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.

Autosomal Dominant Drusen Confirmed by Molecular Genetics

Purpose@#To report a case of autosomal dominant drusen confirmed by molecular genetic testing and the clinical features and findings of a multimodal diagnostic imaging study.Case summary: A 32-year-old male presented with decreased visual acuity in his right eye from 1 year prior to his first visit. On the first visit, his visual acuities were 0.3 in the right eye and 1.2 in the left eye. A fundus examination showed numerous drusen of various sizes widely distributed on the posterior pole of both eyes, as well as subretinal fibrotic change with pigmentation in the right eye. Optical coherence tomography showed extensive hyperreflective deposits beneath the retinal pigment epithelium in both eyes and small amounts of cystic intraretinal fluid in the right eye. Fluorescein angiography and fundus autofluorescence showed the drusen as multiple hyperfluorescent spots, while indocyanine green angiography indicated hypofluorescence corresponding to the drusen. Genetic sequence analysis revealed a pathogenic variant of the EFEMP1 gene, heterozygous c.1033C>T (p.Arg345Trp), which accords with the diagnosis of autosomal dominant drusen. Intravitreal bevacizumab injection was given in the right eye; however, there was no improvement in the amount of intraretinal fluid nor visual acuity. @*Conclusions@#Autosomal dominant drusen is a very rare disease. It is necessary to distinguish it from age-related macular degeneration, as the affected age and clinical features of drusen are different, including the response to anti-vascular endothelial growth factor treatment.

Preservative-free Triamcinolone Acetonide-assisted Visualization of the Internal Limiting Membrane

Purpose@#To evaluate and compare the degree of visualization of the vitreous and internal limiting membrane (ILM) during pars plana vitrectomy (PPV) using preservative-free triamcinolone acetonide (PF-TA) or triamcinolone acetonide suspension (TAS). @*Methods@#We retrospectively analyzed the medical records of 61 eyes of 61 patients who underwent 25-gauge PPV and ILM peeling for various macular diseases. We assigned the patients to PF-TA and TAS groups, i.e., according to the type of triamcinolone acetonide used. The degree of visualization of the vitreous and ILM was classified into four different categories. The number of dye injections during PPV, need for indocyanine green (ICG), time elapsed before ILM peeling, and intraocular pressure (IOP) before surgery, 1 day and 1 month after surgery were determined. @*Results@#The degree of visualization of the vitreous and ILM was significantly better in the PF-TA group compared with the TAS group. Although the number of dye injections during PPV was not different between the PF-TA and TAS groups (2.56 ± 0.07 and 2.37 ± 1.08, respectively, p = 0.06), the need for ICG was significantly different (6 and 22 eyes, respectively, p < 0.01). The time elapsed before ILM peeling was 185.68 ± 130.02 s in the PF-TA group and 411.15 ± 267.38 s in the TAS group (p < 0.01). The IOP was not different before or 1 day after surgery between the PF-TA and TAS groups, but was significantly different 1 month after surgery (12.88 ± 3.10 and 14.41 ± 2.91 mmHg, respectively, p = 0.03). @*Conclusions@#Visualization of the vitreous and ILM was better when using PF-TA compared to TAS. PF-TA-assisted PPV could reduce the usage of ICG and was associated with a reduced latency to ILM peeling. Because this was in turn associated with a lower IOP at postoperative 1 month, PF-TA was safer and more effective than TAS.

Fusion and Suppression in Patients with Unilateral Idiopathic Epiretinal Membrane

