Fundus Perimetry with the Micro Perimeter 1 in Normal Individuals
Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. Ophthalmology
(Impact Factor: 6.14).
06/2005; 112(5):848-54. DOI: 10.1016/j.ophtha.2004.11.051
To determine differential light threshold values obtained with the Micro Perimeter 1 (MP1) in healthy volunteers and to correlate them with conventional automated static threshold perimetry using the Octopus 101 Perimeter.
Prospective comparative observational study.
Thirty healthy volunteers.
In 30 eyes of 30 healthy volunteers, static threshold perimetry was performed with the MP1 Micro Perimeter (Nidek Inc., Italy) and the Octopus 101 (Haag-Streit AG, Switzerland) in the same eye in random order.
Differential light threshold values obtained with the MP1 and their difference to differential light threshold values with the Octopus. Differential light sensitivity was compared for 21 matching points in a rectangular test grid using similar examination settings with Goldmann III stimuli, stimulus presentation time of 100 msec, and white background illumination (1.27 cd/m2).
For the 21 matching locations, mean differential light thresholds with the MP 1 and the Octopus were 15.5+/-0.8 decibels (dB) (range, 13.0-17.1) and 30.2+/-1.2 dB (range, 27.7-32.0), respectively. On the average, the Octopus showed higher threshold values for all test locations than the MP1. The mean difference between both examinations was 14.6+/-1.8 dB for all locations and 14.8+/-1.7 dB excluding the test locations at the blind spot. With a considerably high grade of variation according to the test point location, the difference between the 2 devices varied from 11.4 to 18.3 dB, showing a vertical asymmetry with a larger difference in the lower part of the visual field. Linear regression of the perimetric results for each test point location, excluding the area of the blind spot and the lower line of the test grid, showed significant correlation (r = 0.56; P = 0.036).
The results show that the MP1 provides reproducible threshold values with a systematic difference compared with standard Octopus perimetry of approximately 15 dB. With a larger difference in the lower part of the visual field, differential light sensitivity values in microperimetry with the MP1 are comparable to the threshold values obtained with the Octopus 101 using a correction factor of 11.4 to 18.3 dB according to stimulus location.
Available from: Vineet Ratra
- "Static threshold perimetry with MP1 can be performed using customized testing parameters that allow the examiner to select the pattern, intensity, form, and number of stimuli being projected onto the retina. Microperimetry has been compared with Octopus 101 conventional static perimetry by Springer et al. where they found significant correlation between the two instruments at each test point. However, the difference varied depending on the stimulus location in their study. "
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ABSTRACT: 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.
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/m(2)). Statistical analysis was done with the SPSS 14 using linear regression and independent t-test.
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.
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.
Available from: Gary Stuart Rubin
- "The MP-1 microperimeter (Nidek Technologies, Italy), launched in 2002, is a system which performs retinal-specific microperimetry [22,23]. It comprises an infrared camera which provides a retinal image, updated at 25 Hz, and a LCD display which can be used to present stimuli. "
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ABSTRACT: Scotopic function is an important marker of many retinal diseases and is increasingly used as an outcome measure in clinical trials, such as those investigating gene therapy for Lebers congenital amaurosis. Scotopic visual function has traditionally been measured using an adapted perimetry system such as the Humphrey field analyser (HFA). However this system does not control for fixation errors or poor fixation stability. Here we evaluate the use of an adapted microperimeter to measure visual function at defined retinal regions under scotopic conditions.
A MP-1 microperimeter (Nidek Technologies, Italy) was modified by adding a 1 log unit Neutral Density filter and a 530 nm shortpass filter within the optical path of the instrument. Stray light was shielded. Fine matrix mapping perimetry was performed on five younger (< 35 years) and five older (> 65 years) subjects with no eye disease and good vision. All subjects were fully dark adapted before testing and pupils were dilated with 1% tropicamide. Tests was performed once on the modified MP-1 microperimeter and once using a modified HFA, in a counterbalanced order.
A foveal scotopic scotoma with a sensitivity reduction of >1 log unit was found using each instrument. In addition, the MP-1 system showed the retinal location of the foveal scotoma. Mean test time was 25 minutes for the MP-1 and 32 minutes for the HFA.
A modified MP-1 microperimeter can be used to measure scotopic retinal function, creating results which are comparable to the modified Humphrey field analyser. Advantages of the MP-1 system include the ability to track the retina through testing, retinal localisation of the scotoma and a faster test time.
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ABSTRACT: Ziel dieser Studie war es, bei Patienten mit Chorioretinopathia centralis serosa (CCS) Netzhautfunktion und -morphologie mittels Fundusperimetrie und OCT zu vergleichen.Bei 14 Augen von 14 Patienten mit einseitiger, erstmalig aufgetretener CCS wurde sowohl eine funduskontrollierte Perimetrie mit dem Microperimeter 1 (MP1) als auch eine OCT-Untersuchung durchgeführt. Analysiert wurde die Netzhautdicke ebenso wie die Lichtunterschiedsempfindlichkeit (LUE) im korrespondierenden Gesichtsfeld.Bei allen Patienten bestand eine seröse Abhebung der zentralen neurosensorischen Retina mit einer maximalen Netzhautdicke von 381±82 m. In der Fundusperimetrie zeigte sich ein mittlerer Defekt von 8,3±3,8 dB, der gut mit der Netzhautdicke korrelierte (r=0,73). Ebenso korrelierte die jeweils maximale Netzhautdicke gut mit der LUE im korrespondierenden Gesichtsfeldareal (r=−0,58).Das MP1 ermöglicht eine Quantifizierung funktioneller Ausfälle bei CCS. Obwohl die Sehschärfe im Durchschnitt nur geringfügig reduziert war, zeigten alle Patienten in der Mikroperimetrie ausgedehnte Skotome, die gut mit der Netzhautdicke korrelierten.
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