Mapping the Structure-Function Relationship in Glaucoma and Healthy Patients Measured with Spectralis OCT and Humphrey Perimetry.

PURPOSE: To study the structure-function relationship in glaucoma and healthy patients assessed with Spectralis OCT and Humphrey perimetry using new statistical approaches. MATERIALS AND METHODS: Eighty-five eyes were prospectively selected and divided into 2 groups: glaucoma (44) and healthy patients (41). Three different statistical approaches were carried out: (1) factor analysis of the threshold sensitivities (dB) (automated perimetry) and the macular thickness (µm) (Spectralis OCT), subsequently applying Pearson's correlation to the obtained regions, (2) nonparametric regression analysis relating the values in each pair of regions that showed significant correlation, and (3) nonparametric spatial regressions using three models designed for the purpose of this study. RESULTS: In the glaucoma group, a map that relates structural and functional damage was drawn. The strongest correlation with visual fields was observed in the peripheral nasal region of both superior and inferior hemigrids (r = 0.602 and r = 0.458, resp.). The estimated functions obtained with the nonparametric regressions provided the mean sensitivity that corresponds to each given macular thickness. These functions allowed for accurate characterization of the structure-function relationship. CONCLUSIONS: Both maps and point-to-point functions obtained linking structure and function damage contribute to a better understanding of this relationship and may help in the future to improve glaucoma diagnosis.

Clinical outcomes after Ex-PRESS glaucoma shunt versus non-penetrating deep sclerectomy: two-year follow-up.

PURPOSE: To compare the two-year outcomes of non-penetrating deep sclerectomy (NPDS) and Ex-PRESS glaucoma shunt. METHODS: A retrospective chart review of patients who had undergone NPDS or Ex-PRESS since 2012 was conducted. Patients were excluded if they had undergone eye surgery other than cataract extraction, were diagnosed with ocular pathology other than glaucoma or had less than two-year follow-up. Pre- and postoperative visual acuity, intraocular pressure (IOP), number of hypotensive drugs and visual fields were recorded, as well as intra- and postoperative complications. RESULTS: Thirty-nine eyes were included in the NPDS and twenty-three eyes in the Ex-PRESS group. There were no differences in baseline IOP and hypotensive drugs, IOP reduction or postoperative IOP-lowering medications between groups. Two years after surgery, IOP decrease compared to baseline was 23.5% with NPDS and 24.8% with Ex-PRESS. Qualified success (a 20% IOP reduction, with IOP ≤ 18 mmHg with or without medication) rates were similar: 53.8 and 69.6% for NPDS and Ex-PRESS. Visual fields progressed in four eyes of the NPDS (10.2%) and in three eyes (8.7%) of the Ex-PRESS group. As regards complications, early hypotony was more frequent after NPDS (9 eyes, 23.1%) than Ex-PRESS (2 eyes, 8.7%), although the difference was not statistically significant. CONCLUSIONS: Both NPDS and Ex-PRESS produce an IOP-lowering effect of approximately 25%. Success rates are similar after both procedures, and both seem to lead to a stabilization of visual loss.

Optical Coherence Tomography to Differentiate Papilledema from Pseudopapilledema.

PURPOSE OF REVIEW: Mild papilledema may be difficult to distinguish by clinical observation from pseudopapilledema. An accurate diagnosis is critical to avoid invasive workup and unwarranted treatment. In this review, we focus on the development and subsequent role of optical coherence tomography (OCT) in detecting and differentiating optic nerve head drusen (ONHD) from papilledema and other causes of acquired swelling of the optic disc. RECENT FINDINGS: Newer OCT technologies which permit deeper penetration to improve detection of ONHD were also reviewed. Enhanced depth imaging (EDI) spectral-domain OCT and swept-source (SS) OCT are currently recognized as the most reliable and sensitive tools to diagnose ONHD. OCT devices currently available provide a means to quantify drusen dimensions, to evaluate the integrity of neighboring structures and to monitor axonal and neuronal damage, yielding additional information to better understand the relationship between the morphological features of drusen, and their effects on the structure and function of the optic nerve.

Relationship between corneal biomechanical properties and optic nerve head changes after deep sclerectomy.

