Frequency Doubling Perimetry Research Articles

Retinal Function in Young Adults Following Topical Application of Levodopa to the Eye.

Levodopa has been investigated as a therapeutic solution for ocular disorders involving dysregulation of the dopaminergic system, especially in the context of myopia. However, given the critical role dopamine plays in normal vision, this phase I trial examined whether levodopa/carbidopa eye drops induce any regional changes in retinal structure and function. Twenty-nine healthy male subjects 18 to 30 years of age were randomly assigned to receive either a low (1.4/0.34 µmoles/day, n = 14) or high (2.7/0.68 µmoles/day, n = 15) dose of levodopa/carbidopa eye drops in 1 eye for 28 consecutive days. A placebo solution was applied to all fellow eyes. Measures included visual acuity, regional frequency doubling perimetry, regional multifocal electroretinogram (mfERG) and optical coherence tomography (retinal thickness). Outcome measures were undertaken at baseline, end-of-treatment (4 weeks), and at a follow-up (4 months post-treatment). For low dose treated eyes, regional analysis showed a small, statistically significant change in mfERG recordings (increase in ring 5 amplitude in low dose treated eyes, P < 0.05) and the retinal thickness map (localized retinal thinning in low dose treated eyes, P < 0.05). These changes were not clinically significant. No significant changes were observed in high dose treated eyes. Pharmacokinetic analysis (rabbits) demonstrated that levodopa was not detectable within blood and peaked within the eye at 15 to 30 minutes (and eliminated within 4 hours). No clinically significant effects of levodopa/carbidopa eye drops were found with regard to normal retinal structure and function following short-term use. This study further demonstrates the safety of topical levodopa, which may support its use in the treatment of ocular disorders in which the dopamine system is dysregulated.

EyeLife: A prospective glaucoma screening study with double‐blind genetic pre‐screening conducted within the population‐based Lifelines cohort

Purpose: Glaucoma screening potentially prevents blindness but is currently considered not cost effective due to insufficient screening test specificity given a low disease prevalence in the general population. Genetic pre‐screening could increase the prior probability (higher prevalence in a selected population). The aim of this study was to identify the relative risk of glaucoma in a subgroup of the general population with a high compared to one with a low genetic glaucoma risk.Methods: The study protocol has been published previously (PMID: 33413217). We invited 1600 participants from the European Lifelines cohort (n = 165 000) aged 55+. Participants belonged to either the highest or lowest 20% of a GWAS‐based genetic risk score distribution; subgroups had similar age and gender. Researchers and participants were blinded regarding subgroup allocation. All participants underwent frequency doubling perimetry (FDT), optical coherence tomography (OCT) of the peripapillary retinal nerve fibre layer, and fundus photography to assess the optic nerve head (ONH). Any abnormal test result resulted in an ophthalmic exam including gonioscopy. Participants were classified as definite (abnormal FDT and either abnormal OCT or ONH), probable (either abnormal FDT or abnormal OCT and ONH), or possible (normal FDT with either abnormal OCT or ONH) open‐angle glaucoma (OAG), or as healthy. We obtained the relative risk of combined definite and probable OAG compared to healthy, excluding possible OAG.Results: A total of 1031 participants responded (65%; 493 with high versus 538 with low risk). Of those, 31 (29 versus 2) were classified as definite and 28 (21 versus 7) as probable OAG. The prevalence of combined definite and probable OAG was 5.7%. The relative risk was 6.3 (95% CI 3.1–12.9).Conclusions: Genetic pre‐screening seems a promising way to increase the prior probability of glaucoma and thus make glaucoma screening more cost‐effective.

Magnocellular visual function in developmental dyslexia: deficit in frequency-doubling perimetry and ocular motor skills.

