Static Threshold Perimetry Research Articles

Using high-density perimetry to explore new approaches for characterizing visual field defects

High-density threshold perimetry has found that conventional static threshold perimetry misses defects due to undersampling. However, high-density testing can be both slow and limited by normal fixational eye movements. We explored alternatives by studying displays of high-density perimetry results for angioscotomas in healthy eyes—areas of reduced sensitivity in the shadows of blood vessels. The right eyes of four healthy adults were tested with a Digital Light Ophthalmoscope that gathered retinal images while presenting visual stimuli. The images were used to infer stimulus location on each trial. Contrast thresholds for a Goldmann size III stimulus were measured at 247 locations of a 13°×19° rectangular grid, with separation 0.5°, extending from 11° to 17° horizontally and −3° to +6° vertically, covering a portion of the optic nerve head and several major blood vessels. Maps of perimetric sensitivity identified diffuse regions of reduced sensitivity near the blood vessels, but these showed moderate structure–function agreement that was only modestly improved when effects of eye position were accounted for. An innovative method termed slice display was used to locate regions of reduced sensitivity. Slice display demonstrated that many fewer trials could yield similar structure–function agreement. These results are an indication that test duration might be reduced dramatically by focusing on location of defects rather than maps of sensitivity. Such alternatives to conventional threshold perimetry have the potential to map the shape of defects without the extensive time demands of high-density threshold perimetry. Simulations illustrate how such an algorithm could operate.

Correlations between visual function and inner retinal structure in OPA1 autosomal dominant optic atrophy

AbstractPurpose: To evaluate the influence of autosomal dominant optic atrophy (ADOA) on visual function and inner retinal layer thickness in patients harbouring a pathogenic variant in the OPA1 gene.Methods: We retrospectively investigated clinical data of 59 patients (118 eyes) with ADOA and genetically confirmed OPA1 variants. Visual function was evaluated by best corrected visual acuity (VA), and by mean deviation (MD) of automated static threshold perimetry. Macular ganglion cell layer (mGCL) volume and peripapillary retinal nerve fibre layer (pRNFL) thickness were measured by optical coherence tomography. The analysis was performed for all available data from both eyes in the whole sample. Furthermore, patients were stratified in 2 groups based on variant type (haploinsufficiency: 86 eyes, missense variants: 14 eyes).Results: The mean age at examination was 30.5 ± 16.1 years, VA was 0.55 ± 0.33 logMAR, MD was −4.73 ± 3.59 dB, mGCL volume was 0.60 ± 0.10 mm3, and pRNFL thickness was 63.8 ± 10.6 μm. VA correlated significantly with mGCL volume (p < 0.001) and with pRNFL thickness (p = 0.021). MD also correlated with pRNFL thickness (p = 0.017). Patient age was associated with mGCL volume (p < 0.001) and pRNFL thickness (p = 0.024), but not with VA or MD. MD was significantly lower in the missense group than in the haploinsufficiency group (−9.31 ± 4.07 dB vs. −4.03 ± 2.85 dB; p < 0.001), whereas VA did not differ between groups. Thickness of the pRNFL was also lower in the patients with missense variants, but only the nasal sector was significantly thinner (48.2 ± 12.8 μm vs. 58.2 ± 19.2 μm; p = 0.035).Conclusions: Visual function and inner retinal structure are closely associated in ADOA patients with OPA1 variants. Increasing age may be accompanied by a continuing degeneration of retinal ganglion cells, but seems to have less effect on further loss of visual function. Patients carrying missense variants show more pronounced optic atrophy and visual field defect.

Комплексная ранняя диагностика глаукомы на примере клинического случая

Aim. To present a clinical case of early primary open-angle glaucoma diagnosing using modern examination methods and individual risk factors of glaucoma. Clinical case. A 72-year-old patient came to the clinic with complaints of a feeling of heaviness and blurred vision for several months. During the examination, both standard examinations such as visometry, tonometry, biomicroophthalmoscopy, computer static threshold perimetry were carried out, as well as evaluation of the biomechanical properties of the cornea, optical coherence tomography of the macula and the optic nerve, pattern electroretinography for diagnosis and subsequent evaluation of the effectiveness of prescribed antihypertensive therapy. Key words: primary open-angle glaucoma; early diagnosis of glaucoma.

