Whenever the attendance of the injured employee's treating or consultant physician or podiatrist by deposition or at a hearing is required, such physician or podiatrist shall be entitled to a fee of $450. In instances involving special circumstances, should the board in its judgment deem that the appropriate fee specified above is inadequate, the board may fix a fee in an amount greater than said sum for such hearing, such increased fee to be commensurate with the circumstances in the particular case. The circumstances to be considered are the period of time the physician or podiatrist has consumed in testifying, and traveling time from the physician's or podiatrist's office to the hearing point. Where the attendance is pursuant to a subpoena issued by the board, the Workers' Compensation Law judge, or any officer of the board so designated by the chair, the attendance fee may be limited to no more than $100.