Rate of Corneal Grafting Post-Glaucoma Drainage Device Use in Pediatric and Adult Patients.

PRCIS: Kaplan-Meier analysis was used to compare the rate of corneal grafting after glaucoma drainage device (GDD) placement in pediatric and adult patients. Adults were at an increased risk of receiving a corneal graft after device placement. PURPOSE: The goal of this study was to compare the rate of corneal graft implantation after GDD placement in pediatric and adult patients. PATIENTS: Patients receiving a GDD between January 1, 1985 and December 31, 2017 were selected from the medical records. Patients receiving their first device while <18 years of age were considered children for the extent of the study. METHODS: We compared the rate of receiving a corneal graft after GDD implantation using Kaplan-Meier analysis. Baseline patient characteristics and surgical characteristics were compared using a generalized estimating equation. RESULTS: Corneal grafting occurred in 8.6% of adults and 4.7% of children from the original cohort. The rate of receiving a corneal graft at 5, 10, and 15 years was 9.4%, 16.8%, 39.4% and 1.6%, 1.6%, 12.5% for adults and children, respectively. However, certain characteristics were different between the 2 groups. CONCLUSION: Adult patients were more likely to receive a corneal graft after GDD placement. However, pediatric and adult patients differed in the prevalence of preexisting corneal disease, glaucoma type, GDD type used, and types of previous surgeries. Elucidation of the impact of these factors on corneal graft rate requires a larger cohort size.

Need for Additional Glaucoma Surgery and Complications Following Glaucoma Drainage Device Surgery.

PRCIS: In this longitudinal study of patients with open-angle (OAG), pseudoexfoliative (PXE), or neovascular glaucoma (NVG) receiving glaucoma drainage devices (GDD), posttube cumulative rates of reoperation, corneal graft, and visually threatening complications (VT-complications) increased beyond 5 years and were not significantly affected by glaucoma type. PURPOSE: To study the need for additional glaucoma surgery and development of complications after first GDD surgery in eyes with primary OAG, PXE, or NVG glaucoma. PATIENTS AND METHODS: There were 306 eyes with OAG (n=185), PXE (n=60), or NVG (n=61) glaucoma who received a first GDD between 1996 and 2017. Outcomes including glaucoma reoperation, corneal graft procedure, and VT-complications after GDD were measured. Kaplan-Meier analysis was used to compare cumulative rate of reaching outcomes over time after GDD placement among the 3 glaucoma groups. RESULTS: When comparing the OAG, PXE, and NVG groups, there were no significant differences in post-GDD cumulative rates of reoperation (P=0.33), corneal graft (P=0.26), or VT-complications (P=0.65) over time. For all eyes, the overall cumulative rates for each outcome measure increased beyond 5 years, and specific Kaplan-Meier rates (5-y, 10-y) included: reoperation (16%, 25%), corneal graft (6%, 12%), VT-complications (9%, 14%). When comparing specific GDDs, the Ahmed FP7 had a higher cumulative reoperation rate over time compared with the Baerveldt 350 (P=0.019). CONCLUSION: Glaucoma type did not significantly affect post-GDD cumulative rates of reoperation, corneal graft, and VT-complication among the OAG, PXE, and NVG groups. For all eyes, cumulative rates of reoperation, corneal graft, and VT-complications increased beyond 5 years. The Ahmed FP7 had a significantly higher cumulative reoperation rate compared with the Baerveldt 350 over time.

Three-Decade Evaluation of Cerebrospinal Fluid Pressure in Open-Angle Glaucoma at a Tertiary Care Center.

