[LOWER EYELID BLEPHAROPLASTY].

INTRODUCTION: Eyelid blepharoplasty, including lower eyelid blepharoplasty, are among the most common aesthetic surgeries recently performed. In contrast to upper eyelid blepharoplasty, lower eyelid blepharoplasty is a surgery with mostly an aesthetic indication, in which patients bear all associated costs, and their expectations rise accordingly. Nevertheless, the complexity of the anatomy, the differences in the aging processes of the face and eyelids between patients, the diversity of surgical methods, and the expectations gap make the surgery more challenging in comparison to upper eyelid blepharoplasty. A comprehensive understanding of the eyelid anatomy and the surrounding tissues, as well as matching expectations alongside with thorough preoperative evaluation, are all essential for providing a more personal adjustment of the surgical method and avoiding complications and mental distress for both patients and surgeons. This article briefly reviews the anatomy and aging processes of the lower eyelids, the main surgical approaches, and their common complications. Moreover, we present a framework for how such complications can be avoided.

[OPHTHALMOLOGY - ON THE TIP OF THE SPEAR].

INTRODUCTION: Ophthalmology is a broad branch of medicine, which includes an extensive range of sub-specialties on one hand, and interfaces with other fields of medicine on the other. This issue contains papers from different sub-specialties of ophthalmology, that together cover several of the most important issues in this field. These papers present the topics in a manner compatible with the wide readership of the journal, and touch upon the most current updates and innovations. The original articles in this issue deal with treatments for the prevention of myopia progression in children, treatment of complicated cases of retinal detachment in children, ocular manifestations of vascular abnormalities in patients with coronavirus, and a series of patients with corneal damage due to ultraviolet-C (UVC) lamps intended to clear the air of this virus. The review papers describe glaucoma and the current change in its treatment paradigm, which focuses on earlier intervention, ocular manifestations of systemic autoimmune diseases, and the possibilities for artificial corneal implantation. We hope that this special issue will be of interest and clinical value to its readers.

Post-Intravitreal injection pain reduction using topical NSAIDS: A comparative study.

PURPOSE: To compare the efficacy of two different topical non-steroidal anti-inflammatory drugs (NSAIDs) drops with versus without conservatives after intravitreal injections (IVIs). DESIGN: Prospective, randomized, placebo-controlled, single-blinded comparative study. PARTICIPANTS AND METHOD: A total of 308 eyes of 252 patients receiving an IVI of anti-vascular endothelial growth factor (anti-VEGF) were randomly assigned to receive either a single drop of nepafenac 0.1%, preservative-free diclofenac 0.1%, or artificial tears (control group) immediately after IVI. Primary outcome measure was pain scores immediately, six hours and twenty-four hours post- injection. RESULTS: 166 patients received one topical drop of NSAIDS, of which 90 in the diclofenac group and 76 in the nepafenac group. Additional 86 patients were included in the control group. Mean reported pain score was significantly lower at six hours after IVI in the preservative-free diclofenac group (17.1 ± 23.0) than in the nepafenac group (26.2 ± 31.9) and the control group (27.5 ± 29.2) (p = 0.03). At twenty-four hours post-injection there was no statistically significant difference between the groups. Patients reported less pain compared to previous IVIs and none referred to urgent health care, but these findings were not statistically significant. CONCLUSIONS: The use of topical preservative-free NSAIDs may be superior to preservative- containing NSAIDs in pain relief after IVIs and may be considered as part of the treatment protocol of this population.

SYRINGE DESIGN AND FILLING TECHNIQUE AFFECT ACCURACY OF ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR INTRAVITREAL INJECTIONS.

