[Value of different measurements of the preoperative visual acuity and perception of Purkinje's vessel shadows for prediction of the postoperative visual acuity after vitrectomy in diabetic vitreous hemorrhage].

BACKGROUND

In cases of strong vitreous hemorrhage due to diabetic vitreo-retinopathy there is an uncertainty for the prediction of postoperative visual acuity after vitrectomy. This study compares the value of different preoperative measurements for the prognosis of postoperative visual acuity.

METHOD AND PATIENTS

We evaluated retrospectively the reports of all patients who have been operated by vitrectomy due to diabetic vitreous hemorrhage at our hospital in 2004 (first vitreoretinal surgery). The following measurements were evaluated: preoperative distance and reading VA, last known VA before hemorrhage, laser interference VA, Purkinje's vessel shadow and postoperative distance VA.

RESULTS

42 patients had entire documentation of all evaluated parameters. The preoperative distance VA was 20/1000 (light perception to 20/60), only 3 patients had a reading VA. Laser interference VA was better than red light perception in 13 patients (7 without red light perception). Purkinje's vessel shadows were positive in 22 patients, negative in 17 patients, but 3 patients did not understand the procedure. Prehemorrhage VA was known in 19 patients. Laser interference VA and last known VA prior to hemorrhage (in mean 20 months old) had the best correlation to postoperative VA (p > 0.05). Purkinje's vessel shadow predicts -- if positive -- a postoperative VA of 20/300 or better.

CONCLUSIONS

Postoperative VA after vitrectomy due to diabetic vitreous hemorrhage is best predicted by prehemorrhage VA or laser interference VA, especially if no prehemorrhage VA is known. Positive Purkinje's vessel shadow predicts a postoperative VA of 20/300 or better.