Elevated intraocular pressure (IOP) is the most prevalent risk factor for primary open-angle glaucoma. However, IOP alone does not fully describe a mechanical basis for disease in patients with normal tension glaucoma or primary open-angle glaucoma. The translaminar pressure difference (TLPD) theory proposes that the pressure gradient generated by the difference of IOP and cerebrospinal fluid pressure (CSFp) acting at the level of the optic nerve can lead to cupping and glaucoma when IOP is higher than normal and/or CSFp is lower than normal. The study results to date have generally supported the TLPD theory; however, varying methods, populations, and sample sizes make it difficult to compare results. To further assess whether there is an association between low CSFp and open-angle glaucoma, 30 years of clinical data that assess 96,543 lumbar punctures were analyzed. Patients with open-angle glaucoma showed a significantly lower CSFp than randomly selected normal control patients (9.9 ± 3 mm·Hg (n = 86) versus 12.1 ± 3.6 mm·Hg (n = 114), p < 0.001) following adjustment for age and sex. This retrospective study provides strong evidence for an association between open-angle glaucoma and low CSFp.

Intraocular Pressure Measurement with Pneumatonometry and a Tonometer Tip Cover.

PURPOSE: To investigate the precision and accuracy of IOP measurements using a pneumatonometer and a tonometer tip cover (Tono-Pen® tip cover) acting as a membrane between a cadaver eye model and pneumatonometer probe. METHODS: A total of 480 paired IOP measurements, with and without a Tono-Pen cover, were collected across 4 pressure levels of 7, 10, 20 and 30 mmHg. IOP measurements were obtained by three different pneumatonometer units paired with three different masked operators (three configurations). Four eyes were sampled for each eye pressure level. The sequence of eye pressure, configuration, and measurements with vs. without the Tono-Pen cover was randomized. RESULTS: With the Tono-Pen cover in place, there was a negative bias with a mean IOP difference of - 1.18 mmHg for all 480 paired samples compared with the measurements absent the cover. Compared with the test pressure settings (i.e., 7, 10, 20, 30 mmHg), the overall mean bias was + 0.35 mmHg with the Tono-Pen cover present. With the Tono-Pen cover present, the overall repeatability %CV (percent coefficient of variation) was 3.4% and the reproducibility %CV was 3.8% compared with a repeatability %CV of 3.2% and reproducibility %CV of 5.7% without the Tono-Pen cover. CONCLUSION: Measurement of IOP via pneumatonometry with a Tono-Pen cover in place, also known as the excursion test method, yields precise, accurate and reproducible results. This developed method of pressure measurement is an acceptable and reliable form of IOP measurement.

Glaucoma Drainage Devices and Reasons For Keratoplasty.

PRéCIS:: Over 10 years in a tertiary care setting, glaucoma drainage devices (GDDs) have not increased as a reason for keratoplasty. PURPOSE: The purpose of this study was to determine whether the reasons for keratoplasty have changed between 10 years in a tertiary care setting, with special attention to the rate of GDDs as a reason for keratoplasty. METHODS: Patients aged 18 years or above who underwent keratoplasty at Mayo Clinic, Rochester, MN from 2005 to 2006 and 2015 to 2016 were studied. All reasons for keratoplasty performed in the study time period are assessed, including patients who previously had a GDD implanted in the same eye. After analyzing the reasons for keratoplasty, we assess whether the reasons for keratoplasty have changed between 2005 to 2006 and 2015 to 2016 in association with the increasing placement of GDDs. RESULTS: The number of keratoplasty procedures performed in the 2 time periods increased by 62% from 163 (2005 to 2006) to 264 (2015 to 2016), whereas GDD placement increased by 164% from 80 GDD (2005 to 2006) to 211 GDD (2015 to 2016). Although the performance of keratoplasty increased between the 2 points in time, the frequency of each cause for keratoplasty did not change significantly. The majority of keratoplasties were performed due to corneal disease, and GDDs made up a small portion of reasons for keratoplasty (2005 to 2006, 4.29%; 2015 to 2016, 5.68%). CONCLUSIONS: The frequency of GDDs as a reason for keratoplasty has not changed significantly between 10 years in this tertiary care setting. Patients with GDDs who later required keratoplasty had associated features including multiple surgical procedures and comorbid infection, pseudophakic bullous keratopathy, Fuchs dystrophy, pseudoexfoliation, uveitis, and congenital glaucoma.