PURPOSE: To evaluate the effect of syringe design and filling technique on the accuracy of anti-vascular endothelial growth factor delivery. METHODS: Volume output was measured with three syringe designs: a 1.0-mL slip-tip syringe, a 1.0-mL Luer-lock syringe, and a ranibizumab prefilled syringe-using two filling techniques ("upward" and "downward") and two fluids (water and bevacizumab). A total of 300 simulated injections were performed. Accuracy was determined by difference from the intended volume of 50 µ L and by mean absolute percentage error. RESULTS: Volume outputs were significantly different between syringe designs, with mean values of 61.99 ± 4.18 µ L with the 1-mL slip-tip syringe, 57.43 ± 4.95 µ L with the Luer-lock 1-mL syringe, and 51.06 ± 4.74 µ L with the ranibizumab syringe, making the latter the most accurate syringe. There were 37 cases (12.3%) of underdosing below 50 µ L, the majority of which occurred with the ranibizumab syringe. The "downward" technique reduced the occurrence of air bubbles. CONCLUSION: Intravitreal injections using 1.0-mL syringes are less accurate than using the ranibizumab prefilled syringe, which has a low-volume and low dead-space plunger design. The variability in volume output may result in less predictable treatment response, especially in cases of underdosing, which were more common with the ranibizumab syringe.

Assessment of long-term visual outcomes in aphakic children wearing scleral contact lenses.

BACKGROUND: Timely management of aphakic children is critical for the rehabilitation of adequate visual gain. This study aims to evaluate the long-term efficacy of scleral contact lenses in terms of visual outcomes, complications, and compliance in aphakic children. METHODS: Retrospective data review of children with congenital or acquired cataract, or subluxated crystalline lenses, who underwent lensectomy from 2004 to 2018 and who used scleral contact lenses for refractive correction. Collected data from the follow up period included recorded aphakic refraction and visual acuity, complications following scleral contact lens wear documented in the clinic and ophthalmic emergency room and compliance to lens wear according to parental feedback on every visit in the clinic. RESULTS: 76% of cases, with final best corrected visual acuity (BCVA) of 20/40 or better achieved in seventeen eyes (34%). The rate of amblyopia was 50%. Strabismus developed in 56% of children, and those had less favourable visual outcomes (0.43 ± 0.4 LogMAR without strabismus and 0.8 ± 0.5 LogMAR with strabismus, p = 0.015). No corneal infections were documented during the follow up. Main adverse effect on the ocular surface was superficial punctate keratopathy (n = 16). Compliance was good in 48 children (96%)- except for two cases, the scleral lenses were tolerated well by all children. CONCLUSION: Scleral contact lenses are an effective means of visual rehabilitation in aphakic children after lensectomy and may be used long-term with good compliance of wear, excellent visual outcomes, and tolerable adverse events.

The 100 most cited papers on amblyopia: a bibliographic perspective.

AIM: To analyze the top 100 most cited papers related to amblyopia. METHODS: A bibliographic search in the Institute for Scientific Information Web of Knowledge across 55 years was performed. RESULTS: Eighty-nine of the 100 papers were published in first-quartile journals. Half (50) of the senior authors were from the USA. Most papers dealt with clinical science (72) and included original research (84). Forty-two of the articles related to all three types of amblyopia (refractive, strabismic and deprivation). Thirty-four related to both strabismic and refractive amblyopia. Around two-thirds of the papers dealt with treatment (34) and pathophysiology (30). Almost a quarter (23%) of the papers were multicenter studies. Nearly half (48) of the papers were published between 2000 and 2010. The Pediatric Eye Disease Investigator Group (PEDIG) published the highest number of studies (11), which dealt more with treatment (p = 0.01) and had higher average number of citations per years (p = 0.05). A larger number of articles on the treatment of amblyopia are newer (p = 0.01). There was no correlation between the time of their publication and the number of citations (p = 0.68, r = 0.042). CONCLUSIONS: Half of the papers were published between 2000 and 2010 and were spearheaded by PEDIG. Most papers dealt with treatment and pathophysiology. This study provides an important historical perspective, emphasizing the need for additional research to better understand this preventable and curable childhood vision impairment.

Polypoidal choroidal vasculopathy-characteristics and response to treatment with bevacizumab in caucasian patients.