Сравнительный анализ электрофизиологических и периметрических показателей у пациентов с подозрением на глаукому

Purpose. To compare electrophysiological and perimetric parameters in patients with suspected glaucoma. Materials and methods. 42 patients (84 eyes) with a diagnosis of suspected glaucoma were examined in the RSNPCMG. Visual acuity of patients with ametropia correction was 0.9–1.0. Refractive errors did not exceed 3.0 diopters, concomitant visual analyzer disorders were not detected. None of the examined patients received local drug hypotensive therapy at the time of diagnosis. The average age of the patients was 50.5 ± 2.5 years. The comparison group consisted of 20 people without changes in visual functions of the corresponding gender and age. Electrophysiological and perimetric methods were used: blue-yellow threshold static perimetry, color-component blue-yellow electroretinography of the study of the visual organ to assess the functional state of the visual system with standard methods of examination of the visual organ. Results. The results of standard and color-component methods of perimetry research, as well as electrophysiological indicators were processed using the applied package of research methods Statistica 6.0. When analyzing the main functional perimetric indices and the nature of the topography and depth of defects of the central field of vision (MD, PSD, CPSD), a significant change in the thresholds of light sensitivity of the blue-yellow perimetry relative to the standard method of investigation was noted. When conducting electrophysiological studies, the criteria that have the greatest similarity in damage to the S-cone system of the retina were selected: PERG, oscillatory potentials, synecolumbular electroretinography (S-CON ERG). Conclusion. 1. The developed complex of functional research methods makes it possible to identify the presence of changes in the visual system at the early preclinical stages of the development of glaucoma optic neuropathy. 2. The proposed method of separation of light and color component channels of the visual analyzer increases the sensitivity and specificity of the lesion of the retina of the optic nerve in the development of glaucoma changes. 3. Indicators of oscillatory potentials of ERG are a predictor of ischemic retinal changes in glaucoma. 4. The results of the studies indicate the presence of specific S-cone channels and the effectiveness of detecting damage to retinal ganglion cells using the coniocellular retinal response system. Key words: oscillator potentials, glaucomatous optic neuropathy, blue cone ERG, retinal ganglion cells.

Electrical neurostimulation in glaucoma with progressive vision loss

BackgroundThe retrospective study provides real-world evidence for long-term clinical efficacy of electrical optic nerve stimulation (ONS) in glaucoma with progressive vision loss.MethodsSeventy glaucoma patients (45 to 86 y) with progressive vision loss despite therapeutic reduction of intraocular pressure (IOP) underwent electrical ONS. Closed eyes were separately stimulated by bipolar rectangular pulses with stimulus intensities up to 1.2 mA sufficient to provoke phosphenes. Ten daily stimulation sessions within 2 weeks lasted about 80 min each. Right before ONS at baseline (PRE), vision loss was documented by static threshold perimetry and compared to the same assessment approximately 1 year afterwards (POST). Mean defect (MD) was defined as primary outcome parameter. Perimetries with a reliability factor (RF) of max. 20% were considered.ResultsPerimetry follow-up of 101 eyes in 70 patients fulfilled the criterion of a max. 20% RF. Follow-up was performed on average 362.2 days after ONS. MD significantly decreased from PRE 14.0 dB (median) to POST 13.4 dB (p < 0.01). 64 eyes in 49 patients showed constant or reduced MD as compared to baseline (PRE 13.4 dB vs. POST 11.2 dB). In 37 eyes of 30 patients, MD increased from PRE 14.9 dB to POST 15.6 dB.ConclusionsInnovative treatments that preserve visual function through mechanisms other than lowering IOP are required for glaucoma with progressive vision loss. The present long-term data document progression halt in more than 63% of affected eyes after ONS and, thus, extend existing evidence from clinical trials.

