Deep Learning-based Prediction of Axial Length Using Ultra-widefield Fundus Photography

Purpose@#To develop a deep learning model that can predict the axial lengths of eyes using ultra-widefield (UWF) fundus photography. @*Methods@#We retrospectively enrolled patients who visited the ophthalmology clinic at the Seoul National University Hospital between September 2018 and December 2021. Patients with axial length measurements and UWF images taken within 3 months of axial length measurement were included in the study. The dataset was divided into a development set and a test set at an 8:2 ratio while maintaining an equal distribution of axial lengths (stratified splitting with binning). We used transfer learning-based on EfficientNet B3 to develop the model. We evaluated the model’s performance using mean absolute error (MAE), R-squared (R2), and 95% confidence intervals (CIs). We used vanilla gradient saliency maps to illustrate the regions predominantly used by convolutional neural network. @*Results@#In total, 8,657 UWF retinal fundus images from 3,829 patients (mean age, 63.98 ±15.25 years) were included in the study. The deep learning model predicted the axial lengths of the test dataset with MAE and R2 values of 0.744 mm (95% CI, 0.709–0.779 mm) and 0.815 (95% CI, 0.785–0.840), respectively. The model’s accuracy was 73.7%, 95.9%, and 99.2% in prediction, with error margins of ±1.0, ±2.0, and ±3.0 mm, respectively. @*Conclusions@#We developed a deep learning-based model for predicting the axial length from UWF images with good performance.

Short-term Safety Evaluation of Resident-performed Intravitreal Injection

Purpose@#This study evaluated the short-term safety of resident-performed intravitreal injections. @*Methods@#We retrospectively reviewed the medical records of 503 patients (503 eyes) treated for the first time in our hospital from January 2018 to October 2020 via intravitreal bevacizumab, ranibizumab, aflibercept, or triamcinolone acetonide injections by residents or retina specialists. In terms of short-term ophthalmic complications, patients were followed-up 1 day, 1 week, and 1 month after injection. @*Results@#A total of 503 eyes of 503 patients were included. Intravitreal injections were given to 211 and 292 eyes by residents (the resident group) and retina specialists (the retina specialist group), respectively. There were no between-group differences in baseline characteristics except in terms of the indications for injection. Intraocular pressure elevation >5 mmHg occurred in two eyes (0.95%) in the resident group and five (1.71%) in the retina specialist group, but the difference was not statistically significant. Subconjunctival hemorrhage occurred in 29 eyes (13.74%) of the resident group and 32 eyes (10.96%) of the retina specialist group; again, the difference was not statistically significant. No case of noninfectious endophthalmitis occurred in the resident group but two (0.68%) cases occurred in the retina specialist group; again, the difference was not significant. There were two (0.95%) cases of infectious endophthalmitis in the resident group and one (0.34%) case in the retina specialist group; again, the difference was not significant. No corneal erosion, traumatic lens damage, vitreous hemorrhage, or retinal tearing or detachment were noted in either group. @*Conclusions@#Resident-performed intravitreal injections appear to be safe.

Evaluation of the Safety and Efficacy of Selective Retina Therapy Laser Treatment in Patients with Central Serous Chorioretinopathy

Purpose@#To assess the safety and efficacy of selective retina therapy (SRT) using a Q-switched neodymium-doped yttrium lithium fluoride laser with feedback systems in patients with idiopathic central serous chorioretinopathy (CSC). @*Methods@#This randomized clinical trial enrolled patients having at least 3-month symptom of CSC. From month 3 visit, all subjects in both groups were eligible for SRT retreatment if they showed persistent or recurrent subretinal fluid (SRF). The primary outcome was complete resolution of SRF by optical coherence tomography at 3 months after treatment. The secondary outcomes were changes in SRF, central macular thickness (CMT) and best-corrected visual acuity at the 1-, 3-, and 6-month examinations. @*Results@#Sixty-eight CSC patients were included (SRT, 31; control, 37). After 1 and 3 months, complete resolution of SRF was achieved in 25.8% and 54.8% of SRT group and 17.6% and 35.1% of controls. The differences were not statistically significant (p = 0.424 and p = 0.142, respectively). However, mixed model for repeated measures analyses showed that the reduction of SRF and CMT were observed earlier in SRT group than in the sham group (least squares mean difference, -59.7 µm; 95% confidence interval, -98.2 to -21.2; p = 0.0029; least squares mean difference -67.0 µm; 95% confidence interval, -104.8 to -29.2; p = 0.0007, respectively). Significant reduction of SRF (≥50% reduction from baseline) was more frequently observed in SRT group (80.6%) than the sham group (44.1%) at month 1 (p = 0.007). Early reduction of SRF and CMT was more abundant in SRT group with symptom duration less than 6 months. Treatment related serious adverse events were not observed. @*Conclusions@#SRT using a Q-switched neodymium-doped yttrium lithium fluoride laser with feedback system was safe in this trial and effective for early resolution of SRF in the CSC patients. Early intervention with SRT can be a safe alternative for patients with acute symptomatic CSC.

