Marcelo T. Nicolela

Ocular hypertension and primary open-angle glaucoma: a comparative study of their retrobulbar blood flow velocity.

PurposeTo compare the orbital blood flow velocities of patients with longstanding ocular hypertension and patients with primary open-angle glaucoma. MethodsTwenty patients with ocular hypertension were recruited from our clinic and underwent color Doppler imaging evaluation of their retrobulbar vessels. The blood flow velocities and resistance index of their central retinal artery, temporal short posterior ciliary artery, and ophthalmic artery were compared with those of 20 glaucoma patients individually matched for age and level of the highest untreated intraocular pressure ever recorded. ResultsGlaucoma patients had significantly lower peak systolic velocity and end-diastolic velocity than did patients with ocular hypertension in their central retinal artery (p < 0.001). No significant difference between the groups was observed in the other vessels studied. ConclusionsGlaucoma patients had lower blood flow velocity in the central retinal artery compared with that of ocular hypertension patients of similar age and level of untreated intraocular pressure. This might be important in the development of glaucomatous damage in those patients.

Reproducibility of retinal and optic nerve head blood flow measurements with scanning laser Doppler flowmetry

PURPOSEnTo evaluate the interobserver variability and the reproducibility of retinal and optic nerve head capillary blood flow measurements performed with a new noninvasive equipment, the scanning laser Doppler flowmeter (Heidelberg Engineering, Heidelberg, Germany).nnnMETHODSnBlood flow measurements were performed during three independent sessions in six patients with glaucoma and five normal subjects using the scanning laser Doppler flowmeter (SLDF), which allows the visualization of perfused capillaries and vessels of the retina and optic nerve head and enables the quantification of capillary blood volume, flow, and velocity in any selected area of the perfusion map. To evaluate the interobserver variability in selecting the areas in the perfusion map to be measured, three observers tried to locate the same areas in the perfusion map of images obtained during the first session. To evaluate the reproducibility of the measurements, the observers measured correspondent areas in the peripapillary retina and in the optic nerve head of images from the three sessions. Areas of different sizes (10 x 10 pixels and 4 x 4 pixels) were measured.nnnRESULTSnThe agreement between readings performed by the three observers was very good, with the reliability coefficient for the various parameters varying from 0.90 to 0.98. The reproducibility of retinal and lamina cribrosa measurements with the 10 x 10 pixel square target was good (reliability coefficient for the different parameters ranging from 0.70 to 0.85) and much better than the reproducibility of the 4 x 4 pixel target. The measurements performed in the neuroretinal rim area also had poor reproducibility. The measurements from the patients with glaucoma tended to be more reproducible than those from normal subjects.nnnCONCLUSIONSnThe SLDF allows reproducible blood perfusion measurements of retinal and lamina cribrosa areas when a target square of 10 x 10 pixels is used.

Canadian Glaucoma Study: 3. Impact of risk factors and intraocular pressure reduction on the rates of visual field change.

OBJECTIVESnTo determine rates of visual field change associated with risk factors for progression in the Canadian Glaucoma Study (abnormal anticardiolipin antibody level, age, female sex, and mean follow-up intraocular pressure [IOP]), and to evaluate the effect of IOP reduction on subsequent rates of visual field change in progressing patients.nnnMETHODSnTwo hundred sixteen patients (median age, 65.2 years) were followed up at 4-month intervals with perimetry and were monitored for progression. Patients reaching an end point based on total deviation analysis underwent 20% or greater reduction in IOP. Rates of mean deviation (MD) change were calculated.nnnRESULTSnPatients with 0, 1, and 2 end points had a median of 18, 23, and 25 examinations, respectively. The median MD rate in progressing patients prior to the first end point was significantly worse compared with those with no progression (-0.35 and 0.05 dB/y, respectively). An abnormal anticardiolipin antibody level was associated with a significantly worse MD rate compared with a normal anticardiolipin antibody level (-0.57 and -0.03 dB/y, respectively). Increasing age was associated with a worse MD rate, but female sex and mean follow-up IOP were not. After the first end point, the median IOP decreased from 18.0 to 14.8 mm Hg (20% in individual patients), resulting in a significant MD rate change from -0.36 to -0.11 dB/y.nnnCONCLUSIONSnPatients with abnormal anticardiolipin antibody levels and increasing age had faster visual field change. Modest IOP reduction in progressing patients significantly ameliorated the rate of visual field decline.nnnTRIAL REGISTRATIONnclinicaltrials.gov Identifier: NCT00262626.