Sonographic and ophthalmic assessment of optic nerve in patients with idiopathic intracranial hypertension: A longitudinal study

BackgroundTo assess the validity of neurosonological parameters (transorbital sonography (TOS)) for detection and monitoring of patients with idiopathic intracranial hypertension (IIH). MethodsProspective, single-center, case-controlled study in 25 patients with IIH and 19 controls. Visual parameters of papilledema, visual acuity, computerized static threshold perimetry, fundus examination, and neurosonological parameters of papilledema/optic disc elevation (ODE), optic nerve sheath diameter (ONSD) and optic nerve diameter (OND) were recorded at baseline and only for patients with IIH again within 6 months. ResultsONSD was significantly enlarged among individuals with IIH (6.2 ± 0.73 mm) compared to controls (4.99 ± 0.54 mm; p < 0.001). Bilateral ODE was found in 36/50 eyes in patients at their initial visit and in none of the controls. Re-evaluation 6 months later showed a significant reduction of ONSD (6.0 ± 0.7 mm; p = 0.024) and ODE (0.2 (0–1) mm; p ≤0.001). Best corrected visual acuity (BCVA) and square root of lost variance (sLV) remained stable. Headache intensity (Numeric rating scale, NRS) improved significantly p < 0.001. When compared to patients with first diagnosed IIH (n = 18), the subset of patients with preexisting IIH with acute relapse (n = 7) showed persistent but reduced levels of ICP increase. They also presented significant decrease of BVCA (p = 0.01) and mean defect (MD) (p = 0.012). Re-evaluation 6 months later showed significant change in ODE in both groups. ConclusionsOur study confirmed that TOS and ophthalmological parameters are a valuable and non-invasive method to detect and monitor elevated ICP in IIH.

Frequency of retinal changes in patients with COVID-19: an observational study

In order to enter cells, SARS-CoV-2 virus uses the angiotensin-converting enzyme 2 receptor that is also expressed in retina.Aim.Determination of the frequency and nature of retinal changes, evaluation of visual functions in patients who have got over COVID-19.Materials and methods.This observational research includes 31 patients aged from 28 to 79 that got over COVID-19 (with severity according to computed tomography (CT): 1–3) in the period from 15 to 40 days before the research. Standard ophthalmological examination and optical coherence tomography (OCT) were performed; visual acuity measurement and threshold static perimetry were used to assess visual functions.Results.Pathology of the ocular surface wasn’t detected. Ophthalmoscopy revealed retinal changes in only one patient. At OCT, 27 (87%) patients proved to have de novo changes in the retinal neuroepithelium at the level of the internal plexiform layer and the retinal ganglion cell layer in the form of hyper-reflective polymorphic foci with clear borders; 18 (67%) patients had monocular lesions. The maximum corrected visual acuity didn’t differ from the previously defined one; no violations of retinal light sensitivity were detected. No association was found between the severity of CT lung changes and retinal changes. The detected retinal changes weren’t associated with symptoms of anosmia (hyposmia) and ageusia. OCT repeated after 12–15 days showed no dynamics of hyperreflective foci: they remained unchanged in their shape, echogenicity and size.Conclusion.De novo changes in retinal neuroepithelium at the level of the inner plexiform layer and the retinal ganglion cell layer were detected according to OCT data in 87% of patients who had undergone COVID-19. Anatomical changes in the retina weren’t manifested by functional visual disturbances. There is no association of retinal changes with lesions of I and IX cranial nerve pairs.

An Open-source Static Threshold Perimetry Test Using Remote Eye-tracking (Eyecatcher): Description, Validation, and Preliminary Normative Data.

