Yoon Jeon Kim

Macular and Peripapillary Retinal Nerve Fiber Layer Measurements by Spectral Domain Optical Coherence Tomography in Normal-Tension Glaucoma

PURPOSEnTo evaluate and compare the glaucoma discrimination ability of macular inner retinal layer (MIRL) thickness with that of peripapillary retinal nerve fiber layer (pRNFL) thickness measured by spectral-domain optical coherence tomography (RTVue-100; Optovue Inc, Fremont, CA) in patients with normal-tension glaucoma (NTG).nnnMETHODSnSixty-five healthy subjects and 102 with NTG were enrolled. MIRL thickness provided by a ganglion cell complex (GCC) scan and two RNFL thicknesses measured by the NHM4 (RNFL1) and RNFL 3.45 (RNFL2) modes of the RTVue-100 system were analyzed. The areas under the receiver operating characteristic curves (AUCs) of MIRL and pRNFL thicknesses for discriminating patients with NTG from control subjects were determined. The AUCs were compared between patients with central visual field (VF) defects (VF; <or=10 degrees of fixation) and peripheral VF defects (>10 degrees from fixation).nnnRESULTSnThe average MIRL thickness showed a strong correlation with both RNFL1 and -2 thicknesses (R(2) = 0.773, 0.774, both P < 0.0001). The AUCs for average MIRL, RNFL1, and RNFL2 thicknesses were not significantly different at 0.945, 0.973, and 0.976, respectively. However, the AUCs of the average and superior MIRL thicknesses were significantly less than that of the pRNFL thickness in eyes with moderate-to-advanced glaucoma and eyes with peripheral VF defects.nnnCONCLUSIONSnThe average MIRL thickness showed a strong correlation with pRNFL thickness, because patients with NTG at an early stage showed paracentral VF defects near the fixation point. MIRL thickness showed glaucoma discrimination ability comparable to that of pRNFL thickness in patients with NTG with early VF defects. In eyes with advanced or peripheral VF defect, pRNFL measurement showed a better glaucoma diagnostic ability than did MIRL measurement.

Detection of glaucoma progression by assessment of segmented macular thickness data obtained using spectral domain optical coherence tomography.

PURPOSEnWe evaluated the clinical use of segmented macular layer thickness measurement in terms of glaucoma diagnosis and the ability to detect progression, and to compare such outcomes to those by circumpapillary retinal nerve fiber layer (cRNFLT) and total macular thickness (TMT) measurements.nnnMETHODSnThe study included 141 glaucomatous and 61 healthy eyes. All glaucomatous eyes were subjected to at least four spectral domain optical coherence tomography (SD-OCT) examinations (mean follow-up, 2.13 years). Segmented macular layers were the macular nerve fiber layer (NFL), ganglion cell and inner plexiform layer (GCA), and outer retinal layer (ORL; from outer plexiform layer to retinal pigment epithelium). Areas under receiver operating characteristic curves (AUCs) discriminating healthy from glaucomatous eyes were determined in baseline measurements. The sensitivity and specificity of these parameters in terms of glaucoma progression detection were determined, with reference to assessment of optic disc/retinal nerve fiber layer (RNFL) photographs/visual field (VF) deterioration as standard(s).nnnRESULTSnGCA afforded the best diagnostic performance among three macular layers. The AUC of the GCA thickness (GCAT) was less than that of cRNFLT (0.869 vs. 0.953, P = 0.018), but superior to that of TMT (0.790, P = 0.05). Of the eyes, 38 showed progression during follow-up by standardnnnMETHODSnThe sensitivities of TMT, GCAT, and cRNFLT values in terms of detection of progression were 14%, 8%, and 5%, respectively.nnnCONCLUSIONSnAlthough baseline cRNFL measurement was optimal in terms of glaucoma diagnosis, the GCAT and TMT showed similar levels of sensitivity in progression detection.

