Change of Outer Retinal Thickness in Fellow Eyes of Patients with Unilateral Age-related Macular Degeneration

PURPOSE: To compare the outer retinal thickness in normal fellow eyes of patients with unilateral age-related macular degeneration (AMD) and normal control eyes. METHODS: We retrospectively reviewed the medical records of 60 patients with unilateral exudative AMD including polypoidal choroidal vasculopathy and 60 normal controls. Spectralis optical coherence tomography was performed in the normal fellow eyes of patients with unilateral AMD and in the normal group. The thicknesses between the retinal pigment epithelium (RPE) line and the cone outer segment tips (COST) line, between the COST line and the photoreceptor inner segment/outer segment (IS/OS) line, and between the IS/OS line and the external limiting membrane (ELM) line were measured at the fovea in both groups. RESULTS: The thickness between the RPE and COST lines was 32.4 ± 3.0 µm in normal fellow eyes of patients with unilateral AMD and 35.3 ± 3.5 µm in the normal group (p < 0.001). Total retinal thickness, thicknesses between the COST and the IS/OS lines and the IS/OS and the ELM lines in fellow eyes were not significantly different from those of normal eyes (p = 0.126, 0.615, 0.874). There was no significant difference in total retinal thickness or each outer retinal thickness measured in normal fellow eyes between patients with neovascular AMD and polypoidal choroidal vasculopathy. CONCLUSIONS: The thickness between the RPE and the COST lines was thinner in the fellow eyes of patients with unilateral AMD than in the normal eyes. We suggest that less thickness between the RPE and COST lines might indicate a greater risk of AMD.

Comparison of Central Corneal Thickness Measured by Swept-source Optical Coherence Tomography and Ultrasound Pachymetry

PURPOSE: To analyze and compare ultrasound pachymetry (USP) with a more recently adopted device, the intra ocular lens (IOL) master 700, which are both used to measure central corneal thickness. METHODS: The central corneal thickness was measured in 24 eyes of 12 glaucoma patients and in 83 eyes of 42 normal patients. First, the IOL master 700 was used to measure the central corneal thickness, followed by measurements taken using USP later. The results were analyzed using a paired t-test. We analyzed the agreement and the correlations between the two test devices by using Bland-Altman plots and the Pearson correlation test. To evaluate the reproducibility, measurements with the IOL master 700 were taken twice for a few normal patients within a small time interval. RESULTS: Via the IOL master 700, the thickness of the central cornea showed a high reproducibility and repeatability, demonstrating 2.7 ± 1.7 µm for the test-retest variability, 6.78% for the coefficient of variation, and 0.997 for the intraclass correlation value. The mean measurements using USP and the IOL master 700 are 554.4 ± 37.4 µm and 551.1 ± 37.1 µm, respectively, showing that the IOL master 700 measured significantly smaller values than USP with a p-value < 0.001. The deviations between the two methods are scattered throughout the 95% confidence interval. According to the Pearson correlation test, the measured values of the two test devices were found to have a highly positive correlation (r = 0.977, p < 0.0001). CONCLUSIONS: This study demonstrated that the central corneal thickness (CCT) measured via the IOL master was significantly thinner than that of USP, and the two test devices had a high correlation and good agreement. The CCT value measured via the IOL master 700 also exhibited high reproducibility.

A Case of Double Fovea Artifact Detected with Spectral-domain Optical Coherence Tomography

PURPOSE: In the present study, a case of double fovea artifact on spectral-domain optical coherence tomography (SD-OCT) was reported. CASE SUMMARY: A nine-year-old male presented with blurred vision of both eyes. His best corrected visual acuity (BCVA) was 20/20 in both eyes, and complete ophthalmologic evaluation including fundus examination and fundus photography revealed no abnormality in both eyes. He underwent SD-OCT imaging with the Cirrus HD-OCT. The Macular Cube 512 × 128 protocol of his right eye revealed an unusual pseudo-duplication of the fovea in the vertical meridian. The same protocol in his left eye also rendered a pseudo-duplication of two foveas in the vertical and horizontal meridians on the retinal thickness map. Re-examination with the same OCT system and protocol was performed two weeks later after the patient received counseling on fixation during the examination, and it revealed normal contour of the fovea in both eyes. CONCLUSIONS: Double fovea artifact seen in SD-OCT is a rare artifact that can possibly lead to misdiagnosis and inappropriate clinical treatment. Since the artifact was resolved with better fixation of the patient, repeating the scan with better patient compliance is necessary when such an artifact is encountered.

Clinical Features of Cataract Extraction with Negative-Power Intraocular Lens Implantation in High Myopia

PURPOSE: To evaluate the clinical features of high myopic eyes with cataracts implanted with negative power intraocular lenses (IOLs) at the time of cataract surgery. METHODS: A retrospective chart review was conducted of 18 eyes of 14 patients who underwent cataract surgery with negative power IOLs and 10 eyes in 9 patients with low power IOLs. We investigated axial length, IOL power, preoperative and postoperative best-corrected visual acuity (BCVA) and preoperative and postoperative spherical equivalent (SE) refractive errors. RESULTS: Mean BCVA showed significant improvement in both groups. We measured postoperative SE refraction and the difference between the mean intended and the mean achieved SE refractive errors in the negative power group (17 eyes) was +1.59 ± 1.34 D and +0.31 ± 0.50 D in the low power group. CONCLUSIONS: BCVA was significantly improved in the majority of eyes, although they had myopic macular degeneration or posterior staphyloma. However, the mean achieved postoperative SE refraction was more hyperopic than the predicted postoperative SE error. Additionally, hyperopic refractive error was greater in the negative power group than the low power group. Therefore, we recommend that postoperative hyperopic refractive error should be considered when performing cataract surgery in high myopic patients.