Purpose@#To investigate the presence of fusion and suppression in patients with unilateral idiopathic epiretinal membrane (ERM). @*Methods@#Thirty-five patients with unilateral idiopathic ERM received a full ophthalmologic exam including best corrected visual acuity (BCVA). Patients were divided into suppression and non-suppression groups according to the results of 4 Prism Dioptre Base-out Test and Worth 4 Dot test. Age, symptoms, duration of ERM, BCVA, average M-chart score, results of Titmus test and optical coherence tomography parameters were compared between the two groups. Factors associated with suppression were also evaluated. @*Results@#Eleven (31%) of 35 patients had suppression. The BCVA (0.18 ± 0.12 vs. 0.29 ± 0.12 p = 0.019) and stereopsis (2.25 ± 0.27 vs. 2.66 ± 0.62, p = 0.009) were significantly lower in the suppression group than the non-suppression group. Median age was older (63.21 ± 9.64 vs. 70.82 ± 6.80, p = 0.013) and duration of ERM (7.86 ± 3.69 vs. 18.54 ± 14.92 months, p = 0.004) was longer in the suppression group than the non-suppression group. Average M-chart score was higher in the suppression group. However, not all the patients suffered from metamorphopsia, including the suppression group when using binocular vision. @*Conclusions@#Unilateral suppression is common in unilateral idiopathic ERM and influences the patient’s stereopsis. Suppression was significantly correlated with age, duration of symptoms and metamorphopsia.

Recurrence of Retinal Detachment after Scleral Buckle Removal

Purpose@#To investigate the indications for scleral buckle removal and the risk factors for the recurrence of rhegmatogenous retinal detachment after scleral buckle removal. @*Methods@#In this retrospective study, the medical records of all patients who underwent scleral buckle removal for the treatment of rhegmatogenous retinal detachment were reviewed. @*Results@#Forty eyes (40 patients) were included in this study. The indications for scleral buckle removal included exposure without infection in 23 eyes (57.5%), exposure with infection in seven eyes (17.5%), elevated intraocular pressure in six eyes (15.0%), strabismus or diplopia in three eyes (7.5%), and migration of buckle material in one eye (2.5%). After the removal of the scleral buckle, the recurrence of rhegmatogenous retinal detachment was observed in four eyes (10.0%) during follow-up, and the retina was successfully reattached after pars plana vitrectomy in all the eyes. Most clinical and ocular factors of the eyes with and without the recurrence of retinal detachment during follow-up were not different, but the eyes that underwent encircling removal were more likely to have retinal detachment recurrence during follow-up than those that underwent segmental buckle removal (n = 4 / 16 [25.0%] vs. n = 0 / 24 [0.0%]; p = 0.020). @*Conclusions@#Scleral buckle removal can result in the recurrence of retinal detachment. The benefits and risks of scleral buckle removal should be carefully considered before surgery, and extensive monitoring during follow-up after scleral buckle removal is important, especially for patients who underwent encircling removal.

Clinical Manifestations and Risk Factors of Anterior Chamber Migration of a Dexamethasone Implant

Purpose@#To investigate the clinical features, risk factors, and treatment outcomes for anterior chamber migration of an intravitreal dexamethasone implant (Ozurdex®; Allergan Inc., Irvine, CA, USA). @*Methods@#We retrospectively reviewed the medical records of patients who were diagnosed with anterior chamber Ozurdex® migration. Prior surgical histories were obtained and comprehensive ophthalmic examinations were conducted for all eyes. Treatment strategies and outcomes were also analyzed. @*Results@#Among 1,276 intravitreal Ozurdex® injections, anterior migration occurred in six eyes of six patients (0.47%). All six eyes were pseudophakic, and they had undergone prior vitrectomies. The vitrectomized pseudophakic eyes, in contrast to the nonvitrectomized pseudophakic eyes, were significantly associated with an increased risk of anterior chamber migration (odds ratio [OR] = 19.2, p = 0.009). Moreover, the vitrectomized eyes with reduced zonular/capsular bag complex integrity, in contrast to the vitrectomized eyes with intact zonular/capsular bag complex integrity, were significantly associated with an increased risk of anterior chamber migration (OR = 50.2, p < 0.001). All six eyes underwent surgical intervention: one eye with a repositioning procedure, and the other five eyes with surgical removal of the implant. Corneal edema was resolved within two months after surgery; however, one patient eventually developed corneal endothelial dysfunction. @*Conclusions@#Prior vitrectomy and a defective lens capsule or weak zonules/zonular dehiscence are risk factors for anterior chamber Ozurdex® migration; thus, caution is recommended in these patients. Urgent removal of the implant should be considered when anterior migration of the implant is diagnosed with corneal edema.