This study aimed to verify if patients with developmental dyslexia present deficits coherent with visual magnocellular dysfunction. Participants with confirmed diagnosis of developmental dyslexia (n=62; age range=8-25 years; mean age=13.8 years, standard deviation=3.9; 77% male) were compared to a control group with normal development, matched for age, sex, ocular dominance, visual acuity, and text comprehension. The frequency-doubling technology perimetry was used to evaluate the peripheral visual field contrast sensitivity threshold. The Visagraph III Eye-Movement Recording System was used to evaluate ocular motor skills during text reading. The developmental dyslexia group had significantly worse contrast sensitivity in the frequency-doubling technology, with strong effect size, than the matched control group. The developmental dyslexia group had more eyes classified in the impaired range of sensitivity threshold to detect frequency-doubling illusion than the control group. Moreover, the developmental dyslexia group had poorer ocular motor skills and reading performance, revealed by a difference in ocular fixations, regressions, span recognition, reading rate, and relative efficiency between groups. A significant correlation was found between contrast sensitivity and ocular motor skills. Participants with good relative efficiency had significantly better contrast sensitivity than participants with poor relative efficiency. The developmental dyslexia group presented a markedly worse performance in visual variables related to visual magnocellular function (i.e., frequency-doubling technology perimetry and ocular motor skills) compared with a matched control group. Professionals need to be aware of the importance of evaluating vision of individuals with developmental dyslexia beyond visual acuity and including in their assessments instruments to evaluate temporal processing, with contrast sensitivity threshold.

Treated PDR Reveals Age-Appropriate Vision Deterioration But Distorted Retinal Organization.

PurposeWe determined the progression of visual function, macular structure, and quality of life in patients with regressed proliferative diabetic retinopathy (PDR) after panretinal photocoagulation (PRP).MethodsIn this prospective study, 22 patients who underwent PRP for PDR and 11 age-matched control participants underwent examinations at baseline and after 5 years. Visual acuity, contrast sensitivity, reading acuity, frequency doubling perimetry, Humphrey field analyzer, and dark adaptation were measured. The Low Luminance Questionnaire and National Eye Institute Vision Function Questionnaire-25 were administered. Macular spectral-domain optical coherence tomography was taken.ResultsAfter 5 years, patients who had previously undergone PRP for PDR (18.4 ± 7.9 years previously) showed significant deterioration in contrast sensitivity, reading acuity, frequency doubling perimetry 24-2 pattern standard deviation, and Humphrey field analyzer 10-2 foveal sensitivity, which were equivalent to age-related decreases in control participants. They revealed no further impairment in vision-related activities on questionnaires. In contrast with controls, their maculas showed pathologic disorganization of the retinal layers, especially the nerve fiber layer, which were thicker and constituted a greater proportion of the overall retinal thickness than the norm and associated with impaired vision.ConclusionsPatients with treated PDR had age-related decreases in vision, but stable quality of life. Prior injuries from the diabetes and, possibly, laser treatment led to substantial disruption in the retinal structure, which may explain the loss of vision.Translational RelevanceDespite PRP treatment, patients with regressed PDR had pathologic progression of the nerve fiber layer; further investigation may identify a new therapeutic target to reverse the visual deficits.

SITA standard testing with Humphrey visual field analyzer versus full threshold testing with frequency doubling perimetry: a comparison of patient preference and perception

Purpose: To compare patient preference for Swedish Interactive Threshold Algorithm (SITA) standard 24-2 protocol in Humphrey visual field analyzer (HVF) and full threshold N-30 protocol in frequency doubling perimetry (FDP) by primarily evaluating their perception about the test procedure and test targets along with surveying the factors that influence the patient concentration during perimetry and elements that determine the level of perimetry task difficulty.&#x0D; Methods: This study enrolled a subset of subjects from the Chennai Glaucoma Study. Each subject underwent a comprehensive ophthalmic examination after which they were randomly allocated to perform HVF and FDP with a 30-minute interval between the two procedures. SITA standard 24-2 protocol in HVF and full threshold N-30 protocol in FDP were used. This was followed by the administration of a questionnaire that mainly assessed the components such as (a) the patient preference for test procedure and test targets, (b) the factors influencing the patient concentration during perimetry performance, and (c) the impression about the level of perimetry task difficulty. The patient responses from the survey for each of the subcategories were obtained and analyzed using Chi-square test.&#x0D; Results: A total of 42 subjects with a mean age of 59.7 (SD 9.7) years were included, among which 18 (42.86%) were male and 24 (57.14%) were female. Thirty-two (76.19%) subjects felt both FDP and HVF were easy to perform, eight subjects (19.05%) felt that both perimetry techniques were difficult to perform, and two subjects (4.76%) found FDP procedure was easier than HVF, whereas the distribution was not statistically significant (Chi-square, p = 0.7). Pressing the button as a response to peripheral stimulus perception and inability to maintain steady central fixation for prolonged duration were the most commonly reported factors that influenced the level of difficulty of the perimetry tasks. A dark room ambience set for performing HVF was preferred by 32 (76.20%) subjects.&#x0D; Conclusion: There was no significant difference in the patient preference for test procedure and peripheral test targets. A black central fixation as in FDP and dark room ambience set for HVF were preferred.

