Electrophysiological findings in extensive macular atrophy with pseudodrusen.

PURPOSE: To present electroretinogram findings in extensive macular atrophy with pseudodrusen (EMAP) and describe associated systemic factors. DESIGN: Retrospective case series. METHODS: Data on medical history, visual symptoms, multimodal imaging findings, and visual field were collected from the medical records of patients with extensive macular atrophy with pseudodrusen who attended a visual electrophysiology laboratory. Electrophysiological tests, including full-field electroretinogram, multifocal electroretinogram and photopic negative response, were performed. RESULTS: Eighteen patients (10 [56%] females, age 49-66 years) were included. Of these, 17 (94%) had a history of rheumatic fever in childhood and/or adolescence, 7 (39%) had cardiovascular disease, 4 (22%) had autoimmune disease, and 10 (56%) had inflammatory conditions. The primary visual complaints were nyctalopia (95%), followed by visual field loss (67%) and dyschromatopsia (67%). The key retinal findings included retinal pigmented epithelium atrophy in the macular region and subretinal drusenoid deposits. Regarding electrophysiological results, 100% of patients had abnormalities on multifocal electroretinogram, 94% displayed alterations in photopic negative response, and 78% showed changes in the full-field electroretinogram. CONCLUSIONS: In this cohort, electrophysiologic evaluation demonstrated diffuse retinal dysfunction affecting all layers of the retina in patients with EMAP. The disease is associated with immune-mediated systemic conditions, chiefly rheumatic fever.

Contribution of objectively measured grating acuity by sweep visually evoked potentials to the diagnosis of unexplained visual loss.

PURPOSE: To investigate the diagnostic contribution of grating visual acuity (GVA) measured by sweep pattern-reversal visually evoked potentials (SPRVEP) in unexplained visual loss (UVL). METHODS: This case-control study included adult patients under suspicion of UVL referred to SPRVEP and transient pattern-reversal visually evoked potentials (TPRVEP) testing. Optotype visual acuity (OVA) was measured by ETDRS 4-meter chart and GVA by SPRVEP. UVL patients were assigned into three distinctive categories, according to the presence of ocular disease, motivation, and electrophysiological evaluation, as follows: exaggerators, malingerers, and psychogenic. Healthy controls and patients with organic visual loss were also tested. Receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic performance of GVA and TPRVEP parameters. RESULTS: A total of 76 patients with UVL were analyzed: 60 (79.0%) exaggerators, 11 (14.4%) malingerers, and 5 (6.6%) psychogenic. Controls were 49 subjects evaluated for TPRVEP and 28 subjects for SPRVEP. There were 13 patients with organic visual loss enrolled. Mean difference between OVA and GVA was 1.19±0.67 (median=0.84; 95% CI: 1.04 to 1.34) in UVL and 0.14 ±0.09 (median= 0.14; 95% CI: 0.08 to 0.20) in organic visual loss. The area under the ROC curve (AUC) of GVA to distinguish UVL from healthy controls was 0.998 with a cutoff of 0.09 logMAR showing specificity of 100% and sensitivity of 96.0%. CONCLUSIONS: GVA measured by SPRVEP had good diagnostic validity to discriminate patients with unexplained visual loss from healthy controls and patients with organic visual loss, demonstrating its contribution to the diagnosis of this condition.

Photopic negative response using a handheld mini-ganzfeld stimulator in healthy adults: normative values, intra- and inter-session variability.

