# Microperimetry differences in macular sensitivity threshold between first and second tested eyes

## TL;DR

This study compares macular sensitivity and fixation stability between first and second tested eyes in healthy individuals using microperimetry.

## Contribution

The study reveals that comprehension of the examination may influence microperimetry results, particularly in fast mode.

## Key findings

- Macular sensitivity threshold was higher in the second tested eye in fast mode but similar in expert mode.
- Fixation stability improved in the second tested eye in expert mode.
- A negative correlation was found between macular sensitivity threshold and examination duration.

## Abstract

To comparatively assess the macular sensitivity threshold of microperimetry
and the fixation stability between the first (right) and second (left)
tested eye of normal participants.

Thirty healthy patients were randomly assigned to two groups. The
participants underwent microperimetry in the fast mode and expert mode in
groups I and II, respectively. Each participant underwent a single test and
the right eye was tested first.

The mean macular sensitivity threshold (± standard deviation [SD]) was
24.5 ± 2.3 dB and 25.7 ± 1.1 dB in the first (right) and
second (left) eyes of group I, respectively (p=0.0415) and 26.7 ± 4.5
dB and 27.3 ± 4.0 dB in the first (right) and second (left) eyes of
group II, respectively (p=0.58). There was no statistically significant
difference between eyes in either group (p=0.1512). Regarding fixation
stability (evaluated in the microperimetry expert mode group), the mean
± SD percentage of fixation points within the 1-degree central macula
(P1) was 87.9 ± 11.5% in the right eye and 93.8 ± 6.6% in the
left eye. The paired t-test did not show a statistically significant
difference between eyes (p=0.140). Mean ± SD P2 value was 95.5
± 4.9% in the right eye and 98.5 ± 2.1% in the left eye. The
analysis demonstrated an increase in the percentage of fixation points in
the second tested eye compared with the first one (paired t-test= 2.364;
p=0.034). There was a negative correlation between the macular sensitivity
threshold of the right eye and the duration of the examination for both
groups (microperimetry expert mode: r=-0.717; p=0.0026; microperimetry in
the fast mode: r=-0.843; p<0.0001).

Mean macular sensitivity threshold was higher in the second tested eye in the
microperimetry in the fast mode group and was similar in both eyes in the
expert mode. Our data suggest that comprehension of the examination by the
individual may impact the results of the microperimetry test.