Choroidal Thickness Analysis in Primary Rhegmatogenous Retinal Detachment

Purpose@#We analyzed the choroidal thickness in the subfoveal area and area of retinal detachment (RD) in monocular primary rhegmatogenous retinal detachment (RRD) patients and compared the RD eye with the fellow eye. @*Methods@#We retrospectively analyzed, optical coherence tomography data of both eyes at the first visit in patients who underwent surgery for monocular RRD from January 2013 to December 2016. Choroidal thickness was examined manually in the subfoveal and RD areas by two independent ophthalmologists; subjects without data from at least one of the two investigators were excluded. @*Results@#Ninety-five subjects were included in this study. Of the 95 RD eyes, 61 (64.2%) and 44 (46.3%) eyes showed macula and fovea invasion, respectively. The subfoveal choroidal thickness was statistically significant in the RD eye compared with the fellow eye (244.7 ± 79.0 µm vs. 220.1 ± 78.9 µm; p < 0.001). Moreover, the choroidal thickness of the RD area in the RD eye was thicker compared with the non-detachment area and corresponding area in the fellow eye (273.8 ± 53.4 µm vs. 215.2 ± 44.0 µm and 233.3 ± 56.7 µm, respectively; p < 0.001). @*Conclusions@#In the primary RRD eye, the choroidal thickness in the detachment area was thicker than that of the fellow eye. Further studies are needed to investigate the mechanism of choroidal thickness change and its impact on RD.

Choroidal Thickness Analysis in Primary Rhegmatogenous Retinal Detachment

Purpose@#We analyzed the choroidal thickness in the subfoveal area and area of retinal detachment (RD) in monocular primary rhegmatogenous retinal detachment (RRD) patients and compared the RD eye with the fellow eye. @*Methods@#We retrospectively analyzed, optical coherence tomography data of both eyes at the first visit in patients who underwent surgery for monocular RRD from January 2013 to December 2016. Choroidal thickness was examined manually in the subfoveal and RD areas by two independent ophthalmologists; subjects without data from at least one of the two investigators were excluded. @*Results@#Ninety-five subjects were included in this study. Of the 95 RD eyes, 61 (64.2%) and 44 (46.3%) eyes showed macula and fovea invasion, respectively. The subfoveal choroidal thickness was statistically significant in the RD eye compared with the fellow eye (244.7 ± 79.0 µm vs. 220.1 ± 78.9 µm; p < 0.001). Moreover, the choroidal thickness of the RD area in the RD eye was thicker compared with the non-detachment area and corresponding area in the fellow eye (273.8 ± 53.4 µm vs. 215.2 ± 44.0 µm and 233.3 ± 56.7 µm, respectively; p < 0.001). @*Conclusions@#In the primary RRD eye, the choroidal thickness in the detachment area was thicker than that of the fellow eye. Further studies are needed to investigate the mechanism of choroidal thickness change and its impact on RD.

New Method of Quantitative Analysis of Hard Exudate Using Optical Coherence Tomography: Application in Diabetic Macular Edema

PURPOSE: In the present study, the volume of hard exudates (HEs) was quantitatively measured using optical coherence tomography (OCT) and the agreement and correlation with area of HEs in fundus photography were analyzed. METHODS: The medical records of patients with diabetic macular edema who underwent focal laser treatment and were followed up more than 3 months were retrospectively evaluated. An automated customized program designed for measuring HE volume was used. The HEs in each OCT B-scan binary image were measured using 512 × 128 pixels, 6 mm × 6 mm OCT cube scans. The volume was measured by summing the segmented HEs in each 128 B-scan image. The area was measured in 6 mm x 6 mm fundus photography. The volume and area were measured before and 3 months after the treatment. The agreement of increase and decrease in HEs, and the correlation of volume and area of HEs were analyzed. RESULTS: A total of 35 patients (39 eyes) were included in the study. The volume was significantly reduced from 0.07978 to 0.02565 mm³ at 3 months (p < 0.001). The area was also significantly reduced from 15.35 to 8.60 mm² at 3 months (p < 0.001). The volume was decreased in 34 eyes and increased in 5 eyes. The area was decreased in 37 eyes and increased in 2 eyes. A significant correlation between volume and area was found (p < 0.001) as well as agreement between increase and decrease in volume and area. CONCLUSIONS: In the 3-dimensional quantitative volumetric analysis, the volume and area of HEs were correlated and the direction of increase and decrease was concordant. Considering the distribution of HEs in multiple layers of the retina, volumetric analysis could be considered a substitute for the analysis of HE area.

