Fabio N. Kanadani

Posture-induced Intraocular Pressure Changes: Considerations Regarding Body Position in Glaucoma Patients

Although glaucoma is a multifactorial disease, elevated intraocular pressure (IOP) remains the most important known risk factor. Different systemic and local factors are thought to influence an individuals IOP. There can be a clinically significant rise in IOP when going from upright to horizontal or inverted body positions. Although there is a significant interindividual variability, the magnitude of the IOP change is greater in glaucomatous eyes. As patients usually spend a significant portion of their lives in the horizontal position, mainly during sleep, this is highly relevant. In this review we discuss the relationship between postural changes and IOP fluctuation, including changes in both body and head position. The possible mechanisms involved and the main implications for glaucomatous eyes are discussed. Finally, considerations with regard to sleep position in glaucoma patients are made based on evidence in the literature.

Structural and functional assessment of the macular region in patients with glaucoma

Purpose: To investigate the correlation of a structural measure of the macular area (optical coherence tomography (OCT)) with two functional measures (10-2 Humphrey visual field (HVF) and multifocal visual evoked potential (mfVEP)) of macular function. Methods: 55 eyes with open-angle glaucoma were enrolled. The 10-2 HVF was defined as abnormal if clusters of ⩾3 points with p<5%, one of which had p<1%, were present. The mfVEP was abnormal if probability plots had ⩾2 adjacent points with p<1%, or ⩾3 adjacent points with p<5% and at least one of these points with p<1%. Two criteria were used for the macular OCT: (I) ⩾2 sectors with p<5% or 1 sector with p<1% and (II) 1 sector with p<5%. Results: 54 of the 55 eyes showed an abnormal 10-2 HVF and 50 had central mfVEP defects. The two OCT criteria resulted in sensitivities of 85% and 91%. When both functional tests showed a defect (in 49 eyes), the OCT was abnormal in 45. For the OCT the outer and inner inferior regions were the most likely to be abnormal, and both functional techniques were most abnormal in the superior hemifield. Conclusions: Good agreement exists between macular thickness and functional defects in patients with glaucoma. Study of the macular region may provide a quantitative measure for disease staging and monitoring.

Retinal nerve fibre thickness measured with optical coherence tomography accurately detects confirmed glaucomatous damage

Aim: To assess the accuracy of optical coherence tomography (OCT) in detecting damage to a hemifield, patients with hemifield defects confirmed on both static automated perimetry (SAP) and multifocal visual evoked potentials (mfVEP) were studied. Methods: Eyes of 40 patients with concomitant SAP and mfVEP glaucomatous loss and 25 controls underwent OCT retinal nerve fibre layer (RNFL), mfVEP and 24-2 SAP tests. For the mfVEP and 24-2 SAP, a hemifield was defined as abnormal based upon cluster criteria. On OCT, a hemifield was considered abnormal if one of the five clock hour sectors (3 and 9 o’clock excluded) was at <1% (red) or two were at <5% (yellow). Results: Seventy seven (43%) of the hemifields were abnormal on both mfVEP and SAP tests. The OCT was abnormal for 73 (95%) of these. Only 1 (1%) of the 100 hemifields of the controls was abnormal on OCT. Sensitivity/specificity (one eye per person) was 95/98%. Conclusions: The OCT RNFL test accurately detects abnormal hemifields confirmed on both subjective and objective functional tests. Identifying abnormal hemifields with a criterion of 1 red (1%) or 2 yellow (5%) clock hours may prove useful in clinical practice.

Correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes

Background The purpose of this study was to investigate the correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes. Methods Ninety eyes from 90 patients were included. Thirty patients had been recently diagnosed with glaucoma and had no previous history of treatment for ocular hypotension, 30 had elevated intraocular pressure (IOP) without evidence of glaucoma, and 30 had normal IOP (<21 mmHg) with no detectable glaucomatous damage. Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), blood pressure measurement, pachymetry, Humphrey visual field, and routine ophthalmic examination was performed in each patient. Ocular perfusion pressure was calculated as the difference between mean arterial pressure and IOP. The ocular pulse amplitude was given by DCT. The Pearson correlation coefficient was used to compare the glaucomatous and ocular hypertensive groups, and comparisons with the normal IOP group were done using the Spearman’s rank correlation coefficient. Results Mean IOP by DCT was 22.7 ± 4.3 mmHg in the glaucoma group, 22.3 ± 2.8 mmHg in the ocular hypertension group, and 14.3 ± 1.6 mmHg in the control group. Mean IOP by GAT was 19.0 ± 5.1 mmHg for glaucoma, 22.4 ± 2.1 mmHg for ocular hypertension, and 12.9 ± 2.2 mmHg for controls. Mean ocular pulse amplitude was 3.4 ± 1.2 mmHg in the glaucoma group, 3.5 ± 1.2 mmHg in the ocular hypertension group, and 2.6 ± 0.9 mmHg in the control group. Mean ocular perfusion pressure was 46.3 ± 7.9 mmHg in the glaucoma group, 46.3 ± 7.9 mmHg in the ocular hypertension group, and 50.2 ± 7.0 mmHg in controls. No significant correlation between ocular perfusion pressure and ocular pulse amplitude was found in any of the groups (P = 0.865 and r = −0.032, P = 0.403 and r = −0.156, P = 0.082 and ρ = −0.307 for glaucoma, ocular hypertension, and normal eyes, respectively). Conclusion There is no significant correlation between ocular perfusion pressure and ocular pulse amplitude values in glaucoma, ocular hypertension, or normal eyes. IOP values measured by GAT correlate with those measured by DCT.

