Serial Retinal Nerve Fiber Layer Research Articles

Retinal Nerve Fiber Layer Thickness Progression after Robotic-Assisted Laparoscopic Radical Prostatectomy in Glaucoma Patients

Purpose To investigate the effect of the steep Trendelenburg position surgical procedure on the retinal structure and function during robotic-assisted laparoscopic radical prostatectomy (RALP) in glaucoma patients. Methods At 1 month and 1 day before and at 1 and 2 months after the RALP operation, 10 glaucoma patients underwent standard automated perimetry and optical coherence tomography. After placing patients in a supine position, intraocular pressure (IOP) was measured at 5 min after intubation under general anesthesia (T1), at 5 discrete time points (5, 30, 60, 120, and 180 min; T2-6) and at 5 min after returning to a horizontal supine position (T7). The Guided Progression Analysis software program was used to assess serial retinal nerve fiber layer (RNFL) thicknesses and visual field progression. Results Eight additional patients were newly diagnosed in addition to the two previous glaucoma patients. Average IOP (mmHg) at each time point was as follows: T1 = 11.2 ± 3.8, T2 = 19.0 ± 4.4, T3 = 23.3 ± 6.3, T4 = 25.1 ± 4.3, T5 = 25.5 ± 5.1, T6 = 28.3 ± 4.8, and T7 = 22.6 ± 5.4. IOP significantly increased during RALP. RNFL thickness progressed in two eyes of two patients after the surgery, even though there was no progression of the visual field. Conclusions Two eyes of two patients exhibited significant RNFL thickness progression. Since an increased IOP during the surgery was the probable cause of the changes, ophthalmologic examinations should be performed before and after RALP, especially in glaucoma patients.

The Effect of Steep Trendelenburg Positioning on Retinal Structure and Function during Robotic-Assisted Laparoscopic Procedures.

Purpose Robotic-assisted laparoscopic radical prostatectomy (RALP) has become a standard treatment choice for localized prostate cancer. RALP requires a steep Trendelenburg position, which leads to a significant increase in intraocular pressure (IOP). This study evaluated the effect on the retinal structure and function in patients undergoing RALP. Methods Standard automated perimetry (SAP) and optical coherence tomography (OCT) were performed in 20 males scheduled for RALP at 1 month and 1 day before the operation and at 1 and 3 months after the operation. IOP measurements were made in the supine position at 5 min after intubation under general anesthesia (T1), at 6 discrete time points (5, 30, 60, 120, 180, and 240 min; T2-7), and at 5 min after returning to a horizontal supine position (T8). Serial retinal nerve fiber layer (RNFL) thicknesses and visual field progression were assessed using the guided progression analysis software program. RNFL thickness progression and visual field progression were evaluated by event analysis. Results Average IOP (mmHg) for each time point was as follows: T1 = 12.3 ± 2.6, T2 = 20.4 ± 4.2, T3 = 23.3 ± 3.8, T4 = 24.0 ± 3.2, T5 = 24.3 ± 3.4, T6 = 27.1 ± 7.2, T7 = 29.8 ± 8.7, and T8 = 20.1 ± 4.4. During RALP, IOP significantly increased. There was no progression of the visual field and RNFL thickness after surgery or any other ocular complications found. Conclusions Although IOP significantly increased during RALP, there were no significant changes in the retinal structure and function between the pre- and postoperation observations.

Patterns of glaucoma progression in retinal nerve fiber and macular ganglion cell-inner plexiform layer in spectral-domain optical coherence tomography.

To evaluate the progressive changes of circumpapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thicknesses measured by spectral-domain optical coherence tomography (Cirrus SD-OCT) in open-angle glaucoma. One hundred-fourteen eyes of open-angle glaucoma patients with localized RNFL defect who had 3years' worth of annual RNFL photography and OCT measurements were enrolled in this retrospective study. The progression rates of serial RNFL and GCIPL thicknesses (µm), angular width (°) and area (mm2) of defect on RNFL and GCIPL deviation maps were determined by linear mixed-effect models. Over a mean follow-up period of 3.16years, 50 patients out of a total of 114 patients were classified as progressors based on the structural evaluation. The progressors showed significantly higher progression rates in average, 6 and 11 o'clock sector RNFL thicknesses, angular width and area of defect in RNFL deviation map, as well as inferotemporal and minimum GCIPL thicknesses than the non-progressors. The thicknesses of the 6 o'clock sector RNFL and minimum GCIPL exhibited the highest reduction rates among the RNFL and GCIPL parameters assessed, respectively. When evaluating glaucoma progression by OCT, careful observation of the average, 6 and 11 o'clock sectors in RNFL and inferotemporal and minimum GCIPL thicknesses can be helpful. We can effectively assess early changes of glaucoma progression with GCIPL thickness as well as RNFL thickness.