Long-Term Effects of Multiple Intravitreal Antivascular Endothelial Growth Factor Injections on Intraocular Pressure

PURPOSEnTo evaluate long-term effects of multiple intravitreal antivascular endothelial growth factor (VEGF) injections on intraocular pressure (IOP) in eyes with neovascular age-related macular degeneration (AMD) or retinal vein occlusion (RVO).nnnDESIGNnRetrospective cohort study.nnnMETHODSnThis study enrolled patients who underwent multiple (more than 3) intravitreal anti-VEGF injections and who were followed for more than 12 months after their last injection. IOP elevation was defined as an increase of 5 mm Hg over the baseline measurement on 2 consecutive visits. The frequency of IOP elevation was determined. A hazard ratio of each putative risk factor for IOP elevation was calculated using the Cox proportional hazard model for all participants, incorporating underlying disease as a covariate, as well as for each cohort.nnnRESULTSnIncluded in the analysis were 629 eyes with neovascular AMD and 95 eyes with RVO. Twenty eyes with neovascular AMD (3.0%) and 7 eyes with RVO (7.4%) experienced IOP elevation after multiple anti-VEGF injections, with an overall incidence of 3.7%. In the Cox proportional hazard analysis of total participants, a diagnosis of RVO (3.424, P = 0.005), a history of glaucoma (8.441, P = 0.001), and low baseline IOP (0.865, P = 0.040) were all significant risk factors for IOP elevation after multiple anti-VEGF injections.nnnCONCLUSIONnA history of multiple intravitreal anti-VEGF injections was not a significant risk factor for IOP elevation in our study. IOP elevation was more common in eyes with RVO than with AMD after anti-VEGF injection.

Structural Recovery of the Detached Macula after Retinal Detachment Repair as Assessed by Optical Coherence Tomography

Purpose To investigate correlations between preoperative and postoperative foveal microstructures in patients with macula-off rhegmatogenous retinal detachment (RRD). Methods We reviewed the records of 31 eyes from 31 patients with macula-off RRD who had undergone successful re-attachment surgery. We analyzed data obtained from complete ophthalmologic examinations and optical coherence tomography (OCT) before and 9 to 12 months after surgery. All postoperative OCT measurements were taken with spectral-domain OCT, but a subset of preoperative OCT measurements were taken with time-domain OCT. Results The mean duration of macular detachment was 15.5 ± 15.2 days, and mean preoperative best-corrected visual acuity (BCVA, logarithm of the minimum angle of resolution) was 1.03 ± 0.68. Preoperative visual acuity was correlated with retinal detachment height (p < 0.001) and the existence of intraretinal separation (IRS) along with outer layer undulation (OLU) (p = 0.022), but not with macula-off duration. The final BCVA was significantly correlated with integrity of the junction between the photoreceptor inner and outer segments (IS/OS) combined with the continuity of external limiting membrane (ELM) (p = 0.025). The presence of IRS and OLU on a detached macula were highly correlated with the final postoperative integrity of the IS/OS junction and the ELM (p = 0.017). Conclusions Eyes preoperatively exhibiting IRS and OLU showed a higher incidence of disruption to the photoreceptor IS/OS junction and the ELM at final follow-up. Such a close correlation between preoperative and postoperative structural changes may explain why ultimate visual recovery in such eyes is poor.

Development and Progression of Diabetic Retinopathy and Associated Risk Factors in Korean Patients with Type 2 Diabetes: The Experience of a Tertiary Center

The aim of this study was to evaluate the incidence of and risk factors for the development of diabetic retinopathy (DR) and progression to proliferative DR (PDR) in Korean patients. Patients diagnosed with type 2 diabetes and followed for more than 5 years at a university-based clinic since 2000 were consecutively enrolled in this retrospective cohort study. Based on the DR classification at the initial and final visits, the incidence and progression of DR was determined and patient characteristics were compared according to DR progression. Hazard ratios of each putative risk factor for DR progression were calculated with a multivariate Cox proportional hazard model. Rate of DR development and progression to PDR were 32.1/1,000 and 26.2/1,000 person-years, respectively. A longer duration of diabetes and higher mean HbA1c level were significant risk factors for the development of DR. Regarding progression to PDR, higher mean HbA1c level, higher standard deviation of HbA1c, and higher urine albumin-to-creatinine ratio were significant risk factors. The rates of development of DR and progression to PDR in Koreans with type 2 diabetes are lower than those reported over the last decade. An inadequate blood glycemic control is the common risk factor for development and progression of DR. Graphical Abstract

