Characteristics of retinal vessels in surgically closed macular hole: an optical coherence tomography angiography study.

PURPOSE: The purpose of our study was to investigate characteristics of retinal vessels in eyes with surgically closed macular holes (MH). METHODS: We included patients who underwent surgery for idiopathic MH and a follow-up examination using optical coherence tomography angiography (OCTA). The area of the foveal avascular zone (FAZ) and retinal vascular densities of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were calculated on the postoperative OCTA images and compared with those of age-matched normal controls. RESULTS: Twenty-eight patients with MH and 28 controls were included. Mean postoperative FAZ areas of SCP and DCP (0.317 ± 0.129 mm2 and 0.500 ± 0.174 mm2) were smaller than those of normal controls (0.406 ± 0.131 mm2 and 0.687 ± 0.147 mm2) (P = 0.013 and P < 0.001, respectively). Retinal vascular densities of SCP and DCP in the MH group (32.23 ± 1.45% and 31.85 ± 1.28%) were lower than those of the control group (33.26 ± 1.71% and 33.18 ± 1.89%) (P = 0.019 and P = 0.003, respectively). The retinal vascular densities of SCP and DCP were associated with postoperative mean ganglion cell-inner plexiform layer (GC-IPL) thickness (P = 0.033 and P = 0.035, respectively). The vascular densities were horizontally asymmetric and related to asymmetric distribution of GC-IPL thickness in the MH group. CONCLUSIONS: Surgically closed MH eyes had remodeled retinal vascular patterns, which were related to morphologic changes in the inner retinal layer. The healing process after MH surgery may be involved in asymmetric change in anatomy and hemodynamics of the inner retina.

Effect of Cataract Grade according to Wide-Field Fundus Images on Measurement of Macular Thickness in Cataract Patients.

PURPOSE: To investigate the effects of cataract grade based on wide-field fundus imaging on macular thickness measured by spectral domain optical coherence tomography (SD-OCT) and its signal-to-noise ratio (SNR). METHODS: Two hundred cataract patients (200 eyes) with preoperative measurements by wide-field fundus imaging and macular SD-OCT were enrolled. Cataract severity was graded from 1 to 4 according to the degree of macular obscuring by cataract artifact in fundus photo images. Cataract grade based on wide-field fundus image, the Lens Opacity Classification System III, macular thickness, and SD-OCT SNR were compared. All SD-OCT B-scan images were evaluated to detect errors in retinal layer segmentation. RESULTS: Cataract grade based on wide-field fundus imaging was positively correlated with grade of posterior subcapsular cataracts (rho = 0.486, p < 0.001), but not with nuclear opalescence or cortical cataract using the Lens Opacity Classification System III. Cataract grade was negatively correlated with total macular thickness (rho = -0.509, p < 0.001) and SD-OCT SNR (rho = -0.568, p < 0.001). SD-OCT SNR was positively correlated with total macular thickness (rho = 0.571, p < 0.001). Of 200 eyes, 97 (48.5%) had segmentation errors on SD-OCT. As cataract grade increased and SD-OCT SNR decreased, the percentage of eyes with segmentation errors on SD-OCT increased. All measurements of macular thickness in eyes without segmentation errors were significantly greater than those of eyes with segmentation errors. CONCLUSIONS: Posterior subcapsular cataracts had profound effects on cataract grade based on wide-field fundus imaging. As cataract grade based on wide-field fundus image increased, macular thickness tended to be underestimated due to segmentation errors in SD-OCT images. Segmentation errors in SD-OCT should be considered when evaluating macular thickness in eyes with cataracts.

Use of the Posterior/Anterior Corneal Curvature Radii Ratio to Improve the Accuracy of Intraocular Lens Power Calculation: Eom's Adjustment Method.

Purpose: To evaluate the accuracy of IOL power calculation using adjusted corneal power according to the posterior/anterior corneal curvature radii ratio. Methods: Nine hundred twenty-eight eyes from 928 reference subjects and 158 eyes from 158 cataract patients who underwent phacoemulsification surgery were enrolled. Adjusted corneal power of cataract patients was calculated using the fictitious refractive index that was obtained from the geometric mean posterior/anterior corneal curvature radii ratio of reference subjects and adjusted anterior and predicted posterior corneal curvature radii from conventional keratometry (K) using the posterior/anterior corneal curvature radii ratio. The median absolute error (MedAE) based on the adjusted corneal power was compared with that based on conventional K in the Haigis and SRK/T formulae. Results: The geometric mean posterior/anterior corneal curvature radii ratio was 0.808, and the fictitious refractive index of the cornea for a single Scheimpflug camera was 1.3275. The mean difference between adjusted corneal power and conventional K was 0.05 diopter (D). The MedAE based on adjusted corneal power (0.31 D in the Haigis formula and 0.32 D in the SRK/T formula) was significantly smaller than that based on conventional K (0.41 D and 0.40 D, respectively; P < 0.001 and P < 0.001, respectively). The percentage of eyes with refractive prediction error within ± 0.50 D calculated using adjusted corneal power (74.7%) was significantly greater than that obtained using conventional K (62.7%) in the Haigis formula (P = 0.029). Conclusions: IOL power calculation using adjusted corneal power according to the posterior/anterior corneal curvature radii ratio provided more accurate refractive outcomes than calculation using conventional K.