Steady-State Pattern Electroretinogram and Frequency Doubling Technology in Adult Dyslexic Readers.

PurposeDyslexia is a reading disorder with neurological deficit of the magnocellular pathway. The aim of our study was to evaluate the functionality of the magnocellular–Y (M–Y) retinal ganglion cells in adult dyslexic subjects using steady-state pattern electroretinogram and frequency doubling perimetry.MethodsTen patients with dyslexia (7 females and 3 males), mean age 28.7 ± 5.9 years, and 10 subjects without dyslexia (6 females and 4 males), mean age 27.8 ± 4.1 years, were enrolled in the study and underwent both steady-state pattern-electroretinogram examination and frequency doubling perimetry.ResultsThere was a significant difference in the amplitude of the steady-state pattern electroretinogram of the dyslexic group and the healthy controls (0.610±0.110 μV vs 1.250±0.296 μV; p=0.0001). Furthermore, in the dyslexic group we found a significant difference between the right eye and the left eye (0.671±0.11 μV vs 0.559±0.15 μV; p=0.001). With frequency doubling perimetry, the pattern standard deviation index increased in dyslexic eyes compared to healthy controls (4.40±0.81 dB vs 2.99±0.35 dB; p=0.0001) and in the left eye versus the right eye of the dyslexic group (4.43±1.10 dB vs 3.66±0.96 dB; p=0.031). There was a correlation between the reduction in the wave amplitude of the pattern electroretinogram and the simultaneous increase in the pattern standard deviation values (r=0.80; p=0.001). This correlation was also found to be present in the left eye (r=0.93; p<0.001) and the right eye (r=0.81; p=0.005) of dyslexic subjects.ConclusionOur study shows that there was an alteration of the activity of M–Y retinal ganglion cells, especially in the left eye. It confirms that in dyslexia there is a deficit of visual attention with damage not only of the magnocellular-dorsal pathway but also of the M-Y retinal ganglion cells.

Glaucoma in Community: An Opportunistic Screening in Cataract Screening Programs

Introduction: Glaucoma is an optic neuropathy for which elevated intraocular pressure is considered as major risk factor. Glaucoma is the second most common cause of blindness after cataract. Since visual loss in glaucoma is irreversible, management strategies must be focused upon early detection and prevention of disease progression through strict control of intraocular pressure.&#x0D; Objectives: To estimate the ocular morbidity of glaucoma in community screening camps and to estimate the types of glaucoma.&#x0D; Methodology: It is a Community based opportunistic screening program. Study was carried out at community screening camps for cataract from August 2009 to August 2010. Five hundred five patients equal and above 50 years were examined in five screening camps conducted in Kathmandu valley. Glaucoma suspects were identified on the basis of shallow anterior chamber, intraocular pressure &gt; 20 mm of Hg, abnormal frequency doubling perimetry (FDP), cup to disc ratio (CDR) &gt;0.7:1, asymmetric CDR &gt; 0.2:1, unhealthy NRR and the other disc findings suggestive of glaucoma. Glaucoma suspects were re-examined in tertiary eye hospital (TIO) in order to make a final diagnosis and provide treatment.&#x0D; Result: Out of 505, 67 glaucoma suspects were re-examined in Tilganga Institute of Ophthalmology. Number of patient diagnosed glaucoma was 17 (3.37%). Of them 9 patients (1.78%) had POAG, 4 (0.79 %) had secondary glaucoma, 3 (0.59%) had normal tension glaucoma and 1 (0.20 %) had ocular hypertension.&#x0D; Conclusion: Morbidity of glaucoma is very high in community and more screenings in larger scales are needed in order to decrease the burden of blindness due to glaucoma.

Patient-Reported Outcomes Reveal Impairments Not Explained by Psychophysical Testing in Patients With Regressed PDR.

