Convolutional-neural-network-based versus vision-transformer-based SNR estimation for visible light communication networks.

Visible light communication (VLC) has emerged as a promising technology for future sixth-generation (6 G) communications. Estimating and predicting the impairments, such as turbulence and free space signal scattering, can help to construct flexible and adaptive VLC networks. However, the monitoring of impairments of VLC is still in its infancy. In this Letter, we experimentally demonstrate a deep-neural-network-based signal-to-noise ratio (SNR) estimation scheme for VLC networks. A vision transformer (ViT) is first utilized and compared with the conventional scheme based on a convolutional neural network (CNN). Experimental results show that the ViT-based scheme exhibits robust performance in SNR estimation for VLC networks compared to the CNN-based scheme. Specifically, the ViT-based scheme can achieve accuracies of 76%, 63.33%, 45.33%, and 37.67% for 2-quadrature amplitude modulation (2QAM), 4QAM, 8QAM, and 16QAM, respectively, against 65%, 57.67%, 41.67%, and 34.33% for the CNN-based scheme. Additionally, data augmentation has been employed for achieving enhanced SNR estimation accuracies of 95%, 79.67%, 58.33%, and 50.33% for 2QAM, 4QAM, 8QAM, and 16QAM, respectively. The effect of the SNR step size of a contour stellar image dataset on the SNR estimation accuracy is also studied.

Clinical outcomes of penetrating canaloplasty in patients with traumatic angle recession glaucoma: a prospective interventional case series.

BACKGROUND/AIM: To evaluate the clinical outcomes of penetrating canaloplasty in traumatic angle recession glaucoma at 1 year. METHODS: Patients with angle recession glaucoma underwent penetrating canaloplasty, a new Schlemm's canal-based internal drainage procedure, which creates a direct canal for flow of aqueous humour from the anterior chamber to the ostia of Schlemm's canal via a window created at the corneal scleral bed without use of antimetabolites. Postoperative intraocular pressure (IOP), number of glaucoma medications, and procedure-related complications were evaluated. Success was defined as an IOP ≤21 mm Hg without (complete) or with (qualified) use of glaucoma medication. RESULTS: Forty eyes in 40 patients with angle recession glaucoma underwent successful circumferential catheterisation. The mean patient age was 42±13 years. In patients with penetrating canaloplasty that was deemed to be completely successful, the mean IOP decreased from a preoperative value of 37.8±12.3 mm Hg on 3.3±1.2 anti-glaucoma medications to 18.5±6.4 mm Hg on 1.2±1.4 medications, 14.9±4.6 mm Hg on 0.1±0.5 medications, 15.7±5.4 mm Hg on 0.1±0.4 medications and 14.8±3.6 mm Hg on 0.1±0.5 medications at 1, 3, 6 and 12 months postoperatively (p<0.05). Complete success was achieved in 35/40 eyes (87.5%) at 6 months and in 34/38 (89.5%) at 12 months. Hyphema (18/40, 45.0%) and transient IOP elevation (≥30 mm Hg, 9/40, 22.5%) were the most common postoperative complications. CONCLUSION: Penetrating canaloplasty significantly reduces IOP and has a high success rate in angle recession glaucoma. TRIAL REGISTRATION NUMBER: ChiCTR1900020511.

Refractive outcomes of scleral-sutured posterior chamber intraocular lenses in post-traumatic eyes.

PURPOSE: To evaluate the refractive outcomes of scleral-sutured IOL 2 mm posterior to the limbus in post-traumatic eyes using SRK/T formula. METHODS: This single-center retrospective case series included 35 eyes from 35 post-traumatic patients undergoing scleral-suture of ErgomaX IOLs by a single experienced surgeon. Preoperative predicted refraction, procedure-related complications, and postoperative spherical equivalent (SE) at least 1 month after surgery were recorded. The prediction error (PE) was calculated as the difference between the postoperative SE and preoperative predicted refraction. RESULTS: Of the 35 post-traumatic patients, 28 patients were aphakia without capsular support, and 7 patients were traumatic lens dislocation or subluxation. The mean age at surgery was 56.03 ± 14.56 years and 28 patients were men (80%). The mean postoperative spherical equivalent (SE) and postoperative astigmatism were - 1.23 ± 0.82 D and 1.57 ± 1.14 D, respectively. The mean prediction error (ME) of SRK/T formula was - 0.17 D. The mean absolute error (MAE) was 0.48D. The prediction accuracy was 60.0% for refractive errors of ± 0.50 D and 85.7% for refractive errors of ± 1.00D. Multiple linear regression analyses revealed that IOL power has positive correlation with PE. CONCLUSION: Assumption of in-the-bag IOL position when calculating IOL (52501TY, ErgomaX) power for standardizing scleral-sutured IOL 2 mm posterior to the limbus demonstrates acceptable refractive outcomes. The accuracy of IOL power calculation using the SRK/T formula for eyes needing low IOL power or high IOL power may be affected by the uncertain position of postoperative IOL and further studies are needed.