PURPOSE: To determine normative values, intra- and inter-session variability for a range of parameters derived from the photopic negative response (PhNR) using a handheld mini-Ganzfeld stimulator in healthy normal adults. METHODS: Light-adapted flash full-field electroretinograms (ERGs) were recorded from healthy individuals with no visual complaints, visual acuity equal to or better than 0.0 logMAR (20/20 Snellen), and negative family history for visual diseases. ERGs were recorded from both eyes using a DTL® type fiber electrode after dilation of the pupils with instillation of 1 drop of tropicamide eye drops (1%). The full-field PhNR stimulus conditions were produced by a LED-based ColorBurst™ (Diagnosys LLC, Lowell, MA, USA) handheld stimulator. Red flashes of 1, 5 and 7 cd.s/m2 on a blue background of 10 cd/m2 were presented. A-wave, b-wave and PhNR amplitude (determined by both baseline to trough-BT and peak to trough-PT) and peak times were analyzed. Normal limits were determined as 5% percentile for amplitudes and 95% percentile for latencies. Intra- and inter-session variability were assessed with Wilcoxon signed-rank test, intraclass correlation coefficient (ICC) and the coefficient of variability (COV). RESULTS: Normative limits for PhNR amplitude (µV) using 1, 5 and 7 cd.s./m2 stimuli were, respectively: 20.81; 18.06 and 19.60 for BT and 69.11; 77.98; 76.51 for PT. Peak times (ms) normative limits for 1, 5 and 7 cd.s/m2 intensities were, respectively, 65.98; 78.20 and 77.96. Overall, intra-session variability assessed by coefficients of variation ranged from 1.35 to 10.28%. Inter-session variability disclosed significant intraclass correlation values for all PhNR parameters only for 1 cd.s/m2 stimuli. CONCLUSIONS: The normative values provided by this study are clinically helpful in the diagnosis of inner retinal disorders, especially those affecting retinal ganglion cells such as glaucoma and other optic neuropathies. Further studies, including a larger sample with variable age range would extend the validity of the current results.

Visual function assessed by visually evoked potentials in optic pathway low-grade gliomas with and without neurofibromatosis type 1.

PURPOSE: To investigate the contribution of full-field transient pattern-reversal visually evoked potentials (PRVEP) on cross-sectional evaluations of visual function in patients with and without neurofibromatosis type 1 (NF1) affected by optic pathway low-grade gliomas (OPLGG). METHODS: Participants were children and adolescents referred for visual function evaluation and receiving treatment for OPLGG, linked (NF1-OPLGG) or not to NF1 (Non-NF1-OPLGG). An age-adjusted control group was included for comparison. Monocular full-field PRVEPs were recorded from each eye in accordance with ISCEV standards. Parameters of peak-to-peak P100 amplitude (µV) and P100 peak time (ms) were measured. Cutoff normative values obtained from controls for 15' and 60' check sizes were ≥ 9.0 µV for N75-P100 amplitude and ≤ 103.0 ms for P100 peak time. The association of age, gender, tumor resection and NF1 with P100 amplitude reduction and P100 peak time delay was explored by Firth logistic regression modeling. RESULTS: Participants were 30 patients (15 males, 60% Non-NF1) with ages from 3.6 to 19.9 years (mean ± SD = 9.2 ± 3.8 years; median = 8.4 years) and 19 controls (12 males) with ages from 3.7 to 19.9 years (mean ± SD = 10.4 ± 4.9 years; median = 9.5 years). Overall, 68% of tested eyes presented reduced P100 amplitudes for both check sizes (46% in the NF-1 and 83% in the Non-NF1) and delayed P100 for both check sizes (38% in NF1 and 89% in Non-NF1). Absence of NF1 adjusted for age, gender and tumor resection was significantly associated with marginally reduced P100 amplitude for 15' checks [odds ratio (OR): 6.26; 95% confidence interval (CI) = 0.96-40.94; p = 0.055]. CONCLUSIONS: Full-field PRVEP on cross-sectional evaluations contributed to detect visual dysfunction in two-thirds of patients with OPLGG by highlighting subclinical evidence of visual loss. Abnormalities were more frequent and more severe in OPLGG not linked to NF1 than in NF1-OPLGG; however, there was a difference in surgical management between these groups. PRVEP parameters may provide reliable evidence of visual pathway involvement in OPLGG, helping to hasten treatment before optic atrophy is detected.

Gender-based normative values for pattern-reversal and flash visually evoked potentials under binocular and monocular stimulation in healthy adults.