PURPOSE: To evaluate corneal biomechanical properties and optic nerve head (ONH) changes following deep sclerectomy (DS) and the relation to each other. METHODS: Forty-nine eyes with primary open-angle glaucoma that underwent DS were studied. Corneal biomechanical properties were assessed using the Ocular Response Analyzer and the ONH was evaluated by Spectralis optical coherence tomography with enhanced depth imaging technology before surgery and 3 months postoperatively. Changes in corneal hysteresis (CH), corneal resistance factor (CRF), optic nerve cupping, prelaminar tissue thickness, and lamina cribrosa depth and thickness were registered. A correlation matrix and multiple linear regression models were used to determine predictors of ONH changes. RESULTS: At 3 months after surgery, mean corneal compensated intraocular pressure (IOPcc) significantly decreased by 27.9% (p<00.001) and mean Goldmann-correlated IOP (IOPg) decreased by 30.52% (p<00.001). Mean CH increased and CRF decreased by 18.4% and 10.1%, respectively (p<00.001). There was a significant reversal of ONH cupping mainly due to a prelaminar tissue thickening (p<00.001). Significant associations were found between ONH cupping reversal and prelaminar tissue thickening with preoperative IOPcc (p = 0.046), IOPg (p = 0.02), and CRF (p = 0.002) and with changes in IOP, CH, and CRF (p<00.001, p = 0.004, p = 0.018, respectively) after surgery. CONCLUSIONS: Corneal hysteresis increased and CRF decreased significantly 3 months after DS. Corneal resistance factor was the single largest preoperative factor influencing cupping reversal changes. Despite the influence of preoperative variables, postoperative IOP reduction was the only independent factor influencing changes observed in the ONH after surgery.

Bruch's membrane opening changes and lamina cribrosa displacement in non-arteritic anterior ischaemic optic neuropathy.

PURPOSE: To describe the morphological changes in the lamina cribrosa (LC) and prelaminar tissue (PT) from eyes with non-arteritic anterior ischaemic optic neuropathy (NAION) using enhanced depth imaging (EDI) optical coherence tomography (OCT), and to evaluate whether these changes correlate with retinal nerve fibre layer (RNFL) thickness and visual acuity (VA). DESIGN/METHODS: A prospective case-control study was performed, including 17 study eyes with NAION and 17 control, uninvolved eyes from 17 patients. Eyes underwent scanning with Spectralis-OCT at onset, 2 and 6 months after NAION. Bruch's membrane opening (BMO), anterior LC surface depth (LCD), LC thickness and PT thickness (PTT) were compared between study and control eyes. Correlation analysis was performed to evaluate the association between these parameters, RNFL thickness and VA. RESULTS: At presentation, average PT was 58.6% thicker in NAION eyes compared with healthy control eyes (p=0.001), followed by a significant thinning at 2 and 6 months (p=0.001). A significant LC forward displacement was observed at 2 and 6 months (p=0.001). BMO progressively shrunk at 2 and at 6 months (p<0.05). A significant correlation was found between PTT and RNFL thickness (ρSpearman=0.544, p=0.024) at onset, as well as between PTT and RNFL changes at 6 months (ρSpearman=0.545, p=0.036). BMO and RNFL changes were also correlated at 6 months (ρSpearman=0.750, p=0.001). CONCLUSIONS: At onset, a significant PT thickening, backward LC movement and BMO enlargement occurred in NAION eyes compared with unaffected eyes, and these changes significantly reversed during follow-up. PTT and RNFL changes were significantly correlated.

The new Bruch's membrane opening - minimum rim width classification improves optical coherence tomography specificity in tilted discs.

BACKGROUND AND OBJECTIVE: To investigate and compare the false-positive (FP) diagnostic classification of the Bruch's membrane opening - minimum rim width (BMO-MRW) and retinal nerve fiber layer (RNFL) thickness in healthy eyes with tilted optic disc. MATERIALS AND METHODS: Fifty healthy eyes of 30 participants with tilted optic disc underwent BMO-MRW and RNFL scanning using Spectralis and macular Cirrus optical coherence tomography (OCT) scans. RESULTS: The overall FP rate was significantly lower using BMO-MRW map compared with both RNFL map by Spectralis (8% vs 62%, respectively, P<0.001) and ganglion cell analysis (GCA) map by Cirrus (8% vs 50%, respectively, P<0.001). Specificity was significantly higher using BMO-MRW than RNFL in eyes with low (89.7% vs 41.4%, P<0.001) and moderate myopia (95.2% vs 33.3%, P<0.001). CONCLUSION: OCT-derived BMO-MRW analysis provides significantly greater specificity than RNFL in tilted disc irrespectively of the refractive error, and it is more specific than GCA analysis in tilted disc with moderate myopia.