Central corneal thickness and progression of the visual field and optic disc in glaucoma

Aims: To determine whether central corneal thickness (CCT) is a significant predictor of visual field and optic disc progression in open angle glaucoma. Methods: Data were obtained from a prospective study of glaucoma patients tested with static automated perimetry and confocal scanning laser tomography every 6 months. Progression was determined using a trend based approach called evidence of change (EOC) analysis in which sectoral ordinal scores based on the significance of regression coefficients of visual field pattern deviation and neuroretinal rim area over time are summed. Visual field progression was also determined using the event based glaucoma change probability (GCP) analysis using both total and pattern deviation. Results: The sample contained 101 eyes of 54 patients (mean (SD) age 56.5 (9.8) years) with a mean follow up of 9.2 (0.7) years and 20.7 (2.3) sets of examinations every 6 months. Lower CCT was associated with worse baseline visual fields and lower mean IOP in the follow up. In the longitudinal analysis CCT was not correlated with the EOC scores for visual field or optic disc change. In the GCP analyses, there was a tendency for groups classified as progressing to have lower CCT compared to non-progressing groups. In a multivariate analyses accounting for IOP, the opposite was found, whereby higher CCT was associated with visual field progression. None of the independent factors were predictive of optic disc progression. Conclusions: In this cohort of patients with established glaucoma, CCT was not a useful index in the risk assessment of visual field and optic disc progression.

Hypotony Maculopathy after Filtering Surgery with Mitomycin C

PURPOSEnHypotony maculopathy after glaucoma filtering surgery with adjunctive mitomycin C has been reported to occur in 3% to 14% of cases. The authors evaluated its incidence when using a corneal safety-valve incisior intended to reduce its occurrence. The authors also evaluated a technique for reversing hypotony maculopathy by reoperation using two sets of stitches in the scleral flap, with one set tied tightly to temporarily raise the intraocular pressure, stretch the sclera, and flatten chorioretinal folds.nnnMETHODSnThe authors reviewed the results of 699 procedures performed between April 1991 and October 1994. All were performed or supervised by one surgeon (PFP).nnnRESULTSnHypotony maculopathy developed in 9 (1.3%) of 699 eyes. There was a statistically significant higher incidence in primary filters (4%) as compared to secondary filters or combined procedures. After revision, eight (89%) of nine recovered visual acuity of greater than or equal to 20/30 and the mean intraocular pressure was 14.5 +/- 4 mmHg at a mean follow-up of 15 months.nnnCONCLUSIONnThe incidence of hypotony maculopathy after glaucoma filtering surgery with mitomycin C using a corneal safety-valve incision is less than that reported in the literature without this incision. There is an increased risk in myopes, young patients, and primary filters. Early intervention with the described scleral flap revision technique usually allows restoration of prefiltration visual acuity without compromise of bleb function.

Correlation of capsular pseudoexfoliation material and iridocorneal angle pigment with the severity of pseudoexfoliation glaucoma.

PurposeTo evaluate the correlation between the amount of pseudoexfoliation (PXF) material on the anterior lens capsule, pigment in the iridocorneal angle, presenting intraocular pressure (IOP) and severity of glaucoma in patients with PXF glaucoma/syndrome. Patients and MethodsAnterior lens capsule PXF material and iridocorneal pigment of 98 untreated patients with PXF syndrome/glaucoma were graded from photographs and correlated with untreated IOP and indices of glaucoma severity (cup to disc ratio, and visual field mean deviation, and pattern standard deviation). ResultsThere was a positive statistically significant correlation between the iridocorneal angle pigmentation and IOP (P=0.047, R2=0.2), but not the indices of glaucoma severity (P>0.13). There was no significant correlation between the anterior lens capsule PXF material and IOP or the indices of glaucoma severity (P>0.42). The grade of angle pigmentation, but not lens PXF, in eyes with IOP >21u2009mm Hg was significantly higher than in eyes with IOP ≤21u2009mm Hg (P=0.04). ConclusionsIn patients with PXF syndrome/glaucoma, gonioscopically identified iridocorneal angle pigmentation correlates more strongly with presenting IOP than the amount of PXF material on the anterior lens capsule.