PURPOSE: To investigate the features and treatment response in Caucasian patients with polypoidal choroidal vasculopathy (PCV), initially treated with bevacizumab. METHODS: 45 eyes of 43 treatment-naïve patients with PCV were included in this retrospective study, all uniformly initially treated with three bevacizumab injections monthly. OCT characteristics and clinical parameters were recorded and analyzed at presentation, after the initial 3 bevacizumab injections and at the final follow up period. RESULTS: Following 3 monthly bevacizumab injections visual acuity significantly improved with a mean gain of one line of vision. Central macular thickness (CMT) significantly improved from a mean of 402.1 ± 130.8 µm at presentation to 322.0 ± 96.8 µm (p < 0.01). Subretinal fluid, intraretinal fluid and submacular hemorrhage significantly improved. 53% were later switched to aflibercept and showed better response in the central macular thickness in comparison to those in which bevacizumab injections were continued. No correlation was found between the presence of pachyvessels or increased choroidal thickness and the improvement in VA or CMT. CONCLUSION: Fixed first-line treatment with intravitreal bevacizumab monotherapy in non-Asian PCV patients achieves satisfactory visual and anatomical outcomes.

The 100 most cited papers on retinal detachment: a bibliographic perspective.

The 100 most cited papers on retinal detachment (RD) were analysed using a bibliographic study. The bibliographic databases of the ISI Web of Knowledge were searched, limited to research articles published between 1965 and 2020 in peer-reviewed journals. The papers were ranked in order of number of citations since publication. Ninety of the 100 most cited papers on RD were published in 12 ophthalmology journals, with 74 of them published in American Journal of Ophthalmology (n=31), Ophthalmology (n=23), Archives of Ophthalmology (n=10) and Investigative Ophthalmology and Visual Science (n=10); the remaining 10 papers were published in 8 journals from other fields of medical research. All papers in the top 100 were published in English. The 100 most cited papers on RD originated from 12 different countries, with the majority (72 papers) originating from the USA. The 100 identified papers represent a mix of clinical trials and animal/laboratory studies. This bibliographic study provides a unique perspective and insight into some of the most influential contributions in RD understanding and management over the last 55 years.

The Effect of Syringe-Filling Technique on the Risk for Endophthalmitis after Intravitreal Injection of Anti-VEGF Agents.

PURPOSE: This study aimed to compare the risk for post-injection endophthalmitis between different anti-vascular endothelial growth factor (VEGF) agents and syringe preparation techniques. METHODS: A retrospective study of anti-VEGF injections performed in 3 large ophthalmology departments between 2013 and 2019 was conducted. Injections were categorized according to the drug and the syringe-filling technique - prefilling by a hospital pharmacy, prefilling by a good manufacturing practice (GMP) pharmacy, self-drawing from the vial by the injecting physician, and use of a prefilled syringe. Cases of endophthalmitis were identified, and their rates were analyzed. RESULTS: A total of 197,402 injections were included, and 53 cases of endophthalmitis were identified (0.027% risk). The risk of endophthalmitis following injections with syringes that were prefilled by GMP pharmacies or the manufacturers was significantly lower than that following injections which were self-drawn by the physician (0.019% vs. 0.055%, p < 0.0001). For ranibizumab, risk of endophthalmitis decreased since it became available in a prefilled syringe (0.054% vs. 0.014%, p = 0.066), bordering on statistical significance. CONCLUSIONS: The syringe-filling technique is an important factor determining risk of post-injection endophthalmitis. Use of GMP-grade prefilling by professional pharmacies or the manufacturers significantly reduces this risk and should be the technique of choice for all drugs administered by intravitreal injection.

Treatment of Neovascular Age-Related Macular Degeneration: An Economic Cost-Risk Analysis of Anti-Vascular Endothelial Growth Factor Agents.

