Macular Ganglion Cell Layer Assessment to Detect Glaucomatous Central Visual Field Progression

PURPOSE: To investigate the use of ganglion cell inner plexiform layer (GC-IPL) thickness, as measured by spectral domain optical coherence tomography, to detect central visual field (VF) progression. METHODS: This study included 384 eyes from 384 patients (219 preperimetric and 165 perimetric glaucomatous eyes; average follow-up, 4.3 years). Photographic assessment of retinal nerve fiber layer (RNFL) and serial VF analysis were performed to detect glaucoma progression in the central (within 10°) area. Study inclusion required at least five serial spectral domain optical coherence tomography exams at different visits. The long-term test-retest variability of average GC-IPL thicknesses was calculated in 110 stable preperimetric glaucomatous eyes. The sensitivity and specificity of GC-IPL measurements for the detection of central VF progression were calculated in an event-based analysis using the calculated variability as a cut-off and were compared with those of central RNFL photographic assessment. RESULTS: The intersession test-retest variability, defined as the 95% confidence interval, was 1.76 µm for average GC-IPL thickness. The sensitivity and specificity of the average GC-IPL thickness for detecting central VF progression were 60.7% and 78.9%, respectively. Among six sectors, the inferonasal GC-IPL sector showed the highest sensitivity (53.6%). The sensitivity of the ≥1 sector GC-IPL to detect central VF progression was significantly higher than that of central RNFL photographic progression (p = 0.013). Other GC-IPL parameters showed comparable sensitivity and specificity to detect central VF progression compared with RNFL photographic progression. CONCLUSIONS: Serial GC-IPL measurements show comparable performance in the detection of central glaucomatous VF progression to RNFL photographic assessment.

Effect of Posterior Subtenon Triamcinolone Acetonide Injection on Diabetic Macular Edema Refractory to Intravitreal Bevacizumab Injection

PURPOSE: To evaluate the effects of posterior subtenon triamcinolone acetonide injection on refractory diabetic macular edema (DME) after intravitreal bevacizumab (IVB) injection failure. METHODS: Patients with DME and central subfield thickness (CST) >300 microm who did not respond to IVB injections were retrospectively included. Specifically, we enrolled patients who were diagnosed with refractory DME and who experienced an increase in CST after 1 to 2 IVB injections or no decrease after > or =3 consecutive IVB injections. One clinician injected 20 mg of triamcinolone acetonide into the posterior subtenon space. All patients received ophthalmic examinations at baseline and at 2, 4, and 6 months post-baseline. Examinations included Snellen visual acuity, intraocular pressure, and spectral-domain optical coherence tomography. RESULTS: Forty eyes of 34 patients were included. The average baseline CST was 476 microm. The average CST decreased to 368 microm at 2 months, 374 microm at 4 months, and 427 microm at 6 months (p < 0.001 for all results, Wilcoxon signed-rank test). The average intraocular pressure increased from 15.50 to 16.92 mmHg at 2 months but decreased to 16.30 mmHg at 4 months and 15.65 mmHg at 6 months. Logarithm of the minimum angle of resolution visual acuity improved from 0.56 to 0.50 at 2 months (p = 0.023), 0.50 at 4 months (p = 0.083), and 0.48 at 6 months (p = 0.133, Wilcoxon signed-rank test). No complications were detected. CONCLUSIONS: Posterior subtenon triamcinolone acetonide is an effective and safe treatment for reducing CST in DME refractory to IVB.