Recurrence of Retinal Detachment after Scleral Buckle Removal

Purpose@#To investigate the indications for scleral buckle removal and the risk factors for the recurrence of rhegmatogenous retinal detachment after scleral buckle removal. @*Methods@#In this retrospective study, the medical records of all patients who underwent scleral buckle removal for the treatment of rhegmatogenous retinal detachment were reviewed. @*Results@#Forty eyes (40 patients) were included in this study. The indications for scleral buckle removal included exposure without infection in 23 eyes (57.5%), exposure with infection in seven eyes (17.5%), elevated intraocular pressure in six eyes (15.0%), strabismus or diplopia in three eyes (7.5%), and migration of buckle material in one eye (2.5%). After the removal of the scleral buckle, the recurrence of rhegmatogenous retinal detachment was observed in four eyes (10.0%) during follow-up, and the retina was successfully reattached after pars plana vitrectomy in all the eyes. Most clinical and ocular factors of the eyes with and without the recurrence of retinal detachment during follow-up were not different, but the eyes that underwent encircling removal were more likely to have retinal detachment recurrence during follow-up than those that underwent segmental buckle removal (n = 4 / 16 [25.0%] vs. n = 0 / 24 [0.0%]; p = 0.020). @*Conclusions@#Scleral buckle removal can result in the recurrence of retinal detachment. The benefits and risks of scleral buckle removal should be carefully considered before surgery, and extensive monitoring during follow-up after scleral buckle removal is important, especially for patients who underwent encircling removal.

Clinical Manifestations and Risk Factors of Anterior Chamber Migration of a Dexamethasone Implant

Purpose@#To investigate the clinical features, risk factors, and treatment outcomes for anterior chamber migration of an intravitreal dexamethasone implant (Ozurdex®; Allergan Inc., Irvine, CA, USA). @*Methods@#We retrospectively reviewed the medical records of patients who were diagnosed with anterior chamber Ozurdex® migration. Prior surgical histories were obtained and comprehensive ophthalmic examinations were conducted for all eyes. Treatment strategies and outcomes were also analyzed. @*Results@#Among 1,276 intravitreal Ozurdex® injections, anterior migration occurred in six eyes of six patients (0.47%). All six eyes were pseudophakic, and they had undergone prior vitrectomies. The vitrectomized pseudophakic eyes, in contrast to the nonvitrectomized pseudophakic eyes, were significantly associated with an increased risk of anterior chamber migration (odds ratio [OR] = 19.2, p = 0.009). Moreover, the vitrectomized eyes with reduced zonular/capsular bag complex integrity, in contrast to the vitrectomized eyes with intact zonular/capsular bag complex integrity, were significantly associated with an increased risk of anterior chamber migration (OR = 50.2, p < 0.001). All six eyes underwent surgical intervention: one eye with a repositioning procedure, and the other five eyes with surgical removal of the implant. Corneal edema was resolved within two months after surgery; however, one patient eventually developed corneal endothelial dysfunction. @*Conclusions@#Prior vitrectomy and a defective lens capsule or weak zonules/zonular dehiscence are risk factors for anterior chamber Ozurdex® migration; thus, caution is recommended in these patients. Urgent removal of the implant should be considered when anterior migration of the implant is diagnosed with corneal edema.