PURPOSE: To find the best cost-effective neovascular age-related macular degeneration (nAMD) treatment to improve vision while avoiding complications. The model is based on a cost-risk tradeoff analysis from policymakers' perspective. DESIGN: A powerful and flexible simulation modeled outcomes of 2 years of treatment with the 4 commonly used anti-vascular endothelial growth factor drugs (bevacizumab, ranibizumab, aflibercept, and brolucizumab) across 3 injection protocols, building on prior findings that these drugs are noninferior. The model incorporates blinding complications, their management, and associated costs to society. Each option and several what-if scenarios were simulated 1,000 times with 100,000 hypothetical patients. PARTICIPANTS: One hundred thousand simulated patients using data from published clinical trials. METHOD: Case- and eye-specific cost-risk economic analysis. MAIN OUTCOME MEASURES: Costs of nAMD treatment per patient and number of eyes that become blind as a result of treatment over 2 years. RESULTS: Using published prices and fees, the injection protocol that follows published clinical studies, results showed that the mean±standard deviation cost per patient were $16,859 ± $3.65, $32,949 ± $3.27, $39,831 ± $3.80, and $53,056 ± $2.99 for bevacizumab, brolucizumab, aflibercept, and ranibizumab, respectively. The numbers±standard deviations of treated eyes that became blind were 108 ± 10.18, 694 ± 26.66, 168 ± 12.83, and 108 ± 10.52, respectively. We further provide a lower bound (when all patients are maximally extended) and upper bound (when no patient is extended) to these numbers. For brolucizumab, the upper bound is the 2-month interval injection protocol. CONCLUSIONS: Taking a policymaking perspective, this study suggested that bevacizumab is the preferred first-line therapy. Recommendation for second-line therapy depends on the extent of the policymaker's risk aversion because of the tradeoff between cost and risk of blindness as a result of treatment. If risk neutral, the least expensive option (brolucizumab) is preferred. But if policymakers are moderately to highly risk averse, then aflibercept or ranibizumab are preferred. Because medical advances and different costs may change our findings, we provide a free application (https://eye-inj.shinyapps.io/calc/) for readers who wish to use different cost structures. Simulating outcomes is an innovative approach, unique in ophthalmology, and presents a significant opportunity because it can be adapted easily to different settings (using different costs, risks, and protocols) and to other diseases (e.g., diabetic macular edema), to ultimately improve wide-scale decision-making and use of funds.

Optical Coherence Tomography Biomarkers Predicting Visual Acuity Change after Intravitreal Bevacizumab Injections for Macular Edema Secondary to Branch Retinal Vein Occlusion.

PURPOSE: This study aimed to identify baseline optical coherence tomography (OCT) factors in branch retinal vein occlusion (BRVO) that predict response to bevacizumab injections. METHODS: It is a retrospective case series of consecutive patients that underwent OCT at diagnosis, and the central macular thickness (CMT), extent of disorganized retinal inner layers, and outer retinal layers including external limiting membrane, ellipsoid zone (EZ), and cone outer segment tips (COST) were measured. Patients received 3 consecutive monthly injections of bevacizumab followed by pro re nata treatment. The main outcome measure was improvement in best-corrected visual acuity (BCVA) after 1 year. Results are expressed as mean ± SD, and p value <0.05 was considered statistically significant. RESULTS: Overall, 66 eyes of 66 patients, with an average age of 68.5 ± 11.4 years, were included. The mean BCVA improved significantly from 0.68 logMAR at baseline to 0.50 logMAR at 1 year (p < 0.001). Baseline logMAR BCVA (r = 0.41, p < 0.001) and CMT (r = 0.23, p = 0.04) were associated with improvement while EZ (r = -0.24, p = 0.05) and COST (r = -0.32, p = 0.01) disruption with deterioration in BCVA. CONCLUSION: In patients with naïve BRVO treated with bevacizumab, BCVA improvement at 1 year can be predicted from baseline BCVA, CMT, extent of COST disruption, and EZ disruption.

Optical Coherence Tomography Prognostic Factors in Age-Related Macular Degeneration Patients with Peripapillary Choroidal Neovascularization.