PURPOSE: To determine gender-based normative values for pattern-reversal (PR) and flash (F) visually evoked potentials (VEP) under binocular and monocular stimulation in healthy adults. METHODS: Healthy adults (age ≥18 years) were recruited among university employees and students. Inclusion criteria were absence of abnormalities in fundoscopy, tracking ability, stereopsis and pupillary reflexes; best-corrected visual acuity ≤.00 logMAR; and refractive error (spherical equivalent) from -6.00 to +6.00. Exclusion criteria were previous intraocular surgery, systemic and/or neurological disorders. Binocular and monocular tests were performed according to International Society for Clinical Electrophysiology of Vision standards for PRVEP (reversal rate = 1.9 Hz, checkerboard stimuli 15' and 60' at 100% contrast) and FVEP (3 cd s/m2, rate = 1 Hz). VEP parameters of amplitude (µV) and peak times (ms) were measured. Inter-ocular differences, inter-peak intervals (N135-N75) and binocular summation were determined. RESULTS: Fifty-four subjects (28 females; mean age = 40.4 ± 13.7 years; median = 40.0 years) were included. Mean P100 latencies for 15' and 60' stimuli were, respectively, 94.6 ± 4.7 ms and 96.1 ± 4.2 for women. Mean values of P100 latency for men were 97.4 ± 4.9 for 15' and 97.7 ± 4.2 for 60' stimuli. Larger mean P100 for 15' checks was observed in women (12.8 ± 5.7 µV) than men (8.6 ± 2.5 µV) in PRVEP. Similar results were found for FVEP N2-P2 amplitudes (mean = 14.6 ± 4.9 for women and 9.8 ± 4.0 for men). CONCLUSIONS: Gender-based normative values for PRVEP and FVEP were determined, with women disclosing higher responses than men for smaller stimuli in the visual pathway. The use of gender-based normative values in the analysis of clinical VEP data for diagnostic and therapeutic purposes is recommendable. Additional analysis including inter-peak intervals and binocular summation ratio might improve the diagnostic power of VEP.

Contributing factors to VEP grating acuity deficit and inter-ocular acuity difference in children with cerebral visual impairment.

PURPOSE: To investigate contributing factors to visual evoked potential (VEP) grating acuity deficit (GAD) and inter-ocular acuity difference (IAD) measured by sweep-VEPs in children with cerebral visual impairment (CVI). METHODS: VEP GAD was calculated for the better acuity eye by subtracting acuity thresholds from mean normal VEP grating acuity according to norms from our own laboratory. Deficits were categorized as mild (0.17 ≤ deficit < 0.40 log units), moderate (0.40 ≤ deficit < 0.70 log units) or severe (deficit ≥0.70 log units). Maximum acceptable IAD was 0.10 log units. RESULTS: A group of 115 children (66 males-57 %) with ages ranging from 1.2 to 166.5 months (median = 17.7) was examined. VEP GAD ranged from 0.17 to 1.28 log units (mean = 0.68 ± 0.27; median = 0.71), and it was mild in 23 (20 %) children, moderate in 32 (28 %) and severe in 60 (52 %). Severe deficit was significantly associated with older age and anti-seizure drug therapy. IAD ranged from 0 to 0.49 log units (mean = 0.06 ± 0.08; median = 0.04) and was acceptable in 96 (83 %) children. Children with strabismus and nystagmus had IAD significantly larger compared to children with orthoposition. CONCLUSION: In a large cohort of children with CVI, variable severity of VEP GAD was found, with more than half of the children with severe deficits. Older children and those under anti-seizure therapy were at higher risk for larger deficits. Strabismus and nystagmus provided larger IADs. These results should be taken into account on the clinical management of children with this leading cause of bilateral visual impairment.

Regional Disparities in Prevalence and Causes of Visual Impairment and Blindness, Cataract Surgical Coverage and Ocular Findings in Adults 50 Years and Older in Brazil: A Comparative Analysis between Two Population-Based Cross-Sectional Surveys Performed Within a 10-Year Interval.

PURPOSE: To investigate disparities in the prevalence and causes of visual impairment and blindness, cataract surgical coverage, and ocular findings in older adults from two Brazilian geo-socio-demographic areas, São Paulo and Parintins cities. METHODS: Data from two population-based studies including participants 50 years and older from the cities of São Paulo (São Paulo Eye Study - SPES, 2004) and Parintins (Brazilian Amazon Region Eye Survey - BARES, 2014) were aggregated. RESULTS: A total of 5318 participants (3677 from SPES;1641 from BARES) were included. The prevalence of severe visual impairment (SVI) and blindness were, respectively, 0.74% (0.46-1.02) and 0.77% (0.48-1.05) in SPES and 1.72% (1.09-2.35) and 3.44% (2.55-4.33) in BARES. SVI and blindness were associated with BARES study [OR = 2.27 (1.30-3.95); p = .004 - SVI] [OR:4.07 (2.51-6.60); p < .001- blindness]; and older age [OR = 10.93 (4.20-28.45); p < .001 - SPES; OR = 17.96 (8.75-36.83); p < .001 - BARES] while higher education level was a protective factor [OR = 0.21 (0.05-0.95) - SPES; p = .042; OR = 0.21 (0.05-0.91); p = .037 - BARES]. Cataract was the main cause of bilateral severe visual impairment (25.93% in SPES and 64.29% in BARES) and bilateral blindness (21.43% in SPES and 35.71% in BARES). Cataract surgical coverage was significantly lower in BARES (36.32%) compared to SPES (57.75%). CONCLUSION: The prevalence of SVI and blindness was three times higher in older adults from the Brazilian Amazon compared to those living in São Paulo city, despite a 10-year interval between the two studies. These disparities should be mitigated by initiatives to promote access to eye care services targeting underprivileged and remote Brazilian areas.

