Current Issue : October-December Volume : 2023 Issue Number : 4 Articles : 6 Articles
Age-related macular degeneration (AMD) is an eye disease that leads to progressive vision loss. Its prevalence has been increasing due to population aging. Previously, it was commonly believed that the disease affects the central retina, that is, the macula. However, recent studies have shown that it also involves the peripheral retina. Novel imaging techniques revealed various degenerative lesions that extend beyond the central macula. While their prevalence remains unknown, they seem to be more frequent in patients with late AMD. These findings suggest that the term “agerelated retinal dysfunction” might be more adequate to describe some cases of AMD. They also raise the question about the role of electroretinography (ERG) as an objective measure of retinal function. The most common types of ERG tests used in AMD are multifocal (mfERG) and full-field ERG (ffERG). mfERG is more sensitive to macular changes, but the test is difficult to perform when fixation is unstable. On the other hand, ffERG reflects the function of the entire retina, not only the macular area. It helps assess the impact of peripheral retinal lesions and overall retinal function in patients with AMD. As ffERG results are normal in early-stage AMD, any abnormalities indicate that the disease is more severe and affects the entire retina. Anti-vascular endothelial growth factor injections improve retinal function in patients with neovascular AMD, as demonstrated by an increase in their ERG responses. More research is needed to assess the association between local and general retinal dysfunction. In this review, ffERG findings in patients with AMD are described and the usefulness of ffERG is discussed based on previous studies and cases from our own clinical practice....
Background. To study the effect of cycloplegia on ocular parameters in children with myopia and hyperopia. Methods. Forty-two myopia and forty-four hyperopia eyes in children between 5 and 10 years of age were included. Measurements were taken before and after cycloplegia using 1% atropine sulfate ointment. The ocular parameters included central corneal thickness (CCT), corneal curvature (CC), anterior chamber depth (ACD), pupil diameter (PD), axial length (AL), and central retinal thickness (CRT). Results. There was no significant difference in CCT, CC, and CRT between the two groups without cycloplegia, but the ACD of the myopia (3.64 ± 0.28 mm) group was significantly higher than that of hyperopia (3.40 ± 0.24 mm; t−4.522; P < 0.0001). The average PD of the myopia (4.85 ± 0.87 mm) group was significantly smaller than that of the hyperopia group (5.47 ± 1.15 mm; t 2.903; P < 0.0046). The average AL of myopia (24.25 ± 0.77 mm) was significantly higher than that of hyperopia (21.73 ± 1.24 mm; t 12.084; P < 0.0001). However, it was found that the average PD of myopia (7.68 ± 0.51 mm) was significantly larger than that of hyperopia (7.41 ± 0.57 mm; t 2.364; P 0.0202) under cycloplegia. As for the changes in refractive factors before and after cycloplegia, deepened ACD and enlarged PD were noted in both the groups after cycloplegia. Conclusions. Cycloplegia not only affects ACD and PD but also leads to the reversal of PD differences between the two groups. Cycloplegia effects enabled us to study changes in all known ocular parameters in a short period....
Purpose. To investigate the clinical effectiveness of canaloplasty performed with an ab interno technique using the iTrack microcatheter (Nova Eye Medical) in patients with mild-moderate glaucoma as compared to severe glaucoma. Methods. This is a retrospective single-center case series. Patients were preoperatively categorized as mild/moderate vs. severe glaucoma assessed using the mean deviation (MD) score and controlled group (baseline intraocular pressure (IOP) ≤18 mmHg) vs. uncontrolled group (>18 mmHg). All patients with glaucoma were eligible for recruitment except those who had undergone previous glaucoma surgery (with the exception of selective laser trabeculoplasty or SLT). Patients underwent canaloplasty via an ab interno surgical technique with or without phacoemulsification and were monitored for IOP, glaucoma medication usage, and surgical complications. Results. In total, 72 eyes were followed for 3.4 ± 0.5 years. Mean pre-op IOP (mmHg) was 19.3 ± 7.7 in the standalone group (n 9) and 18.5 ± 5.6 in the combined group (n 63) (p 0.38). At the last follow-up, mean IOP reduced by 36% to 12.4 ± 4.4 (p 0.02) in the standalone group and by 26% to 13.7 ± 4.8 in the combined group (p < 0.001). Mean pre-op IOP (mmHg) was 18.6 ± 5.2 in the severe group (n 24) and 18.6 ± 6.2 in the mild-moderate group (n 48) (p 0.48). Mean IOP was 14.1 ± 6.3 (−24%; p < 0.001) and 13.3 ± 3.7 (−29%; p < 0.001), respectively, at the last follow-up. Mean glaucoma medication usage decreased from 2.5 ± 0.9 to 2.1 ± 0.9 (−15%; p 0.083) in the severe group and 2.3 ± 1.0 to 1.4 ± 1.3 (−40%; p < 0.001) in the mild/ moderate group. There was one localized Descemet’s membrane detachment in the moderate group. Conclusion. iTrack canaloplasty achieved a statistically significant IOP reduction in mild-moderate and severe eyes and was found to be an effective option for reducing IOP and medications in patients with mild-moderate primary open-angle glaucoma (POAG). In severe eyes, it has reduced IOP while the medications remained stable....
Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular age-related macular degeneration (nAMD) that is characterized by a branching neovascular network and polypoidal lesions. It is important to differentiate PCV from typical nAMD as there are differences in treatment response between subtypes. Indocyanine green angiography (ICGA) is the gold standard for diagnosing PCV; however, ICGA is an invasive detection method and impractical for extensive use for regular long-term monitoring. In addition, access to ICGA may be limited in some settings. The purpose of this review is to summarize the utilization of multimodal imaging modalities (color fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), and fundus autofluorescence (FAF)) in differentiating PCV from typical nAMD and predicting disease activity and prognosis. In particular, OCT shows tremendous potential in diagnosing PCV. Characteristics such as subretinal pigment epithelium (RPE) ring-like lesion, en face OCT-complex RPE elevation, and sharp-peaked pigment epithelial detachment provide high sensitivity and specificity for differentiating PCV from nAMD.With the use of more practical, non-ICGA imaging modalities, the diagnosis of PCV can be more easily made and treatment tailored as necessary for optimal outcomes....
Purpose. Evidence suggests that choroid is thinner in myopes as compared to nonmyopes. However, choroidal thickness varies with the refractive error, age, axial length, and ethnicity. The purpose of this study was to determine the subfoveal choroidal thickness (SFCT) in high myopic Nepalese subjects and to investigate its association with the mean spherical equivalent refractive error (MSE), axial length, and age. Methods. Ninety-two eyes of 92 high myopic subjects (MSE ≤ −6 diopters) and 83 eyes of 83 emmetropic subjects (MSE: 0.00 Diopters) were included in the study. SFCTwas assessed using spectral domain optical coherence tomography, and the axial length was measured using partial coherence interferometry. SFCT was measured manually using the inbuilt tool within the imaging software. Results. SFCT in the high myopic subjects was significantly thinner (mean ± SD: 224.17 ± 68.91 μm) as compared to the emmetropic subjects (353.24 ± 65.63 μm) (mean difference, 127.76 ± 130.80 μm, and p < 0.001). In high myopic subjects, there was a significant negative correlation of choroidal thickness with the axial length (rho−0.75; p < 0.001) and MSE (rho−0.404; p < 0.01). Regression analysis demonstrated a decrease of choroidal thickness by 40.32 μm (p < 0.001) for every 1 millimeter increase in the axial length and by 11.65 μm (p < 0.001) for every 1 diopter increase in the MSE. Conclusion. High myopic Nepalese subjects had significantly thinner choroid as compared to emmetropes. The MSE and axial length were inversely correlated with the SFCT. Age had no effect on SFCT in this study. These findings may have implications in interpreting choroidal thickness values in clinical and epidemiological studies in myopes, especially in the south Asian population....
Background. To analyze the tolerance on distance vision of different combined residual astigmatic situations in patients implanted with a novel wavefront shaping extended depth of focus (EDoF) intraocular lens (IOL). Methods. The study included patients implanted with the Acrysof® IQ Vivity® IOL. Uncorrected (UDVA) and corrected distance visual acuity (CDVA) were measured three months after surgery, considering CDVA as the reference situation of the study. Distance VA was also measured in different refractive situations: (A) with 0.50 diopters (D) of positive (myopization) and negative (hyperopization) defocus and (B) with a residual mixed astigmatic refraction induced by adding a combination of −0.25D spherical and 0.50D cylindrical lenses placed in vertical (against the rule-ATR), oblique, and horizontal (with the rule-WTR) positions. Results. The study included 30 eyes of 30 patients. UDVA and CDVA were −0.04 ± 0.05 and −0.05 ± 0.05 logMAR, respectively. VA values with +0.50D and −0.50D of defocus were 0.01 ± 0.06 and 0.00 ± 0.04 logMAR, respectively. VA was better with distance correction (p < 0.001) and no differences were found between the myopic and the hyperopic situations (p 0.09). Distance VA for the ATR, oblique, and WTR astigmatic situations was 0.01 ± 0.05, 0.01 ± 0.06, and 0.01 ± 0.04 logMAR, respectively. VA was better for the reference situation (p < 0.001) and no differences were found among the three astigmatic situations (p 0.21). Conclusions. Low residual defocus and mixed astigmatic errors, regardless of its orientation, seem to be tolerated by patients implanted with the studied EDoF IOL. This trial is registered with NCT05392998. Registered 26 May 2022-Retrospectively registered....
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