PURPOSE: The aim of the study was to investigate the correlation between optical coherence tomography (OCT) findings and visual acuity outcomes after treatment with intravitreal bevacizumab (IVB) injections for age-related macular degeneration (AMD) patients with peripapillary choroidal neovascularization (PPCNV). METHODS: The study involved a retrospective case series of consecutive patients diagnosed with PPCNV secondary to AMD. All patients were treated with IVB injections with a follow-up time of 1 year. Data collected included best-corrected visual acuity (BCVA) and automated and manually measured OCT parameters. RESULTS: A total of 68 eyes were diagnosed with PPMV. Of them, 30 eyes of 30 patients aged 84.3 ± 6.9 years of which 63.3% female gender were included. Baseline BCVA was 0.46 ± 0.62 logMAR (Snellen 20/57), average choroidal thickness was 193.2 ± 22 µm, and mean number of IVB injections was 7.2 ± 1.9. After 1 year, BCVA was 0.56 ± 0.78 logMAR (Snellen 20/72) (p = 0.28). Eyes with greater central retinal thickness (r = -0.36, p = 0.05), greater subretinal hyper-reflective material (SHRM) area (r = -0.37, p = 0.05), and greater sub-retinal fluid (SRF) area (r = -0.73, p < 0.001) had a significantly smaller improvement in BCVA. Eyes with pigment epithelium detachment (PED) (0.68 ± 0.90 vs. 0.21 ± 0.12, p = 0.03) had a significantly worse BCVA. CONCLUSIONS: Our data suggest that AMD-related PPCNV with greater foveal thickness, PED size, SHRM, and SRF areas have worse final BCVA prognosis.

Drug Delivery via the Suprachoroidal Space for the Treatment of Retinal Diseases.

The suprachoroidal space (SCS), a potential space between the sclera and choroid, is becoming an applicable method to deliver therapeutics to the back of the eye. In recent years, a vast amount of research in the field has been carried out, with new discoveries in different areas of interest, such as imaging, drug delivery methods, pharmacokinetics, pharmacotherapies in preclinical and clinical trials and advanced therapies. The SCS can be visualized via advanced techniques of optical coherence tomography (OCT) in eyes with different pathologies, and even in healthy eyes. Drugs can be delivered easily and safely via hollow microneedles fitted to the length of the approximate thickness of the sclera. SCS injections were found to reach greater baseline concentrations in the target layers compared to intravitreal (IVT) injection, while agent clearance was faster with highly aqueous soluble molecules. Clinical trials with SCS injection of triamcinolone acetonide (TA) were executed with promising findings for patients with noninfectious uveitis (NIU), NIU implicated with macular edema and diabetic macular edema (DME). Gene therapy is evolving rapidly with viral and non-viral vectors that were found to be safe and efficient in preclinical trials. Here, we review these novel different aspects and new developments in clinical treatment of the posterior segment of the eye.

Intravitreal air bubbles following intravitreal injections: a comprehensive analysis.

PURPOSE: To evaluate the prevalence of residual air bubbles following intravitreal injections of anti-VEGF agents, and to compare two techniques designed to reduce their occurrence. METHODS: Patients who received intravitreal injections reported the presence of air bubbles following the procedure, and were followed to determine when they disappeared. Two techniques used to reduce air bubbles prior to injection were compared-tapping the syringe with the needle up ("upwards" technique) or down ("downwards" technique). Rates of residual air bubbles were compared between techniques, and between different drugs. RESULTS: The study included 344 intravitreal injections, 172 injected with each technique. The overall rate of residual air bubbles was 11.3%, with 94.9% resolution by 48 h. The rate was significantly lower with the "downwards" technique (7.5% vs. 15.1%, p = 0.027). It was also significantly lower with ranibizumab injected using pre-filled syringes than with bevacizumab and aflibercept (0% vs. 12.1% and 14.7%, p < 0.0001). A questionnaire revealed patients reported medium levels of discomfort and a high importance of avoiding air bubbles. CONCLUSIONS: Residual air bubbles are a common occurrence, likely to be experienced by most patients undergoing repeated injections. This phenomenon may be significantly reduced by using the described "downwards" technique, or pre-filled syringes.