Impact of pterygium on central corneal thickness measured by optical coherence tomography in older adults.

PURPOSE: To measure the central corneal thickness (CCT) using anterior segment optical coherence tomography (AS-OCT) in older adults with and without pterygium from the Brazilian Amazon Region Eye Survey (BARES). METHODS: BARES is a population-based epidemiological cross-sectional study conducted in Parintins city. Participants were residents ≥45 years of age identified through a door-to-door interview. Eligible participants were invited for a comprehensive eye exam. Pterygium occurrence and severity were assessed by ophthalmologists through slit-lamp examination considering its location (nasal or/and temporal) and severity (lesion with extension <3 mm, ≥3 mm not reaching the pupillary margin or ≥3 mm reaching the pupillary margin). CCTs were obtained and measurements from the more severely affected eye were included. Images were analyzed offline by masked observers. RESULTS: A total of 671 subjects, 533 (79.4%) with pterygium in at least one eye and 138 (20.6%) without pterygium in either eye, were examined. The mean CCT evaluated by multiple linear regression and adjusted for demographic variables and pterygium severity was 521 ± 34 µm (median = 521; range = 304-665). Decreased CCT was significantly associated with age and pterygium severity. Individuals aged 65-74 years had CCT 7 µm thinner than those aged 45-54 years (p = 0.044), individuals aged 75 years and older had CCT 15 µm thinner than those aged 45-54 years (p = 0.001), and eyes with severe pterygium had CCT 33 µm thinner than eyes without pterygium (p < 0.001). CONCLUSIONS: The CCT analysis in this population-based sample shows that a thinner cornea is associated with pterygium severity and older age.

Visual function assessed by visually evoked potentials in adults with orbital and other primary intracranial tumors.

PURPOSE: The purpose of this study was to assess visual function by visually evoked potentials in adults with orbital and other primary brain tumors affecting the optic pathway. METHODS: In this retrospective case-control series, patients with orbital (intraconal and extraconal) or midline/chiasmatic tumors were included. Visually evoked potentials using pattern-reversal visually evoked potential and flash visually evoked potential stimuli were performed according to the international standards. Outcome measures were visually evoked potential parameters of amplitude (µV) and peak times (ms) measured both for the P100 component (pattern-reversal visually evoked potentials) and the N2P2 complex (flash visually evoked potential). Individual results were also compared with gender-based normative values. RESULTS: A group of 21 adult patients (17 females) and age- and sex-matched controls were evaluated. Tumor location was intraconal (6 meningiomas, 3 hemangiomas, 1 glioma), extraconal (6 meningiomas), and midline (3 pituitary adenomas, 2 hypothalamic/chiasmatic low-grade gliomas). Abnormal fundus (76%), abnormal pupillary reflexes (71%), reduced visual acuity (62%), strabismus (48%), and proptosis (38%) were present. Visually evoked potential abnormalities were found in at least one eye of all cases. Affected eyes had significantly reduced amplitudes and prolonged peak times for pattern-reversal visually evoked potentials (p < .001) and significantly reduced amplitudes for flash visually evoked potential (p < .001). In unilateral orbital tumors, abnormally prolonged pattern-reversal visually evoked potential peak times were also detected in some contralateral eyes (n = 6/16). CONCLUSION: Visually evoked potential abnormalities were found in all adult patients with orbital and other intracranial primary tumors, even in eyes with normal exam and good visual acuity. Visually evoked potential can be used as a non-invasive ancillary test to characterize and monitor visual function in subjects with these neoplastic lesions.

Grating visual acuity impairment assessed by sweep visually evoked potentials in children with optic pathway tumors unable to perform optotype acuity tests.

