Background: Results of a retrospective study of perioperative changes in intraocular pressure (IOP) following radical prostatectomy (RPE) for prostate cancer.
Patients and methods: In 25 consecutive patients, PSA (prostate specific antigen) and IOP were measured with Goldmann tonometry before and after a mean of 10 days following RPE. The data of three patients with proven glaucoma were evaluated separately. The data of 22 patients without glaucoma were analysed with non-parametric statistical methods. The primary objective of the investigation was the statistical analysis of the changes in the IOP of the right eyes. The results for the left eyes are presented as secondary objective.
Results: The mean IOP in the right eye decreased from 13.95 ± 2.95 mmHg (n = 22) preoperatively to 12.18 ± 1.99 mmHg postoperatively; the average reduction in pressure was 1.77 ± 2.44 mmHg. In the left eyes, the IOP of 14.45 ± 3.16 mmHg preoperatively decreased to 12.05 ± 2.21 mmHg postoperatively. The average reduction in pressure was 2.41 ± 3.53 mmHg. The PSA level decreased from 18.70 ± 21.66 ng/ml preoperatively (median: 11.3 ng/ml) to 2.21 ± 3.13 ng/ml postoperatively (median: 1.25 ng/ml). The decline in IOP and the difference in PSA are highly statistically significant (Wilcoxon test for paired samples, n = 22, p < 0.01). There was no linear relationship between the reductions in IOP and PSA (Pearson correlation coefficient: r = 0.137, p = 0.542 for right eyes, r = 0.062, p = 0.784 for left eyes).
Conclusion: Our case series shows that there is a statistically significant decrease in IOP following RPE, and to a clinically relevant extent. The changes in PSA and IOP might be linked by changes in prostaglandin metabolism in the prostate and/or the seminal vesicles. This theory remains to be confirmed by further studies. The increase in IOP during the development of prostate cancer might also be linked to changes in prostaglandin metabolism and composition. It is conceivable that prostaglandin analogues could be developed to reduce IOP.
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