Comparison of 1% Prednisolone and 0.1% Bromfenac Solutions for Preventing Macular Edema after Cataract Surgery

PURPOSE: To compare the clinical effectiveness of 1% Prednisolone acetate ophthalmic solution and 0.1% Bromfenac sodium hydrate ophthalmic solution on prevention of cystoid macular edema after cataract surgery. METHODS: A retrospective chart review of 349 patients who received phacoemulsification with intraocular lens implantation in Severance Hospital from July 2013 to January 2016 was performed. In these patients, 192 eyes received 1% Prednisolone acetate ophthalmic solution, and 157 eyes were treated with topical 0.1% Bromfenac sodium hydrate ophthalmic solution. The incidence and severity of cystoid macular edema (CME) were evaluated by retinal foveal thickness on optical coherence tomography for patients who showed best corrected visual acuity (BCVA) less than 0.5 (log MAR ≥ 0.3). RESULTS: There was no significant difference between the two groups in age (p = 0.708), sex (p = 0.977), or the side of operated eye (p = 0.443). The two groups showed BCVA 0.04 ± 0.09 (Steroid group) and 0.03 ± 0.07 (nonsteroidal anti-inflammatory drug [NSAID] group) at 1 month after the surgery and the difference was not significant (p = 0.947). One eye in the topical steroid group had cystoid macular edema, and 3 eyes in the steroid group showed elevated intraocular pressure (IOP) over 30 mm Hg. There were no IOP elevations or macular edema in the NSAID group. CONCLUSIONS: The results showed that 0.1% Bromfenac sodium hydrate ophthalmic solution had a similar effect to 1% Prednisolone acetate ophthalmic solution on preventing CME after cataract surgery. This indicates that topical NSAID can be considered along with topical steroids in order to prevent CME after cataract surgery.

Clinical Efficacy of Topical Diquafosol Tetrasodium after Laser Epithelial Keratomileusis

PURPOSE: To evaluate the clinical effectiveness of topical diquafosol tetrasodium (DQS) after laser epithelial keratomileusis (LASEK). METHODS: This randomized prospective study included 97 eyes of 49 patients who were scheduled for LASEK. Patients in the DQS group used both 0.3% sodium hyaluronate and 3% DQS for 3 months after surgery while patients in the control group used only 0.3% sodium hyaluronate. Corneal staining score, tear film break-up time (TF-BUT), Schirmer test and ocular surface disease index (OSDI) were evaluated before surgery and 2, 4, 8, 12 and 16 weeks after surgery. RESULTS: There was no significant difference in visual acuity, spherical equivalent and corneal haziness between the 2 groups after surgery. Corneal staining score was significantly lower in the DQS group than in the control group 2 weeks after LASEK (p < 0.01) and increased in the control group after LASEK compared with the preoperative value (2 weeks after LASEK, p < 0.01), but decreased in the DQS group (12 and 16 weeks after LASEK, p < 0.05). TF-BUT was significantly higher in the DQS group than in the control group 2 to 16 weeks after LASEK (p < 0.01) and increased values were observed in the DQS group after LASEK compared with the preoperative value (4 to 16 weeks after LASEK, p < 0.05). The mean OSDI was significantly higher 4 to 16 weeks after LASEK in the control group than in the DQS group (p < 0.01). CONCLUSIONS: Subjective dry eye symptoms and objective markers were worse for 4 weeks after LASEK. The use of 3% DQS for 12 weeks after surgery improved these symptoms and markers with the effect lasting 16 weeks after LASEK.

Thickness in Ganglion Cell-Inner Plexiform Layer on Spectral-Domain Optical Coherence Tomography after Cataract Surgery

PURPOSE: To assess changes in ganglion cell-inner plexiform layer (GCIPL) thickness after cataract surgery using spectral-domain optical coherence tomography (OCT). METHODS: Forty-three eyes of 33 patients, who underwent cataract surgery were imaged with spectral-domain OCT before and after surgery to measure peripapillary retinal nerve fiber layer (RNFL) and GCIPL thickness, signal strength (SS), quadrant, 12 clock-hour RNFL thickness and sectoral GCIPL thickness. RESULTS: The postoperative SS, RNFL and GCIPL thickness were higher than before surgery (p < 0.05). Multivariate analysis showed that endothelial cell count and preoperative SS were significantly correlated with SS changes in RNFL parameters and preoperative SS was significantly correlated with SS changes in GCIPL parameters. Univariate analysis indicated that age was significantly correlated with RNFL thickness changes in RNFL parameters and no factor was correlated with GCIPL thickness in GCIPL parameters (p < 0.05). CONCLUSIONS: Cataracts may decrease peripapillary RNFL and GCIPL thickness measurements and SS on OCT scans. Peripapillary RNFL and GCIPL thickness measurements should be interpreted with caution in eyes with significant cataracts.