PURPOSE: To determine visual impairment due to optic pathway tumors in children unable to perform recognition acuity tests. METHODS: Grating visual acuity scores, in logMAR, were obtained by sweep visually evoked potentials (SVEP) in children with optic pathway tumors. The binocular grating visual acuity deficit was calculated by comparison with age-based norms and then assigned to categories of visual impairment as mild (from 0.10 to 0.39 logMAR), moderate (from 0.40 to 0.79 logMAR), or severe (≥0.80 logMAR). Interocular differences were calculated by subtraction and considered increased if >0.10 logMAR. RESULTS: The participants were 25 children (13 boys; mean ± SD age, 35.1 ± 25.9 months; median age, 32.0 months) with optic pathway tumors (24 gliomas and 1 embryonal tumor), mostly located at the hypothalamic-chiasmatic transition (n=21; 84.0%) with visual abnormalities reported by parents (n=17; 68.0%). The mean grating acuity deficit was 0.60 ± 0.36 logMAR (median, 0.56 logMAR). Visual impairment was detected in all cases and was classified as mild in 10 (40.0%), moderate in 8 (32.0%), and severe in 7 (28.0%) children, along with increased interocular differences (>0.1 logMAR) (n=16; 64.0%). The remarkable ophthalmological abnormalities were nystagmus (n=17; 68.0%), optic disc cupping and/or pallor (n=13; 52.0%), strabismus (n=12; 48.0%), and poor visual behavior (n=9; 36.0%). CONCLUSION: In children with optic pathway tumors who were unable to perform recognition acuity tests, it was possible to quantify visual impairment by sweep-visually evoked potentials and to evaluate interocular differences in acuity. The severity of age-based grating visual acuity deficit and interocular differences was in accordance with ophthalmological abnormalities and neuroimaging results. Grating visual acuity deficit is useful for characterizing visual status in children with optic pathway tumors and for supporting neuro-oncologic management.

Visual evoked potentials findings in non-affected subjects from a large Brazilian pedigree of 11778 Leber's hereditary optic neuropathy.

To investigate pattern-reversal visual evoked potentials (PRVEP) in asymptomatic maternally and non-maternally related members from a large Brazilian 11778/ND4 LHON pedigree. Transient PRVEP for check sizes 15' and 60' were recorded from asymptomatic mutation carriers and non-mutant descendants of affected/non-affected males, all with best-corrected visual acuity of 20/20. A control group of spouses (off-pedigree) was also included. Parameters of N75, P100 and N135 latencies (ms) and N75-P100 peak-to-peak amplitude (µV) as well as temporal dispersion (latency of N135-latency of N75) were determined. Longitudinal testing was obtained in a subseries of carriers in three annual consecutive visits. We tested 48 asymptomatic mutation carriers, 19 descendants of affected males, 9 descendants of non-affected males and 27 off-pedigrees, all of the latter being non-mutant. All non-mutant male descendants did not differ from off-pedigree controls. Statistically prolonged P100 latencies were found in mutation carriers (P = 0.0143) when compared with off-pedigrees for check sizes 15', as well as significantly larger temporal dispersions for both check size 15' (P = 0.0012) and check size 60' (P = 0.0271). Serial testing in 15 mutation carriers disclosed prolonged P100 latencies and larger temporal dispersion that did not change over time. Subclinical PRVEP abnormalities were detected in this large group of asymptomatic carriers of the 11778/ND4 LHON mutation from the same family, confirming and extending previous psychophysical and structural findings of a selective involvement of the parvocellular pathway. PRVEP is a useful test to characterize and monitor visual dysfunction in this devastating disease.

Retinal function in patients treated with tamoxifen.

Tamoxifen, an effective treatment of breast cancer, has been shown to cause ocular toxic effects. The purpose of this study was to determine retinal toxicity by full-field and focal electroretinograms (ERGs) in patients treated with tamoxifen. Fullfield and focal ERGs were obtained from three groups: Tamoxifen-14 females (47-72 years, mean 58.3 + or - 9.1) with normal fundus, treated with tamoxifen from 2 to 37 months; No Treatment-10 females (39-65 years, mean 50.1 + or - 8.7) with previous breast cancer diagnosis and before tamoxifen treatment; Control-13 normal female volunteers (41-81 years, mean 52.7 + or - 12.1). Peak-to-peak amplitude and b-wave implicit time were measured and statistically analyzed.Mean peak-to-peak amplitudes and implicit time from full-field and focal ERGs were comparable for the three different groups. Low-dosage tamoxifen showed no retinotoxic effect assessed by full-field and focal ERG in this small group of women with breast cancer.

Impaired Ganglion Cell Function Objectively Assessed by the Photopic Negative Response in Affected and Asymptomatic Members From Brazilian Families With Leber's Hereditary Optic Neuropathy.