Two Cases of Outer Retinal Folds Developing after Vitrectomy in Patients Exhibiting Rhegmatogenous Retinal Detachment

PURPOSE: We report two cases of retinal folds developing after pars plana vitrectomy in patients exhibiting rhegmatogenous retinal detachment. CASE SUMMARY: (Case 1) A healthy 52-year-old male visited our clinic complaining of blurred vision in his right eye. His visual acuity was 0.8 in that eye. Fundal examinations revealed upper retinal detachment and retinal tears at the 12 and 1 o'clock positions. He underwent pars plana vitrectomy with gas injection, and 1 week later, the retina was reattached. A retinal fold was detected at the 4 o'clock position; the fold extended for two disc diameters from the optic disc to the equator. The fold resolved spontaneously after 3 months. (Case 2) A 59-year-old male visited our clinic complaining of blurred vision in his right eye. His visual acuity was “counting fingers” in that eye. Fundal examination revealed a retinal tear at the 11 o'clock position and upper retinal detachment involving the macula. He underwent pars plana vitrectomy with gas injection. A retinal fold was detected in the temporal region of the disc running from the 7 o'clock position to the equator. Over 11 months of observation without treatment, optical coherence tomography (OCT) revealed that the retinal fold resolved. CONCLUSIONS: We report the first two Korean cases of spontaneous relief of retinal folds developing after vitrectomy, and the OCT patterns of the folds.

Multiple Subretinal and Intraretinal Hemorrhages as a First Sign of Infective Endocarditis

PURPOSE: To report a patient with multiple subretinal and intraretinal hemorrhages in the absence of retinal/choroidal lesions, diagnosed with infective endocarditis (IE). CASE SUMMARY: We describe the case of a 44-year-old male with an acute decrease of vision in his right eye. Ophthalmic evaluation revealed multiple subretinal and intraretinal hemorrhages, but no choroidal or other retinal lesions. A systemic examination revealed a pansystolic murmur and blood cultures with echocardiography were suggestive of IE. CONCLUSIONS: Thorough systemic evaluations are important when patients present with subretinal and intraretinal hemorrhages in the absence of other retinal/choroidal lesions.

Comparison of Inner Retinal Thickness between the Fellow Eyes of Unilateral Branch Retinal Vein Occlusion and Normal Control

PURPOSE: The purpose of this study was to compare inner retinal thickness and retinal nerve fiber layer (RNFL) thickness between fellow eyes with unilateral branch retinal vein occlusion (BRVO) and normal control eyes. METHODS: Retrospective cross-sectional study including 59 patients diagnosed with unilateral BRVO and 51 control subjects. Using spectral domain optical coherence tomography, we investigated the average, 4 quadrant, and 12 clock-hour RNFL thicknesses and the average, minimum, superior, superonasal, superotemporal, inferior, inferonasal, and inferotemporal thicknesses of the ganglion cell-inner plexiform layer (GCIPL) layer. RESULTS: Patients with unilateral BRVO had a higher incidence of hypertension. In the fellow eyes of the unilateral BRVO patients, 7 and 11 o'clock RNFL thicknesses were significantly thinner than for the control eyes. There was no significant difference in the GCIPL thickness between the two groups CONCLUSIONS: The RNFL thickness of the fellow eyes of the unilateral BRVO patients showed significant decreases in the 7 and 11 o'clock sectors (p=0.005, 0.017, respectively), whereas there was no significant difference in the GCIPL thickness between the two groups. In the RNFL thickness analysis, the 7 and 11 o'clock sectors were found to be dominant locations of decreased RNFL thickness for the open angle glaucoma. Further, glaucomatous change should be carefully monitored in the fellow eyes of unilateral BRVO patients.