Application and comparison of active and transfer learning approaches for modulation format classification in visible light communication systems.

Automatic modulation classification (AMC) is a crucial part of adaptive modulation schemes for visible light communication (VLC) systems. However, most of the deep learning (DL) based AMC methods for VLC systems require a large amount of labeled training data which is quite difficult to obtain in practical systems. In this work, we introduce active learning (AL) and transfer learning (TL) approaches for AMC in VLC systems and experimentally analyze their performances. Experimental results show that the proposed novel AlexNet-AL and AlexNet-TL methods can significantly improve the classification accuracy with small sizes of training data. To be specific, using 60 labeled samples, AlexNet-AL and AlexNet-TL increase the classification accuracy by 6.82% and 14.6% compared to the result without AL and TL, respectively. Moreover, the use of data augmentation (DA) operation along with our proposed methods helps achieve further better performances.

Reversed scleral tunnel technique for repair of iridodialysis after blunt force trauma: a retrospective clinical study.

BACKGROUND: To investigate the efficacy and safety of reversed scleral tunnel technique for repairing iridodialysis after blunt force trauma. METHODS: A total of 51 eyes of 51 patients with iridodialysis undergoing surgery were included in this study. Patients were divided into 2 groups: group A (the reversed scleral tunnel technique) and group B (the control group). Before the procedure and at 1, 3, and 6 months afterward, data on the patients' age, gender, treatments, diagnosis, mechanism of injury, best-corrected visual acuity (BCVA), intraocular pressure (IOP), degree of iridodialysis, lens status, concomitant ocular damage, number of sutures, complications, and follow-up time were collected and compared between the 2 groups. RESULTS: Iridodialysis was repaired and the pupil shape was restored to nearly round in all eyes. Standard phacoemulsification or lens removal was performed in all eyes. A final BCVA ≥20/60 was achieved in 13 eyes (48.1%) in Group A and 13 eyes (54.2%) in Group B. The IOP remained stable during the follow-up period in all eyes except 2 eyes (7.4%) in Group A and 3 eyes (12.5%) in Group B with angle recession. There were no statistically significant differences in BCVA and IOP between group A and group B. Intraoperatively, A significantly lower percentage of extensive subconjunctival hemorrhage occurred in Group A compared to Group B (1 eye versus 24 eyes, χ2 = 47.1, P = 0.00). Hyphema was observed in 2 eyes (7.4%) in Group A and 1 eye (4.2%) in Group B. Postoperatively, two eyes (7.4%) in Group A and 2 eyes (8.3%) in Group B developed retinal detachment. No other complications were noted during the follow-up period. CONCLUSIONS: The reversed scleral tunnel technique is a safe and effective approach for repairing iridodialysis after blunt force trauma with few complications, favorable cosmetic and visual outcomes.

SILICONE OIL-FILLED FOLDABLE CAPSULAR VITREOUS BODY VERSUS SILICONE OIL ENDOTAMPONADE FOR TREATMENT OF NO LIGHT PERCEPTION AFTER SEVERE OCULAR TRAUMA.

