当出血情况严重且使视力严重下降，特别是当其持续时间超过3个月时则须要行玻离体切割术。

Vitrectomy may be indicated for severe hemorrhage and substantially diminished visual acuity, especially if it persists longer than 3 months.

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出血轻微，但持续的时间很长。

The bleeding has been mild but very prolonged.

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目的为了减轻上颌窦根治术后病人出血、肿胀、疼痛程度及缩短其持续时间。

Objective to attenuate the swelling and pain and shorten the sustaining duration, and to decrease the blood loss of the patients undergoing maxillary sinus radical treatment.

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