PurposeWe evaluated the correlations between visual deficits and patient-reported symptoms in patients with regressed proliferative diabetic retinopathy (PDR) to determine whether there is a psychophysical basis for vision-related impairments.MethodsVisual acuity, reading acuity, contrast sensitivity, frequency doubling perimetry (FDP), Humphrey field analyzer (HFA), and dark adaptation assessed visual function. The National Eye Institute Vision Function Questionnaire-25 (NEI VFQ-25) and Low Luminance Questionnaire (LLQ) assessed quality of life.ResultsWe recruited 30 adults who received panretinal photocoagulation (PRP) for PDR and 15 control subjects; 22 diabetic and 11 control participants completed a second evaluation 5 years later. Visual acuity of the worse-seeing eyes tended to correlate better with NEI VFQ-25 and LLQ than did the acuity of the better-seeing eyes. Other vision measures were generally not associated with either questionnaire, especially responses related to driving ability and mental health. Visual acuity only detected subnormal performance in 43% to 45% of patients, while FDP 24-2, HFA 60-4, and LLQ detected abnormal performance in >80% of patients.ConclusionsPoor visual acuity may explain some vision-related impairments in daily function. However, many patients with regressed PDR have normal acuity but reduced visual field and poor quality of life. In these patients, their reported symptoms were not fully explained by visual acuity or any psychophysical tests alone.Translational RelevanceVisual acuity is a poor indicator of overall visual function in people with regressed PDR. In clinical settings, visual field tests and patient-reported outcomes may provide more comprehensive assessments of their functional deficits than visual acuity.

Reading deficits in diabetic patients treated with panretinal photocoagulation and good visual acuity.

Patients with proliferative diabetic retinopathy (PDR) treated with panretinal photocoagulation (PRP) can have abnormal visual functioning that may be missed by Snellen visual acuity alone. We investigated reading deficits in patients treated with PRP for PDR using the Minnesota reading (MNREAD) test. Thirty patients treated with PRP and 15 controls underwent best-corrected visual acuity (BCVA), the MNREAD, frequency doubling perimetry (FDP), and fundus photography. Panretinal photocoagulation (PRP)-treated subjects were compared to controls on MNREAD results by two-sample t-tests and Wilcoxon tests and Pearson correlations were used to assess the association between performance on MNREAD and other central visual function tests within PRP subjects. Panretinal photocoagulation (PRP)-treated patients had reduced MNREAD acuity (p<0.0001) and increased critical print size (p=0.01) compared to controls but not a significantly reduced maximum reading speed (p=0.06). Logmar MNREAD acuity was strongly positive correlated with logMAR BCVA (r=0.58, p=0.0098) and strongly negatively correlated with FDP foveal threshold (r=-0.63, p=0.0030). Maximum reading speed was positively correlated with FDP foveal threshold (r=0.57, p=0.0143) and FDP mean deviation (r=0.51, p=0.0432). Visual acuity did not correlate with the sensitivities on the FDP. The MNREAD test reveals that PRP reduces reading ability and other aspects of macular function, and thus provides new understanding of how vision-related quality of life is impaired. These findings may lead to improved means to evaluate and enhance vision following treatment for PDR.

Eye Movement Perimetry and Frequency Doubling Perimetry: clinical performance and patient preference during glaucoma screening.

To evaluate the screening accuracy of an Eye Movement Perimetry (EMP) in comparison with Frequency Doubling Perimetry (FDP) and to investigate the patient preference and perception towards these visual field screening methods. A total of 104 healthy subjects (mean age (SD) of 48 (14) years) and 73 glaucoma patients (mean age (SD) of 52 (13) years) were recruited. All the participants underwent a comprehensive ophthalmic evaluation including the 24-2 SITA standard protocol on the Humphrey Field Analyzer (HFA). This was followed by the 26-point protocol in EMP and the C-20-1 protocol in FDP. During EMP, all subjects were instructed to fixate a central target and to look at the detected peripheral target, followed by refixation of the central target and Saccadic Reaction Time (SRT) towards each of the "seen" stimuli was calculated. Next, a questionnaire was administered to evaluate the patient preference and perception towards the perimetry techniques. Mean SRTs and Robin scores were used to plot Receiver Operating Characteristics (ROC) curves to determine the screening accuracies. From the questionnaire survey, the frequency distributions of the responses were calculated. Robin score and SRT were significantly increased in glaucoma patients in comparison with the age-matched healthy subjects (p < 0.001). The ROC analysis revealed comparable Area Under the Curve (AUC) values (0.95, p = 0.81) with a specificity of 95.2% for FDP and 96.2% for EMP with a sensitivity of 87.7%. Thirty-seven percent of the older age group (≥ 40years) and 65% of severe glaucoma patients showed preference for EMP over FDP. This study results indicate that the customized protocol in EMP provides efficient and rapid means of screening visual field defects in glaucoma, which compared well with FDP. Elderly healthy participants and patients with moderate and severe glaucomatous defectspreferred EMP as it permitted natural reflexive eye movements thereby resembling a real-life test setting.

