Yasuko Tatsumi

Association of retinal nerve fibre layer thickness measured by confocal scanning laser ophthalmoscopy and optical coherence tomography with disc size and axial length

Aims: To investigate the influence of age, disc size and axial length on the retinal nerve fibre layer (RNFL) thickness measurements of Heidelberg Retina Tomograph (HRT) and optical coherence tomography (OCT). Methods: A total of 162 eyes of 162 Japanese normal subjects aged between 20 and 83 were enrolled in this study. The disc area and mean RNFL thickness were measured with HRT. The disc area was also measured using the fast optic nerve scan protocol, and the average RNFL thickness was measured using the fast RNFL thickness scan mode with Stratus OCT. The correlations of age, disc area and axial length with RNFL thickness measured with HRT and OCT were analysed. The associations between axial length and disc area measured with HRT and OCT were also calculated. Results: RNFL thickness measured with the two instruments decreased with age. There was a significantly negative correlation between the mean RNFL thickness and disc area measured with HRT. The RNFL thickness measured with OCT correlated positively with the disc area measured with OCT, but not with the disc area measured with HRT. Both RNFL thickness and disc area measured with OCT were inversely correlated with axial length, whereas the two parameters measured with HRT had no association with axial length. Conclusion: In addition to the effect of ageing, the disc size affected the RNFL thickness measured with HRT, whereas the axial length influenced the RNFL thickness and disc area measured with OCT. These variables must be taken into consideration when measuring eyes with the lower or upper boundary of the normal range.

Comparison of Pentacam Scheimpflug Camera with Ultrasound Pachymetry and Noncontact Specular Microscopy in Measuring Central Corneal Thickness

Purpose: Although central corneal thickness (CCT) can be measured by several methods, interchangeability of different modalities has not been fully investigated. CCT is known to correlate with intraocular pressure (IOP). The aim of this study was to evaluate the agreement of Pentacam Scheimpflug system with noncontact specular microscopy (NCSM) and ultrasound (US) pachymetry in measuring CCT and the relation between IOP taken with Goldmann applanation tonometer (GAT) and the CCT measured with these three methods. Methods: The right eyes of 135 enrolled persons without antiglaucoma drug use (100 females and 35 males), who comprised 32 patients with primary open-angle glaucoma, 14 with ocular hypertension, 45 with primary angle-closure glaucoma, and 44 controls, were studied. Intermethod comparison of CCT was made by the 95% limits of agreement analysis according to Bland and Altman. Linear regression analysis was used to assess the relationship between IOP and CCT taken with each modality. Results: The mean CCT (±SD) taken with Scheimpflug, US, and NCSM was 559.49 ± 38.44 μ m, 553.01 ± 39.33 μ m, and 552.04 ± 42.95 μ m, respectively. The average values of CCT taken with the three instruments were not significantly different (one-factor ANOVA; p = 0.26), although the marginal mean difference between Scheimpflug and US or NCSM was statistically significant (paired t test; p = 0.0009 and 0.005, respectively). The 95% limits of agreement were 6.47 ± 43.21 μm between Scheimpflug and US, 7.45 ± 58.86 μ m between Scheimpflug and NCSM, and 0.98 ± 51.69 μ m between US and NCSM. There was a positive association between IOP and CCT measured with US or NCSM, whereas there was no correlation between IOP and CCT measured with Scheimpflug. Conclusions: Although CCT values measured with Scheimpflug, US, and NCSM are closely similar, clinicians should keep in mind that these methods are not simply interchangeable.

Retinal Nerve Fiber Layer Thickness in Optic Tract Syndrome

BackgroundOptic tract syndrome (OTS) is characterized by incongruous homonymous hemianopia and a perpendicular pattern of bilateral optic atrophy due to the optic tract lesion. However, loss of retinal nerve fiber layer thickness (RNFLT) associated with OTS has not been quantitatively assessed.CaseA 20-year-old woman with blunt head trauma showed normal visual acuity, color vision, ocular motility, and intraocular pressure. Because of a relative afferent pupillary defect in her left eye and left-sided homonymous hemianopia, we suspected right-sided optic tract damage, although magnetic resonance imaging detected no intracranial lesion.ObservationsUsing optical coherence tomography (OCT), the RNFLT of this case was measured at 31 months after the trauma and compared with age-matched normal controls (n = 41). Nasal, temporal, superior, and inferior quadrant RNFLT was reduced by 22%, 21%, 5%, and 46% in the right eye and 76%, 64%, 25%, and 27% in the left eye, respectively. The reduction was > 3 × the standard deviation of the normal mean values in the nasal and temporal quadrants of the left eye and in the inferior quadrant of the right eye.ConclusionsOCT can determine the RNFLT reduction corresponding to the characteristic patterns of optic atrophy of OTS. Jpn J Ophthalmol 2005;49:294–296