Hypotony Management through Transconjunctival Scleral Flap Resuturing: Analysis of Surgical Outcomes and Success Predictors

ABSTRACT Aim To investigate surgical outcomes and success predictors of transconjunctival scleral flap resuturing for the management of hypotony due to overfiltration following trabeculectomy with mitomycin C. Materials and methods Noncomparative, retrospective, interventional case series in which all glaucoma patients from two glaucoma services undergoing transconjunctival scleral flap resuturing between May 2012 and July 2016 were enrolled. Included eyes had to have hypotony [intraocular pressure (IOP) < 6 mm Hg] and/or hypotony maculopathy caused by excessive filtration following trabeculectomy. Key exclusion criteria were wound/bleb leaking and postoperative ocular trauma or infection. Preoperative and postoperative IOP, best-corrected visual acuity (BCVA), fundus imaging, surgical complications, and any subsequent related events or procedures were recorded. Rates of postsurgical hypotony and/or maculopathy resolution and possible success predictors were investigated. Results A total of 22 patients (22 eyes) with a mean age of 56.4 ± 15.2 years were included. Median follow-up was 245 days [interquartilerange (IR); 120-817 days] and mean IOP was increased from 2.9 ± 1.5 mm Hg (1-6 mm Hg) to 8.5 ± 3.1 mm Hg (2-16 mm Hg) at the last follow-up visit (p < 0.01). Approximately 75% of the cases (16 out of 22) had an IOP between 7 and 18 mm Hg at the end of the follow-up period. Median BCVA (log MAR) at last follow-up visit [0.1 (IR; 0.0- 0.3)] was significantly better than preoperative BCVA [0.4 (IR; 0.11.0); p < 0.01]. Hypotony resolved in 81% of the cases, while maculopathy resolution was found in 85% of the cases. Time interval between trabeculectomy and flap resuturing was the only factor significantly associated with patient’s IOP at last follow-up visit (R2 = 0.23; p = 0.036). Success rates (IOP > 6 mm Hg at last follow-up visit) were halved in those left untreated for more than 6 months. No serious adverse event was recorded. Conclusion Our findings support the use of transconjunctival scleral flap resuturing as an effective and safe alternative for hypotony management due to overflitration following trabeculectomy. As time interval seems to influence the odds of hypotony resolution, early intervention is recommended. How to cite this article Scoralick ALB, Almeida I, Ushida M, Dias DT, Dorairaj S, Prata TS, Kanadani FN, Hypotony Management through Transconjunctival Scleral Flap Resuturing: Analysis of Surgical Outcomes and Success Predictors. J Curr Glaucoma Pract 2017;11(2):58-62.

Intraocular Pressure Spikes within First Postoperative Hours following Standard Trabeculectomy: Incidence and Associated Factors

Purpose: To evaluate the incidence of intraocular pressure (IOP) spikes within the first postoperative hours following trabeculectomy (TRAB) and to determine possible associated factors. Methods: An observational study was carried out. We enrolled consecutive patients undergoing standard TRAB with mitomycin C. They were examined twice within the first few postoperative hours (hours 1-2 and 4-6) and 3 times after TRAB (on days 1, 7, and 30). Demographic and ocular data were collected. Main outcome measurements were postoperative IOP values at each time point and the frequency of IOP spikes, defined as IOP ≥25 mm Hg. Results: A total of 40 eyes of 40 patients were included (mean age 59.62 ± 13.37 years). Although IOP was significantly reduced to 11.14 ± 7.99 mm Hg at hours 1-2 (p < 0.01) and to 11.52 ± 7.30 mm Hg at hours 4-6 (p < 0.01), IOP spikes were documented in 3 patients (7.5%). In the group of patients with IOP spikes, we noted that there was a high incidence of black patients and that the surgeries had been performed by fellow surgeons. Conclusion: Although the majority of the cases (92.5% of the patients) did not present IOP spikes, 7.5% of our patients presented the event. In selected cases, such as those with advanced disease, fixation threat, and of black race, IOP should be monitored during the first few postoperative hours for the identification and adequate management of potential IOP spikes, preventing undesirable outcomes.

Frequency-doubling technology perimetry and multifocal visual evoked potential in glaucoma, suspected glaucoma, and control patients.

Introduction The gold standard in functional glaucoma evaluation is standard automated perimetry (SAP). However, SAP depends on the reliability of the patients’ responses and other external factors; therefore, other technologies have been developed for earlier detection of visual field changes in glaucoma patients. The frequency-doubling perimetry (FDT) is believed to detect glaucoma earlier than SAP. The multifocal visual evoked potential (mfVEP) is an objective test for functional evaluation. Objective To evaluate the sensitivity and specificity of FDT and mfVEP tests in normal, suspect, and glaucomatous eyes and compare the monocular and interocular mfVEP. Methods Ninety-five eyes from 95 individuals (23 controls, 33 glaucoma suspects, 39 glaucomatous) were enrolled. All participants underwent a full ophthalmic examination, followed by SAP, FDT, and mfVEP tests. Results The area under the curve for mean deviation and pattern standard deviation were 0.756 and 0.761, respectively, for FDT, 0.564 and 0.512 for signal and alpha for interocular mfVEP, and 0.568 and 0.538 for signal and alpha for monocular mfVEP. This difference between monocular and interocular mfVEP was not significant. Conclusion The FDT Matrix was superior to mfVEP in glaucoma detection. The difference between monocular and interocular mfVEP in the diagnosis of glaucoma was not significant.