Diagnostic Accuracy of Nonmydriatic Fundus Photography for the Detection of Glaucoma in Diabetic Patients.

PURPOSE: To determine the diagnostic accuracy for glaucoma of a set of criteria with nonmydriatic monoscopic fundus photography (NMFP) in diabetics. METHODS: Diabetics recruited from a screening program for diabetic retinopathy and diabetic glaucoma patients recruited from our glaucoma unit were included. Any patient with evidence of diabetic retinopathy was excluded. Diabetic patients had to have no visual field defects to be included as controls. Glaucoma patients had to have a glaucomatous field defect in at least one eye to be included. One NMFP was taken per eye for all subjects. These photographs were evaluated by two masked glaucoma specialists for the presence of the following: bilateral cup to disc (C/D) ratio ≥ 0.6, notching or thinning of the neuroretinal rim, disc hemorrhages, and asymmetry in the C/D ratio between both eyes ≥ 0.2. This evaluation led to a dichotomous classification: if any of the above criteria was present, the patient was classified as glaucoma. If none were present, the patient was classified as normal. RESULTS: 72 control subjects and 72 glaucoma patients were included. Evaluation of NMFP had a sensitivity of 79.17% and a specificity of 80.56% for specialist 1 and a sensitivity of 72.22% and a specificity of 88.88% for specialist 2 for the detection of glaucoma. The overall accuracy was 79.83% and 80.55%, respectively. DISCUSSION: NMFP evaluation by a glaucoma specialist may be useful for the detection of glaucoma in diabetics.

Comparative diagnostic accuracy of ganglion cell-inner plexiform and retinal nerve fiber layer thickness measures by Cirrus and Spectralis optical coherence tomography in relapsing-remitting multiple sclerosis.

OBJECTIVE: To estimate sensitivity and specificity of several optical coherence tomography (OCT) measurements for detecting retinal thickness changes in patients with relapsing-remitting multiple sclerosis (RRMS), such as macular ganglion cell-inner plexiform layer (GCIPL) thickness measured with Cirrus (OCT) and peripapillary retinal nerve fiber layer (pRNFL) thickness measured with Cirrus and Spectralis OCT. METHODS: Seventy patients (140 eyes) with RRMS and seventy matched healthy subjects underwent pRNFL and GCIPL thickness analysis using Cirrus OCT and pRNFL using Spectralis OCT. A prospective, cross-sectional evaluation of sensitivities and specificities was performed using latent class analysis due to the absence of a gold standard. RESULTS: GCIPL measures had higher sensitivity and specificity than temporal pRNFL measures obtained with both OCT devices. Average GCIPL thickness was significantly more sensitive than temporal pRNFL by Cirrus (96.34% versus 58.41%) and minimum GCIPL thickness was significantly more sensitive than temporal pRNFL by Spectralis (96.41% versus 69.69%). Generalised estimating equation analysis revealed that age (P = 0.030), optic neuritis antecedent (P = 0.001), and disease duration (P = 0.002) were significantly associated with abnormal results in average GCIPL thickness. CONCLUSION: Average and minimum GCIPL measurements had significantly better sensitivity to detect retinal thickness changes in RRMS than temporal pRNFL thickness measured by Cirrus and Spectralis OCT, respectively.

Measurement of retinal nerve fiber layer and macular ganglion cell-inner plexiform layer with spectral-domain optical coherence tomography in patients with optic nerve head drusen.