Visual Field Progression With Frequency-Doubling Matrix Perimetry and Standard Automated Perimetry in Patients With Glaucoma and in Healthy Controls

IMPORTANCEnA new analysis method called permutation of pointwise linear regression measures the significance of deterioration over time at each visual field location, combines the significance values into an overall statistic, and then determines the likelihood of change in the visual field. Because the outcome is a single P value, individualized to that specific visual field and independent of the scale of the original measurement, the method is well suited for comparing techniques with different stimuli and scales.nnnOBJECTIVEnTo test the hypothesis that frequency-doubling matrix perimetry (FDT2) is more sensitive than standard automated perimetry (SAP) in identifying visual field progression in glaucoma.nnnDESIGN, SETTING, AND PARTICIPANTSnPatients with open-angle glaucoma and healthy controls were examined by FDT2 and SAP, both with the 24-2 test pattern, on the same day at 6-month intervals in a longitudinal prospective study conducted in a hospital-based setting. Only participants with at least 5 examinations were included.nnnINTERVENTIONnData were analyzed with permutation of pointwise linear regression.nnnMAIN OUTCOME AND MEASUREnPermutation of pointwise linear regression is individualized to each participant, in contrast to current analyses in which the statistical significance is inferred from population-based approaches. Analyses were performed with both total deviation and pattern deviation.nnnRESULTSnSixty-four patients and 36 controls were included in the study. The median age, SAP mean deviation, and follow-up period were 65 years, -2.6 dB, and 5.4 years, respectively, in patients and 62 years, +0.4 dB, and 5.2 years, respectively, in controls. Using total deviation analyses, statistically significant deterioration was identified in 17% of patients with FDT2, in 34% of patients with SAP, and in 14% of patients with both techniques; in controls these percentages were 8% with FDT2, 31% with SAP, and 8% with both. Using pattern deviation analyses, statistically significant deterioration was identified in 16% of patients with FDT2, in 17% of patients with SAP, and in 3% of patients with both techniques; in controls these values were 3% with FDT2 and none with SAP.nnnCONCLUSIONS AND RELEVANCEnNo evidence was found that FDT2 is more sensitive than SAP in identifying visual field deterioration. In about one-third of healthy controls, age-related deterioration with SAP reached statistical significance.

Combined Baerveldt glaucoma drainage implant and trabeculectomy with mitomycin C for refractory glaucoma.

PurposeTo describe the surgical technique and clinical outcomes of a procedure for refractory glaucoma, concurrent Baerveldt glaucoma implant (BGI) and trabeculectomy with mitomycin C. Materials and MethodsMedical records of all patients who underwent combined Prolene-ligated BGI and trabeculectomy with mitomycin C were retrospectively reviewed. Main outcome measures were intraocular pressure (IOP), number of glaucoma medications, visual acuity, and complications. Kaplan-Meier survival analysis was used to determine success, defined as IOP < 22 mm Hg, no reoperation for glaucoma, and no loss of light perception vision. ResultsThe mean ± SD follow-up period for 38 eyes of 36 patients was 34 ± 36 months (range, 3–121 months), during which 18 of 38 eyes (47%) required laser suture lysis of the Prolene suture. Intraocular pressure was reduced from a mean (± SD) preoperative value of 35.7 ± 12.8 to 12.7 ± 4.7 mm Hg at 1-year follow-up and 11.9 ± 5.5 mm Hg at the last follow-up visit (P < 0.001). Number of medicines used for glaucoma was reduced from a mean ± SD preoperative value of 2.5 ± 0.9 to 0.5 ± 0.6 at 1-year follow-up and 0.6 ± 0.8 at the last follow-up visit (P < 0.001). LogMar visual acuity remained stable at mean of 1.15 ± 0.85 preoperatively, compared with 1.14 ± 1.05 at 1-year follow-up, but declined to 1.61 ± 1.01 at the last follow-up visit, a loss of an average of four lines of vision (P = 0.004). Cumulative success was 91% at year 1, 86% at year 2, and 81% at year 3. Three eyes (8%) had suprachoroidal hemorrhages, one eye (3%) needed reoperation for an extruded implant, one (3%) eye had poor vision due to chronic hypotony, three eyes (8%) required additional glaucoma surgery during the postoperative period, and one eye (3%) needed revision of the implant for pressure control. ConclusionsCombined BGI and mitomycin C trabeculectomy provides excellent postoperative IOP control in patients with refractory glaucoma.

