Comparison of retinal nerve fiber layer thickness measurements using time domain and spectral domain optical coherence tomography, and visual field sensitivity.

PURPOSE: To investigate the relationship between the peripapillary retinal nerve fiber layer (RNFL) thickness, as measured by Stratus time domain optical coherence tomography (OCT) (Stratus OCT) and Cirrus spectral domain OCT (Cirrus HD-OCT), and the severity indices of the visual field (VF) defects in glaucoma patients. METHODS: This was a prospective, cross-sectional study. Correlations between the individual VF sensitivity at 52 test points and the Stratus OCT and Cirrus HD-OCT, which determined peripapillary RNFL thicknesses from 6 sectors, were calculated in 54 eyes with open-angle glaucoma and 22 normal control eyes. The association between the RNFL thickness and VF sensitivity was evaluated using a second-order regression model. RESULTS: A significant correlation was found for the RNFL thicknesses determined by the 2 OCT devices (r=0.51 to 0.95; P<0.001). VF sensitivities at each test point were also significantly correlated with the sectoral RNFL thicknesses. The inferotemporal RNFL sector exhibited the highest coefficient of determination, whereas the superotemporal test point had the highest VF sensitivity (Stratus, 0.70; Cirrus, 0.62). CONCLUSIONS: The structure-function relationship was comparable between Cirrus HD-OCT and Stratus OCT RNFL measurements.

Unintentional displacement of the retina after standard vitrectomy for rhegmatogenous retinal detachment.

OBJECTIVE: To study unintentional displacement of the retina after standard vitrectomy for rhegmatogenous retinal detachment (RRD). DESIGN: Prospective interventional case series. PARTICIPANTS: Forty-three eyes of 43 consecutive patients with cystic RRD involving 1 or more quadrants underwent successful standard vitrectomy with 20% sulfur hexafluoride gas injection. Neither scleral buckling nor retinotomy was performed. METHODS: Fundus autofluorescence (FAF) imaging was subsequently recorded to detect displacement of the retina using the Topcon TRC-50DX (Topcon, Tokyo, Japan) at 10 days and 1, 3, and 6 months postoperatively. Fluorescein angiography was also recorded using standard techniques for patients with abnormal FAF findings. Cyclotorsion and vertical deviation were measured postoperatively. MAIN OUTCOME MEASURES: The proportion of eyes with postoperative retinal displacement detected by FAF imaging. RESULTS: The mean age of these 43 patients was 60 years with a range of 39 to 77 years. Of the 43 eyes, retinal detachment involved 1 quadrant in 2 eyes, 2 quadrants in 31 eyes, 3 quadrants in 8 eyes, and 4 quadrants in 2 eyes. After complete reattachment of the retina, FAF photography demonstrated hyperfluorescent lines superiorly parallel to retinal vessels within the vascular arcade in 27 of the 43 eyes (62.8%). Fluorescein angiography did not demonstrate any abnormalities corresponding to the linear autofluorescence. This autofluorescence was hypothesized to originate from increased metabolic activity of the retinal pigment epithelium that had been preoperatively located under the major retinal vessels and was postoperatively exposed to light because of downward displacement of the retina. Of the 27 eyes with retinal displacement, 1 to 5 degrees of extorsion were seen in 16 eyes (59.3%), and 1 to 4 degrees of vertical deviation were seen in 13 eyes (48.1%). None of the 27 patients had diplopia or slant. The extent of retinal detachment (P = 0.019) and the macular status (on or off) (P = 0.016) were significantly associated with postoperative displacement of the retina. CONCLUSIONS: In eyes with RRD treated with standard vitrectomy and gas injection, the retina may move downward after the surgery. If the extent of retinal detachment is large, or macular detachment is present, unintentional postoperative retinal translocation may easily occur. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Stratus optical coherence tomography study of filtering blebs after primary trabeculectomy with a fornix-based conjunctival flap.

