A mathematical model for describing the retinal nerve fiber bundle trajectories in the human eye: average course, variability, and influence of refraction, optic disc size and optic disc position.

Previously we developed a mathematical model for describing the retinal nerve fiber bundle trajectories in the superior-temporal and inferior-temporal regions of the human retina, based on traced trajectories extracted from fundus photographs. Aims of the current study were to (i) validate the existing model, (ii) expand the model to the entire retina and (iii) determine the influence of refraction, optic disc size and optic disc position on the trajectories. A new set of fundus photographs was collected comprising 28 eyes of 28 subjects. From these 28 photographs, 625 trajectories were extracted. Trajectories in the temporal region of the retina were compared to the existing model. In this region, 347 of 399 trajectories (87%) were within the 95% central range of the existing model. The model was extended to the nasal region. With this extension, the model can now be applied to the entire retina that corresponds to the visual field as tested with standard automated perimetry (up to approximately 30° eccentricity). There was an asymmetry between the superior and inferior hemifields and a considerable location-specific inter-subject variability. In the nasal region, we found two "singularities", located roughly at the one and five o'clock positions for the right optic disc. Here, trajectories from relatively widespread areas of the retina converge. Associations between individual deviations from the model and refraction, optic disc size and optic disc position were studied with multiple linear regression. Refraction (P = 0.021) and possibly optic disc inclination (P = 0.09) influenced the trajectories in the superior-temporal region.

A 1024-Channel 10-Bit 36- µW/ch CMOS ROIC for Multiplexed GFET-Only Sensor Arrays in Brain Mapping.

This paper presents a 1024-channel neural read-out integrated circuit (ROIC) for solution-gated GFET sensing probes in massive µECoG brain mapping. The proposed time-domain multiplexing of GFET-only arrays enables low-cost and scalable hybrid headstages. Low-power CMOS circuits are presented for the GFET analog frontend, including a CDS mechanism to improve preamplifier noise figures and 10-bit 10-kS/s A/D conversion. The 1024-channel ROIC has been fabricated in a standard 1.8-V 0.18- µm CMOS technology with 0.012 mm 2 and 36 µ W per channel. An automated methodology for the in-situ calibration of each GFET sensor is also proposed. Experimental ROIC tests are reported using a custom FPGA-based µECoG headstage with 16×32 and 32×32 GFET probes in saline solution and agar substrate. Compared to state-of-art neural ROICs, this work achieves the largest scalability in hybrid platforms and it allows the recording of infra-slow neural signals.

Comparison of advanced visual field defects measured with the Tübingen Mobile Campimeter and the Octopus 101 perimeter.

PURPOSE: To compare the results of advanced visual field defects (VFD) measured with the conventional reference perimeter Octopus 101 (O-101) and the new portable Tübingen Mobile Campimeter (TMC). METHODS: Thirty-seven subjects (18 to 75 years), 13 with advanced arcuate scotomas, 12 with VFD respecting vertical meridians, 6 with concentric constriction and 6 healthy controls were included. First examination was with O-101: grid 30 degrees -NO, 192 stimuli, 10 cd/m(2) background luminance, stimulus size: Goldmann III (26'); second examination was with TMC: 84 stimuli (subset of grid 30 degrees -NO), stimulus size 34', stimulus luminance 320-370 cd/m(2), background luminance 8-20 cd/m(2). Pointwise accuracy (proportion of concordant locations), sensitivity, and specificity were estimated into 95% confidence intervals (CI) by averaging individual logits. Examination durations were compared. RESULTS: TMC results are highly concordant with O-101 results for all defect classes. For the entire sample, the percentage of discordant points (perceived with TMC but not with O-101) among all discordant points was 35% (CI: 30% to 40%). Analyzed by VFD pattern, accuracy was highest in healthy controls scotomas (97.9%; CI: 97% to 98.5%) and lowest in arcuate scotomas (80.6 %; CI: 77.3% to 83.5%). Sensitivity was highest in concentric constriction (94.5%; CI: 82.9% to 98.4%) and lowest in healthy controls (59.1%; CI: 26.3% to 85.3%). Specificity was highest in healthy controls (98.1%; CI: 96.6% to 98.9%) and lowest in concentric constriction (77.4%; CI: 62.1% to 87.7%). Mean examination time was 4.6 minutes (TMC) and 9.8 minutes (O-101). CONCLUSIONS: The results indicate that the TMC is a feasible device for detection of VFD.