Quantification of retinal nerve fiber layer thickness reduction associated with a relative afferent pupillary defect in asymmetric glaucoma

Aim: The relative afferent pupillary defect (RAPD) is an important clinical sign of asymmetrical retinal ganglion cell and axonal damage. Although glaucoma essentially affects bilateral eyes, a subset of patients manifests asymmetrical glaucomatous optic neuropathy (GON), which exhibits an RPAD in the more advanced eyes. However, the degree to which axonal loss occurs before an RAPD is clinically detectable has not been substantiated. The purpose of this study is to assess the relationship between the depth of a clinically detectable RAPD and the reduction ratio of retinal nerve fiber layer (RNFL) thickness in the more advanced eyes relative to that in the contralateral less advanced eyes of patients with asymmetrical GON. Methods: Enrolled were 29 consecutive glaucoma patients with the clinically detectable RAPD. An RAPD was quantified by placing log-scaled neutral density filters over the less advanced eyes while performing the swinging flashlight test. Average RNFL thickness was determined using the Fast RNFL thickness programme of optical coherence tomography 3000. Correlation coefficient and Linear regression analyses were used in assessing the relationship between the RAPD and the ratio of RNFL thickness in the more advanced eyes relative to that in the less advanced. Results: RAPD ranged from 0.6 to 2.4 log units. The log-scaled RAPD had a statistically significantly inversed correlation with the average RNFL thickness ratio (rs = −0.729, p<0.0001). Linear regression analysis found an equation that the average RNFL thickness ratio in the more affected eyes relative to that in the less advanced (%)  = (0.827−0.169×RAPD (log units))×100 (R2 = 0.557, p<0.0001). Conclusions: When an RAPD is clinically detected, the RNFL thickness in the more advanced eyes was in average reduced to about 73% of that in the less advanced.

Disagreement between Heidelberg Retina Tomograph and optical coherence tomography in assessing optic nerve head configuration of eyes with band atrophy and normal eyes

Background/aims: To evaluate to what extent the optic nerve head (ONH) parameters as measured with Heidelberg Retina Tomograph (HRT) differed from those measured with optical coherence tomography (OCT) in eyes with compressive optic neuropathy (CON) that had band atrophy (BA) of the optic disc. Methods: A total of 30 eyes from 19 patients with BA due to chiasmal tumour and 162 eyes from 162 normal subjects were examined with HRT and Stratus OCT using the fast optic nerve scan protocol. Parameters measured by the two devices, including the disc area, cup/disc (C/D) area ratio, cup area, cup volume, rim area and rim volume, were compared between the eyes of BA patients and controls. Bland–Altman plots were used to evaluate agreement for each parameter between OCT and HRT in both groups of eyes. Intermethod discrepancy of the measurements for each parameter was compared between the two groups of eyes. Results: Eyes with BA had smaller cup and larger rim parameters than control eyes when measured with HRT, whereas they had significantly larger cup and significantly smaller rim parameters than control eyes when measured with OCT. HRT measurements tended to be consistently lower in the C/D area ratio and cup area and higher in the rim area and rim volume than OCT measurements for both control eyes and eyes with BA. The intermethod discrepancy for all the parameters except the disc area was significantly larger in eyes with BA than in control eyes. Conclusion: The increased optic disc excavation was detected with OCT but not with HRT in CON eyes with BA of the optic disc. Thus, the distinct algorithms used by these two modalities affected the measurements of ONH parameters, particularly when assessing optic discs with temporal rim thinning.

Nipradilol protects rat retinal ganglion cells from apoptosis induced by serum deprivation in vitro and by diabetes in vivo.