PURPOSE: To compare the anatomical and functional outcomes of silicone oil (SO)-filled foldable capsular vitreous body (FCVB) and SO endotamponade in vitrectomy for patients with no light perception after ocular trauma. METHODS: A total of 64 patients (64 eyes) with no light perception caused by severe ocular trauma were divided into FCVB and SO groups based on the surgical treatment. The main outcome measurements were retinal reattachment rate, intraocular pressure, best-corrected visual acuity, and number of operations. RESULTS: Both the FCVB group (29 eyes) and the SO group (35 eyes) showed significant improvement in postoperative best-corrected visual acuity and intraocular pressure. The two groups showed no significant differences in final intraocular pressure and the retinal reattachment rate. The postoperative vision (≥LP) in the FCVB group was significantly worse than in the SO group (FCVB [4/29] vs. SO [18/35], P = 0.003). However, the number of surgeries in the FCVB group was significantly lower than in the SO group (FCVB [1.10] vs. SO [2.23], P < 0.001). CONCLUSION: Vitrectomy combined with SO endotamponade shows better short-term improvement in the treatment of no light perception caused by severe ocular trauma. However, SO-filled FCVB can effectively prevent many complications caused by direct SO endotamponade, such as secondary surgeries or SO dependence.

Internal Limiting Membrane Peeling versus Nonpeeling to Prevent Epiretinal Membrane Formation following Vitrectomy for Posterior Segment Open-Globe Injury.

PURPOSE: Approximately 30% of patients with an open-globe injury (OGI) develop a secondary epiretinal membrane (ERM). This study was performed to assess whether internal limiting membrane (ILM) peeling in the treatment of posterior segment OGI prevents ERM formation. METHODS: The medical records of 33 patients who underwent vitrectomy for posterior segment OGI from 2016 to 2019 were retrospectively analyzed. Of these patients, 17 underwent ILM peeling during the vitrectomy and 16 did not. The patients' demographic and surgical data were collected. The associations of ILM peeling with the preoperative findings of posterior segment OGI and development of a postoperative ERM were analyzed. Student's t-test was used to evaluate differences in continuous variables, and the chi-squared test or Fisher's exact test was used for categorical variables. Time-to-event curves were calculated from postestimation Cox proportional hazards models. RESULTS: An ERM developed in three eyes (17.6%) in the ILM peeling group and in eight eyes (50.0%) in the nonpeeling group (p < 0.05). There was no statistically significant difference between the groups in visual acuity at baseline (1.68 vs. 1.58 logMAR, p=0.68) or at final follow-up (0.72 vs. 0.78 logMAR, p=0.66). Median visual acuity significantly improved in both groups (p < 0.001). In the multivariable models, ILM peeling (odds ratio, 0.19; 95% confidence interval, 0.04-0.91; p=0.04) and worse preoperative vision (odds ratio, 0.29; 95% confidence interval, 0.10-0.80; p=0.02) were associated with lower likelihood of ERM formation. CONCLUSION: Preventative treatment with ILM peeling contributed to decreased development of an ERM in patients with OGI involving areas near the fovea.

Multi-user accessible indoor infrared optical wireless communication systems employing VIPA-based 2D optical beam-steering technique.

Infrared optical wireless communication system can achieve ultrahigh capacity and high privacy data transmission. However, for using narrow infrared laser beam as carrier to transmit signal, the high-speed data transmission can only be achieved by point-to-point connection. With the rapid number increasement of consumer electronic devices, such connection method puts a heavy burden on the number of transmitters. Thus, the transmitting end with the point-to-multipoint capability or multi-user accessibility is required. In this paper, we present a multi-user accessible indoor infrared optical wireless communication system employing passive diffractive optics based on a virtually imaged phased array (VIPA). Multiple beams can be generated in a point-to-multipoint scheme by using VIPA-based beam-steering antenna (BSA). On the other hand, by tuning wavelength of laser source, fast 2D steering of multiple beams with the same steering trajectory is supported, which can be used for user ends with changing locations. In the experiment, 5 beams are generated by utilizing only one transmitter. All five beams can realize 12.5 Gb/s on-off-keying (OOK) data rate transmission. Free-space optical wireless transmission at 3.6-m communication distance is demonstrated for system performance verification and evaluation. a total 3.44°×7.9° scanning field of view of five beams is achieved.

COMPARING VITRECTOMY, SILICONE OIL ENDOTAMPONADE WITH/WITHOUT CYCLOPEXY TO TREAT CYCLODIALYSIS CLEFTS WITH SEVERE OCULAR TRAUMA.