A chemoenzymatic approach to enantiomerically pure amines using dynamic kinetic resolution: application to the synthesis of norsertraline.

Racemization catalyst 5 c and the enzyme Candida antarctica lipase B were combined in a one-pot dynamic kinetic resolution (DKR) of primary amines in which a wide range of amines were transformed to their corresponding amides in up to 95 % isolated yield and >99 % ee. The DKR protocol was applicable with either isopropyl acetate or dibenzyl carbonate as the acyl donor. In the latter case, release of the free amine from the carbamate products was carried out under very mild conditions. The racemization of (S)-1-phenylethylamine with several different Ru catalysts was also evaluated. Catalyst 5 c, of the Shvo type, was able to selectively racemize amines and was also compatible with the reaction conditions used for DKR. A racemization study of three different amines with varying electronic properties was also performed. Competitive racemization of a 1:1 mixture of the deuterated and non-deuterated amine was carried out with 5 c and a primary kinetic isotope effect was observed for all three amines, providing support that the rate-determining step is beta-hydride elimination. The chemoenzymatic DKR protocol was applied to the synthesis of norsertraline (16) by using a novel route starting from readily available 1,2,3,4-tetrahydro-1-naphthylamine (1 o).

Specification of progression in glaucomatous visual field loss, applying locally condensed stimulus arrangements.

PURPOSE: The goal of this work was to (i) determine patterns of progression in glaucomatous visual field loss, (ii) compare the detection rate of progression between locally condensed stimulus arrangements and conventional 6 degrees x 6 degrees grid, and (iii) assess the individual frequency distribution of test locations exhibiting a local event (i.e., an abrupt local deterioration of differential luminance sensitivity (DLS) by more than -10 dB between any two examinations). METHODS: The visual function of 41 glaucomatous eyes of 41 patients (16 females, 25 males, 37 to 75 years old) was examined with automated static perimetry (Tuebingen Computer Campimeter or Octopus 101-Perimeter). Stimuli were added to locally enhance the spatial resolution in suspicious regions of the visual field. The minimum follow-up was four subsequent sessions with a minimum of 2-month (median 6-month) intervals between each session. Progression was identified using a modified pointwise linear regression (PLR) method and a modified Katz criterion. The presence of events was assessed in all progressive visual fields. RESULTS: Eleven eyes (27%) showed progression over the study period (median 2.5 years, range 1.3-8.6 years). Six (55%) of these had combined progression in depth and size and five eyes (45%) progressed in depth only. Progression in size conformed always to the nerve fiber course. Seven out of 11 (64%) of the progressive scotomata detected by spatially condensed grids would have been missed by the conventional 6 degrees x 6 degrees grid. At least one event occurred in 64% of all progressive eyes. Five of 11 (46%) progressive eyes showed a cluster of events. CONCLUSIONS: The most common pattern of progression in glaucomatous visual fields is combined progression in depth and size of an existing scotoma. Applying individually condensed test grids remarkably enhances the detection rate of glaucomatous visual field deterioration (at the expense of an increased examination time) compared to conventional stimulus arrangements.

Spatial characteristics of visual field progression determined by Monte Carlo simulation: diagnostic innovations in glaucoma study.