One-year Outcome of Intravitreal Dexamethasone Implant for Macular Edema Secondary to Central Retinal Vein Occlusion

PURPOSE: In the present study, 1-year outcome of intravitreal dexamethasone implant in macular edema secondary to central retinal vein occlusion (CRVO) was evaluated. METHODS: The medical records of 22 patients (22 eyes) with macular edema secondary to CRVO were reviewed retrospectively. All patients were treated with intravitreal dexamethasone implant more than twice a year and followed up at least for 1 year from the first dexamethasone implant injection. The best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) were measured every 2 months after the first injection. Adverse effects, including cataract formation and elevation of IOP, were analyzed. RESULTS: The mean patient age was 64.3 ± 9.5 years and 10 patients (45.5%) were male. The average number of injections was 2.4 ± 0.6 and the interval between the first and second injection was 22.0 ± 6.4 weeks. The mean BCVA (log MAR) was 0.82 ± 0.50 and 0.72 ± 0.62 at baseline and after 1 year, respectively. Vision was significantly improved for 8 months after the first injection (p < 0.05). However, vision was not different from baseline after 1 year. The CMT was significantly decreased compared to baseline (p < 0.001). Subgroup analysis revealed that BCVA was improved and CMT decreased significantly when intravitreal dexamethasone concentration was presumed sufficient. Moreover, CMT decreased significantly in hypertensive and ischemic groups compared with normotensive and non-ischemic groups, respectively (p < 0.001). Elevated IOP was observed in 6 eyes (27.3%), but all 6 eyes became normal after topical agent was applied. Cataract formation was observed in 3 eyes (13.6%). CONCLUSIONS: Intravitreal dexamethasone implant resulted in visual acuity stabilization and macular edema reduction in patients having macular edema secondary to CRVO without significant adverse events.

A Case of Focal Laser Photocoagulation Added to Systemic Immunomodulatory Therapy for Bilateral Lupus Chorioretinopathy

PURPOSE: To report a patient diagnosed with bilateral lupus chorioretinopathy who received focal laser photocoagulation. CASE SUMMARY: A 20-year-old female presented with decreased vision in her left eye. She had been treated with systemic corticosteroids, immunosuppressants, plasmapheresis and hemodialysis during systemic lupus erythematosus flare-up. Retinal hemorrhage and cotton wool spots were observed in both eyes on funduscopic examination. Optical coherence tomography showed bilateral serous retinal detachment. Flurorescein angiography (FA) revealed multiple leakages of dye in both maculae. Despite improvements of the systemic disease, subretinal fluid was not resolved. Focal laser photocoagulation was applied to multiple leakage spots identified on FA in both eyes and serous detachment improved. After several months, additional focal laser photocoagulation was performed because there was a small amount of subretinal fluid, which was completely resolved.

Strategies for Mutation Discovery in Retinitis Pigmentosa: Transition to the Next Generation

Retinitis pigmentosa (RP) is the most common hereditary retinal disorder and is characterized by progressive retinal degeneration and decline in vision. RP comprises a heterogeneous group of disorders caused by various genetic variants. Since the first discovery of the causal mutation in the RHO gene using positional cloning, numerous mutations have been detected in more than 60 loci and 50 genes. However, causal genes have not been discovered in about 50% of cases. We attempt here to review the strategies to identify causal alleles of retinitis pigmentosa. These include conventional methods as well as state-of-the-art technologies based on next-generation sequencing.

Retinopathy Associated With Systemic Lupus Erythematosus

PURPOSE: To investigate the clinical characteristics of retinopathy associated with systemic lupus erythematosus (SLE) and its risk factors. METHODS: Medical records of patients who were diagnosed with SLE were reviewed retrospectively. The presence of retinal hemorrhage, vasculitis and a cotton wool patch were regarded as lupus retinopathy, but concomitant diabetic retinopathy and hypertensive retinopathy were excluded from the study. The correlation between the development of lupus retinopathy and the presence of positive autoantibodies was also investigated. RESULTS: Ocular morbidity was found in 173 of 260 (66%) SLE patients. Retinopathy was detected in 52 eyes of 33 patients (12%), which included 36 eyes of 21 patients (63%) with classic retinopathy and 11 eyes of 10 patients (30%) with vaso-occlusive retinopathy. The presence of classic retinopathy coincided with the flare-up of lupus activity and completely resolved without visual impairment. However, vaso-occlusive retinopathy was not related with lupus activity, and resulted in significant visual impairments of 20/200 or less in six eyes of five patients. The disease activity of lupus assessed by the maximum SLE disease activity index was higher in patients with retinopathy (p<0.05), and the prevalence of antiphospholipid antibody was higher in patients with vaso-occlusive retinopathy than in patients with classic retinopathy (66.7% vs. 37.5%, p<0.05). CONCLUSIONS: Vaso-occlusive retinopathy in SLE can result in permanent visual impairment. Patients with high SLE activity or positive anti-phospholipid antibodies have a high possibility of developing SLE retinopathy and should be referred for ophthalmologic examination.