Minimally Invasive Microincision Vitrectomy Surgery with an Intraoperative Dexamethasone Implant for Refractory Diabetic Macular Edema

Purpose: To evaluate the 1-year results of 25-gauge microincision vitrectomy surgery (MIVS25) combined with intraoperative dexamethasone (DEX) implant for persistent diabetic macular edema (DME). Methods: This study enrolled patients who had a history of DME for ≥12 months and underwent MIVS25 and DEX implant injection. Best corrected visual acuity (BCVA) and central retinal thickness (CRT) were assessed postoperatively. Results: Eighteen eyes were included in the analysis. Preoperatively, logMAR BCVA was 0.90 and CRT was 594 µm on average. CRT decreased until the 3-month follow-up visit and tended to increase at 6 months, but stabilized at 12 months with additional treatments in five eyes at 5 months postoperatively. Statistically significant improvement in BCVA was noted 1 month after treatment and at each subsequent follow-up visit (p < 0.001). Conclusion: MIVS25 combined with DEX implant injection might be utilized as an effective and safe alternative treatment for intractable DME.

Ocular pulse amplitude as a dynamic parameter and its relationship with 24-h intraocular pressure and blood pressure in glaucoma

Abnormal ocular blood flow (OBF) has been suspected as one of the underlying mechanisms of glaucoma. The ocular pulse amplitude (OPA) is considered a possible surrogate parameter for ocular blood flow (OBF) measurement and has been studied in its association with glaucoma. Although there have been several studies that reported various ocular and systemic factors in association with OPA, all of these studies were based on a single measurement of these factors as well as OPA. The purpose of this study was to determine the 24-h (h) dynamic variability and any associations between OPA and intraocular pressure (IOP) and blood pressure (BP) variables using 24-h data collected from untreated patients with normal-tension glaucoma (NTG). One hundred and forty-four patients with NTG were consecutively enrolled. All patients underwent 24-h monitoring of IOP, OPA, and BP variables. A cosinor model was used to describe the patterns and statistical significance of the 24-h OPA rhythm, as well as the IOP and BP variables. Associations between 24-h OPA data, IOP and BP variables, and ocular and demographic factors were also assessed using the generalized estimating equation. Over the course of 24-h, OPA (pxa0=xa00.007) demonstrated significant dynamic diurnal rhythms that were similar to the other dynamic variables (all pxa0<xa00.05). Based on the 24-h data, IOP (pxa0<xa00.001), arterial pulse pressure (pxa0=xa00.034), and the spherical equivalent (pxa0<xa00.001) positively correlated with the OPA, whilst male sex (pxa0<xa00.001) negatively correlated with the OPA. These results indicate that OPA is primarily influenced by IOP as well as arterial pulse pressure, spherical equivalent, and gender. In conclusion, OPA is a dynamic ocular parameter that demonstrates a 24-h short-time fluctuation in NTG patients.

Long-term Effects of Pancreas Transplantation on Diabetic Retinopathy and Incidence and Predictive Risk Factors for Early Worsening