PURPOSE: To determine the spatial characteristics of glaucomatous visual field progression in persons with glaucomatous-appearing optic neuropathy (GON) from the Diagnostic Innovations in Glaucoma Study (DIGS). METHODS: Changes in pattern deviation (PD) plot values from the average of two baseline examinations to two follow-up examinations were evaluated in test locations. All were eligible, full threshold, pattern 24-2, standard automated perimetry (SAP) examinations (Humphrey Field Analyzer II; Carl Zeiss Meditec, Inc., Dublin, CA) in visual field series from 200 patients with GON confirmed on two occasions by stereophoto review. The proportion of patients exhibiting PD plot progression was determined at each of 52 locations for patients with a baseline abnormal result (P < 5% or worse) in one or more of 52 PD locations in either the first or second baseline test for a total of 2704 location pairings for each possible level of negative PD change from -1 to -50 dB. Progression was defined as any worsening of PD plot value in the follow-up test relative to the average PD plot value in the baseline tests. Monte Carlo simulation was used to determine the significance of the observed patterns of PD plot progression. RESULTS: Changes in PDs were dependent on their location relative to abnormal PD locations in the first test. Of those patients with an abnormality at a location at baseline (mean, 0.23 +/- 0.07), the proportion of patients changing by -2 dB or more ranged between 0.09 and 0.55 (mean, 0.29 +/- 0.06) across locations. For changes of -6 dB or more, the proportions ranged between 0.00 and 0.26 (mean, 0.08 +/- 0.04) of patients. These proportions and the proportional probabilities for each of 2704 location pairings are reported for selected levels of change. The proportional probabilities are consistent with a map of the retinal nerve fiber layer bundles. CONCLUSIONS: Visual field progression occurs in retinotopically constrained patterns consistent with changes along the nerve fiber bundle.

The normal age-corrected and reaction time-corrected isopter derived by semi-automated kinetic perimetry.

PURPOSE: To determine the increase in isopter extent, resulting from the measurement of, and correction for, individual reaction time (RT; the latency between stimulus presentation and individual patient response), derived under the standardized conditions of semi-automated kinetic perimetry (SKP), and to model the age- and RT-corrected normative isopter values for SKP applicable to any Goldmann stimulus combination. DESIGN: Cross-sectional observational study. PARTICIPANTS: Eighty-three healthy participants aged 10 to 80 years (11-12 participants per decade of age). METHODS: One eye of each participant underwent SKP using the Octopus 101 perimeter (Haag-Streit, Koeniz, Switzerland). Four Goldmann stimulus combinations, III4e at 25 degrees/second, III4e at 5 degrees/second, I3e at 5 degrees/second, and I2e at 2 degrees/second, were presented centripetally (i.e., in a direction toward the center of the bowl) along the 8 cardinal meridia in random order. The local kinetic threshold (LKT) for each stimulus combination along each meridian was corrected for the angular distance traveled during the individual geometric mean RT and was modeled in terms of the covariables stimulus size, stimulus luminance, meridian, and age, and then presented in terms of a graphical reference plot. MAIN OUTCOME MEASURES: The variation of the LKT with RT, stimulus combination, meridian, and age. RESULTS: The median of the individual geometric mean RTs initially decreased and then increased with increase in age and was greater for stimulus combinations producing small isopters compared with those generating large isopters. Reaction time-corrected LKTs were fitted optimally by a multiple regression model (R2 = 0.86). For large (> or =size III) and intense (4e) stimuli, RT-corrected LKTs were independent of age and mainly were influenced by instrument- and facial anatomy-related characteristics. Reaction time-corrected LKTs, particularly for small (< or = size II) stimuli, exhibited a clear age dependence above the age of 40 years particularly for reduced luminance stimuli (< or = 2e), with an approximate reduction in angular extent of 2 degrees per decade for the I1e stimulus. CONCLUSIONS: The development of a graphical reference plot with mean isopters and accompanying reference intervals for age- and RT-corrected SKP, applicable to any individual patient, should facilitate the evaluation of clinical data and the implementation of a computerized alternative to manual Goldmann kinetic perimetry.

Quantification of stato-kinetic dissociation by semi-automated perimetry.

The difference in threshold sensitivities that are found when examining the visual field (VF) with static versus kinetic perimetric methods is called stato-kinetic dissociation (SKD). In this pilot study, we describe a semi-automated procedure for quantifying SKD. Fifteen patients with VF defects were examined with kinetic and static perimetry. SKD values were defined as positive when the static scotoma was larger than the kinetic one. We found significant local variations of SKD along scotoma borders with the individual reaction time as an important criterion when determining kinetic thresholds. There was a verifiable SKD in all patients with locally negative values in eight subjects.

