  We investigated the impact of metric fluctuations on the higher-dimensional
black hole geometry. We generalized the four-dimensional model to higher
dimensions to treat quantum vacuum fluctuations by the classical approach. A
fluctuating black hole is portrayed by a higher-dimensional Vaidya metric with
a spherically oscillating mass. Assuming a small fluctuation amplitude, we
employed a perturbation method to obtain a radially outgoing null geodesic
equation up to the second order in the fluctuation. Furthermore, the
fluctuation of the event horizon up to the second order depends on the number
of spacetime dimensions. Therefore, the time-averaged values of the
thermodynamic variables defined at the horizon also feature dimension-dependent
correction terms. A general solution was obtained for rays propagating near the
horizon within a fluctuating geometry. Upon examining this in a large $D$
limit, we found that a complete solution can be obtained in a compact form.