PURPOSE: To investigate the relationship between filtering bleb function and Stratus optical coherence tomography (OCT) images. METHODS: We studied 72 eyes of 65 consecutive patients who had a fornix-based conjunctival flap in primary trabeculectomy with mitomycin C (MMC). Filtering blebs with various types of glaucoma were examined using Stratus OCT. Success rates were defined as intraocular pressure (IOP) < or = 15 mmHg and IOP reduction > or = 25% without medication or additional surgery. Success rates among classified groups were compared using Kaplan-Meier survival curves and the log-rank test. RESULTS: Blebs were classified into three different categories on the basis of the following Stratus OCT patterns: cystoid type (multiple cysts inside the bleb; 17 eyes), diffuse type (low to high reflective areas that were mixed inside the bleb; 31 eyes) and layer type (medium to high reflective layer inside the bleb; 24 eyes). Success rates in the cystoid-, diffuse- and layer-type blebs were 94%, 97% and 75% (P = 0.02), respectively. CONCLUSION: In trabeculectomy with MMC and a fornix-based conjunctival flap, there is a significant association between the success rates and the postoperative Stratus OCT findings of filtering blebs.

Effect of trabeculectomy on intraocular pressure fluctuation with postural change in eyes with open-angle glaucoma.

PURPOSE: To investigate the effect of trabeculectomy on the intraocular pressure (IOP) fluctuations caused by the postural change in patients with open-angle glaucoma. METHODS: Prospective, nonrandomized study. Ten eyes of 10 patients with primary open-angle glaucoma and 3 eyes of 3 patients with normal-tension glaucoma who underwent trabeculectomy were studied. The IOP at the baseline and 3 months after trabeculectomy was measured in both sitting and supine positions. A pneumatonometer was used to measure the IOP in both sitting and supine position. RESULTS: The mean IOP in the sitting position was 19.6+/-5.1 mm Hg at the baseline and 9.4+/-2.9 mm Hg after trabeculectomy (P<0.01, paired t test). The mean difference in IOP between the sitting and supine position was 4.1+/-1.6 mm Hg at the baseline and 2.2+/-1.5 mm Hg after trabeculectomy (P=0.01, paired t test). CONCLUSIONS: Trabeculectomy might decrease not only the IOP in the sitting position but also the magnitude of IOP elevation associated with the postural change.

Risk factors for developing avascular filtering bleb after fornix-based trabeculectomy with mitomycin C.

PURPOSE: To investigate risk factors for developing avascular filtering blebs after primary fornix-based trabeculectomy with mitomycin C (MMC). METHODS: One-year observational case series. Ninety eyes of 90 patients who underwent primary trabeculectomy with MMC and a fornix-based conjunctival flap were examined. The appearance of the filtering bleb was classified at the last examination into 2 groups: vascular bleb or avascular bleb. Potential predictors that were entered into the model were age at surgery, sex, glaucoma diagnosis, preoperative intraocular pressure (IOP), number of antiglaucoma medications before surgery, use of topical steroid before surgery, duration of MMC application, laser suturolysis, excessive filtration, combination with cataract surgery, and needling revision. IOP was evaluated at 6 and 12 months postoperatively. RESULTS: Avascular blebs were seen in 28 eyes (31%) at 12 months. Logistic regression analysis revealed that the risk factors for developing avascular blebs after primary fornix-based trabeculectomy included secondary glaucoma [odds ratio (OR)=3.927, P=0.015], excessive filtration (OR=3.215, P=0.043), and not performing laser suturolysis after trabeculectomy (OR=3.597, P=0.031). The mean IOP was decreased from 30.3+/-13.4 mm Hg to 8.8+/-3.9 mm Hg in the avascular bleb group and from 24.6+/-9.9 mm Hg to 10.5+/-3.3 mm Hg in the vascular bleb group at 12 months (P<0.01, both groups, paired t test). CONCLUSIONS: Secondary glaucoma, excessive filtration, and no performance of laser suturolysis after trabeculectomy might be risk factors for development of avascular filtering blebs in primary fornix-based trabeculectomy.