Comparison between semiautomated kinetic perimetry and conventional Goldmann manual kinetic perimetry in advanced visual field loss.

PURPOSE: To compare quantitatively visual field (VF) results obtained using a new standardized semiautomated kinetic perimetry (SKP) with those obtained by conventional Goldmann manual kinetic perimetry (MKP) in patients with advanced VF loss. DESIGN: Prospective, single-center, observational comparative case series. SUBJECTS AND METHODS: Seventy-seven eligible patients (36 suffering from advanced retinal nerve fiber layer loss, 20 with concentric constriction of the VF, and 21 with hemianopia) were included in the study. One eye of each patient was examined on the same day with MKP and SKP. Three isopters, identical in both tests, were chosen to assess the extent of the VF loss. To compare the location and size of the corresponding isopters obtained with MKP and SKP, intersection areas of superimposed isopters were expressed as a percentage of union areas. MAIN OUTCOME MEASURES: The area and position of isopters for a defined stimulus condition obtained with both methods were compared. Test duration and patients' preference were also evaluated. RESULTS: Isopters obtained with Goldmann MKP enclosed areas smaller by 20% (confidence interval [CI], 12%-27%). The mean intersection area of Goldmann and SKP VFs was 1763.1 square degrees (CI, 1558.6-1967.7) smaller than the union for stimulus III4e over all groups of patients. Semiautomated kinetic perimetry was preferred by 60% of patients with concentric constriction of the VF. Median duration of the examination was 15 minutes and did not differ significantly between the 2 methods. CONCLUSIONS: Our results indicate that SKP isopter shape and size were very comparable to those obtained on the same eyes with MKP. Semiautomated kinetic perimetry may represent a more standardized method of kinetic perimetry, which still takes advantage of perimetrist-patient interaction to diagnose and monitor advanced VF loss in clinical practice.

VFMA: Topographic Analysis of Sensitivity Data From Full-Field Static Perimetry.

PURPOSE: To analyze static visual field sensitivity with topographic models of the hill of vision (HOV), and to characterize several visual function indices derived from the HOV volume. METHODS: A software application, Visual Field Modeling and Analysis (VFMA), was developed for static perimetry data visualization and analysis. Three-dimensional HOV models were generated for 16 healthy subjects and 82 retinitis pigmentosa patients. Volumetric visual function indices, which are measures of quantity and comparable regardless of perimeter test pattern, were investigated. Cross-validation, reliability, and cross-sectional analyses were performed to assess this methodology and compare the volumetric indices to conventional mean sensitivity and mean deviation. Floor effects were evaluated by computer simulation. RESULTS: Cross-validation yielded an overall R2 of 0.68 and index of agreement of 0.89, which were consistent among subject groups, indicating good accuracy. Volumetric and conventional indices were comparable in terms of test-retest variability and discriminability among subject groups. Simulated floor effects did not negatively impact the repeatability of any index, but large floor changes altered the discriminability for regional volumetric indices. CONCLUSIONS: VFMA is an effective tool for clinical and research analyses of static perimetry data. Topographic models of the HOV aid the visualization of field defects, and topographically derived indices quantify the magnitude and extent of visual field sensitivity. TRANSLATIONAL RELEVANCE: VFMA assists with the interpretation of visual field data from any perimetric device and any test location pattern. Topographic models and volumetric indices are suitable for diagnosis, monitoring of field loss, patient counseling, and endpoints in therapeutic trials.

Increased detection rate of glaucomatous visual field damage with locally condensed grids: a comparison between fundus-oriented perimetry and conventional visual field examination.

