gms | German Medical Science

Purpose: To assess the efficiency, stability and safety of pars plana clip Ahmed-Valve implant surgery in therapy refractive secondary glaucoma patients.

Methods: 22 patients and a total of 27 eyes were included in this retrospective study, all of which underwent a pars plana vitrecomy and a pars plana administrated Ahmed-valve implant due to therapy refractive secondary glaucoma. The collective of patients consisted of 21 female and 1 male patient. The age varied between 27 and 81 years at the time of surgery. The IOP, visual acuity and number of applied pharmaceutical active topical agents were monitored at the time of indication of the surgery as well as 1, 3, 6, 12 and 24 months post-operatively. The incidence of post-operative complications, particularly tenon cysts with accompanied IOP re-raise was also investigated and monitored at 1, 3, 6, 12 and 24 after revision respectively. All data is displayed as mean values with SEM and compared with a student t-test.

Results: The mean IOP at the time of indication of the operation was 30.2±4.2 mmHg. 12 months after surgery the mean IOP was 14.3±3.0 mmHg. 24 months after surgery the mean IOP was 13.9±3.1 mmHg. The t-test reveals a highly significant lowering effect after 12 and 24 months (p<0.001). The difference between 12 and 24 months was no longer significant (p=0.33). The mean visual acuity was 20/200 before the surgery and remained stable after 24 months (20/100). Before implant surgery the mean number of topical agents applied was 2.8±0.6, after 12 months it was 1.2±0.6 and 1.2±0.6 after 24 months. The most frequent complication was a tenon cyst that appeared in 12 of 27 eyes. The mean occurrence of this IOP-raising tenon cyst was after 3.7±1.8 months but all occurred before 8 months. At the time of indication of a cyst revision the mean IOP was 27.3±2.7 mmHg. 12 months after revision of the tenon cyst the IOP was 14.5±2.0 mmHg. Other complications included endophthalmitis (n=1), retinal detachment (n=2), persistent hypotonia (n=2).

Conclusion: Pars plana clip Ahmed-valve implant surgery is an efficient and long lasting surgery in highly complicated glaucoma eyes. In the long run visual acuity and IOP levels can be controlled and stabilized. However, one has to take into account that there are some minor and some severe post-operative complications that might make further operations necessary.