Rates of retinal nerve fibre layer thickness change in glaucoma patients and control subjects

PurposeTo examine the rates of retinal nerve fibre layer thickness (RNFLT) change in glaucoma patients and healthy, age-similar control subjects with three techniques: scanning laser polarimetry with variable corneal compensation (VCC) and enhanced corneal compensation (ECC), and time-domain optical coherence tomography (OCT).MethodsSixty-one patients and thirty-three controls were examined with each technique and with standard automated perimetry (SAP) every 6 months. Rates of global RNFLT change and SAP mean deviation (MD) change were estimated with linear mixed-effects models.ResultsThe median (interquartile range) baseline age was 64.4 (58.2, 71.0) years for patients and 62.4 (56.3, 70.1) years for controls (P=0.56). There was a median of seven examinations over 3.1 years for patients and six examinations in 3.0 years for controls. Baseline visual field MD and RNFLT for all imaging modalities were significantly lower (P<0.01) in patients compared with controls. Rates of RNFLT change were not significantly different between patients and controls (P≥0.19). Mean rates of VCC-measured RNFLT change were −0.18 and −0.37u2009μm per year in patients and controls, whereas the respective figures for ECC and OCT were −0.13 and −0.31u2009μm per year, and 0.04 and 0.61u2009μm per year. Mean rates of MD change were −0.20 and 0.03u2009dB per year in patients and controls, respectively (P=0.01).ConclusionRates of RNFLT change in glaucoma patients were not statistically different from control subjects for any modality. A significantly negative rate of MD change in patients suggests a genuine, continued deterioration in these patients not reflected by RNFLT changes.

Retinal arterial diameter changes in progressive and nonprogressive glaucoma.

PurposeTo determine if the degree of retinal arterial diameter change is different between patients with progressive and nonprogressive open-angle glaucoma. Material and MethodsIn this prospective cohort study, 44 eyes of 44 open-angle glaucoma patients (mean age, 67.5 years; age range, 52–84 years; mean follow-up period, 4.9 years; follow-up range, 1.3–7.5 years) were included. The change in arterial diameter between the baseline and the most recent follow-up optic disc photograph was determined. The diameter of the 4 major arteries was measured at the optic disc margin and at the thinnest and broadest locations within 1 optic disc diameter from the disc margin. Patients were stratified into progressing and nonprogressing groups according to visual field and optic disc criteria. ResultsVisual field progression was observed in 13 (30%) patients and optic disc progression in 24 (55%) patients. On average, the arterial diameters at the edge of the optic disc decreased significantly by 2.37% (95% CI, −3.31% to −1.41%) per year of follow-up (P <0.001). No significant difference in generalized or focal arterial narrowing was observed between progressive and nonprogressive groups regardless of the criterion used (P >0.462). With this sample, the power to detect a 10% difference in arterial narrowing between the 2 groups was 66%. There was no relationship between the rates of visual field progression and arterial diameter change in the whole group (P = 0.171) or in groups segregated into progressing and nonprogressing patients (P >0.104). ConclusionArterial diameters decreased in both progressive and nonprogressive glaucoma. In this study, there was little evidence that arterial narrowing was more pronounced in progressive disease.