PURPOSE: Comparing the anatomical and functional outcomes of vitrectomy, silicone oil endotamponade without cyclopexy (VEWOC) and with cyclopexy (VEWC) in patients with traumatic cyclodialysis clefts and severe ocular comorbidities. METHODS: A total of 55 patients (55 eyes) with traumatic cyclodialysis clefts were divided into VEWOC and VEWC groups according to the surgery undergone. Besides the cyclodialysis clefts, all study eyes had one or more additional conditions caused by severe ocular trauma: cataract, lens dislocation, vitreous hemorrhage, retinal detachment, choroidal detachment, maculopathy, suprachoroidal hemorrhage, subretinal hemorrhage, or proliferative vitreoretinopathy. The minimum postoperative follow-up period for all patients was six months. The main measures of outcome were rate of successful anatomical repair, intraocular pressure, and best-corrected visual acuity. RESULTS: Both the VEWOC group (33 eyes) and the VEWC group (22 eyes) showed significant improvement in postoperative best-corrected visual acuity and intraocular pressure at the final follow-up. The groups had no significant differences in terms of anatomical success rates (VEWOC 29/33 vs. VEWC 20/22, P = 1.000), final best-corrected visual acuity (VEWOC 1.60 ± 0.76 [median Snellen acuity: counting fingers, range: light perception to 20/20] vs. VEWC 1.46 ± 0.66 [median Snellen acuity: 20/800, range: light perception to 20/32], P = 0.485), and final intraocular pressure (VEWOC 13.40 [8.20-17.80] vs. VEWC 11.40 [6.65-14.00] mmHg, P = 0.311). However, the intraocular pressure on postoperative Day 1 was significantly different between the groups (VEWOC 10.40 [6.40-14.60] vs. VEWC 6.40 [4.70-7.98] mmHg, P = 0.002). CONCLUSION: This study showed that both surgical approaches were equally effective in treating cyclodialysis clefts secondary to severe ocular trauma. Therefore, it may be unnecessary to perform cyclopexy in addition to the vitrectomy procedure in such cases.

Vitrectomy with Air Endotamponade for Traumatic Cyclodialysis.

BACKGROUND: Various techniques have been described for repairing cyclodialysis clefts, but there is no consensus regarding the optimal treatment. This study investigated the clinical efficacy of a novel surgical approach that is used to manage traumatic cyclodialysis. METHODS: We prospectively enrolled 7 patients (7 eyes) with traumatic cyclodialysis of the concomitant lens and other vitreous diseases. Ultrasound biomicroscopy was used to diagnose cyclodialysis, and all eyes underwent pars plana vitrectomy with air endotamponade. The main outcome measures were postoperative anatomical success rates, best-corrected visual acuity (BCVA), and intraocular pressure (IOP). RESULTS: All patients were male, and their age ranged from 46 to 64 years (mean: 54.3 years). After the surgical intervention, the extent of the cyclodialysis cleft ranged from 1 to 4 clock hours (mean: 2.3 clock hours) and the detached ciliary body of all cases was completely restored; the anatomical success rate was 100%. The BCVA significantly increased from 1.40 ± 0.49 to 0.42 ± 0.31 (P = 0.002). The IOP increased from 8.91 ± 1.77 to 14.67 ± 6.38, but the difference was not significant (P = 0.056). The postoperative IOP of most patients was temporarily elevated or lowered after surgery. At the last follow-up, there were still two abnormal cases, including one with ocular hypertension and one with hypotony. CONCLUSIONS: This study revealed that vitrectomy with air endotamponade is an effective and minimally invasive alternative surgical approach for small traumatic cyclodialysis clefts.

Risk Factors for Residual Vitreous Cortex at the Fovea after Posterior Vitreous Detachment during Vitrectomy in Ocular Trauma.

PURPOSE: To investigate the frequency and patterns of the residual vitreous cortex (RVC) at the fovea after posterior vitreous detachment (PVD) during vitrectomy after ocular trauma and the risk factors associated with its occurrence. METHODS: A cross-sectional, multicenter, and observational study was conducted in 72 consecutive patients who underwent pars plana vitrectomy after ocular trauma. In patients with PVD after vitrectomy, RVC patterns were visualized using triamcinolone acetonide staining and were classified as diffuse or focal. A multivariate logistic regression analysis was performed to evaluate the association between RVC and various factors, such as the patient's age, preoperative visual acuity, days after injury, the existence of spontaneous PVD, and the type of injury prior to vitrectomy. RESULTS: Of the 72 eyes with trauma, 35 eyes (48.6%) showed RVC on the macula, of which 19 (54.3%) were of the diffuse type and 16 (45.7%) were of the focal type. A multivariate logistic regression analysis showed that age (OR = 0.933, P=0.025) and days after injury (OR = 0.862, P=0.013) had a significant impact on RVC. CONCLUSIONS: RVC at the fovea is very common after spontaneous or surgical PVD during vitrectomy. Younger patients are more likely to show RVC if vitrectomy is performed soon after injury.