Estimating the rate of retinal ganglion cell loss to detect glaucoma progression: An observational cohort study.

This study aimed to evaluate the relationship between glaucoma progression and estimates of the retinal ganglion cells (RGCs) obtained by combining structural and functional measurements in patients with glaucoma.In the present observational cohort study, we examined 116 eyes of 62 glaucoma patients. Using Cirrus optical coherence tomography (OCT), a minimum of 5 serial retinal nerve fiber layer (RNFL) measurements were performed in all eyes. There was a 3-year separation between the first and last measurements. Visual field (VF) testing was performed on the same day as the RNFL imaging using the Swedish Interactive Threshold Algorithm Standard 30–2 program of the Humphrey Field Analyzer. Estimates of the RGC counts were obtained from standard automated perimetry (SAP) and OCT, with a weighted average then used to determine a final estimate of the number of RGCs for each eye. Linear regression was used to calculate the rate of the RGC loss, and trend analysis was used to evaluate both serial RNFL thicknesses and VF progression.Use of the average RNFL thickness parameter of OCT led to detection of progression in 14 of 116 eyes examined, whereas the mean deviation slope detected progression in 31 eyes. When the rates of RGC loss were used, progression was detected in 41 of the 116 eyes, with a mean rate of RGC loss of −28,260 ± 8110 cells/year.Estimation of the rate of RGC loss by combining structural and functional measurements resulted in better detection of glaucoma progression compared to either OCT or SAP.

Lamina Cribrosa Reversal after Trabeculectomy and the Rate of Progressive Retinal Nerve Fiber Layer Thinning

To determine whether the reversal of lamina cribrosa (LC) displacement observed after trabeculectomy is associated with the rate of progressive retinal nerve fiber layer (RNFL) thinning in primary open-angle glaucoma (POAG). Observational case series. Thirty-four patients with POAG who underwent trabeculectomy and were followed up for at least 2.5 years, during which the RNFL thickness was measured by serial spectral-domain (SD) optical coherence tomography (OCT). The participants underwent enhanced depth imaging scanning of the optic nerve using SD OCT before surgery (PREOP), at a 6-month postoperative follow-up (FU1), and at a subsequent follow-up that was performed at least 2.5 years postoperatively (FU2), and serial RNFL thickness was measured at least 5 times during the study period. Preoperative and postoperative LC depths (LCDs) as determined on 7 selected B-scan images from each eye were averaged to produce the mean LCD. The rate of RNFL thinning was determined by linear regression of serial OCT RNFL thickness measurements over time. Factors associated with the rate of OCT RNFL thinning. The intraocular pressure (IOP) decreased from 23.8±7.9 mmHg (mean±standard deviation) to 11.0±4.4 mmHg at FU1 (P<0.001) and subsequently increased to 13.1±5.2 mmHg at an overall follow-up of 3.5±0.8 years (P=0.003). The LCD was reduced from 589.90±148.32 to 508.57±136.28 μm at FU1 (P<0.001). A subsequent slight but nonsignificant increase in the LCD was noted at FU2 (516.48±145.87 μm; P=0.410). A faster rate of RNFL thinning was associated with a shorter follow-up period (P=0.032), higher IOP at PREOP (P=0.011) and FU2 (P=0.014), and a larger increase in LCD from FU1 to FU2 (P<0.001). The changes in LCD between PREOP and FU1 and between PREOP and FU2 were not associated with the rate of RNFL thinning. Eyes with sustained LCD reduction over a long period had a slow rate of progressive RNFL thinning after trabeculectomy. A large LCD reduction in the early postoperative period was not associated with the long-term rate of progression if it was not maintained during subsequent follow-up.

