Effect of glaucoma tube shunt parameters on cornea endothelial cells in patients with Ahmed valve implants.
OBJECTIVE
The aim of this study was to assess the effect of various tube parameters on corneal endothelial cell density (ECD) after insertion of Ahmed valves.


METHODS
Thirty-nine eyes of 33 patients with previous superotemporal (ST) Ahmed valve implantation and 20 eyes of 13 participants with previous uncomplicated phacoemulsification and intraocular lens implantation but no history of glaucoma surgery were evaluated. Various tube parameters were measured with anterior segment optical coherence tomography. ST, central, and inferonasal (IN) ECD and pachymetry were measured. Endothelial cell loss and corneal thickness in the ST cornea was compared with those in the IN cornea.


RESULTS
The mean age of the operated patients was 58 ± 22 years, and the mean time since glaucoma surgery was 2.5 ± 2.6 years. Thirty-two of the 39 study eyes were pseudophakic. The ECD was significantly lower in the ST endothelium than in the IN endothelium in eyes with glaucoma tube surgery (P < 0.001), although this relative reduction in ST ECD was not greater than that seen in pseudophakic control eyes (P = 0.16). In univariate analysis, tube angle relative to the cornea and distance from the tip of the tube to the cornea were significant risk factors for decreased ST endothelial cell loss when assessed relative to the IN ECD (P = 0.01 and P = 0.02, respectively). In multivariate analysis, only the distance of the tube tip to the cornea remained significantly associated with ST endothelial cell loss.


CONCLUSIONS
Although this was a retrospective study with inherent limitations, tubes that are closer to the cornea seem to lead to increased loss of adjacent endothelial cells.
*Department of Ophthalmology, University of California San Francisco, San Francisco, CA; †Department of Ophthalmology, People's Hospital, Peking University, Beijing, China; ‡Francis I. Proctor Foundation, University of California San Francisco, San Francisco, CA; and §Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD.
Euna B
EB
Koo
Jing
J
Hou
Ying
Y
Han
Jeremy D
JD
Keenan
Robert L
RL
Stamper
Bennie H
BH
Jeng
D000328:Adult; D000368:Aged; D002452:Cell Count; D055954:Corneal Endothelial Cell Loss / Q000175:diagnosis / Q000209:etiology*; D063171:Corneal Pachymetry; D004728:Endothelium, Corneal / Q000473:pathology*; D005260:Female; D005901:Glaucoma / Q000601:surgery*; D020327:Glaucoma Drainage Implants / Q000009:adverse effects*; D006801:Humans; D007429:Intraocular Pressure; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence