Regional Corneal Thickness in Eyes With Mini Glaucoma Shunt Drainage Device
Purpose
To assess and compare the corneal thickness in the superior quadrant adjacent to the Ex-PRESS drainage implant between the eye with the implant and the fellow, previously unoperated eye in a retrospective manner
Methods
Subjects: 11 active patients at Dean McGee Eye Institute (currently, still in data collection with a goal n value of 20-30)
Data acquisition: Measure K thickness using an anterior segment optical coherence tomography imaging device (VisanteTM, Carl Zeiss Meditec)
Inclusion/Exclusion Criteria: Ages 18-100 with a diagnosis of primary open angle, pseudoexfoliative or pigmentary glaucoma who have had an Ex-PRESS glaucoma drainage device implanted in one eye (at least 3 months postop) with no glaucoma surgery performed in an otherwise healthy fellow eye. Patients were excluded if they had any other forms of glaucoma aside from what is mentioned above, if they had a prior intraocular surgery in either eye (aside from phacoemulsification with intraocular lens implantation) and if there was any underlying corneal pathology or history of ocular trauma.
Results
By using the Wilcoxon signed-rank test, the differences recorded for superior regional corneal thickness (defined as operative – non-operative eye) are all positive (thicker) except for two patients in this review of 21 patients (median difference is positive p= 0.0001; mean difference is 46 – interquartile range: 17-84) . These results suggest the SRCT tends to be higher than in the operative eye compared to the non-operative eye.
In contrast, the central corneal thickness differences were not significantly different from zero (p=0.628).
Conclusion
This data reveals a statistically significant increase in the superior regional corneal thickness when comparing the operative eye to the non-operative eye. Despite these results, it must be noted that there was no clinical evidence of corneal decompensation/edema in these patient’s postoperatively.