PurposeTo describe, validate, and provide preliminary normative data for an open-source eye-movement perimeter (Eyecatcher).MethodsVisual field testing was performed monocularly in 64 normally sighted young adults, using (i) a Humphrey Field Analyzer (HFA) and (ii) the novel Eyecatcher procedure. Eyecatcher used a remote eye-tracker to position stimuli relative to the current point of fixation, and observers responded by looking towards the stimulus. In both tests, Goldman III stimuli were sampled from a 24-2 grid, and were presented against a 10 cd/m2 background. Participants completed each test twice to assess test–retest repeatability.ResultsMean Sensitivity (MS) did not differ between Eyecatcher and the HFA (P = 0.086), and both tests exhibited similar test–retest repeatability (CoREyecatcher = ±1.86 dB; CoRHFA = ±1.95 dB). Eyecatcher was also able to detect changes in sensitivity across the normal visual field (the “Hill of Vision”), and could differentiate the physiological blind spot from adjacent retinal locations. Mean sensitivities and 95% limits of agreement are described for each pointwise location.ConclusionsEyecatcher can use eye movements to assess visual fields in young, normally sighted adults. In such observers, it provides results similar to the current gold standard clinical device (HFA).Translational RelevanceGiven further development, eye movement perimeters such as Eyecatcher could be particularly useful for individuals unable to perform traditional perimetric assessments, such as young children or stroke patients. Full technical details and information on how to freely acquire the source code are included.

The worse eye revisited: Evaluating the impact of asymmetric peripheral vision loss on everyday function

In instances of asymmetric peripheral vision loss (e.g., glaucoma), binocular performance on simple psychophysical tasks (e.g., static threshold perimetry) is well-predicted by the better seeing eye alone. This suggests that peripheral vision is largely ‘better-eye limited’. In the present study, we examine whether this also holds true for real-world tasks, or whether even a degraded fellow eye contributes important information for tasks of daily living. Twelve normally-sighted adults performed an everyday visually-guided action (finding a mobile phone) in a virtual-reality domestic environment, while levels of peripheral vision loss were independently manipulated in each eye (gaze-contingent blur). The results showed that even when vision in the better eye was held constant, participants were significantly slower to locate the target, and made significantly more head- and eye-movements, as peripheral vision loss in the worse eye increased. A purely unilateral peripheral impairment increased response times by up to 25%, although the effect of bilateral vision loss was much greater (>200%). These findings indicate that even a degraded visual field still contributes important information for performing everyday visually-guided actions. This may have clinical implications for how patients with visual field loss are managed or prioritized, and for our understanding of how binocular information in the periphery is integrated.

Visual function in chronic Leber\u2019s hereditary optic neuropathy during idebenone treatment initiated 5 to 50\xa0years after onset

PurposeLeber’s hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by a subacute and progressive impairment and subsequent degeneration of retinal ganglion cells (RGCs). In most cases, it results in optic nerve atrophy and permanently reduced visual acuity (VA). Idebenone has recently been approved in Europe for treating LHON. However, published clinical data has only focused on efficacy in patients within the first years after disease onset. The present study is the first to evaluate possible effects of idebenone treatment in patients with LHON when initiated after more than 5 years from disease onset.MethodsOral treatment with idebenone 300 mg tid was started in seven patients 5 to 51 years after LHON onset. All patients had genetically confirmed primary LHON mutations (m11778G>A, m14484T>C, and m13051G>A). Visual function of all fourteen eyes was tested every 3 months using logarithmic reading charts and automated static threshold perimetry. The obtained clinical data were analyzed retrospectively using a multivariate analysis for VA and the Wilcoxon signed-rank test for visual field data.ResultsBefore treatment, VA was 0.78 ± 0.38 logMAR (range 0.24 to 1.50 logMAR). During the first year of therapy, VA improved significantly by an average of − 0.20 ± 0.10 logMAR or 10 ± 5 ETDRS letters (P = 0.002; VA range 0.06 to 1.30 logMAR). Seven of fourteen eyes showed an improvement of 2 or more lines. Visual field mean deviation increased from − 8.02 ± 6.11 to − 6.48 ± 5.26 dB after 12 months, but this change was not statistically significant (P = 0.056).ConclusionsThe increase in VA of patients who have had LHON for more than 5 years observed soon after start of treatment may not constitute a coincidental spontaneous recovery. We hypothesize that the treatment response in chronic LHON was the result of a reactivated signal transduction in surviving dysfunctional RGCs. The results of this study indicate a beneficial effect of idebenone on improvement of visual function in LHON patients with established optic atrophy.

Plug and play perimetry: Evaluating the use of a self-calibrating digital display for screen-based threshold perimetry

This study evaluated the feasibility of using a ‘self-calibrating’ display (EIZO CG277) to perform screen-based threshold perimetry. Such displays incorporate their own integrated photometer, so could potentially be used ‘straight out of the box’, without the need for time-consuming and costly luminance calibration by skilled experts. Concerns remain, however, due to the fact that the internal calibration of such devices is imperfect, and lingering doubts regarding the accuracy of screen-based perimetry in general. To evaluate such a system, automated static threshold perimetry was performed in thirty-two normal-sighted adults. In one condition, participants performed a novel screen-based perimetry test, for which the screen was calibrated extensively using traditional photometric techniques/equipment. In a second condition, the same test was performed, but the display was calibrated using only the screen’s integrated photometer (and assuming uniformity across the display). For reference, participants also completed a traditional visual-field assessment using a Humphrey Field Analyzer (HFA). All three tests were performed twice to assess test-retest repeatability (six tests total). The results showed no differences when comparing screen-based perimetric measurements made with internal self-calibration vs full manual calibration (either in terms of mean sensitivity, pointwise sensitivity, test-retest repeatability, or test duration). Furthermore, the accuracy and precision of both were indistinguishable from the current gold standard (HFA), although the HFA was approximately two minutes (~30%) faster. These results indicate that self-calibrating commercial monitors can be used to perform screen-based perimetry almost as well as current clinical devices, and without the need for any specialized knowledge or equipment to setup or maintain. This could facilitate perimetric testing in currently hard-to-reach settings, such as community centers, stroke wards, homes, rural locations, or developing countries.

Threshold Static Automated Perimetry of the Full Visual Field in Idiopathic Intracranial Hypertension.

To characterize visual loss across the full visual field in idiopathic intracranial hypertension (IIH) patients with mild central visual loss. We tested the full visual field (50° nasal, 80° temporal, 30° superior, 45° inferior) of 1 eye of 39 IIH patients by using static perimetry (size V) with the Open Perimetry Interface. Participants met the Dandy criteria for IIH and had at least Frisén grade 1 papilledema with better than -5 dB mean deviation (MD) centrally. Two observers (MW and AS) evaluated the visual field defects, adjudicated any differences, and reviewed optical coherence tomography data. We found a greater MD loss peripherally than centrally (central 26°). The median MD (and corresponding median absolute deviations) was -1.37 dB (1.61 dB) for the periphery and -0.77 dB (0.87 dB) for the central 26°, P < 0.001. There were about 30% more abnormal test locations identified in the periphery (P = 0.12), and the mean defect depth increased with eccentricity (P < 0.001). The most frequent defect found was a temporal wedge (23% of cases) in the periphery with another 23% that included this sector with inferior temporal loss. Although the presence of papilledema limited correlation, 55% of the temporal wedge defects had optical coherence tomography retinal nerve fiber layer deficits in the corresponding superonasal location. Other common visual field defects were inferonasal loss, superonasal loss, and superior and inferior arcuate defects. Seven patients (18%) had visual field defects in the periphery with normal central visual field testing. In IIH patients, we found substantial visual loss both outside 30° of the visual field and inside 30° with the depth of the defect increasing linearly with eccentricity. Temporal wedge defects were the most common visual field defect in the periphery. Static threshold perimetry of the full visual field appears to be clinically useful in IIH patients.

Macular sensitivity in patients with congenital stationary night-blindness

AimTo evaluate and correlate mean light sensitivity thresholds (MLST) in patients with congenital stationary night-blindness (CSNB) in comparison with healthy subjects using microperimetry (MP1).MethodsEleven patients with CSNB and 13 healthy...