The 100 most-cited papers on age-related macular degeneration: a bibliographic perspective.

The 100 most-cited papers on age-related macular degeneration (AMD) were analysed using a bibliographic study. The bibliographic databases of the Institute for Scientific Information Web of Knowledge were searched, limited to research articles published between 1965 and 2020 in peer-reviewed journals. The papers were ranked in order of number of citations since publication. Five of the top 10 (and 3 of the top 4) papers reported randomised clinical trial results for either anti-vascular endothelial growth factor agents or nutritional supplements. Four of the top 10 papers reported genotype-phenotype associations between AMD and variants in Complement Factor H. This bibliographic study provides perspective and insight into many of the most influential contributions in the understanding and management of AMD and its evolution over time.

FULL-THICKNESS MACULAR HOLE IN AGE-RELATED MACULAR DEGENERATION PATIENTS WITH TWO DISTINCT ENTITIES: A Multicenter Study.

PURPOSE: To describe optical coherence tomography characteristics of full-thickness macular holes (FTMHs) in age-related macular degeneration patients. METHODS: A multicenter, retrospective, observational case series of patients diagnosed with age-related macular degeneration and FTMHs seen between January 1, 2009, and January 3, 2020. Clinical charts and spectral-domain optical coherence tomography images were reviewed. Optical coherence tomography findings included FTMH-inverted trapezoid or hourglass appearance, central macular thickness (CMT), complete retinal pigment epithelium and complete retinal outer retinal atrophy, and presence of pigment epithelium detachment and epiretinal membrane. The mean outcome was the morphologic and functional characterization of different subtypes of FTMHs. RESULTS: A total of 86 eyes of 85 consecutive patients, with mean age of 80.31 ± 8.06 and mean best-corrected visual acuity of 1.17 ± 0.58 logarithm of the minimal angle of resolution. Two different subtypes of FTMHs were identified: tractional and degenerative. Fifty (58%) degenerative FTMHs characterized with inverted trapezoid appearance and 36 (42%) tractional FTMHs characterized with hourglass appearance. Degenerative FTMHs presented with 66% of CMT < 240 µm, 14% of CMT > 320, and 70% of complete retinal outer retinal atrophy, in comparison with 41% of CMT < 240 µm, 42.9% of CMT > 320%, and 20% of complete retinal outer retinal atrophy in the tractional FTMH group (P = 0.002, 0.003, <0.001, respectively). The presence of epiretinal membrane and pigment epithelium detachment where significantly higher in tractional FTMHs (P = 0.02, 0.03, respectively). CONCLUSION: Degenerative and tractional FTMHs may be two distinct clinical entities. Discerning degenerative from tractional FTMHs is possible by using optical coherence tomography features including shape of the FTMHs, CMT, internal-external ratio of FTMHs, and presence of complete retinal outer retinal atrophy, pigment epithelium detachment, and epiretinal membrane.

Detection of Intraorbital Foreign Bodies Using Magnetic Resonance Imaging and Computed Tomography.