Suturing technique for scleral fixation of toric intraocular lens in the traumatic aphakic eye with corneal astigmatism.

PURPOSE:: To describe the clinical outcomes of traumatic aphakic eyes with corneal astigmatism after using a novel technique for toric intraocular lens suture fixation. METHODS:: In total, 12 eyes of 12 patients who underwent a new scleral suture fixation technique of one-piece toric intraocular lens (SN6AT series, Alcon Inc., TX, USA) were included in our retrospective study. Preoperative patient status, postoperative visual acuity and refractive outcomes, postoperative intraocular lens rotation, tilt, decentration, and complications were analyzed. RESULTS:: The mean follow-up was 11.6 ± 1.0 months. The mean preoperative best-corrected visual acuity was 0.55 ± 0.32 in the logarithm of minimum angle of resolution equivalent; the postoperative best-corrected visual acuity was 0.45 ± 0.34. The mean preoperative total corneal astigmatism was 2.51 ± 1.67 D. The mean postoperative residual astigmatism was 0.77 ± 0.54 D. The mean intraocular lens rotation was 3.33° ± 1.37° (range, 1°-6°). The mean intraocular lens tilt in horizontal direction was 3.64° ± 1.02° (range, 2.6°-6.3°) and in vertical direction it was 3.19° ± 1.07 ° (range, 1.6°-5.2°). The mean intraocular lens decentration in horizontal direction was 0.14 ± 0.03 mm (range, 0.089-0.192 mm) and in vertical direction it was 0.15 ± 0.02 mm (range, 0.113-0.181 mm). One patient had mild vitreous hemorrhage and two other patients had high postoperative residual sphere and astigmatism, respectively. But no other serious complications were observed. CONCLUSION:: Scleral suture fixation of foldable toric intraocular lens to correct corneal astigmatism can be a safe and effective alternative technique to manage traumatic aphakic eyes that lack adequate capsular support.

Surgical removal of subfoveal perfluorocarbon liquid using combined flute needle and vacuum aspiration in silicone oil-filled eyes: A novel technique to remove subfoveal PFCL.

We report a procedure using a pressure-controllable flute needle to remove subfoveal retention of perfluorocarbon liquid (PFCL) under silicone oil. With a two-port pars plana approach, we used a 27-gauge dental injection needle to create a retinotomy at the farthest edge of the PFCL bubble from the fovea. A 27-gauge flute needle was then inserted into the edge of the subfoveal PFCL to aspirate it with vacuum pressure. Three patients with subfoveal retained PFCL were treated by this procedure within silicone oil tamponade 1 month after the first operation. They promptly underwent successful removal of the PFCL with postoperative retinal reattachment and good visual outcome. This procedure allows safe and early treatment for subfoveal retained PFCL. Many medical institutions around the world could implement this procedure using common dental injection needles and flute needles.

Treatment of Bacillus cereus endophthalmitis with endoscopy-assisted vitrectomy.

To evaluate the use of endoscopy-assisted vitrectomy in patients with sight-threatening Bacillus cereus endophthalmitis.A retrospective analysis was conducted in 15 eyes with Bacillus cereus endophthalmitis. Patients were divided into 2 groups: endoscopy-assisted vitrectomy (5 eyes) and conventional vitrectomy (10 eyes). The following clinical data were recorded and analyzed: sex, age, latent period, symptom duration, follow-up time, visual acuity pre- and postsurgery, recurrence of endophthalmitis, incidence of phithisis bulbi, and incidence of enucleation.In the conventional vitrectomy group, postoperative visual acuity ranged from no light perception in 5 patients (50%), light perception in 3 patients (30%), 20/1000 in 1 patient (10%), and 20/50 in 1 patient (10%). In the endoscopy-assisted vitrectomy group, postoperative visual acuity ranged from no light perception in 2 patients (40%), light perception in 1 patient (20%), and hand movements in 2 patients (40%). There was no statistically significant difference between the 2 groups in terms of the final postoperative visual acuity (F = 0.006, P = .937). There is no difference between the 2 groups in terms of the incidence of enucleation. The median symptom duration was 4 hours (range: 2-6 hours) in the conventional group and 9 hours (range: 7-11 hours) in the endoscopy-assisted vitrectomy group. The difference in the symptom duration between the 2 groups was statistically significant (P = .002).There is no statistical significant difference between the 2 groups in terms of visual acuity and incidence of enucleation. Therefore, endoscopy-assisted vitrectomy can be considered as an alternative treatment for treatment of B cereus endophthalmitis particularly for cases when symptom duration was more than 6 hours.

