was partially resolved after CoQ10 therapy. High dose CoQ10 therapy may improve the prognosis of subacute visual impairment in HMSN VI. To confirm the effectiveness of CoQ10 on HMSN VI, further studies are needed.

Understanding and interpreting vision safety issues with vigabatrin therapy

Vigabatrin is an irreversible inhibitor of γ-aminobutyric acid (GABA) transaminase. It is effective as adjunctive therapy for adult patients with refractory complex partial seizures (rCPS) who have inadequately responded to several alternative treatments and as monotherapy for children aged 1 month to 2 years with infantile spasms. The well-documented safety profile of vigabatrin includes risk of retinopathy characterized by irreversible, bilateral, concentric peripheral visual field constriction. Thus, monitoring of visual function to understand the occurrence and manage the potential consequences of peripheral visual field defects (pVFDs) is now required for all patients who receive vigabatrin. However, screening for pVFDs for patients with epilepsy was conducted only after the association between vigabatrin and pVFDs was established. We examined the potential association between pVFDs and epilepsy in vigabatrin-naïve patients and attempted to identify confounding factors (e.g., concomitant medications, method of vision assessment) to more accurately delineate the prevalence of pVFDs directly associated with vigabatrin. Results of a prospective cohort study as well as several case series and case reports suggest that bilateral visual field constriction is not restricted to patients exposed to vigabatrin but has also been detected, although much less frequently, in vigabatrin-naïve patients with epilepsy, including those who received treatment with other GABAergic antiepileptic therapy. We also reviewed published data suggesting an association between vigabatrin-associated retinal toxicity and taurine deficiency, as well as the potential role of taurine in the prevention of this retinopathy.

Rapid plasticity of visual responses in the adult lateral geniculate nucleus

Compared to the developing visual system, where neuronal plasticity has been well characterized at multiple levels, little is known about plasticity in the adult, particularly within subcortical structures. We made intraocular injections of 2-amino-4-phosphonobutyric acid (APB) in adult cats to block visual responses in On-center retinal ganglion cells and examined the consequences on visual responses in the lateral geniculate nucleus (LGN) of the thalamus. In contrast to current views of retinogeniculate organization, which hold that On-center LGN neurons should become silent with APB, we find that ∼50% of On-center neurons rapidly develop Off-center responses. The time course of these emergent responses and the actions of APB in the retina indicate the plasticity occurs within the LGN. These results suggest there is greater divergence of retinogeniculate connections than previously recognized and that functionally silent, nonspecific retinal inputs can serve as a substrate for rapid plasticity in the adult.

Retinal nerve fibre layer attenuation: clinical indicator for vigabatrin toxicity

PURPOSE

To investigate whether persistent visual field defects among patients exposed once to the antiepileptic drug vigabatrin (VGB) were associated with peripapillary retinal nerve fibre layer thickness (RNFLT) attenuation.

METHODS

Nine individuals with partial epilepsy and VGB-attributed visual field loss (group 1; 18 eyes) and seven age- and gender-matched individuals with epilepsy and no previous VGB exposure (group 2; 14 eyes) were included in the study. Full-field 120 point screening perimetry out to 60 degrees from central fixation using the Humphrey Field Analyzer was performed. RNFLT was quantified by optical coherence tomography (OCT) using Fast RNFLT protocol, Stratus OCT (3.0) after pupillary dilation. The results from the right eye are presented in this article.

