Comparison of the effectiveness of different corneal curvature measurement methods for IOL implantation in traumatic aphakic eyes with corneal injury.

BACKGROUND/AIM: To assess the refractive outcomes of secondary intraocular lenses (IOL) in patients with traumatic aphakic eyes with corneal penetrating injury and compare different corneal curvature measurement methods. METHODS: Patients with unilateral penetrating eye injuries underwent corneal wound repair and cataract extraction, followed by secondary IOL implantation. Corneal curvature measurements were taken on the contralateral healthy eye (Group A), from the affected eye before removing corneal sutures (Group B), or after suture removal (Group C). The refractive outcomes were compared among the three groups. RESULTS: The study included 261 eyes. The Mean Absolute Error (MAE) in Group C (0.99 ± 0.85 D) was significantly smaller than that in Group A (1.87 ± 1.71 D) and Group B (1.37 ± 1.20 D) (both P < 0.001). Moreover, the percentage of eyes with IOL prediction errors within ± 0.50 D in Group C (40%) was higher than that in group A (21.7%) (OR = 2.364, 95%CI: 1.272-4.392, P = 0.006) and group B (28.0%) (OR = 1.714, 95%CI: 0.948-3.099, P = 0.073), and the percentage of eyes with IOL prediction errors within ± 1.0 D in Group C (90.9%) was higher than that in group A (67.9%) (OR = 4.758, 95%CI: 2.131-10.626, P < 0.001) and group B (75.0%) (OR = 3.370, 95%CI: 1.483-7.660, P = 0.003) as well. CONCLUSIONS: In traumatic aphakic eyes with corneal sutures, IOL power calculation based on the corneal curvature of the injured eye after removing the corneal sutures yields the best refractive outcomes.

Accuracy of 10 MHz ultrasonography for evaluation of posterior lens capsule in traumatic cataract.

PURPOSE: To investigate the performance of 10 MHz ultrasonography in detecting posterior lens capsule defects before traumatic cataract surgery. METHODS: This retrospective analysis includes patients with traumatic cataracts who underwent cataract surgery. Preoperative 10 MHz ultrasonography was performed to evaluate whether the posterior lens capsule was defective or intact, and the results were compared to the intraoperative findings. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and kappa were calculated. RESULTS: The study included 140 eyes of 140 patients. There were 68 eyes with closed-globe injuries and 72 eyes with open-globe injuries. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and kappa of 10 MHz ultrasonography was 86.76%, 90.28%, 89.39%, 87.84%, 88.57% and 0.771, respectively. The accuracy was 86.11% and 91.18% in open-globe and closed-globe injury groups, respectively. CONCLUSION: The accuracy of 10 MHz ultrasonography in evaluating the posterior lens capsule in traumatic cataracts is high. Preoperative 10 MHz ultrasonography would help to make an appropriate surgical plan.

Accurate C/D ratio estimation with elliptical fitting for OCT image based on joint segmentation and detection network.

Proper estimation of the cup-to-disc ratio (C/D ratio) plays a significant role in ophthalmic examinations, and it is urgent to improve the efficiency of C/D ratio automatic measurement. Therefore, we propose a new method for measuring the C/D ratio of OCTs in normal subjects. Firstly, the end-to-end deep convolution network is used to segment and detect the inner limiting membrane (ILM) and the two Bruch's membrane opening (BMO) terminations. Then, we introduce an ellipse fitting technique to post-process the edge of the optic disc. Finally, the proposed method is evaluated on 41 normal subjects using the optic-disc-area scanning mode of three machines: BV1000, Topcon 3D OCT-1, and Nidek ARK-1. In addition, pairwise correlation analyses are carried out to compare the C/D ratio measurement method of BV1000 to existing commercial OCT machines as well as other state-of-the-art methods. The correlation coefficient between the C/D ratio calculated by BV1000 and the C/D ratio calculated by manual annotation is 0.84, which indicates that the proposed method has a strong correlation with the results of manual annotation by ophthalmologists. Moreover, in comparison between BV1000, Topcon and Nidek in practical screening among normal subjects, the proportion of the C/D ratio less than 0.6 calculated by BV1000 accounts for 96.34%, which is the closest to the clinical statistics among the three OCT machines. The above experimental results and analysis show that the proposed method performs well in cup and disc detection and C/D ratio measurement, and compared with the existing commercial OCT equipment, the C/D ratio measurement results are relatively close to reality, which has certain clinical application value.

Smartphone ophthalmoscope as a tool in teaching direct ophthalmoscopy: a crossover randomized controlled trial.

To evaluate the effectiveness of smartphone ophthalmoscope (SO) in teaching ophthalmoscopy, compared with direct ophthalmoscope (DO). In this cross-over study, 45 final-year medical students attending sessions at a single institution were randomly allocated to two groups (A and B). Both groups attended two training sessions. In the first session, Group A students were taught ophthalmoscopy using DO and Group B students using SO. In the second session, the training sessions were crossed over. A series of eye models with 10 letters placed on the inner surface were designed to assess the students' skill on ophthalmoscopy. Students performed ophthalmoscopy on the eye models, recorded their findings, and completed a questionnaire of feedback on DO and SO. The main outcome measure was the score of ophthalmoscopy, assessed by the student correctly recording each letter (score 1 for each letter). For Group A, the mean score of ophthalmoscopy on the eye model using DO and SO was 3.9±2.4 and 8.2±2.2, respectively. For Group B, the mean score of ophthalmoscopy on the eye model using SO and DO 8.7±1.8 and 5.7±3.5 . Students scored significantly higher in ophthalmoscopy when using SO than DO (P<0.001). They expressed better visualization of the fundus using SO than DO (4.49±0.65 vs 4.13±0.81, P=0.004). Students' performance of ophthalmoscopy was better when SO was used compared with DO. The use of SO as an adjunctive tool is recommended to improve the effectiveness of teaching ophthalmoscopy.