PURPOSE: We analyze the detectability of intraorbital foreign bodies (OrbFBs) of various types and sizes using computed tomography (CT) and magnetic resonance imaging using a three-Tesla machine (MRI 3 T). METHODS: An ex vivo model of sheep eyes with preserved extraocular muscles and orbital fat tissue placed in the orbital cavity of the human skull was created for this study. Foreign bodies made of four different materials - plastic, bottle glass, stone and wood - each in three different sizes (large, intermediate and small) were inserted into the soft tissue of the orbit in the extraocular space. Each orbit was scanned by CT and MRI. Images were analyzed by a senior radiologist and underwent masked review by three oculoplastic surgeons. RESULTS: Analysis of MRI and CT scans identified distinguishing characteristics for each of the four materials. This information was further integrated into a clinical algorithm. CT allowed easier identification of most of the embedded materials compared to MRI. Smaller OrbFB size was associated with lower detectability. Review of CT yielded 94.4% agreement between oculoplastic specialists in detecting OrbFbs using CT scans and allowed detection of most OrbFBs. In contrast, the overall agreement with MRI was lower: 66.7% with T1 MPRAGE, 50% with T1TSE, 88.9% with T2 TSE and 72.2% with T2 TSE FS. Plastic was the most difficult material to detect in all size categories. CONCLUSIONS: CT offers a clear advantage over MRI for detecting and localizing nonmetallic OrbFBs of all sizes, except for plastic. Plastic OrbFBs can be detected with CT depending on size but are more visible in MRI scans.

The Role of Anterior Chamber Depth on Post-operative Refractive Error After Phacovitrectomy.

PURPOSE: To investigate the effect of phacovitrectomy on the post-operative anterior chamber depth (ACD) and refractive outcomes, and to analyze the potential differences between vitreous filling with BSS, air and gas. METHODS: Patients who underwent phacovitrectomy were included in this study and invited for repeated post-operative examination including refraction and biometry at least 3 months after the surgery. Data retrieved included demographic information, indication for phacovitrectomy, surgical details, type of vitreous filling (BSS, air or gas), pre-operative and post-operative biometric data including K-readings, axial length (AL), and ACD, as well as spherical equivalent (SE) values of the target and final refraction. RESULTS: Forty-three eyes of 43 patients were included in this study, including 10 eyes filled with BSS, 18 with air and 15 with gas. The mean difference between the final measured spherical equivalent (SE) and the SE of the intended target refraction was 0.61±0.68 D (p = 0.019). Only 58.1% of eyes had a final SE within ±0.5D of the target refraction. Following surgery, AL remained unchanged, while mean pre-operative ACD increased significantly from 3.11±0.34 mm to 4.77±0.47 mm (p < 0.001). There was no difference in refractive error between the vitreous fillings and no correlation with AL or ACD. CONCLUSIONS: Phacovitrectomy is associated with lower accuracy of post-operative refraction compared to cataract surgery. This may be attributed to a significant change in ACD, influencing the effective lens position of the IOL, and may require adjustment of the pre-operative calculations.

Safety of 3 Tesla Magnetic Resonance Imaging on iStent Implants: An Ex-Vivo Study.

PRCIS: Our study shows that iStent implant does not cause significant image artifacts, heating, or displacement during magnetic resonance imaging (MRI) scan. This device can be safely used in patients undergoing MRI scans using 3 Tesla (3T) machines. PURPOSE: The iStent is a medical grade titanium implant commonly implanted in the anterior chamber angle of glaucomatous eyes in order to reduce intraocular pressure and medication burden. As many people now have these devices implanted in their eyes, the issue of their compatibility with MRI in terms of safety and interference with interpretation of these studies commonly arises. The purpose of this study is to evaluate the safety of 3T MRI scans in eyes that have undergone iStent implantation and to assess the interference of the implant to the scan interpretation. MATERIALS AND METHODS: An ex vivo model of sheep eye with an iStent and proximately placed heat detector probe was used to study changes in the temperature during MRI 3T scan. The study included 2 fresh eyes with preserved extraocular muscles and orbital fat tissue placed in the orbital cavity of a human skull. Each eye with orbital content was scanned with a 3T MRI machine. RESULTS: No displacement of the implant was observed during MRI scanning. The heat detector showed mild temperature elevation during the first minutes of the scan from 14.6 to 16.5°C. The iStent was best visualized in T2 turbo spin echo sequences and showed no significant artifacts. CONCLUSION: iStent implants did not move during the MRI scan, showed minimal interaction with the magnetic field in terms of heating and image distortion. These interactions were not strong enough to present a substantial risk to patients with this implant undergoing an MRI scan.