PURPOSE: To evaluate the effect of optic nerve head drusen (ONHD) on the retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) using Cirrus optical coherence tomography (OCT). METHODS: Fifty-seven eyes of thirty patients with ONHD and thirty-eight eyes of twenty age-matched and sex-matched control subjects underwent circumpapillary and macular scanning using Cirrus OCT. The percentages of eyes with abnormal GCIPL and RNFL values according to the Cirrus normative data were analysed and compared. RESULTS: Overall, eyes with ONHD showed abnormally reduced values for average and minimum GCIPL thicknesses in 35 % and 45 % of cases compared to 2 % for both values in control eyes (P < 0.001). Average RNFL thickness comparison between eyes with ONHD and normal eyes revealed abnormal thinning in 33 % vs. 0 %, respectively (p = 0.002). The percentage of abnormal thinning increased with higher grades of ONHD for all the parameters evaluated, so that in grade III drusen, values were abnormally reduced in 80 % of eyes in all three analyses. Regarding buried ONHD, 30 % and 4 % of eyes had an abnormally reduced minimum GCIPL and average RNFL thickness, respectively. Furthermore, 26 % of these eyes had abnormal GCIPL exams with a normal or increased RNFL thickness. CONCLUSIONS: Both RNFL and GCIPL analysis reveal significant thinning in eyes with ONHD directly correlated with drusen severity. In buried ONHD, the abnormality rate was significantly higher with GCIPL compared to RNFL evaluation, suggesting that GCIPL analysis might be an early structural indicator of neuronal loss in the setting of thickened RNFL.

A comparison of false positives in retinal nerve fiber layer, optic nerve head and macular ganglion cell-inner plexiform layer from two spectral-domain optical coherence tomography devices.

BACKGROUND: The incidence of false positive (FP) results of optic coherence tomography (OCT) retinal nerve fiber layer (RNFL) color code in healthy subjects can be very high with Cirrus OCT. Recent evidence has shown that OCT parameters derived from macular ganglion cell-inner plexiform layer (GCIPL) have excellent ability to discriminate between normal eyes and eyes with early glaucoma. METHODS: This was a prospective, cross-sectional study. One hundred eyes from 50 healthy volunteers underwent circumpapillary scanning by Cirrus and Spectralis OCT and macular scanning using Cirrus OCT. FP rates for each of the OCT parameters, using predefined criteria for an abnormal test were calculated. Comparative analysis was performed using the McNemar test. A generalized estimating equations model (GEE) was used to compare demographic and clinical factors between the eyes with normal findings and eyes with abnormal results. RESULTS: The overall RNFL color-code FP rate was significantly higher for Cirrus (39 %) than for Spectralis (18 %) (P = 0.000). The Spectralis RNFL FP rate showed no significant difference when compared to the FP rate by Cirrus GCIPL (13 %) and ONH (11 %) analysis. Axial length, mean spherical equivalent, presence of peripapillary atrophy, and tilted disc were significantly related to the RNFL FP occurrence displayed by both devices. CONCLUSIONS: Spectralis might be more specific than Cirrus when evaluating the RNFL thickness for Caucasians and moderate myopic population. GCIPL and ONH analysis might be more useful than RNFL thickness to evaluate this population using Cirrus OCT.

Comparison of corneal haze and visual outcome in primary DSAEK versus DSAEK following failed DMEK.

BACKGROUND: Descemet membrane endothelial keratoplasty (DMEK) is being proposed as the procedure of choice in corneal endothelial disease as it achieves better visual and refractive outcomes than Descemet stripping automated endothelial keratoplasty (DSAEK). Nevertheless, primary graft failure is frequent, especially during the learning curve, and secondary back-up procedure consists on DSAEK. We aim to compare corneal haze and visual acuity of patients undergoing primary DSAEK vs. patients undergoing DSAEK as a back-up procedure after primary DMEK failure. METHODS: This study is a comparative case series that included 19 eyes from 16 patients with early stages of corneal failure and limitation of daily activities after primary DSAEK or secondary DSAEK. A control group of non-operated corneas included 10 aged-matched normal eyes. The study was conducted at University Hospital Ramón y Cajal and Vissum Hospital, Madrid, Spain. Corneal densitometry readings and postoperative best-corrected visual acuity in subjects with primary and secondary DSAEK were recorded 6 months after the surgery using the Pentacam Scheimpflug system (Oculus, inc.,Wetzlar, Germany). RESULTS: In primary DSAEK median densitometry values (range) were statistically significantly higher (p < 0.05) than normal subjects for the full thickness, posterior and anterior part of the paracentral cornea; and the anterior part of the central cornea. In secondary DSAEK, median densitometry values were statistically significantly higher than normal subjects at all levels of the central and paracentral cornea. In secondary DSAEK, median densitometry values (range) were statistically significantly higher than in primary DSAEK in the full-thickness, anterior part and interface of the central cornea and in the full-thickness and posterior part of the paracentral cornea. Median visual acuity between groups (p = 0.47) was statistically better for the primary DSAEK group, which also had a higher percentage of patients achieving BCVA of ≥ 20/40 and ≥ 20/25 than the secondary DSAEK group (100% vs. 62% and 60% vs. 0% respectively). CONCLUSIONS: There is an increase in central corneal light scattering after secondary DSAEK performed after a failed DMEK as compared to primary DSAEK. This has a negative impact on final visual acuity that needs to be considered in each patient when starting DMEK surgery.