Correlation Between the Ganglion Cell-Inner Plexiform Layer Thickness Measured With Cirrus HD-OCT and Macular Visual Field Sensitivity Measured With Microperimetry

To evaluate relationships between the macular visual field (VF) mean sensitivity and the ganglion cell and inner plexiform layer (GCA) thicknesses. Seventy-one glaucoma patients and 29 healthy subjects were included in this cross-sectional study. At each visit, GCA thicknesses were measured by Cirrus HD-OCT and static threshold perimetry was performed using Macular Integrity Assessment (MAIA). The relationship between the VF sensitivity and GCA thickness was examined globally, and in the superior hemiretina, inferior hemiretina, and six VF sectors with both VF and optical coherence tomography (OCT) in retinal view. Regression analysis was used to investigate the relationship between the GCA thickness and macular sensitivity. Macular VF sensitivity (dB) and GCA thickness relationships were statistically significant in each sector (R = 0.365-0.706, all P < 0.001). The highest correlation observed was between the inferotemporal average mean sensitivity and the inferotemporal average GCA thickness (R = 0.706) with both VF and OCT in retinal view. Strength of the structure-function relationship for each of the corresponding inferior sectors was higher than those for the corresponding superior sectors. The strength of the structure-function relationship of the temporal sector was higher than that of the nasal sector. GCA thickness measured by Cirrus HD-OCT showed statistically significant structure-function associations with central VF. Inferotemporal central VF had the strongest association.

Comparison between Humphrey Field Analyzer and Micro Perimeter 1 in normal and glaucoma subjects

Purpose:To determine the correlation between fundus perimetry with Micro Perimeter 1 (MP1) and conventional automated static threshold perimetry using the Humphrey Field Analyzer (HFA) in healthy individuals and in subjects with glaucoma.Materials and Methods:In this study, we enrolled 45 eyes with glaucoma and 21 eyes of age-matched, healthy individuals. All subjects underwent complete ophthalmic examination. Differential light sensitivity was measured at 21 corresponding points in a rectangular test grid in both MP1 and HFA. Similar examination settings were used with Goldmann III stimulus, stimulus presentation time of 200 ms, and white background illumination (1.27 cd/m2). Statistical analysis was done with the SPSS 14 using linear regression and independent t-test.Results:The mean light thresholds of 21 matching points in control group with MP1 and HFA were 14.97 ± 2.64 dB and 30.90 ± 2.08 dB, respectively. In subjects with glaucoma, the mean values were MP1: 11.73 ± 4.36 dB and HFA: 27.96 ± 5.41 dB. Mean difference of light thresholds among the two instruments was 15.86 ± 3.25 dB in normal subjects (P < 0.001) and 16.22 ± 2.77 dB in glaucoma subjects (P < 0.001). Pearson correlation analysis of the HFA and MP1 results for each test point location in both cases and control subjects showed significant positive correlation (controls, r = 0.439, P = 0.047; glaucoma subjects, r = 0.812, P < 0.001). There was no difference between nasal and temporal points but a slight vertical asymmetry was observed with MP1.Conclusion:There are significant and reproducible differences in the differential light threshold in MP1 and HFA in both normal and glaucoma subjects. We found a correction factor of 17.271 for comparison of MP1 with HFA. MP1 appeared to be more sensitive in predicting loss in glaucoma.

Peripheral Visual Field Thresholds using Humphrey Field Analyzer Program 60–4 in Normal Eyes

Various methods have been used for testing peripheral visual field disturbances such as defects caused by drug toxicity. Static threshold perimetry with Humphrey Field Analyzer (HFA) is widely available. The aim of this study was to better define the normal thresholds for peripheral visual field (PVF) sensitivity and to refine analysis strategies. Automated PVF testing was performed with HFA 60-4 program in 33 normal subjects. Test locations were organized into inner, middle, and outer eccentricity rings and divided into 4 zones: nasal, temporal, superior, and inferior. The threshold visual sensitivity (TVS) in decibels was established for each point. The majority of points with the lowest TVS and highest between-subject variability were located within the nasal area of the outer ring. Points with the highest TVS and least variability were detected in the inner ring and in the temporal area of the middle and outer rings. Mean zone TVS decreased and variability increased with increasing eccentricity. The areas that demonstrate the highest between-subject consistency and thus might best reveal peripheral visual abnormalities with HFA 60-4 are the inner ring, inferior and temporal zone of the middle ring, and temporal zone of the outer ring. These observations may be useful for developing strategies to detect peripheral field loss at an early stage when central vision is not yet affected.