OBJECTIVE: To compare detection rates of glaucomatous visual field defects (VFDs) between the conventional 6 degrees x 6 degrees stimulus grid and locally condensed target arrangements in morphologically suspicious regions. METHODS: A total of 66 eyes of 66 patients with glaucoma or patients suspected of having glaucoma (34 females and 32 males; age range, 14-85 years) were enrolled in this study. Individual, local target condensation was realized by fundus-oriented perimetry (FOP) using a campimeter and compared with the results of conventional automated perimetry (CAP), obtained with the Humphrey Field Analyzer (30-2 grid). RESULTS: Twenty-three of the 66 patients showed normal findings with both methods; 27 had concordantly pathological results. In 15 patients we obtained normal findings with CAP, whereas FOP revealed early glaucomatous VFDs. Only one patient showed VFDs with CAP, whereas FOP results were normal. Scotoma detection rates significantly differed between the 2 methods (P<.001, sign test). Test duration with FOP was more than doubled compared with CAP. When considering only FOP points coinciding with the 6 degrees spacing of the 30-2 grid, there was no longer a significant difference between FOP and CAP (P>.25, sign test). This indicated that the target pattern, rather than the perimetric device, was most relevant for detecting glaucomatous VFDs. Follow-up throughout a series of 3 subsequent sessions at 6-month intervals revealed repeatable results in more than two thirds of all eyes for both FOP and CAP. CONCLUSIONS: Fundus-oriented perimetry that uses individually condensed test grids significantly increases the detection rate of glaucomatous VFDs in morphologically conspicuous areas compared with CAP using equidistant (6 degrees x 6 degrees) target arrangements. Repeatability is comparable between both methods.

Enantioselective Rh-catalyzed hydrogenation of vinyl carboxylates with monodentate phosphite ligands.

[reaction: see text] Alkyl-substituted vinylcarboxylates, which normally show poor enantioselectivity in Rh-catalyzed hydrogenation with traditional chiral diphosphines, undergo highly enantioselective reactions with BINOL- and carbohydrate-based monophosphite ligands.

Regiocontrolled Ru-catalyzed addition of carboxylic acids to alkynes: practical protocols for the synthesis of vinyl esters.

The catalytic activity of commercially available, air and water stable ruthenium complexes in the addition of carboxylic acids to terminal alkynes was found to be drastically enhanced by the addition of small quantities of base. Moreover, the regioselectivity of the reaction can be controlled by the choice of the base so that both the Markovnikov (Na2CO3) and the anti-Markovnikov products (DMAP) are now easily accessible in excellent selectivities.

[Recent developments in kinetic perimetry]. / Postepy w perymetrii kinetycznej.

The manual kinetic perimetry using Goldmann instrument is still widely used and remains a "gold standard" in examining patients with any kind of advanced visual field loss and impaired co-operability. Nevertheless, Goldmann instrument has several disadvantages, such as examiner dependence, response variability, lack of standardization of parameters, poor repeatability. The latest development in kinetic perimetry, which was realized at the University Eye Hospital in Tuebingen (Germany) is semi-automated kinetic perimetry (SKP), using Octopus 101 instrument (Interzeag/Haag-Streit, Koeniz-Bern, Switzerland). It is an examiner-independent, standardized and reproducible method. Additionally, obtained results can be corrected for the mean individual reaction time. This paper will briefly present characteristic, advantages and application of SKP in clinical practice.

[Quantification of isopters using semiautomated kinetic perimetry (SKP) in glaucoma patients with advanced retinal nerve fiber layer (RNFL) loss]. / Pomiar powierzchni izopter z uzyciem pólautomatycznej perymetrii kinetycznej (PPK) u pacjentów z zaawansowana jaskra.

