Original article
Short-Term Enhancement of Visual Field Sensitivity in Glaucomatous Eyes Following Surgical Intraocular Pressure Reduction

https://doi.org/10.1016/j.ajo.2014.11.012Get rights and content

Purpose

To examine the hypothesis that surgical intraocular pressure (IOP) reduction leads to enhancement of visual field (VF) sensitivity in glaucomatous eyes.

Design

Prospective case-control study.

Methods

Patients with uncontrolled IOP requiring trabeculectomy or aqueous drainage device were enrolled. Controls consisted of medically treated glaucoma patients with stable IOP and no change in medical therapy during follow-up. Two baseline preoperative VFs and 3 follow-up VF examinations at 1, 2, and 3 months postoperatively were used for analysis. The same number of VF examinations measured within an 18-month interval was used for control eyes. VF locations with significant change were defined as exceeding 95% test-retest confidence limits based upon the mean sensitivity using the 2 baseline VF exams. The number of significantly changing locations per eye and changes in mean and pattern standard deviation (PSD) from the mean baseline fields were compared between groups using a Poisson generalized estimating equation model.

Results

Thirty eyes of 30 surgically treated glaucoma patients and 41 eyes of 28 stable controls were enrolled. Postoperative IOP was decreased at follow-up 3 compared with baseline (P < .001) in the surgical eyes, but was similar in control eyes (P = .92). At follow-up 3, the number of test locations improving in central (P = .014) and peripheral (P = .019) VF locations was significantly greater in the surgical eyes. The number of eyes with improved PSD at follow-up 3 was significantly greater in the surgical eyes compared with controls (P = .02).

Conclusions

Short-term enhancement of central and peripheral VF sensitivity occurs after surgical reduction of IOP in glaucomatous eyes and may represent a potential biomarker for retinal ganglion cell response to therapeutic interventions in glaucoma.

Section snippets

Patients and Methods

This prospective cohort study was approved by the Institutional Review Board for Human Research at the University of Miami and followed the tenets of the Declaration of Helsinki. Case subjects made up of glaucoma patients who met eligibility criteria with uncontrolled IOP on maximal medical therapy requiring trabeculectomy or aqueous drainage device implantation, who gave informed consent to participate, were enrolled. Control subjects were medically treated glaucoma patients with stable IOP

Results

The study population consisted of 30 eyes of 30 surgically treated glaucoma patients (age 68.3 ± 18.4 years) and 41 eyes of 28 controls (age 67.4 ± 7.3 years). The baseline MD values in the surgical group (−7.6 ± 4.9 dB) and the control group (−5.6 ± 4.2 dB) were similar (P > .05). The mean time interval between the baseline and follow-up 3 examination was greater (P < .001) in control eyes (18.3 ± 2.91 months) compared to surgical eyes (4.9 ± 1.96 months). The population demographics and

Discussion

The total RGC population in a glaucomatous eye consists of RGCs that are physiologically normal, dysfunctional, nonviable, and atrophic undergoing variable stages of degeneration. Commercially available posterior segment imaging technologies provide structural measures of RGCs and axons no longer viable that have subsequently become atrophic. Quantification of RGC function is of considerable interest to clinicians and scientists who seek biomarkers for early diagnosis, prediction and

Tracy M. Wright, MD, received his Bachelor of Arts degree in biology from Harvard University in 2002 and his medical degree from Yale University in 2009. He completed his residency in ophthalmology at New York University in 2013 and his fellowship in glaucoma at Bascom Palmer Eye Institute in 2014. He is currently an Assistant Professor of Ophthalmology at Bascom Palmer Eye Institute.

References (20)

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Tracy M. Wright, MD, received his Bachelor of Arts degree in biology from Harvard University in 2002 and his medical degree from Yale University in 2009. He completed his residency in ophthalmology at New York University in 2013 and his fellowship in glaucoma at Bascom Palmer Eye Institute in 2014. He is currently an Assistant Professor of Ophthalmology at Bascom Palmer Eye Institute.

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