Long-term Efficacy of Vitrectomy for Macular Edema Secondary to Branch Retinal Vein Occlusion in Patients Treated with Intravitreal Injections

PURPOSE: To evaluate the long-term efficacy of pars plana vitrectomy (PPV) on refractory or recurrent macular edema due to branch retinal vein occlusion (BRVO) after intravitreal steroid or anti-vascular endothelial growth factor injections. METHODS: We retrospectively reviewed the medical records of patients with macular edema due to BRVO who underwent PPV after intravitreal triamcinolone acetonide or bevacizumab injections and followed-up for at least 12 months. The best corrected visual acuity (BCVA) and subfoveal macular thickness were measured at 1, 3, 6, 12 months postoperatively and were compared with the preoperative values. The patients received additional intravitreal injections if they had recurrence of macular edema after surgery. The frequency of intravitreal injections (per year) were compared pre- and postoperatively. RESULTS: A total of 41 eyes of 41 patients were included and the mean duration of follow up was 58.7 ± 30.0 (15 - 124) months. The BCVA (logMAR) at 1, 3, 6, 12 months postoperatively, and last follow up was 0.52 ± 0.42, 0.46 ± 0.38, 0.41 ± 0.26, 0.50 ± 0.34, and 0.49 ± 0.37, respectively, which was significantly different from the preoperative values (0.90 ± 0.47, p < 0.001). The subfoveal macular thickness at 1, 3, 6, 12 months postoperatively, and last follow up was 342.72 ± 84.10 µm, 365.02 ± 110.73 µm, 359.45 ± 119.28 µm, 360.96 ± 124.33 µm, and 329.34 ± 119.69 µm, respectively, which was also significantly different (p < 0.001) from the preoperative values (484.9 ± 112.8 µm, p < 0.001). The frequency of intravitreal injections was significantly decreased after surgery (3.58 ± 2.05 times/year vs. 0.60 ± 0.83 times/year, p < 0.001). CONCLUSIONS: Pars plana vitrectomy could improve BCVA, decrease subfoveal macular thickness, and decrease recurrence in BRVO patients with refractory or recurrent macular edema after intravitreal injection. PPV could be an effective treatment option for these patients.

Subretinal transplantation of putative retinal pigment epithelial cells derived from human embryonic stem cells in rat retinal degeneration model / 대한생식의학회지

OBJECTIVE: To differentiate the human embryonic stem cells (hESCs) into the retinal pigment epithelium (RPE) in the defined culture condition and determine its therapeutic potential for the treatment of retinal degenerative diseases. METHODS: The embryoid bodies were formed from hESCs and attached on the matrigel coated culture dishes. The neural structures consisting neural precursors were selected and expanded to form rosette structures. The mechanically isolated neural rosettes were differentiated into pigmented cells in the media comprised of N2 and B27. Expression profiles of markers related to RPE development were analyzed by reverse transcription-polymerase chain reaction and immunostaining. Dissociated putative RPE cells (10(5) cells/5 microL) were transplanted into the subretinal space of rat retinal degeneration model induced by intravenous sodium iodate injection. Animals were sacrificed at 1, 2, and 4 weeks after transplantation, and immnohistochemistry study was performed to verify the survival of the transplanted cells. RESULTS: The putative RPE cells derived from hESC showed characteristics of the human RPE cells morphologically and expressed molecular markers and associated with RPE fate. Grafted RPE cells were found to survive in the subretinal space up to 4 weeks after transplantation, and the expression of RPE markers was confirmed with immunohistochemistry. CONCLUSION: Transplanted RPE cells derived from hESC in the defined culture condition successfully survived and migrated within subretinal space of rat retinal degeneration model. These results support the feasibility of the hESC derived RPE cells for cell-based therapies for retinal degenerative disease.

Bilateral Retinal Dysplasia and Secondary Glaucoma Associated with Homozygous Protein C Deficiency

PURPOSE: Protein C deficiency is an autosomal recessive disorder, which predisposes the patient to potentially blinding and widespread lethal thromboembolic complications, especially in the homozygous type. We here report the first Korean case of ophthalmic involvement and its surgical treatment in homozygous protein C deficiency. METHODS: A 3.4kg, full term girl was born by normal delivery but showed bilateral leukocoria on day 2. Laboratory results disclosed a very low protein C activity level (10%) in the patient and moderately decreased levels in the other family members. Ophthalmic examination showed bilateral corneal opacity and shallow anterior chamber. B-scan ultrasonography which showed intravitreal mass lesions without microphthalmos and a funnel-shaped retinal detachment suggested bilateral retinal dysplasia. RESULTS: As the eyes were under progression of secondary glaucoma, bilateral lensectomies were performed at 2 months old and corneal opacity was regressed to some degree. However, at 14 months old, the left eye showed moderate corneal opacity with a band keratopathy. CONCLUSIONS: Although visual outcome was very poor after surgery, we could impede or slow down the progression of secondary glaucoma and save the eyeballs in the infant with homozygous protein C deficiency.