PURPOSE: To quantify the area of isopters obtained using a new technique of kinetic visual field examination--semi-automated kinetic perimetry (SKP)--in case of advanced retinal nerve fiber layer (RNFL) loss, caused by glaucoma. MATERIAL AND METHODS: Forty-one subjects (19 men, 22 women; mean age 66.5 +/- 12.5 years) suffering from open-angle glaucoma (30 patients), normal tension glaucoma (5 patients), juvenile glaucoma (2 patients) and PEX glaucoma (4 patients) were examined, using SKP program implemented in Octopus 101 instrument (Haag-Streit, Koeniz, Switzerland). One eye of each patient was tested using three stimuli according to the Goldmann classification. The stimuli III4e and I4e were obligatory. Additionally one stimulus (I3e or I2e) was used depending on the character of the defect. The stimulus angular velocity was kept constant at the level of 3 degrees/s. Obtained visual field (VF) results were classified according to the Aulhorn classification into stage III (26 VF) and IV (15 VF). The areas of isopters were measured in deg2. RESULTS: The mean area of isopter III4e was 9860 deg2, I4e--5171 deg2, I3e--1093 deg2, I2e--1093 deg2 in the group of Aulhorn stage III. In the group of Aulhorn stage IV the mean area of isopter III4e was 7488 deg2, I4e--3736 deg2, I3e--1109 deg2 and I2e--818 deg2. The mean test time was 16 min. (range 9-25 min.), 15.7 min. in the group of Aulhorn stage III and 16.5 min. in the group of Aulhorn stage IV, respectively. CONCLUSION: SKP seems to be an effective method for quantitative assessment and evaluation of isopter and scotoma areas (in deg2). In this study it was demonstrated that in case of more advanced stages of glaucomatous visual field loss (Aulhorn stage IV), the areas of isopters appeared to be smaller.

[Comparison of SKP (semi-automated kinetic perimetry) and SASP (suprathreshold automated static perimetry) techniques in patients with advanced glaucoma]. / Porównanie zastosowania pólautomatycznej perymetrii kinetycznej (PPK) oraz nadprogowej perymetrii statycznej (SASP) u chorych z zaawansowana jaskra.

PURPOSE: To compare the results of conventional suprathresold automated static perimetry (SASP) and a new method of kinetic visual field examination (semi-automated kinetic perimetry--SKP) in patients with advanced retinal nerve fibre layer (RNFL) defects, caused by glaucoma. MATERIAL AND METHODS: Nineteen patients (10 women and 9 men) suffering from advanced open-angle glaucoma (17 patients) and low tension glaucoma (2 patients) were enrolled in this study. The mean age was 65.3 years (range 49.0-82.9 years). One eye of each subject was examined with SKP and SASP, both implemented in Octopus 101 perimeter (Haag-Streit, Koeniz, Switzerland) on the same day. The examiner using SKP did not know the SASP results. The static visual field examination was performed first. In order to compare visual fields results obtained with both methods, only central 30 degree area of the visual fields was taken into consideration. The area obtained by creating a virtual isopter (option of SKP software) located between the position of defective and intact visual field regions of SASP and the area of I4e isopter obtained with SKP (stimulus angular velocity 3 degrees/s) were measured in deg2 and compared. RESULTS: The mean area (+/-SD) of I4e isopter obtained with SKP was 1882 deg2 (+/- 510 deg2) and the mean area of SASP 30 degree visual field was 1737 deg2 (+/- 546 deg2). This difference was not statistically significant. CONCLUSION: Quantitative comparison of static and kinetic perimetry is a difficult task to perform. The SKP software offers a possibility of direct quantitative assessment of the area of each isopters in deg2. This study shows that the results of visual field examinations obtained with both methods in this group do not differ significantly between SASP and SKP.

[Applicability of semi-automated kinetic perimetry (SKP) in the assessment of the visual field loss due to retinitis pigmentosa]. / Zastosowanie pólautomatycznej perymetrii kinetycznej (PPK) do oceny ubytków w polu widzenia spowodowanych przez zwyrodnienie barwnikowe siatkówki.

PURPOSE: To assess the applicability of a new technique of kinetic visual field examination--semi-automated kinetic perimetry (SKP)--in patients suffering from the visual field defects due to retinitis pigmentosa. METHODS: Thirty-five patients (19 women, 16 men: mean age 38.4 years) suffering from retinitis pigmentosa (10 with with Usher syndrome, one with Bardet-Biedl syndrome and one with Refsum syndrome) were examined using SKP software, implemented in Octopus 101 instrument (Haag-Streit, Koeniz, Switzerland). Three stimuli (1114e and 14e obligatory) were used to assess the hill of vision of each patient. The area of each isopter was measured in deg2. The test time was measured automatically in minutes. RESULTS: The visual field results were classified as complete or incomplete midperipheral "ring scotoma" (group I--13 patients) and concentric loss of the visual field (group II--22 patients). The area of 1114e isopter was 6147.5 deg2 in the group I and 1961.7 deg2 in the group II. The area of 14e isopter was 1468.4 deg2 and 781.7 deg2, respectively. The mean test time was 10 min. (range 4-20 min.): 8 min. in the group I and 13 min. in the group II. CONCLUSIONS: There is a large diversity of patterns of the visual field loss in retinitis pigmentosa. SKP, in contrary to widely used manual perimeter, gives a possibility of quantification of the visual field area. Future studies may be able to monitor the progression of the visual field loss caused by retinitis pigmentosa.