Influence of Lamina Cribrosa Thickness and Depth on the Rate of Progressive Retinal Nerve Fiber Layer Thinning

To determine whether lamina cribrosa (LC) depth (LCD) and LC thickness (LCT) are associated with a faster rate of progressive retinal nerve fiber layer (RNFL) thinning in primary open-angle glaucoma (POAG). Prospective, observational study. One hundred ten eyes diagnosed with POAG (n = 110 patients) in which RNFL thickness had been measured by serial spectral-domain (SD) optical coherence tomography (OCT) for at least 2.5 years. The participants underwent enhanced depth imaging volume scanning of the optic nerve, and circumpapillary RNFL thickness measurements were obtained using SD OCT. The participants were followed up regularly with serial RNFL thickness measurements at 6-month or longer intervals. Lamina cribrosa depth was measured at 7 equidistant planes and LCT was measured at 3 locations (superior midperipheral, midhorizontal, and inferior midperipheral). The rate of RNFL thinning was determined by linear regression of serial OCT RNFL thickness measurements over time. Factors associated with the rate of OCT RNFL thinning. A faster rate of RNFL thinning was associated with disc hemorrhage during follow-up (P < 0.001), wider β-zone parapapillary atrophy with Bruch's membrane (P = 0.037), larger global RNFL thickness (P = 0.026), larger LCD (P < 0.001), and smaller LCT (P = 0.002). The association between LCD and the rate of RNFL thinning was explained better using a fractional polynomial model (R(2) = 0.223) than a linear model (R(2) = 0.134; P = 0.010). Davies' test revealed a statistically significant breakpoint for LCD (489.7 μm), above which a faster rate of global RNFL thinning was associated with a larger LCD. A thinner LC and a larger LC displacement had a significant influence on the rate of progressive RNFL thinning.

Use of the structure-function relationship in detecting glaucoma progression in early glaucoma.

BackgroundTo evaluate the use of optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness and visual field (VF) measurements in detecting disease progression in patients with early glaucoma.MethodsOver a 3-year period, this study examined 60 eyes of 39 glaucoma patients whose total deviation in the superior or inferior hemifield was more than -6 dB. All eyes underwent at least four serial RNFL measurements performed by Cirrus OCT, with the first and last measurements separated by at least three years. On the same day as the RNFL imaging, VF testing was also performed by using the Swedish Interactive Threshold Algorithm Standard 30–2 program of the Humphrey Field Analyzer. Serial RNFL thicknesses and VF progression were assessed using the Guided Progression Analysis (GPA) software program. RNFL thickness progression and VF progression were evaluated by the event analysis.ResultsThe mean observation period was 57.6 ± 10.0 months, and during this time, a total of 366 OCT and 366 VF measurements were performed. Using only OCT, progression was found in 2 eyes, while progression was found in 1 eye when only using VF GPA. When combined measurement findings were used, the analysis found progression in 8 eyes.ConclusionsWhen mild VF defect is present, OCT RNFL thickness measurements can be helpful in discerning glaucoma progression.

Evaluation of relationship between retinal nerve fiber layer thickness progression and visual field progression in patients with glaucoma

To evaluate the capability of optical coherence tomography (OCT), retinal nerve fiber layer (RNFL) thickness, and visual field (VF) measurements in glaucoma progression detection. The study examined 62 eyes of 37 glaucoma patients observed over a 3-year period. All eyes underwent at least four serial RNFL measurements performed by Cirrus OCT, with the first and last measurements separated by at least 3 years. VF testing was performed by using the Swedish interactive threshold algorithm (SITA) Standard 30-2 program of the Humphrey field analyzer (HFA) on the same day as the RNFL imaging. Both serial RNFL thicknesses and VF progression were assessed by the guided progression analysis (GPA) software program. RNFL thickness progression was evaluated by event analysis. Total deviation (TD) in the superior or inferior hemifield was also examined. A total of 295 OCT scans and 295 VFs were analyzed. Five eyes exhibited progression by OCT only and 8 eyes exhibited progression by VF GPA only. When the analysis was based on the combined measurement findings, progression was noted in 6 eyes. The average of the progressive hemifield TD at baseline for combined RNFL and VF progression was -3.21±1.38 dB, while it was -2.17±1.14 dB for RNFL progression and -9.12±3.75 dB for VF progression. The average of the progressive hemifield TD indicated a significant advancement of VF progression as compared to RNFL progression (P=0.002). When a mild VF defect is present, OCT RNFL thickness measurements are important in helping discern glaucoma progression.