Defining the Residual Vision in Leber Congenital Amaurosis Caused byRPE65Mutations

To quantify the residual vision in Leber congenital amaurosis (LCA) caused by RPE65 mutations. Patients with RPE65-LCA (n = 30; ages, 4-55) were studied using electroretinography (ERG), full-field stimulus testing (FST), kinetic and static threshold perimetry, and optical coherence tomography (OCT). All patients with RPE65-LCA had abnormal ERGs even at the youngest ages. There were no detectable rod ERGs and only reduced cone ERGs. By chromatic FST, however, 59% of patients had measurable rod- and cone-mediated function. The remaining 41% had only cone-mediated function. Extent of kinetic fields varied widely in the first two decades of life but, by the end of the third decade, there was very little measurable field. Regional patterns of visual loss were evident using dark-adapted static threshold perimetry. The mildest dysfunctions showed relatively homogeneous sensitivity loss beyond the central field. Mid-peripheral dysfunction was a later feature; finally, only central and peripheral islands remained. Colocalized measures of visual function and retinal structure by OCT showed that visual function was detectable when a photoreceptor layer was detectable. Residual rod as well as cone function is detectable in RPE65-LCA. The finding of different regional patterns of visual loss in these patients suggests that the optimal retinal site(s) for subretinal gene delivery to achieve efficacy are likely to change with disease progression.

Correlation between retinal nerve fibre layer thickness and retinal sensitivity

To evaluate the relationship between retinal nerve fibre layer (RNFL) thickness measured by optical coherence tomography (OCT) and light threshold values obtained with the Micro Perimeter 1 (MP1). Forty-nine normal subjects and 37 glaucoma patients were included. Thickness of the RNFL around the optic disc was measured with Stratus OCT scans, and static threshold perimetry was performed with the MP1 at the same visit. Total average and mean 12-clock-hour RNFL thickness were measured with Stratus OCT. An automated 4-2-1 staircase strategy with Goldmann III stimuli was used for MP1. The correspondence between Stratus OCT and MP1 RNFL measurements in each clock-hour was best fit by a second-order polynomial. Average RNFL thickness in the normal group was significantly higher than that in the glaucoma group in each clock hour. Comparing the normal and glaucomatous groups, retinal sensitivity differed significantly at 6, 7, 8 and 11 o'clock. In these regions, structure-function relationships were generally stronger than in other regions. Structure-function associations may be strong when loss of nerve fibres is severe. However, significant reduction in retinal sensitivity does not emerge until the atrophy of nerve fibres is severe.

Role of Central Corneal Thickness on Baseline Parameters and Progression of Visual Fields in Open Angle Glaucoma

To evaluate the relationship of central corneal thickness (CCT) to baseline visual field parameters and visual field progression in patients with primary open-angle glaucoma (POAG). Charts of consecutive patients with POAG were reviewed to obtain visual field data. Visual field was measured by standard threshold static perimetry. Variables analyzed included mean deviation (MD) and pattern standard deviation (PSD). A total of 121 eyes examined over 4 years were evaluated. A significant negative relationship between CCT and PSD (correlation coefficient: -0.02, p<0.05) was found. Analyses comparing CCT to change in PSD and MD (visual field progression) were statistically not significant. Patients with thinner corneas initially present with a greater visual field defect, indicating that thin corneas may contribute to advanced glaucomatous damage at the time of diagnosis. However, CCT does not seem to be a significant risk factor for progression of the disease.

Central visual field impairment during and following cystoid macular oedema

Aim:To determine differential light threshold values obtained with the Micro Perimeter 1 (MP1) in uveitis patients suffering from cystoid macular oedema (CMO) and to compare these measures to retinal thickness.Methods:Static...