Purpose: The photopic negative response (PhNR) is an electrophysiological method that provides retinal ganglion cell function assessment using full-field stimulation that does not require clear optics or refractive correction. The purpose of this study was to assess ganglion cell function by PhNR in affected and asymptomatic carriers from Brazilian families with LHON. Methods: Individuals either under suspicion or previously diagnosed with LHON and their family members were invited to participate in this cross-sectional study. Screening for the most frequent LHON mtDNA mutations was performed. Visual acuity, color discrimination, visual fields, pattern-reversal visual evoked potentials (PRVEP), full-field electroretinography and PhNR were tested. A control group of healthy subjects was included. Full-field ERG PhNR were recorded using red (640 nm) flashes at 1 cd.s/m2, on blue (470 nm) rod saturating background. PhNR amplitude (µV) was measured using baseline-to-trough (BT). Optical coherence tomography scans of both the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) were measured. PhNR amplitudes among affected, carriers and controls were compared by Kruskal-Wallis test followed by post-hoc Dunn test. The associations between PhNR amplitude and OCT parameters were analyzed by Spearman rank correlation. Results: Participants were 24 LHON affected patients (23 males, mean age=30.5 ± 11.4 yrs) from 19 families with the following genotype: m.11778G>A [N = 15 (62%), 14 males]; m.14484T>C [N = 5 (21%), all males] and m.3460G>A [N = 4 (17%), all males] and 14 carriers [13 females, mean age: 43.2 ± 13.3 yrs; m.11778G>A (N = 11); m.3460G>A (N = 2) and m.14484T>C (N = 1)]. Controls were eight females and seven males (mean age: 32.6 ± 11.5 yrs). PhNR amplitudes were significantly reduced (p = 0.0001) in LHON affected (-5.96 ± 3.37 µV) compared to carriers (-16.53 ± 3.40 µV) and controls (-23.91 ± 4.83; p < 0.0001) and in carriers compared to controls (p = 0.01). A significant negative correlation was found between PhNR amplitude and total macular ganglion cell thickness (r = -0.62, p < 0.05). Severe abnormalities in color discrimination, visual fields and PRVEPs were found in affected and subclinical abnormalities in carriers. Conclusions: In this cohort of Brazilian families with LHON the photopic negative response was severely reduced in affected patients and mildly reduced in asymptomatic carriers suggesting possible subclinical abnormalities in the latter. These findings were similar among pathogenic mutations.

Population-Based Cataract Surgery Complications and Their Impact on Visual Status in the Brazilian Amazon Region.

PURPOSE: To investigate cataract surgery prevalence, complications, visual outcomes, and coverage in a population of older adults from the Brazilian Amazon region. DESIGN: Population-based cross-sectional study. METHODS: Individuals ≥45 years of age from urban and rural areas of Parintins City, Brazil, were identified by cluster random sampling. Participants underwent ophthalmic examination, including uncorrected visual acuity, acuity with presenting correction (APC), and best-corrected visual acuity (BCVA) from each eye. In those with previous cataract surgery, surgical technique and complications including its contribution to vision impairment were noted. The association of surgical complications and surgical coverage with sociodemographic variables was assessed by multiple logistic regression. RESULTS: A total of 2,384 persons were determined to be eligible, and 2,041 (85.6%) were examined. Overall, prevalence of cataract surgery was 8.6%, with 11.3% urban and 5.0% rural. Surgical complications were associated with males, older age, and urban residency and were found in 60.4%, with posterior capsule opacification in 29.6% and posterior capsule rupture in 16.3%. Among the 270 eyes having cataract surgery, APC ≥20/32 was found in 44.4%, APC 20/40 to 20/63 in 20.8%, APC <20/63 to 20/200 in 14.4%, APC <20/200 to 20/400 in 2.6%, and APC <20/400 in 17.8%. Low surgical coverage was found with 57.9% of those with visual impairment due to cataract not being treated surgically. CONCLUSIONS: Although a reasonable prevalence of cataract surgery was found, a high complication rate, poor visual outcomes, and low cataract surgery coverage indicated that actions to improve quality and appropriate postsurgical management should be planned and implemented by public health authorities.

Presbyopia and Ocular Conditions Causing Near Vision Impairment in Older Adults From the Brazilian Amazon Region.