Disorganization of Retinal Inner Layers (DRIL) and Neuroretinal Dysfunction in Early Diabetic Retinopathy.

PurposeTo elucidate the relationship between disorganization of retinal inner layers (DRILs) and retinal function in diabetic patients without diabetic retinopathy (DR) and with nonproliferative DR, but without diabetic macular edema (DME).MethodsFifty-seven participants with diabetes mellitus (DM) and 18 healthy controls underwent comprehensive ophthalmic examination, fundus photography, and spectral-domain optical coherence tomography. Scans of the fovea were evaluated for the presence of DRIL. Retinal function was evaluated using Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity, the quick contrast sensitivity function (qCSF) on the AST Sentio Platform, short-wavelength automated perimetry (SWAP), standard automated perimetry (SAP), and frequency doubling perimetry (FDP). ANOVA and Kruskal-Wallis were used to compare retinal function in subjects with and without DRIL. Tukey-Kramer test and Wilcoxon were used for post hoc analysis.ResultsDRIL was identified in 9 of 57 diabetic subjects. DRIL subjects had higher body mass index and longer diabetes duration compared to diabetic subjects without DRIL (P = 0.03 and P = 0.009, respectively). Subjects with DRIL had reduced ETDRS visual acuity (P = 0.003), contrast sensitivity function (P = 0.0003), and SAP performance (PSD, P < 0.0001) compared to controls and diabetic subjects without DRIL. Structural analysis revealed inner retinal thinning, and some outer retinal thinning, associated with DRIL.ConclusionsDiabetic subjects with DRIL have reduced retinal function compared to those without DRIL, and defective retinal lamination may be an early cellular consequence of diabetes responsible for this in some patients. Following further longitudinal studies, DRIL may be a readily available and reliable structural biomarker for reduced retinal function in early diabetic neuroretinal disease.

A comparison between Humphrey and frequency doubling perimetry for chiasmal visual field defects.

To evaluate and compare the diagnostic ability of frequency doubling technology perimetry (FDT) with standard automated perimetry (SAP) using Humphrey Field Analyser for the detection of visual field defects produced by chiasmal lesions. Fifteen patients with documented chiasmal disease and previously diagnosed of bitemporal hemianopia with Humphrey perimetry were prospectively evaluated. All of them underwent a new SAP (SITA 24-2) followed by FDT tests (C-20 threshold). Diagnostic criteria for hemianopia were established according to the total deviation plot and the threshold values of FDT. A patient was diagnosed with hemianopia if one or both criteria were met. Based on these criteria, FDT sensitivity was calculated. Testing time and global indexes for both perimetric strategies were compared. The sensitivity of FDT was 75.0% (18 out of 24 eyes); the criterion based on threshold values was met more often (70.83%) than the criterion based on the total deviation plot (50.0%). Linear correlation was better for the external column than for the internal column of the visual field. Testing time with FDT was 122.16 seconds shorter than with SAP (p<0.001). The mean value for mean deviation (MD) was -13.62 dB (SD 6.88) for SAP and -8.83 dB (SD 5.94) for FDT (p<0.001). Compared with standard automatic perimetry, FDT has a low sensitivity for detecting temporal hemianopias and also has more difficulty in defining the vertical limits of the defects. There f o re, it does not appear to be an adequate method for the detection of chiasmal visual field defects.

Multidimensional Functional and Structural Evaluation Reveals Neuroretinal Impairment in Early Diabetic Retinopathy.