RESULTS

Among the patients with VGB-attributed visual field loss, five patients had only peripheral field defect (group 1a) and the remaining four had advanced field defects both in the periphery and within 30° from central fixation (group 1b). None of the patients in the control group had manifest visual field loss. The mean RNFLT among the patients with VGB-attributed visual field loss was significantly attenuated compared to the controls [mean total RNFLT: group 1: 75.6 ± 12.7 μm, group 2: 103.5 ± 9.7 μm, mean difference 27.9 μm, (CI 15.9-39.9; p < 0.001)]. RNFLT values classified as borderline according to normative database (Stratus OCT) occurred more frequently among individuals with VGB-attributed visual field loss than in controls (frequency in group 1: 6/9; group 2: 0/7, p = 0.011). The nasal, superior and inferior quadrants of RNFLT in individuals with VGB-attributed visual field loss were significantly attenuated, while no difference was detected in temporal quadrants compared to controls. Both individuals with peripheral and those with advanced visual field losses in the VGB group had attenuated mean total RNFLT compared to controls (p = 0.006, p = 0.002, respectively). Occurrence of borderline classification of total RNFLT ≤5th percentile was more frequent among individuals with advanced visual field loss than among controls (p = 0.048).

CONCLUSION

Persistent visual field loss attributed to VGB is associated with reduced peripapillary RNFLT and was detected both among patients with advanced and among patients with only peripheral visual field defects. Measurements of RNFLT with OCT might be considered as a diagnostic supplement in the follow-up of patients exposed to vigabatrin.

Effects of erectile dysfunction drugs on eyes

With the increasingly extensive application of erectile dysfunction (ED) drugs , it is of importance for an ophthalmologist to understand the association between these drugs and human eyes. In this study, we retrospectively studied the effects of ED drugs on human eyes, including visual symptoms, ophthalmological electrophysiology, ocular blood flow, intraocular pressure, visual field, retina, cerebral hemodynamics and nervous system and retinal blood vessels, particularly focusing on the relationship between these agents and nonarteritic ischemic optic neuropathy (NAION), in order to highlight the ocular adverse effects induced by these agents thus contributing to preventive measures.

[Assessment of visual function under treatment with topical antiglaucoma agents and systemic vasodilators. Clinical study on glaucoma patients]

The authors present some observations regarding the use of topical anti-glaucoma therapy and systemic vasodilators.

MATERIAL AND METHODS

The study was carried out on a series of 996 glaucoma patients, of which 54.1% with primary open-angle glaucoma, 5.7% closed-angle glaucoma, and 17.6% with normal intraocular pressure.

RESULTS

Intraocular pressure and visual field were assessed after the use of such therapeutic methods as carbonic anhydrase inhibitors (dorzolamide) and prostaglandin (latanoprost) and dorzolamide (cosopt) association.

CONCLUSIONS

The favorable progression of glaucoma could be improved by using new etiopathogenic mechanisms and treatment approaches.

Retinal disorders in northern Brazilian patients treated with chloroquine assessed by multifocal ERG

The effects of chloroquine intake on the retinal function in a Brazilian population of patients were assessed by multifocal electroretinography. Twenty-four randomly chosen eyes of patients treated with chloroquine for rheumatoid arthritis and systemic lupus erythematosus were examined using multifocal electroretinography (mfERG). Control measurements were acquired from 21 randomly chosen eyes of age-matched healthy subjects. None of the study participants had an inherited retinal disease or a Snellen visual acuity reduced to less than 20/40. In patients and control subjects, cumulative chloroquine dose, total daily dose, duration of treatment, retinal examination, visual field defects, visual acuity, and the mfERG were assessed. The average amplitudes and implicit times of the N1, P1, and P2 components of the mfERGs were measured in the central hexagon (R1) and in five rings (R2-R6). The values measured in patients and normal subjects were compared. The P1 amplitudes in R2 were significantly decreased in the patients. In addition, the amplitudes of N1 and N2 in R1 were significantly smaller in the patients. The implicit times of none of the components were significantly different between patients and controls. The response amplitude was not significantly correlated with cumulative dose and duration of intake. There was no correlation with retinal appearance, visual field, and visual acuity. In agreement with earlier data, the central mfERG amplitudes were decreased in chloroquine patients indicating functional alterations in the retina. These changes are also present in a Brazilian population suggesting that the effects of chloroquine are general and that genetic background and life circumstances probably have, if at all, only little effect.