Reaction time during semi-automated kinetic perimetry (SKP) in patients with advanced visual field loss.

PURPOSE: This study aimed to evaluate reaction time (RT) in patients with advanced visual field (VF) loss using semi-automated kinetic perimetry (SKP). METHODS: Seventy-eight patients with advanced VF loss caused by glaucoma (31) or retinitis pigmentosa (19), homonymous VF loss caused by post-chiasmal lesions (18) and unilateral anterior ischaemic optic neuropathy (AION) (10) were examined with SKP (Octopus 101 perimeter). One eye in each patient was enrolled. Additionally, VFs in the 10 healthy fellow eyes of the patients with AION were compared with those in the 10 affected eyes. Reaction time was assessed during the SKP session by presenting kinetic stimuli (III4e) with constant angular velocities of 3 degrees /second moving linearly along so-called 'RT vectors' at four different locations inside the III4e isoptre. Each stimulus presentation was repeated four times in randomized order. RESULTS: The geometric mean RT was 794 ms (95% reference interval [RI] 391-1615 ms) in patients with glaucoma, 702 ms (95% RI 306-1608 ms) in patients with retinitis pigmentosa and 675 ms (95% RI 312-1460 ms) in patients with hemianopia. Increases in RT for every 1 degree of eccentricity were 1%, 0.9% and 0.4%, respectively. The geometric mean RT in the 10 patients with unilateral optic neuropathy was 644 ms in affected eyes and 435 ms in unaffected eyes, reflecting an increase of 51% (95% confidence interval 42-62%). CONCLUSIONS: We found substantial inter-subject variability in RT in patients with advanced VF loss. It is possible to correct the position of the isoptres by assessing individual RT. There were no relevant differences in RT between the disease groups. Reaction time increases with eccentricity. In monocular disease (AION), RT is prolonged, compared with in healthy fellow eyes. However, in clinical routine the RT-related displacement of isoptres is negligible in the vast majority of cases.

Spatial pattern of glaucomatous visual field loss obtained with regionally condensed stimulus arrangements.

PURPOSE: To assess the spatial distribution of glaucomatous visual field defects (VFDs) obtained with regionally condensed stimulus arrangements. METHODS: Sixty-three eyes of 63 glaucoma subjects were examined with threshold-estimating automated static perimetry (full threshold 4-2-1 dB strategy with at least three reversals) on an automatic campimeter or a full-field perimeter. Stimuli were added by the examiner to regionally enhance spatial resolution in regions that were suspicious for a glaucomatous VFD. These regions were characterized by contiguous local VFDs, attributable to the retinal nerve fiber bundle course according to the impression of the examiner. The added stimulus locations were subsets of a predefined, dense perimetric grid. All VFD locations with P < 0.05 (total deviation plots) were assessed by superimposing the visual field records of all participants. RESULTS: Glaucomatous VFD loss occurred more frequently in the upper than in the lower hemifield, with a typical retinal nerve fiber-related pattern and a preference of the nasal step region. More than 50% of the eyes with predominantly mild to moderate glaucomatous field loss showed defective locations in the immediate superior paracentral region within an eccentricity of 3°. CONCLUSIONS: Conventional thresholding white-on-white perimetry with regionally enhanced spatial resolution reveals that glaucomatous visual field loss affects the immediate paracentral area, especially the upper hemifield, in many eyes with only mild to moderate glaucomatous visual field loss. Detailed knowledge about the spatial pattern and the local frequency distribution of glaucomatous VFDs is an essential prerequisite for creating regionally condensed stimulus arrangements for adequate detection and follow-up of functional glaucomatous damage.