PurposeTo test whether quantitative functional tests and optical coherence tomography (OCT)-defined structure can serve as effective tools to diagnose and monitor early diabetic neuroretinal disease.MethodsFifty-seven subjects with diabetes (23 without diabetic retinopathy [no DR], 19 with mild nonproliferative diabetic retinopathy [mild NPDR], 15 with moderate to severe [moderate NPDR]), and 18 controls underwent full ophthalmic examination, fundus photography, spectral-domain optical coherence tomography (SD-OCT), e-ETDRS (Early Treatment Diabetic Retinopathy Study) acuity, and the quick contrast sensitivity function (qCSF) method. Perimetry testing included short-wavelength automated perimetry (SWAP), standard automated perimetry (SAP), frequency doubling perimetry (FDP), and rarebit perimetry (RBP).ResultsETDRS acuity and RBP were not sensitive for functional differences among subjects with diabetes. AULCSF, a metric of qCSF, was reduced in diabetics with moderate compared to mild NPDR (P = 0.03), and in subjects with no DR compared to controls (P = 0.04). SWAP and SAP mean deviation (MD) and foveal threshold (FT) were reduced in moderate compared to mild NPDR (SWAP, MD P = 0.002, FT P = 0.0006; SAP, MD P = 0.02, FT P = 0.007). FDP 10-2 showed reduced MD in moderate compared to mild NPDR (P = 0.02), and FDP 24-2 revealed reduced pattern standard deviation (PSD) in mild NPDR compared to no DR (P = 0.02). Structural analysis revealed thinning of the ganglion cell layer and inner plexiform layer (GCL+IPL) of moderate NPDR subjects compared to controls. The thinner GCL+IPL correlated with impaired retinal function.ConclusionsThis multimodal testing analysis reveals insights into disruption of the neuroretina in diabetes and may accelerate the testing of novel therapies.

Undiagnosed Primary Open-Angle Glaucoma in Korea: The Korean National Health and Nutrition Examination Survey 2008–2009

ABSTRACTPurpose: To evaluate the characteristics of patients with previously undiagnosed primary open-angle glaucoma (POAG) in Korea.Methods: This study examined data from 391 subjects obtained from the 2008–2009 Korean National Health and Nutrition Examination Survey (KNHANES). The KNHANES is a population-based, cross-sectional epidemiological survey. Participants aged 19 years or older completed standardized interviews and dilated ocular examinations, including measurement of intraocular pressure, visual fields with frequency doubling perimetry, and fundus photography. Data from the 361 patients with previously undiagnosed POAG were analyzed and compared with data from the 30 patients with previously diagnosed glaucoma.Results: A total of 92.3% of POAG cases were undiagnosed before this study. Adjusted for age and sex, the strongest risk factor for undiagnosed glaucoma was longer elapsed time since last eye doctor visit. Glaucoma patients who had not visited an eye specialist in the last 3 years were 22 times (95% confidence interval, CI, 4.49–105.64, p < 0.001) more likely to have undiagnosed disease compared with patients who had visited an eye specialist in the last month. Another significant factor for previously undiagnosed glaucoma was smaller cup-to-disc ratio (odds ratio, OR, 0.60/0.1 units, 95% CI 0.43–0.85/0.1 units, p = 0.004). The higher vertical cup-to-disc ratio of a subject’s two eyes was significantly different between those with previously undiagnosed (0.69) and diagnosed (0.78) POAG (p = 0.001).Conclusions: The undiagnosed POAG group had a longer interval from last eye doctor visit and smaller vertical cup-to-disc ratio compared to the diagnosed group.

Glucose variability and inner retinal sensory neuropathy in persons with type 1 diabetes mellitus.

PurposeTo quantify early neuroretinal alterations in patients with type 1 diabetes mellitus (T1DM) and to assess whether glycemic variability contributes to alterations in neuroretinal structure or function.MethodsThirty patients with T1DM and 51 controls underwent comprehensive ophthalmic examination and assessment of retinal function or structure with frequency doubling perimetry (FDP), contrast sensitivity, dark adaptation, fundus photography, and optical coherence tomography (OCT). Diabetic participants wore a subcutaneous continuous glucose monitor for 5 days, from which makers of glycemic variability including the low blood glucose index (LGBI) and area under the curve (AUC) for hypoglycemia were derived.ResultsSixteen patients had no diabetic retinopathy (DR), and 14 had mild or moderate DR. Log contrast sensitivity for the DM group was significantly reduced (mean±SD=1.63±0.06) compared with controls (1.77±0.13, P<0.001). OCT analysis revealed that the inner temporal inner nuclear layer (INL) was thinner in patients with T1DM (34.9±2.8 μm) compared with controls (36.5±2.9 μm) (P=0.023), although this effect lost statistical significance after application of the Bonferroni correction for multiple comparisons. Both markers of glycemic variability, the AUC for hypoglycemia (R=-0.458, P=0.006) and LGBI (R=-0.473, P=0.004), were negatively correlated with inner temporal INL thickness.ConclusionsPatients with T1DM and no to moderate DR exhibit alterations in inner retinal structure and function. Increased glycemic variability correlates with retinal thinning on OCT imaging, suggesting that fluctuations in blood glucose may contribute to neurodegeneration.

