Relationship between the Lamina Cribrosa, Outer Retina, and Choroidal Thickness as Assessed Using Spectral Domain Optical Coherence Tomography

PURPOSE: To evaluate the characteristics and relationship between peripapillary choroidal thickness (pCT), lamina cribrosa thickness (LCT), and peripapillary outer retinal layer thickness (pORT) as determined using spectral domain optical coherence tomography (SD-OCT) enhanced depth imaging (EDI). METHODS: In total, 255 participants were included (87 healthy subjects, 87 glaucoma suspects (GS), and 81 glaucoma cases). The pORT, defined as the thickness between the posterior outer plexiform layer and the retinal pigment epithelium (RPE) interface, and the pCT, between the outer margin of the RPE and the choroidal-scleral interface, were manually measured using EDI scanning of the circumpapillary retinal nerve fiber layer (RNFL). LCT was determined by EDI scanning of the optic nerve head (ONH). Baseline characteristics, including axial length (AXL) and the SD-OCT measurements of the participants, were compared among the three groups. The correlation between putative factors and pCT was determined using univariate and multivariate linear regression analyses. RESULTS: In all three groups, both pORT and pCT were thinnest in the inferior area among the four quadrants. In the healthy group, the mean peripapillary RNFL, pORT, and LCT were significantly greater in comparison with those of the GS and glaucoma groups (p < 0.001, p < 0.038, and p < 0.001, respectively). The pCT demonstrated no significant differences among the three groups (p = 0.083). Only age and AXL were associated with pCT by multivariate analysis. CONCLUSIONS: The pCT is substantially thinner in the inferior area of the ONH. In addition, the pCT demonstrates the strongest correlation with age and AXL, but was not associated with glaucoma or LCT.

Comparison between Glaucomatous and Non-glaucomatous Eyes with Unilateral Retinal Vein Occlusion in the Fellow Eye

PURPOSE: To evaluate and compare the clinical and angiographic characteristics of retinal vein occlusion (RVO) in glaucomatous and non-glaucomatous eyes with unilateral RVO in the fellow eye. METHODS: Twenty-one glaucomatous eyes (GL group) and 25 age-matched non-glaucomatous eyes (non-GL group) with unilateral RVO in the fellow eye were included in this study. Fluorescein angiographic images were assessed in both groups by 3 retina specialists in order to determine the RVO occlusion site. The occlusion site was divided into 2 types: arteriovenous (AV)-crossing and non-AV-crossing (optic cup or optic nerve sited). The clinical characteristics and prevalence of AV-crossing and non-AV-crossing RVO were compared between the 2 groups. RESULTS: The mean baseline intraocular pressures of the RVO eye and the fellow eye did not differ between the 2 groups (RVO eye: 14.3 +/- 2.5 mmHg [non-GL group], 15.5 +/- 3.9 mmHg [GL group], p = 0.217; fellow eye: 14.4 +/- 2.5 mmHg [non-GL group], 15.7 +/- 3.7 mmHg [GL group], p = 0.148). The prevalence of systemic disease did not differ between the 2 groups (e.g., diabetes mellitus and hypertension, p = 0.802 and 0.873, respectively). AV-crossing RVO was significantly more frequent in the non-GL group (19 eyes; 76%) than in the GL group (4 eyes, 19%, p < 0.001). CONCLUSIONS: Non-AV-crossing RVO, i.e., optic cup- or optic nerve-sited RVO, is more frequently associated with glaucomatous changes in the fellow eye. Therefore, this type of RVO should be monitored more carefully for indications of glaucoma in the fellow eye.

Comparison of Surgical Parameters and Outcomes According to the Phacoemulsification Technique

PURPOSE: To compare intraoperative parameters and postoperative results between divide-and-conquer and multiple phaco-chop technique. METHODS: Two different techniques were performed by one operator on the patients with bilateral cataract. One eye was phacoemulsified by divide-and-conquer technique (D eye), and the other was performed by multiple phaco-chop technique (M eye). Changes of central corneal thickness during the operation, total phaco-time and phaco-energy were measured. RESULTS: Total 29 patients were included. The change of central corneal thickness were 8.4 +/- 11.8 microm in D eye and 11.5 +/- 16.7 microm in M eye, which showed no significant difference (p = 0.350) and total phaco-time were 70.1 +/- 32.9 seconds in D eye and 71.1 +/- 55.0 seconds in M eye, which also showed no significant difference (p = 0.689). However, phaco-energy were 12.4 +/- 8.3 power x s in D eye and 8.4 +/- 9.9 power x s in M eye, and this result showed significantly larger energy when using divide-and-conquer technique (p < 0.001). CONCLUSIONS: There was no significant difference in change of central corneal thickness and phaco-time between two techniques, divide-and-conquer and multiple phaco-chop technique. However, significantly smaller phaco energy was used by multiple phaco-chop technique compared with divide-and-conquer technique.