PURPOSE: To investigate the prevalence and causes of near vision impairment (NVI) in a population of older adults from the Brazilian Amazon Region. DESIGN: Population-based cross-sectional study. METHODS: Cluster sampling was used in randomly selecting subjects 45 years of age and older from urban and rural areas of Parintins city, Brazil. Participants underwent ophthalmic examination, including uncorrected (UCNVA), presenting (PNVA), and best-corrected near visual acuity (BCNVA) from each eye; biomicroscopy; funduscopy; and subjective refraction, including testing with additional lenses for near vision optical correction. A principal cause for NVI was assigned by the ophthalmologist and presbyopia was defined as UCNVA ≤ 20/40 changing to > 20/40 with BCNVA. Free-of-charge glasses were provided for those in need. RESULTS: A total of 2384 subjects were enumerated and 2025 had reliable NVA measurements from both eyes. The prevalence of NVI in the better-seeing eye was 96.5% with UCNVA, decreasing to 81.1% with PNVA and to 20.5% with BCNVA. Presbyopia was the principal cause of NVI in 71.8%, followed by cataract (16.5%) and pterygium (2.5%), and was associated with younger age and high schooling. Glasses for near vision were prescribed and provided to 1414 (69.8%) participants. CONCLUSIONS: A high prevalence of NVI was detected even in those wearing glasses for near. Prescription and provision of low-cost reading glasses should be considered by Brazilian health authorities to address this easily and promptly correctable form of vision impairment.

[Pattern-reversal visual evoked potential abnormalities in patients with defined multiple sclerosis]. / Alterações encontradas no potencial visual evocado por padrão reverso em pacientes com esclerose múltipla definida.

INTRODUCTION: Multiple sclerosis is an idiopathic demyelinating disease that may affect the optic nerve leading to acute unilateral visual loss, which could be observed by means of evoked visual potential (VEP). This exam is much valued for studying prechiasmatic visual paths in multiple sclerosis. PURPOSE: To analyze the findings of pattern reversal VEP in patients with prior diagnosis of multiple sclerosis and to compare them to visual acuity. METHODS: Twenty-four patients with a definite diagnosis of multiple sclerosis were submitted to pattern reversal VEP from October 2001 to March 2007. RESULTS: In P100 component response, at 15' and 1 degree stimuli, 19 eyes presented latency response up to 115 ms in both stimuli, which coincided in 6 eyes with latency response between 116 and 135 ms; 11 eyes had a latency response higher than 135 ms, and four eyes did not respond to stimuli. Correlating visual acuity with P100 latency for 15', in Pearson r correlation, r=0.85 with p=0.000000123, and for 1 degree, r = 0.87 with p=0.0000000338. CONCLUSION: Approximately 60.4% of patients presented abnormalities. However, the correlation between the P100 latency (15' and 1 degree) and visual acuity was statistically significant; therefore the better the visual acuity, the better the response to stimuli of the pattern-reversal VEP.

Retinal function in patients with the neuronal ceroid lipofuscinosis phenotype.

PURPOSE:: To analyze the clinical features, visual acuity, and full-field electroretinogram (ERG) findings of 15 patients with the neuronal ceroid lipofuscinosis (NCL) phenotype and to establish the role of ERG testing in NCL diagnosis. METHODS:: The medical records of five patients with infantile NCL, five with Jansky-Bielschowsky disease, and five with juvenile NCL who underwent full-field ERG testing were retrospectively analyzed. RESULTS:: Progressive vision loss was the initial symptom in 66.7% of patients and was isolated or associated with ataxia, epilepsy, and neurodevelopmental involution. Epilepsy was present in 93.3% of patients, of whom 86.6% presented with neurodevelopmental involution. Fundus findings ranged from normal to pigmentary/atrophic abnormalities. Cone-rod, rod-cone, and both types of dysfunction were observed in six, one, and eight patients, respectively. CONCLUSION:: In our study, all patients with the NCL phenotype had abnormal ERG findings, and the majority exhibited both cone-rod and rod-cone dysfunction. We conclude that ERG is a valuable tool for the characterization of visual dysfunction in patients with the NCL phenotype and is useful for diagnosis.

The Photopic Negative Response: An Objective Measure of Retinal Ganglion Cell Function in Patients With Leber's Hereditary Optic Neuropathy.