Color-code agreement among stratus, cirrus, and spectralis optical coherence tomography in relapsing-remitting multiple sclerosis with and without prior optic neuritis.

PURPOSE: To evaluate the agreement of retinal nerve fiber layer (RNFL) color codes among Stratus, Cirrus, and Spectralis optical coherence tomography (OCT) in patients with relapsing-remitting multiple sclerosis. DESIGN: Prospective cohort study. METHODS: In 140 eyes from 70 patients having relapsing-remitting multiple sclerosis from January 2011 to September 2011, peripapillary RNFL thickness was measured using the fast RNFL program by Stratus, the optic disc cube protocol by Cirrus, and the N-site axonal analysis by Spectralis. RESULTS: Overall, a moderate to good RNFL color code agreement was found (0.435-0.884), except for the nasal quadrant. The temporal quadrant was the most abnormal color coding by both Cirrus (64.7%) and Spectralis (61.7%) in both the optic neuritis (ON) and non-ON group and by Stratus (58.8%) in the ON group. Abnormal temporal RNFL color-code rate was significantly higher in ON eyes than non-ON eyes by Cirrus (P < .001), Stratus (P < .001), and Spectralis (P = .030). Overall, Cirrus significantly displayed abnormal findings while both Stratus and Spectralis displayed normal results for the inferior quadrant (P < .05). On the other hand, Spectralis OCT showed a significantly higher rate of abnormal findings while Cirrus displayed normal results for the temporal quadrant in non-ON eyes (P < .001). CONCLUSIONS: We found a substantial color-code disagreement among devices in patients with relapsing-remitting multiple sclerosis regarding the ON antecedent. In non-ON eyes, Spectralis yielded a significantly higher thinning for temporal quadrant than Cirrus, suggesting that N-site axonal analysis could define axonal damage in relapsing-remitting multiple sclerosis patients earlier than conventional RNFL analysis.

Comparison of toric intraocular lenses and peripheral corneal relaxing incisions to treat astigmatism during cataract surgery.

PURPOSE: To evaluate and compare toric intraocular lens (IOL) implantation and spherical IOL implantation with peripheral corneal relaxing incisions to manage astigmatism during phacoemulsification. SETTING: Ophthalmology Service, Hospital Ramón y Cajal, Madrid, Spain. DESIGN: Prospective randomized comparative case series. METHODS: Eyes with cataract and corneal astigmatism (1.00 to 3.00 diopters [D]) had toric IOL implantation or peripheral corneal relaxing incisions. Outcome measures were visual outcomes, slitlamp assessment, digital toric IOL axis determination, spectacle need, and patient satisfaction. RESULTS: Three months postoperatively, the mean uncorrected distance visual acuity (UDVA) was 0.13 ± 0.10 (SD) in the toric IOL group and 0.19 ± 0.12 in the relaxing incisions group; the UDVA was better than 0.20 in 75% of eyes and 60% of eyes, respectively. Refractive cylinder decreased significantly in both groups, with a mean residual refractive astigmatism of 0.61 ± 0.41 D in the toric IOL group and 1.32 ± 0.60 D in the relaxing incisions group (P<.01). The mean toric IOL rotation was 3.65 ± 2.96 degrees, with no significant differences between slitlamp and digital photograph measurements. There was a trend toward better mesopic contrast sensitivity with glare in the toric IOL group. There were no differences in VF-14 or patient satisfaction results; 15% of patients in the toric IOL group and 45% in the relaxing-incision group required distance spectacles postoperatively. CONCLUSION: Although refractive astigmatism decreased in both groups, toric IOL implantation was more effective and predictable, resulting in greater spectacle independence.