Comparison of the effects of dorzolamide/timolol and latanoprost/timolol fixed combinations upon intraocular pressure and progression of visual field damage in primary open-angle glaucoma

OBJECTIVE

To report the long-term effect of the dorzolamide/timolol (DTFC) and latanoprost/timolol (LTFC) fixed combinations on intraocular pressure (IOP) and visual field defects over time in naïve primary open-angle glaucoma (POAG) patients.

STUDY DESIGN AND METHODS

Prospective, 4-year, open-label, interventional study.

SETTING

high-volume outpatient clinic.

PATIENTS

178 patients were assigned to receive medical treatment with either DTFC or LTFC.

INTERVENTION

over 4 years, tri-monthly IOP and yearly visual field assessment (Octopus 101, Program G2). outcomes: effect of treatment on IOP, visual field indices mean defect (MD), and visual field indices variance loss (VL) over time.

RESULTS

DTFC and LTFC significantly (p < or = 0.001) reduced mean IOP over time (from 22.6 +/- 3.0 to 13.8 +/- 1.9 mmHg and from 22.3 +/- 4.0 to 14.7 +/- 1.9 mmHg, respectively). In all, 56 patients (70.9%) and 14 (17.9%) showed a significant MD improvement in the DTFC- and LTFC-treated groups, respectively, p = 0.0001. DTFC progressively and significantly decreased mean VL (from 30.21 +/- 23.88 to 8.11 +/- 8.50 dB). Mean sensitivity slopes during follow-up were 1.14 dB/year and -0.34 dB/year for DTFC and LTFC treatment groups, respectively; p = 0.028.

CONCLUSION

Both treatments significantly reduced IOP as compared with baseline. Additionally, treatment with dorzolamide/timolol fixed combination seem to be effective in preventing glaucomatous visual field progression. This study has some limitations that should be noted, among them its open-label design.

Topical carbonic anhydrase inhibitors and visual function in glaucoma and ocular hypertension

BACKGROUND

Dorzolamide and brinzolamide are topical carbonic anhydrase inhibitors (CAI) indicated for patients with glaucoma and ocular hypertension.

SCOPE

An evidence-based review of clinical trials of dorzolamide and brinzolamide was undertaken to determine an effect of these medications on visual function (primarily visual field) in open-angle glaucoma and ocular hypertension. Using the keywords 'dorzolamide' and 'brinzolamide', all articles describing trials of these medications reporting on visual acuity, contrast sensitivity and visual field from September 1966 to July 2009 were found in MEDLINE and EMBASE databases. No information from other sources was included in this review.

FINDINGS

A relatively modest number of trials was identified, where impact of therapy on one or more of the visual function modes was reported. In the studies of less than 1 year duration (3 days to 1 year, 23 studies) in all but three studies treatment with topical CAIs did not influence visual function, in two studies with dorzolamide some improvement in the contrast sensitivity was observed and in one open-label retrospective no-control-group study with dorzolamide visual field indices improved significantly. A different picture was seen in long-term studies, which were designed and powered to detect changes in visual field. One large study (European Glaucoma Prevention Study) with dorzolamide versus placebo failed to detect significant protective effect of the drug on glaucoma occurrence in ocular hypertensives. Several interesting aspects of this study are discussed in detail. The other two long-term studies reported on the superiority of adding dorzolamide over timolol therapy alone, and the superiority of the combination of dorzolamide and timolol over brinzolamide and timolol in terms of improving ocular blood flow (retrobulbar Color Doppler Imaging--CDI parameters) as well as in terms of visual field preservation in glaucoma patients over 4 to 5 years.

CONCLUSION

For the first time one study could demonstrate that an improvement in ocular blood flow in the long run results in preservation of visual field in glaucoma patients. Dorzolamide, combined with the beta-blocker timolol, seems to be superior in this regard to brinzolamide plus timolol.