Retinopathy Associated With Systemic Lupus Erythematosus

PURPOSE: To investigate the clinical characteristics of retinopathy associated with systemic lupus erythematosus (SLE) and its risk factors. METHODS: Medical records of patients who were diagnosed with SLE were reviewed retrospectively. The presence of retinal hemorrhage, vasculitis and a cotton wool patch were regarded as lupus retinopathy, but concomitant diabetic retinopathy and hypertensive retinopathy were excluded from the study. The correlation between the development of lupus retinopathy and the presence of positive autoantibodies was also investigated. RESULTS: Ocular morbidity was found in 173 of 260 (66%) SLE patients. Retinopathy was detected in 52 eyes of 33 patients (12%), which included 36 eyes of 21 patients (63%) with classic retinopathy and 11 eyes of 10 patients (30%) with vaso-occlusive retinopathy. The presence of classic retinopathy coincided with the flare-up of lupus activity and completely resolved without visual impairment. However, vaso-occlusive retinopathy was not related with lupus activity, and resulted in significant visual impairments of 20/200 or less in six eyes of five patients. The disease activity of lupus assessed by the maximum SLE disease activity index was higher in patients with retinopathy (p<0.05), and the prevalence of antiphospholipid antibody was higher in patients with vaso-occlusive retinopathy than in patients with classic retinopathy (66.7% vs. 37.5%, p<0.05). CONCLUSIONS: Vaso-occlusive retinopathy in SLE can result in permanent visual impairment. Patients with high SLE activity or positive anti-phospholipid antibodies have a high possibility of developing SLE retinopathy and should be referred for ophthalmologic examination.

Visual Outcome of Cytomegalovirus Retinitis in Korean Patients With Acquired Immune Deficiency Syndrome

PURPOSE: To investigate the clinical characteristics and visual outcome of cytomegalovirus retinitis in Korean patients with acquired immunodeficiency syndrome (AIDS) in the highly active antiretroviral therapy (HAART) era. METHODS: The medical records of 252 patients from Seoul National University Hospital who were diagnosed with AIDS between 2003 and 2006 were reviewed retrospectively. In addition, 15 patients (19 eyes) Having cytomegalovirus (CMV) retinitis with a minimum follow-up period of more than a year were included. Visual acuity, immune status, involved retinal area, and bilaterality were analyzed. RESULTS: All patients were treated with the HAART regimen and an anticytomegaloviral agent with the exception of two patients. In all patients, immune recovery developed and retinitis was inactivated. Moderate (< or = 0.4) and severe (< or = 0.1) visual loss developed in 10 (52%) eyes and 9 (47%) eyes, respectively. Retinal detachment and involvement of posterior pole accounted for more than 80% (8 out of 10) of moderate, and 88% (8 out of 9) of severe visual loss. Patients with bilateral retinitis were more likely to develop retinal detachment and visual loss. Delayed immune recovery was associated with moderate visual loss. CONCLUSIONS: Posterior pole involvement and retinal detachment were the major cause of visual loss in CMV retinitis in AIDS patients. Bilateral involvement and delayed immune recovery were related to retinal detachment and a poor visual outcome.

The Surgical Outcomes of Simple Keratectomy for Limbal Dermoids

PURPOSE: To evaluate the results of simple keratectomy for limbal dermoids. METHODS: We reviewed the ocular records of 29 consecutive patients with limbal dermoids who had undergone simple keratectomy in Seoul National University Children's hospital from 1989 to 2006. The preoperative and postoperative visual acuity and astigmatism levels as well as the cosmetic outcomes were measured. RESULTS: The mean age at surgery was 28 months (range, 6~70 months), and the mean follow-up period was 56 months (range, 18~168 months). The mean visual acuity at the last follow-up was 20/30. The mean preoperative and postoperative cylinder was -2.64D and -2.12D, respectively, in the affected eye (p=0.064); and -0.79D and -0.43D, respectively, in the fellow eye (p=0.149). There was a significant correlation between preoperative astigmatism and the final visual acuity in the involved eye. No opaque lesions were visible at a distance of 1 meter in 16 of the 29 eyes (55.2%), and there were no significant complications related to the surgery. CONCLUSIONS: Simple keratectomy of limbal dermoids can be a good surgical technique to get a cosmetically acceptable corneal clarity without complication.