Early Ahmed glaucoma valve implantation after penetrating keratoplasty leads to better outcomes in an Asian population with preexisting glaucoma.
BACKGROUND
To evaluate the efficacy of Ahmed Glaucoma Valve (AGV) surgery and the optimal interval between penetrating keratoplasty (PKP) and AGV implantation in a population of Asian patients with preexisting glaucoma who underwent PKP.


RESULTS
In total, 45 eyes of 45 patients were included in this retrospective chart review. The final intraocular pressures (IOPs), graft survival rate, and changes in visual acuity were assessed to evaluate the outcomes of AGV implantations in eyes in which AGV implantation occurred within 1 month of post-PKP IOP elevation (Group 1) and in eyes in which AGV implantation took place more than 1 month after the post-PKP IOP evaluation (Group 2). Factors that were associated with graft failure were analyzed, and the overall patterns of complications were reviewed. By their final follow-up visits, 58% of the patients had been successfully treated for glaucoma. After the operation, there were no statistically significant differences between the groups with respect to graft survival (p = 0.98), but significant differences for IOP control (p = 0.049) and the maintenance of visual acuity (VA) (p<0.05) were observed. One year after surgery, the success rates of IOP control in Group 1 and Group 2 were 80% and 46.7%, respectively, and these rates fell to 70% and 37.3%, respectively, by 2 years. Factors that were associated with a high risk of AGV failure were a diagnosis of preexisting angle-closure glaucoma, a history of previous PKP, and a preoperative IOP that was >21 mm Hg. The most common surgical complication, aside from graft failure, was hyphema.


CONCLUSIONS
Early AGV implantation results in a higher probability of AGV survival and a better VA outcome without increasing the risk of corneal graft failure as a result of post-PKP glaucoma drainage tube implantation.
Department of Ophthalmology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Ming-Cheng
MC
Tai
Yi-Hao
YH
Chen
Jen-Hao
JH
Cheng
Chang-Min
CM
Liang
Jiann-Torng
JT
Chen
Ching-Long
CL
Chen
Da-Wen
DW
Lu
D000368:Aged; D044466:Asian People; D016039:Corneal Transplantation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006085:Graft Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D019919:Prosthesis Implantation / Q000379:methods*; D012189:Retrospective Studies; D013624:Taiwan; D016896:Treatment Outcome; D014792:Visual Acuity