Iris reconstruction combined with iris-claw intraocular lens implantation for the management of iris-lens injured patients.

AIM: To study the efficiency and safety of iris reconstruction combined with iris-claw intraocular lens (IOL) implantation in the patients with iris-lens injuries. SETTINGS AND DESIGN: Retrospective, noncomparable consecutive case series study. MATERIALS AND METHODS: Eleven patients (11 eyes) following iris-lens injuries underwent iris reconstructions combined with iris-claw IOL implantations. Clinical data, such as cause and time of injury, visual acuity (VA), iris and lens injuries, surgical intervention, follow-up period, corneal endothelial cell count, and optical coherence tomography, were collected. RESULTS: Uncorrected VA (UCVA) in all injured eyes before combined surgery was equal to or <20/1000. Within a 1.1-4.2-year follow-up period, a significant increase, equal to or better than 20/66, in UCVA was observed in six (55%) cases, and in best-corrected VA (BCVA) was observed in nine (82%) cases. Postoperative BCVA was 20/40 or better in seven cases (64%). After combined surgery, the iris returned to its natural round shape or smaller pupil, and the iris-claw IOLs in the 11 eyes were well-positioned on the anterior surface of reconstructed iris. No complications occurred in those patients. CONCLUSIONS: Iris reconstruction combined with iris-claw IOL implantation is a safe and efficient procedure for an eye with iris-lens injury in the absence of capsular support.

A novel method for the localization and management of traumatic cyclodialysis cleft.

Purpose. To propose a novel surgical method for the localization and management of traumatic cyclodialysis clefts. Methods. Five patients with traumatic cyclodialysis clefts who underwent the innovative surgery were retrospectively reviewed. The new method was introduced to repair a cyclodialysis cleft with two running sutures from the middle to each end of the cleft under the guidance of a probe. Preoperative and postoperative visual acuity (VA), intraocular pressure (IOP), slit lamp and gonioscopic results, ultrasound biomicroscopy (UBM), and optical coherence tomography (OCT) findings were recorded. Results. Cyclodialysis clefts were completely closed postoperatively in four patients (four eyes); this was confirmed by progressively improved VA, restoration into the normal range of the IOP, disappearance of suprachoroidal fluid, and reduced macular edema. Only one patient with multiple clefts had an incomplete reattachment. Conclusions. This clinical study offers a novel and efficient method to localize and repair the cyclodialysis clefts.

Anterior and pan-endophthalmitis caused by Candida albicans and Aspergillus fumigatus: report of two cases.

We report two posttraumatic fungal endophthalmitis cases with anterior and entire segment involvement caused, respectively, by Candida albicans and Aspergillus fumigatus. The anterior endophthalmitis induced by C. albicans presented multifocal lesions with hyphael structures in anterior chamber, but without involvement of posterior vitreous. The pan-endophthalmitis caused by A. fumigatus displayed significant hypopyon and vitritis. Treatment strategies are anterior chamber cleaning for anterior endophthalmitis and vitrectomy for pan-endophthalmitis, excepting systemic and topical antifungal drug applications including intravitreal injection for both types of endophthalmitis. There is a much better outcome in the case with anterior segment involvement than that with entire segment involvement. This case report provides evidence that the different types of posttraumatic fungal endophthalmitis related to different fungal infections indeed existed and should be managed with different strategies.

Vitrectomy and internal limiting membrane peeling with perfluoropropane tamponade or balanced saline solution for myopic foveoschisis.