METAGENOMIC NEXT-GENERATION SEQUENCING DETECTS PATHOGENS IN ENDOPHTHALMITIS PATIENTS.

PURPOSE: To investigate the utility of metagenomic next-generation sequencing (mNGS) in identifying the pathogens in endophthalmitis. METHODS: In this prospective study, 36 cases of endophthalmitis were recruited. All patients received surgical treatment and intraocular drug lavage. The samples of vitreous or aqueous humor were extracted for mNGS and microbiological culture. The diagnostic performance of pathogens was compared between mNGS and culture. RESULTS: The positive rates of mNGS and culture were 88.89% (32/36) and 27.78% (10/36), respectively. There was a statistically significant difference between mNGS and culture (Chi-square = 27.657; P < 0.01). Staphylococcus epidermidis, Streptococcus pneumoniae, and Klebsiella pneumoniae were the most pathogenic bacteria in traumatic, postoperative, and endogenous endophthalmitis, respectively. The concordance of pathogen identified by mNGS and culture was 70% for culture-positive cases. Antibiotic resistance genes were identified in 9 cases. There was a marginal correlation between the final visual acuity and the microbial sequence read (Spearman correlation coefficient = 0.498; P = 0.05). CONCLUSION: Metagenomic next-generation sequencing has a higher positive rate of identifying pathogens in endophthalmitis than in culture. It can also provide information on antibiotic resistance and visual prognosis. However, caution must be taken when interpreting the results of mNGS because they may not be concordant with culture.

A simple eye model for objectively assessing the competency of direct ophthalmoscopy.

BACKGROUND: Direct ophthalmoscopy is an important investigative technology not only for ophthalmologists, but also for general practitioners and other specialists. The purpose of this study was to develop a simple and robust eye model for effective and objective assessment of ophthalmoscopic competency. METHODS: A series of eye models were assembled using commonly available materials, including 26-mm-diameter double-hemispherical brown plastic balls and convex lenses. A 6-mm circular opening was drilled on one hemisphere as a pupil behind which the lens was glued to provide the refractive component. Ten pieces of letters were placed on the inner surface of the other hemisphere. Ophthalmoscopic skills of ophthalmologist residents were first subjectively assessed using a checklist by two tutors and then objectively by using the eye models. The discrimination index was calculated to evaluate the effectiveness of assessment. Finally, a feedback questionnaire was completed. RESULTS: Totally 76 residents were recruited. The checklist score was 9.25 ± 0.47, with a discrimination index of 0.11. The model-assessment score was 4.24 ± 3.10, with a discrimination index of 0.79. There was no correlation between the checklist score and model scores (r = 0.133, P = 0.251). Two-thirds of the participants agreed or strongly agreed that model-assessment could reflect the ability to visualize the fundus. CONCLUSIONS: We have developed simple eye models to assess the competency of ophthalmoscopy with excellent discriminatory power to differentiate competence levels of ophthalmology residents.

TMP prevents retinal neovascularization and imparts neuroprotection in an oxygen-induced retinopathy model.

PURPOSE: To evaluate the effects of tetramethylpyrazine (TMP) on retinal neovascularization (NV) and neuroprotection in an oxygen-induced retinopathy (OIR) model. METHODS: Neonatal C57BL/6J mice were subjected to 75% oxygen from postnatal day 7 (P7) to P12 and then returned to room air. TMP (200 mg/kg) or normal saline was given daily from P12 to P17. Immunostaining, HE staining, TUNEL assay, and RT-PCR were used to assess the effects of TMP on retinal neurovascular repair. RESULTS: TMP effectively prevented pathologic NV and accelerated physiologic revascularization by enhancing the formation of endothelial tip cells at the edges of the repairing capillary networks and preserving the astrocytic template in the avascular retina. TMP also prevented morphologic changes and significantly decreased TUNEL-positive cells in the avascular retina by rescuing neurons such as amacrine, rod bipolar, horizontal, and Müller cells. In TMP-treated mice retinas, there was a less obvious loss of amacrine cell bodies and their distinct bands; the number of both rod bipolar and horizontal cell bodies, as well as the density of their dendrites in the outer plexiform layer, was greater than that in OIR control mice. TMP not only decreased the loss of alignment of Müller cell bodies and distortion of processes but reduced the reactive expression of GFAP in Müller cells. Furthermore, HIF-1α and VEGF mRNA expression were downregulated in TMP-treated mice retinas. CONCLUSIONS: TMP improved neurovascular recovery by preventing NV and protecting retinal astroglia cells and neurons from ischemia-induced cell death partially due to its downregulation of HIF-1α and VEGF mRNA expression.