Clear Lens Extraction for the Correction of Severe High Myopia: Seven-year Follow-up

PURPOSE: To evaluate the postoperative outcomes and complications 7 years after clear lens extraction (CLE) for the correction of high myopia. METHODS: The medical records of 23 eyes of 15 patients who had undergone CLE to correct myopia higher than -12 diopter and who could be followed up for more than 7 years were reviewed. A scleral tunnel incision and continuous curvilinear capsulorhexis were made, followed by phacoemulsification and posterior chamber intraocular lens implantation. Refractive error, visual acuity and postoperative complications were recorded. RESULTS: Mean follow-up was 98.2 (84~118) months. Posterior capsular opacification developed in 12 eyes (52.2%) and neodymium: YAG laser posterior capsulotomy was performed in 7 eyes. Retinal detachment developed in 3 eyes of 2 patients at 6 months, 34 months, and 9 years after CLE. At 7 years after CLE, the spherical equivalent (SE) of 14 (60.9%) of 20 eyes was within +/- 2 diopter of targeted refractive error. Shift to myopia occurred by 1 diopter compared to SE at 1 year after CLE. Best corrected visual acuity improved by 2 lines in 14 eyes (60.9%) and was 0.5 or better in 17 eyes (73.9%). CONCLUSIONS: CLE for correction of high myopia had good visual outcomes with acceptable predictability. However, long term follow-up revealed gradual increase of serious complications like retinal detachment, posterior capsular opacification, and myopic shift by 1 diopter between 1 year and 7 years after CLE.

Comparison and Correlation Analysis of Intraocular Pressure Measured with the Pressure Phosphene Tonometer and the Goldmann Tonometer

PURPOSE: To compare the intraocular pressure (IOP) measured by the pressure phosphene tonometer (PPT) and the Goldmann applanation tonometer (GAT) according to the feedback of the IOP measured by GAT and the use of the dominant hand during the measurement. METHODS: In a group of 40 eyes of 40 normal subjects in their twenties and thirties without diagnostic specificity, IOP was measured with PPT three times by themselves and with the GAT by one examiner on 3 different days. In 20 eyes of the feedback group, the subjects were informed of their IOP measured by GAT and were allowed to measure with PPT again. In each group, half of the eyes (20 eyes) were assigned to use the dominant hand to measure the IOP (dominant group) and the other half (20 eyes) were assigned in the other way (nondominant group). RESULTS: In feedback, nonfeedback and dominant groups, comparison of the first day showed statistically significant differences of mean IOP. But on the third day, there were no significant differences among all 4 groups and there were significant correlations. There was a stronger correlation between the two methods in the feedback group (r=0.721) than in the nonfeedback group. The correlation coefficient of all 40 eyes was 0.605 (p<0.001). CONCLUSIONS: PPT has a strong correlation with GAT in the range of normal IOP and is thought to be more useful as a self tonometer for the measurement of both eyes with the periodical measurement of IOP by GAT in clinics.