Purpose: To investigate if nipradilol has an anti-apoptotic effect in serum-deprived RGC-5 cells and in the streptozotocin-induced diabetic rat retina. Methods: Apoptosis was quantified by activated caspase-3 immunohistochemistry or terminal dUTP nick end-labeling assay. Results: Nipradilol dose-dependently suppressed apoptosis in a protein kinase A- and G-dependent manner and counteracted glutamate-induced calcium entry in the RGC-5 cells and reduced apoptotic cells in the retinal ganglion cell layer of 4- and 12-week diabetic retinas compared to controls when instilled for 5 days. Removal of the nitric oxide moiety from nipradilol blocked these effects. Conclusions: Nipradilol protects RGCs from apoptosis induced by serum-deprivation in vitro and by diabetes in vivo. The NO-related signaling pathway mediates the anti-apoptotic ability of nipradilol.

Filtering Bleb Structure Associated with Long-Term Intraocular Pressure Control after Amniotic Membrane-Assisted Trabeculectomy

Purpose/Aim: To determine whether amniotic membrane transplantation (AMT) at trabeculectomy affects intrableb structures and which intrableb parameters are significantly correlated with the long-term intraocular pressure (IOP) control. Materials and Methods: Enrolled were 64 eyes of 56 glaucoma patients who underwent trabeculectomy without (36 eyes) or with (28 eyes) AMT. Bleb structure was evaluated by ultrasound biomicroscopy (UBM) at least one year after surgery. IOP control was defined as good when the eyes had a more than 30% decrease in the preoperative IOP and an IOP value <18 mmHg if the preoperative IOP was higher than 21 mmHg. Logistic regression analyses were conducted to identify factors significantly associated with IOP control. Results: Intervals between surgery and the timing of the UBM examinations (median; 2.5 years) and the overall frequency of good IOP control (28/36 in the eyes without AMT and 17/28 in those with AMT; chi-square test, P = 0.2276) were similar in the two groups. The eyes with AMT had a significantly lower number of type H (high reflective) or L (low reflective) blebs and a higher number of type E (encapsulated) blebs compared to those without AMT (P < 0.0001). Among independent variables, which included age, sex, glaucoma type, lens status, the number of ocular hypotensives, and previous intraocular surgeries, only type F (flattened) bleb in eyes without AMT (P = 0.0008, odds ratio [OR] = 0.0256) and no or limited intrableb fluid-filled space in eyes with AMT were significantly associated with poor IOP control (P = 0.0026, OR = 0.0111, and 0.0071, 0.0167, respectively). Conclusions: Intrableb structures after trabeculectomy alone versus AMT-assisted trabeculectomy were distinct. The bleb wall reflectivity in the former and the extent of the subconjunctival fluid-filled space in the latter were factors associated with long-term IOP control.

Comparison of mean deviation with AGIS and CIGTS scores in association with structural parameters in glaucomatous eyes.

ObjectiveTo evaluate which of the 3 clinically used visual field indices including mean deviation (MD), Advanced Glaucoma Intervention Study (AGIS) score, and Collaborative Initial Glaucoma Treatment Study (CIGTS) score are best in evaluating functional damage of glaucomatous optic neuropathy. MethodsIn 213 glaucomatous eyes, peripapillary retinal nerve fiber layer thickness (RNFLT) and optic disc configuration were measured with Stratus optical coherence tomography and Heidelberg Retina Tomograph-2, respectively. Visual field was measured with standard automated perimetry 30-2. Correlations of the structural parameters compared with the 3 VF indices using second polynomial regression were calculated. In addition, these correlations were analyzed among eyes of 3 different stages of glaucoma, as defined by MD score (early, MD≥−6 dB; moderate, −12 dB≤MD<−6 dB; advanced, MD<−12 dB). ResultsAmong structure-function relationships in all subjects, the highest correlation determination (R2) was MD with RNFLT (=0.298). CIGTS score showed better R2 than MD or AGIS score with rim area, but these values were not higher than any R2 with RNFLT. In analyses of 3 groups depending on MD, statistically significant structure-function correlations were observed only in patients with an advanced stage. ConclusionsNo clear difference was found among MD and AGIS/CIGTS scores in expressing functional damage of glaucomatous eyes. MD is suggested to be no worse than others in monitoring glaucoma in clinical setting.