Background Limited data are available regarding the long-term effects of pancreas transplantation on the progression of diabetic retinopathy (DR) and the incidence and associated risk factors for early worsening of DR. Methods Patients who underwent successful pancreas transplantation between January 2007 and October 2015 and were followed for 1 year or longer were consecutively enrolled. Variables regarding demographic, systemic, metabolic, and surgical factors were reviewed for each patient. DR progression was defined as (i) development or aggravation of macular edema requiring intravitreal anti-VEGF injections and/or (ii) progression of DR severity requiring panretinal photocoagulation (PRP) and/or pars planar vitrectomy (PPV). Early worsening was defined as progression within 1 year of posttransplant. Results Three hundred three eyes of 153 patients were included in the analysis. At the pretransplant ocular evaluation, 221 eyes (72.9%) showed advanced DR with history of PRP and/or PPV. During a mean follow-up period of 4.2 years, 62 eyes (20.5%) experienced DR progression, and early worsening was noted in 57 eyes (18.8%). DR with recent PRP within pretransplant 1 year and pancreas transplant alone were significant risk factors for early worsening. Conclusions In 4 of 5 patients who received pancreas transplant, the degree of DR remained stable over time after transplantation. Meanwhile, early worsening of DR could occur in patients at risk, particularly within the first posttransplant year. We suggest that physicians should have a high index of suspicion and carefully monitor for early worsening of DR and timely manage possible ocular deterioration.

Macular capillary plexuses after epiretinal membrane surgery: an optical coherence tomography angiography study

Aims To investigate macular vascular integrity using optical coherence tomography angiography (OCTA) in patients undergoing vitrectomy for idiopathic epiretinal membrane (ERM) removal and to determine its association with structural and visual outcomes. Methods Forty-three patients with unilateral ERM who were followed for ≥6 months after surgery were included. Ophthalmological evaluations included best-corrected visual acuity (BCVA) and spectral-domain OCT (SD-OCT) before surgery and 6 months after surgery. We obtained en face OCTA images of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) for both eyes 6 months after ERM removal. We compared eyes with ERM to unaffected fellow eyes as controls and used interocular differences in the analyses. Results Compared with the fellow eyes, eyes with ERM after surgery had a lower parafoveal vascular density (VD) and a smaller foveal avascular zone (FAZ) area in both SCP and DCP (all p<0.001). Interocular differences in the FAZ area and parafoveal VD were correlated with preoperative and postoperative central foveal thicknesses (all p<0.05). In addition, interocular differences in macular vascular integrity had a tendency to be correlated with SD-OCT parameters of the inner retinal layers. Finally, greater interocular differences in the FAZ area and parafoveal VD of both plexuses were significantly associated with worse postoperative BCVAs (all p<0.05). Conclusions Assessing macular capillary plexuses via OCTA may be useful to quantify structural changes of the inner retinal layer and predict visual function in patients undergoing ERM removal surgery.

Influence of Vitrectomy-related Factors on the Outcome of Ahmed Glaucoma Valve Implantation

Purpose To evaluate the outcome of Ahmed glaucoma valve (AGV) implantation in eyes with refractory secondary glaucoma following pars plana vitrectomy (PPV) and the associated prognostic factors. Methods A total of 146 eyes in 146 patients who underwent AGV implantation after PPV (followed up for ≥1 year) were included. AGV implantation was considered successful when the intraocular pressure (IOP) was 6 to 21 mmHg regardless of using IOP-lowering medication. The hazard ratios (HRs) associated with surgical failure were determined with Cox proportional analysis. Results The most common cause for PPV was complications of proliferative diabetic retinopathy (50%). The mean and peak IOPs between PPV and AGV implantation were 26.9 ± 6.6 and 35.9 ± 10.2 mmHg, respectively. AGV implantation was performed on average 18.7 months after PPV, and its overall success rate was 80.1% during a mean follow-up period of 43.6 months. In multivariate analyses, rubeosis observed before AGV implantation (HR, 4.07; 95% confidence interval, 1.57 to 10.6; p = 0.004) and higher peak IOP before AGV (HR, 1.04; 95% confidence interval, 1.00 to 1.07; p = 0.034) were predictive of failure. However, no PPV-related factors were associated with the surgical outcome of AGV implantation. Conclusions The outcome of AGV implantation is good in refractory glaucoma following PPV. Rubeosis after PPV and higher peak IOP before AGV are risk factors for poor outcomes. Patients who undergo PPV should be followed for the development of rubeosis and IOP control.