Optimizing the Detection of Preperimetric Glaucoma by Combining Structural and Functional Tests

We evaluated the performance of low contrast achromatic (LLA) multifocal visual evoked potentials (mfVEP) in preperimetric glaucoma and compared its diagnostic performance to other early diagnostic tests. We identified the clinically most useful tests and combinations in preperimetric glaucoma. We studied 59 patients with at least one glaucomatous disc, with normal, reliable visual fields in that eye, and 17 normal controls. All participants underwent complete ophthalmic examination including Humphrey visual fields (HVF), short wavelength automated perimetry (SWAP), frequency doubling perimetry (FDT Matrix), Spectralis optical coherence tomography (OCT), Heidelberg retinal tomography (HRT 3), and color stereoscopic optic disc photographs. We recorded mfVEPs using LLA stimulation. We studied 85 eyes of 59 patients (64.89 ± 8.15 years) and 34 eyes of 17 controls (64.28 ± 13.06 years; P = 0.64). Heidelberg retinal tomography and LLA mfVEP demonstrated the best sensitivities (50.6% and 51.8%, respectively) in identifying preperimetric glaucoma, and were not significantly different from each other. Both tests had significantly better sensitivity than all other tests (P < 0.0001). Of the eyes, 76.5% were identified by the combination of (any one of) LLA mfVEP and HRT. Sensitivity of the combination was significantly better than any of the individual tests (P < 0.05 for all pairs), or any other combinations of tests, with better negative than positive predictive value. The LLA mfVEP test identified approximately 50.6% eyes with preperimetric glaucoma, which was significantly higher than other perimetric methods, and similar to HRT. The combination of LLA mfVEP and HRT had exceptionally high sensitivity of 76.5% for preperimetric glaucoma.

Multimodal Characterization of Proliferative Diabetic Retinopathy Reveals Alterations in Outer Retinal Function and Structure

To identify changes in retinal function and structure in persons with proliferative diabetic retinopathy (PDR), including the effects of panretinal photocoagulation (PRP). Cross-sectional study. Thirty adults who underwent PRP for PDR, 15 adults with untreated PDR, and 15 age-matched controls. Contrast sensitivity, frequency doubling perimetry (FDP), Humphrey visual fields, photostress recovery, and dark adaptation were assessed. Fundus photography and macular spectral-domain optical coherence tomography (SD OCT) were performed. To quantify retinal layer thicknesses, SD OCT scans were segmented semiautomatically. Visual function measures were compared among patients with PDR and PRP, untreated patients with PDR, and controls. Mean retinal layer thicknesses were compared between groups. Correlation analyses were performed to evaluate associations between visual function measures and retinal layer thicknesses. A significant reduction of FDP mean deviation (MD) was exhibited in PRP-treated patients with PDR (MD ± standard deviation, -8.20±5.76 dB; P < 0.0001) and untreated patients (-5.48±4.48 dB; P < 0.0001) relative to controls (1.07±2.50 dB). Reduced log contrast sensitivity compared with controls (1.80±0.14) also was observed in both PRP-treated patients (1.42±0.17; P < 0.0001) and untreated patients (1.56±0.20; P = 0.001) with PDR. Compared with controls, patients treated with PRP demonstrated increased photostress recovery time (151.02±104.43 vs. 70.64±47.14 seconds; P = 0.001) and dark adaptation speed (12.80±5.15 vs. 9.74±2.56 minutes; P = 0.022). Patients who underwent PRP had diffusely thickened nerve fiber layers (P = 0.024) and diffusely thinned retinal pigment epithelium (RPE) layers (P = 0.009) versus controls. Untreated patients with PDR also had diffusely thinned RPE layers (P = 0.031) compared with controls. Patients with untreated PDR exhibited inner retinal dysfunction, as evidenced by reduced contrast sensitivity and FDP performance, accompanied by alterations in inner and outer retinal structure. Patients who underwent PRP had more profound changes in outer retinal structure and function. Distinguishing the effects of PDR and PRP may guide the development of restorative vision therapies for patients with advanced diabetic retinopathy.

Comparative Analysis of Visual Field Plotting by Octopus Interzeag 1-2-3, Humphrey Field Analyser II and Frequency Doubling Perimetry in Glaucoma Patients in South Indian Population.