Comparison of Indocyanine Green and Triamcinolone Acetonide for Internal Limiting Membrane Peeling in Macular Hole

PURPOSE: To compare the surgical outcomes and complications of triamcinolone acetonide (TA) with those of indocyanine green (ICG) staining of the internal limiting membrane (ILM) during idiopathic macular hole surgery. METHODS: Twenty-four eyes of 23 consecutive patients with an idiopathic macular hole underwent vitrectomy, ILM peeling, and intravitreal gas injection. For enhanced visualization of ILM, ICG was used in 13 eyes and TA in the remaining 11 eyes. Functional and anatomical success rates and surgical complications were compared between the groups. RESULTS: The mean follow-up periods were 10.8 months (ICG group) and 7.5 months (TA group). Best corrected visual acuity increased by two or more lines in 10 eyes (76.9%) of the ICG group and in eight eyes (72.7%) of the TA group (P=1.000). Anatomical closure after the first surgery was achieved in 10 eyes (76.9%) of the ICG group and in all 11 eyes of the TA group (100%) (P=0.223). Postoperative atrophic changes in the retinal pigment epithelium (RPE) in the macular hole bed was found in two eyes of the ICG group and in three eyes of the TA group. All of these (5 eyes) showed the photoreceptor outer segment defect in the closed macular areas by optical coherence tomography and had a postoperative best corrected visual acuity of 0.3 or less. CONCLUSIONS: In view of the potential toxicities of ICG, TA appears to be a promising alternative adjuvant for ILM peeling during macular hole surgery. However, postoperative RPE atrophy was detected as a postoperative complication in both the ICG and TA groups. Further study is needed to evaluate the TA toxicity in macular hole surgery.

Clinical Results of Posterior Capsule Ruptures in the First 1000 Phacoemulsification Cases

PURPOSE: To analyze the results of posterior capsule rupture (PCR) that occurred in the first 1000 cases performed by a newly trained phacoemulsification surgeon. METHODS: The medical records of 47 eyes of 45 patients who suffered PCR among the first 1000 cases of cataract surgery performed by one newly trained surgeon were reviewed. All surgeries started with the plan of phacoemulsification and there was no supervision by any experienced surgeon. RESULTS: Over the course of the series of 1000 cases, the PCR incidence rate steadily fell from 12% in the first 100 cases to 4.7% (47 cases) for all 1000 cases as the operator gained experience with the techniques. However, after the change of phaco machine and the technique of nucleus removal, the incidence increased abruptly to 11% and then decreased again. There was no significant difference in PCR incidence between surgeries of the first eye and the second eye of the 335 patients who underwent cataract surgery in both eyes by the surgeon (p=0.534). PCR occurred most commonly in the course of phacoemulsification (83.0%) and mainly in the eyes with severe nucleus sclerosis. CONCLUSIONS: In the early stages of the career of a phacoemulsification surgeon, the PCR incidence showed a learning curve that decreased with increasing experiences, then it increased again after the change of operational procedure before finally decreasing once more. In the surgery of the second eye, poor patient cooperation could be overcome with a careful approach, and PCR occurred most commonly in the course of phacoemulsification (83.0%).

Clinical Features and Natural History of the Acquired Third, Fourth, and Sixth Cranial Nerve Palsy

PURPOSE: To analyze the clinical features and natural history of acquired third, fourth, and sixth cranial nerve palsy. METHODS: We reviewed the medical records of 89 patients who were diagnosed with acquired third, fourth, and sixth nerve palsy from January 2003 to March 2005. The natural course of the disease and the factors affecting recovery were analyzed for the 66 patients who had their first ocular examination within 3 months from onset and were followed up for at least 6 months. RESULTS: The average age of onset was 50.1 years. The sixth cranial nerve was affected most frequently (n=43, 48.3%). Vascular disease (n=27, 30.3%) was most common etiology of cranial nerve palsy, followed by an undetermined cause (n=19, 21.3%). Of the 66 patients who had their first ocular examination within 3 months from onset and were followed up for at least 6 months, 40 (60.6%) patients showed a decrease in the angle of deviation by more than 10 prism diopters, and of these, 32 (48.5%) patients made a complete recovery from pareses. The recovery rates for patients with vascular disease or undetermined etiology (p=0.001), milder initial eyeball deviation and ocular motor restriction (p<0.001) were higher. CONCLUSIONS: In the natural course of the disease, the recovery rate of acquired third, fourth, and sixth nerve palsy was 60.6%. The most favorable prognosis occurred with vascular disease, undetermined etiology, and less severe paralysis on onset.