PURPOSE: The purpose of the study was to evaluate visual and anatomical outcomes in patients with myopic foveoschisis who underwent vitrectomy and internal limiting membrane (ILM) peeling with perfluoropropane (C3F8) tamponade or balanced saline solution in the vitreous cavity. METHODS: Retrospective comparison of a consecutive surgical series. Eighteen eyes of 17 patients scheduled for myopic foveoschisis surgery were recruited at the affiliated Eye Hospital of Wenzhou Medical College, Zhejiang, China. Pars plana vitrectomy and ILM peeling with indocyanine green staining were performed in all patients. Refractive lens exchange was simultaneously performed in 12 phakic eyes. Finally, the vitreous cavity was filled with balanced saline solution in seven eyes of seven patients (Group A). Fluid-air exchange was performed in another 11 eyes of 11 patients (Group B), followed by injection of 18% C3F8. Patients were evaluated using best-corrected visual acuity (BCVA) testing and optical coherence tomography scans. RESULTS: All patients completed more than 6 months of follow-up. In two groups, preoperative factors were not significantly different. In Group B, the postoperative BCVA was significantly greater than the preoperative BCVA (t = 4.401, P = 0.001) but not significantly different in Group A (t = 1.970, P = 0.096). The BCVA change in Group B was significantly greater than Group A at the last visit (Z = 2.23, P = 0.025). In both groups, the BCVA change was significantly correlated with the preoperative BCVA, respectively. The BCVA was improved by 0.2 logarithm of the minimum angle of resolution or more in 10 eyes (91%) in Group B and 4 eyes (56%) in Group A. All eyes in both groups did not have decreases in the postoperative BCVA. In 3 months after vitrectomy, 6 eyes in Group A did not have anatomical resolutions. However, it was interesting to see that the height of retinoschisis at the central macular region gradually decreased until anatomical resolution was achieved. In Group B, all eyes had anatomical resolutions in 3 months after vitrectomy. None of the eyes developed macular hole during the surgery and the period of routine follow-up period. CONCLUSION: Vitrectomy with ILM peeling does not increase the risk of iatrogenic macular hole formation. The poor elasticity of the ILM and the traction of membranous structure on the surface of the ILM play important roles in the development of myopic foveoschisis. In eyes undergoing vitrectomy and ILM peeling for myopic foveoschisis, C3F8 tamponade results in more rapid anatomical resolution and greater improvement in BCVA than balanced saline solution.

Endoscopic Vitrectomy for Severe Posttraumatic Endophthamitis with Visualization Constraints.

For the following two cases with severe traumatic endophthamitis, a standard three-port pars plana vitrectomy was unavailable due to poor visualization of the anterior ocular segment. Endoscopic vitrectomy was elected to treat severe endophthalmitis successfully. Endoscopic vitrectomy for severe traumatic endophthalmitis is not only feasible and effective but also has the greatest degree of decrease in damaging eyeball integrity. Hence it is favorable to the restoration of ocular function and shape.

Trochlear calcification and intraorbital foreign body in ocular trauma patients.

OBJECTIVE: To distinguish trochlear calcification and intraorbital foreign body after eye injury in order to avoid misdiagnosis as well as mistreatment. METHODS: The orbital CT images of 403 patients, who visited the Eye Hospital or the Second Affiliated Hospital of Wenzhou Medical College during May 2005-April 2007, were reviewed. The diagnosis of trochlear calcification and intraorbital foreign body was made together by a skilled radiologist as well as an ophthalmologist. General information and CT characteristics in the patients with trochlear calcification were collected. RESULTS: Using CT scan images, 27 among 403 patients (6.69%) were identified with trochlear calcification. Three patients (3/27, 11.11%) were misdiagnosed by radiologists as intraorbital foreign body. Among the 27 patients with trochlear calcification, 23 (85.19%) were male and 4 (14.81%) were female, with an unilateral calcification in 7 patients (7/27, 25.93%) and bilateral in 20 (74.07%) . The highest occurrence of trochlear calcification was in 31-40 years old group (13/403, 3.23%) which reached to 12.87% (13/101) after age-correction. There were 3 types of trochlear calcification on the basis of CT images: commas, dot and inverted "U". CONCLUSIONS: The trochlear calcification is not an uncommon phenomenon and should not be diagnosed as intraorbital foreign body, especially when it co-exists with eye injury in 31-40 years old group. Injury history and our classification method on the basis of CT images could help to avoid misdiagnosis.