Standard achromatic perimetry tests the differential light sensitivity whereas the frequency doubling technology tests the contrast sensitivity. The aim of this study was to compare and correlate the visual field indices with three different types of perimeters namely frequency doubling perimetry (FDP), Humphrey field analyser (HFA) and Octopus Interzeag 1-2-3 (OI) for detecting glaucomatous field defects. Prospective cross-sectional observational study. Hundred eyes of 50 glaucoma patients were studied. All the patients underwent visual field examinations by Octopus Interzeag 1-2-3, Humphrey field Analyser II and Frequency Doubling perimetry (FDP). The correlations of the global indices were compared. The time taken to perform the test with the three perimeters was analysed. The visual field plotting by the perimeters were comparable and significant positive correlation was observed. The time taken to perform visual field test by Octopus Interzeag 1-2-3 was shorter than the other two methods. The visual field plotting by Octopus Interzeag 1-2-3, Humphrey field analyser and frequency doubling technology perimetry were comparable and Octopus field plotting takes lesser time than the rest two methods.

Screening First Degree Relatives of Persons with Primary Open Angle Glaucoma in India.

ABSTRACTPurpose: To report the results of screening first degree relatives of persons identified with primary open angle glaucoma in a tertiary eye hospital glaucoma services.Design: A cross-sectional study of first degree relatives of persons with primary open angle glaucoma.Materials and methods: First degree relatives of patients identified with primary open angle glaucoma were invited to participate in a screening evaluation in the base hospital to detect glaucoma. All participating individuals had comprehensive eye examination including vision screening, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, frequency doubling peri-metry and dilated fundus examination. Persons with definite and suspected glaucoma were subject to full threshold automated perimetry.Results: A 514 first degree relatives of 346 persons with primary open angle glaucoma, of 4972 individuals who were invited to participate attended the screening examination (Response Rate 7%). Fifty-five percent of those who attended were males and mean age of participants was 56.8 years. Sixty-eight relatives (13.3% of those screened) were detected to have definite glaucoma. Sixty percent of those detected with definite glaucoma were siblings. Fifteen percent of siblings, 4% of off-springs and 20% of parents who attended the screening examination had definite open angle glaucoma.Conclusion: Prevalence of open angle glaucoma amongst first degree relatives of persons with glaucoma is higher than in the general population as reported in previous studies. Significant barriers, however, exist in the uptake of eye care services among relatives of persons known to have primary open angle glaucoma.How to cite this article: Rajendrababu S, Gupta N, Vijayakumar B, Kumaragurupari R, Krishnadas SR. Screening First Degree Relatives of Persons with Primary Open Angle Glaucoma in India. J Curr Glaucoma Pract 2014;8(3):107-112.

Parallel rarebits: A novel, large‐scale visual field screening method

BackgroundRarebit perimetry () is a computer‐based perimetric testing program with sensitivity and specificity for detection of visual field defects comparable to traditional automated perimetry. To make large‐scale screening more efficient, we developed a parallel rarebit perimetric method to screen groups of subjects simultaneously. We then used this method to report the mean hit rate (MHR) among subjects aged 13 to 19 years.MethodsRarebit perimetry was installed on computers in an existing school computer laboratory. All subjects provided medical and demographic information and underwent a basic visual examination. Testing instructions were provided to groups of up to 35 subjects and rarebit perimetry was subsequently administered. Two or three test supervisors answered questions and ensured that subjects were well aligned with their test screens. Mean hit rate, reaction times, error rates and testing time were calculated, and time estimates for rarebit, frequency doubling perimetry and Humphrey 24‐2 Swedish Interactive Thresholding Algorithm (SITA) fast test were compared.ResultsA total of 364 rarebit perimetric tests were conducted on 182 subjects. Of these, 154 subjects met our inclusion criteria for the reference range (three testing errors or less and visual acuity 6/9 or better). The average mean hit rate was 94.3 ± 4.63 per cent. Screening of 500 subjects using this parallel rarebit perimetric method would require approximately nine hours, which is far less than an estimated 77 hours required for frequency doubling perimetry ‐20 screening tests or an estimated 127 hours required for Humphrey 24‐2 SITA fast tests.ConclusionUsing our methods, rarebit perimetry can be administered in parallel to groups of subjects. The mean hit rate was comparable to that reported in previously published studies. This parallel technique may improve the efficiency of large‐scale visual field screenings.