Purpose: The photopic negative response (PhNR) is a slow negative component of a flash photopic full-field ERG that has been shown to be specific for retinal ganglion cell (RGC) activity. Direct evaluation of RGC function is desirable in patients with Leber's hereditary optic neuropathy (LHON) in which the loss of central acuity can make it difficult to monitor patients with standard metrics. The purpose of this study was to evaluate the use of PhNR as an objective noninvasive clinical metric in LHON. Methods: Full-field photopic ERG recordings were collected in subjects with the mt.11778G>A/ND4 LHON mutation using a red on blue stimulus. The PhNR was identified using a computer-based automated detection system, and data were manually examined to remove movement artifacts. Results: The PhNR amplitude was compared between controls (n = 13), carriers (n = 17), and affected (n = 6). Mean PhNR amplitude decreased significantly across groups (P < 0.0001). Post hoc Tukey's test revealed a significant decrease in PhNR amplitude between carriers and controls (P < 0.05) and between carriers and affected (P < 0.01). Conclusions: We are able to demonstrate that the PhNR amplitude is significantly decreased in patients affected by LHON compared to carriers in a well-described pedigree. Surprisingly, there was also a decrease in PhNR in carriers, suggesting potential subclinical RGC dysfunction in some carriers. This is important in patients affected with LHON who typically have a dense central scotoma. The PhNR may be a useful objective outcome measure for future clinical trials.

[Clinical and electroretinographic profile of commotio retinae]. / Perfil clínico e eletrorretinográfico da comoção retiniana.

PURPOSE: To investigate clinical, anatomic and electroretinographic changes in eyes that suffered blunt ocular trauma with commotio retinae. METHODS: Patients who presented commotio retinae after unilateral blunt ocular trauma less then 72 hours before were submitted to visual acuity testing, biomicroscopy, binocular indirect ophthalmoscopy, fluorescein angiography, optical coherence tomography and full-field electroretinography. Full-field ERG was repeated after 15 and 30 days. RESULTS: Sixteen patients were included in the study. On the first examination there was a statistically significant difference between affected and fellow eye in all response amplitudes, without b/a ratio alteration, and a delay in single-flash cone response and 30-Hz flicker implicit time. On the second examination, the difference between the eyes remained for oscillatory potentials, but disappeared on the last examination. In fluorescein angiography, all patients presented mottled hyperfluorescence and hypofluorescent areas, due to alterations in the pigment barrier. On optical coherence tomography, we found optically empty spaces at the site of the lesion. CONCLUSION: Found changes suggested photoreceptor and ganglion cells, but not Müller cell functional alterations, as well as pigment mobilization. These changes disappeared 30 days after the trauma.

Dysfunction in the fellow eyes of strabismic and anisometropic amblyopic children assessed by visually evoked potentials.

PURPOSE:: To evaluate visual acuity and transient pattern reversal (PR) visual evoked potentials (VEPs) in the fellow eyes of children with strabismic and/or anisometropic amblyopia. METHODS:: Children diagnosed with strabismic and/or anisometropic amblyopia were recruited for electrophysiological assessment by VEPs. Monocular grating and optotype acuity were measured using sweep-VEPs and an Early Treatment Diabetic Retinopathy Study chart, respectively. During the same visit, transient PR-VEPs of each eye were recorded using stimuli subtending with a visual angle of 60', 15', and 7.5'. Parameters of amplitude (in µV) and latency (in ms) were determined from VEP recordings. RESULTS:: A group of 40 strabismic and/or anisometropic amblyopic children (22 females: 55%, mean age= 8.7 ± 2.2 years, median= 8 years) was examined. A control group of 19 healthy children (13 females: 68.4%, mean age= 8.2 ± 2.6 years, median= 8 years) was also included. The fellow eyes of all amblyopes had significantly worse optotype acuity (p=0.021) than the control group, regardless of whether they were strabismic (p=0.040) or anisometropic (p=0.048). Overall, grating acuity was significantly worse in the fellow eyes of amblyopes (p=0.016) than in healthy controls. Statistically prolonged latency for visual angles of 15' and 7.5' (p=0.018 and 0.002, respectively) was found in the strabismic group when compared with the control group. For the smaller visual stimulus (7.5'), statistically prolonged latency was found among all fellow eyes of amblyopic children (p<0.001). CONCLUSIONS:: The fellow eyes of amblyopic children showed worse optotype and grating acuity, with subtle abnormalities in the PR-VEP detected as prolonged latencies for smaller size stimuli when compared with eyes of healthy children. These findings show the deleterious effects of amblyopia in several distinct visual functions, mainly those related to spatial vision.