Retinal Nerve Fiber Layer Imaging with Spectral-domain Optical Coherence Tomography: Patterns of Retinal Nerve Fiber Layer Progression

To examine the use of the retinal nerve fiber layer (RNFL) thickness map generated by a spectral-domain optical coherence tomography (OCT) to detect RNFL progression and identify the pattern of progressive changes of RNFL defects in glaucoma. Prospective, longitudinal study. One hundred eighty-six eyes of 103 glaucoma patients. Patients were followed at 4-month intervals for ≥ 36 months for RNFL imaging and visual field examination. Both eyes were imaged by the Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA) and had visual field testing at the same visits. We defined RNFL progression by Guided Progression Analysis (Carl Zeiss Meditec) of serial RNFL thickness maps. The pattern of RNFL progression was evaluated by comparing the baseline RNFL thickness deviation map and the RNFL thickness change map. Visual field progression was defined by trend analysis of visual field index and event analysis based on the Early Manifest Glaucoma Trial criteria. The presence and the pattern of RNFL progression. A total of 2135 OCT images were reviewed. Twenty-eight eyes (15.1%) from 24 patients (23.3%) had RNFL progression detected by RNFL thickness map analysis. Three RNFL progression patterns were observed: (1) widening of RNFL defects (24 eyes, 85.7%), (2) deepening of RNFL defects (2 eyes, 7.1%, both had concomitant widening of RNFL defects), and (3) development of new RNFL defects (5 eyes, 17.9%). The inferotemporal meridian (324°-336°) 2.0 mm away from the optic disc center was the most frequent location where RNFL progression was detected. Thirteen eyes (46.4%) had concomitant visual field progression; 61.5% (n = 8) of these had RNFL progression that preceded or occurred concurrently with visual field progression. Forty-two eyes from 37 patients (22.6%) had visual field progression by trend and/or event analyses without progression in the RNFL thickness map. Analysis of serial RNFL thickness maps generated by the spectral-domain OCT facilitates the detection of RNFL progression in glaucoma.

Evaluation of Retinal Nerve Fiber Layer Progression in Glaucoma: A Comparison between the Fast and the Regular Retinal Nerve Fiber Layer Scans

To compare the performance of the fast (256 A-scans in each scan circle) and the regular (512 A-scans in each scan circle) retinal nerve fiber layer (RNFL) scan protocols for detection of glaucoma progression using the Stratus optical coherence tomography (OCT) device (Carl Zeiss Meditec, Dublin, CA). Retrospective, longitudinal study. One hundred twenty-nine eyes from 72 glaucoma patients. All patients had been followed up for 2.9 to 6.1 years with a median follow-up of 4 months. All eyes had at least 4 serial RNFL measurements obtained with both the fast and the regular RNFL scans. Visual field (VF) assessment was performed on the same day as RNFL imaging. Retinal nerve fiber layer thickness and VF progression were evaluated with linear regression analysis against age. The mean rate of average RNFL thickness reduction was estimated with linear mixed modeling. The agreement of progression detection and the rate of change of RNFL thicknesses. A total of 1373 fast and 1373 regular RNFL scans and 1236 VF tests were analyzed. With reference to the average RNFL thickness, the fast RNFL scan detected more eyes with progression (21 eyes from 19 patients vs. 15 eyes from 13 patients) than the regular scan at a comparable level of specificity (96.9% vs. 96.1%). More eyes were found to have increasing RNFL thickness with age at individual clock hours (except for 3, 5, 6, and 11 o'clock) when the measurements were obtained with the regular scan. The agreement between the fast and the regular scan for detection of RNFL progression was fair to moderate, with κ values ranging between 0.14 and 0.49. The rate of average RNFL thickness progression was -1.01 μm per year for the fast RNFL scan and -0.77 μm per year for the regular scan. The choice of scan protocols in the Stratus OCT has a significant impact in the evaluation of RNFL progression. The fast RNFL scan seems to be preferable to follow RNFL damage in glaucoma.

Serial Retinal Nerve Fiber Layer Changes in Patients With Toxic Optic Neuropathy Associated With Antituberculosis Pharmacotherapy

To analyze serial changes in retinal nerve fiber layer (RNFL) thickness after development of visual loss in patients with toxic optic neuropathy (TON) associated with antituberculosis pharmacotherapy, as well as to determine if RNFL changes correlate with clinical findings. Five patients with TON underwent serial optical coherence tomography (OCT) and ophthalmologic examination, which consisted of visual acuity, color vision, pupillary light reflexes, visual fields, and funduscopy. Four of the five patients showed normal RNFL thickness on initial OCT. RNFL thickness remained within normal range throughout the follow-up period (range 5.5-50.5 months, average 22.0 +/- 24.8 months after initial visual symptoms) in 3 patients and gradually decreased in 2 patients (4 and 26.5 months after initial visual symptoms), especially in the temporal segment. All patients exhibited improved visual acuity and visual fields. Four patients showed improved color vision. RNFL changes may not be obvious at initial presentation, but became manifest in 2 of the 5 patients over time. OCT may not be useful in identifying the RNFL defect in the early stage, but may be helpful for the follow up of the patients with TON.