TANGENTIAL RETINAL DISPLACEMENT INCREASES AFTER MACULAR PUCKER SURGERY: An Apparent Nonsense.

PURPOSE: To measure the tangential retinal displacement and vision before and after macular pucker surgery and study if pars plana vitrectomy with epiretinal membrane peeling allows the reconstitution of previous anatomy or else it results in a different configuration. METHODS: Retrospective series of patients undergoing pars plana vitrectomy for epiretinal membrane, with >6-month follow-up before and after surgery, complete with best-corrected visual acuity, optical coherence tomography, M-Charts, and infrared retinography. Tangential retinal displacement between earliest visit (T E ), time of surgery (T 0 ), and latest available visit (T L ) of the examined retina, concentric circles at 0.5, 1.5, and 4.5 mm radii, and the central horizontal and vertical meridians were measured. Tangential displacement was calculated as the optical flow of consecutive infrared photographs. RESULTS: The study comprised 32 patients: 15 men and 17 women. Average preoperative and postoperative follow-up were 23.4 ± 27.9 months and 19.2 ± 11.8 months, respectively. Best-corrected visual acuity reduced before surgery (0.69 ± 0.16 Snellen to 0.46 ± 0.17; P < 0.001) and increased after (0.866 ± 0.16 Snellen; P < 0.001). Horizontal and vertical metamorphopsia increased between before surgery but only horizontal metamorphopsia significantly reduced after. Average tangential displacement before surgery was 35.6 ± 29.9 µ m versus 56.6 ± 41.3 µ m after ( P = 0.023). Preoperative and postoperative displacement within the fovea was less than over the entire area ( P < 0.001). CONCLUSION: Retinal tangential displacement between diagnosis and surgery (T E - T 0 ) is less than the displacement occurring after surgery (T 0 - T L ). Postoperative displacement does not represent the restoration of the anatomy existing before the disease ensued but rather the resulting equilibrium of newly deployed forces.

RETINAL TECTONICS AFTER MACULAR PUCKER SURGERY: Thickness Changes and En Face Displacement Recovery.

PURPOSE: To study visual function, retinal layer thickness changes, and tangential displacement after pars plana vitrectomy for epiretinal membrane. METHODS: Retrospective series of patients undergoing pars plana vitrectomy for epiretinal membrane, with 6-month follow-up including best-corrected visual acuity, optical coherence tomography, M-charts, epiretinal membrane grading, and infrared fundus photograph at time 0 (T0, preop) at months 1 (T1), 3 (T3), and 6 (T6) postop (±1 week). Retinal layer thickness and tangential ( en face ) retinal displacement between successive times for the entire retinal surface and the central horizontal and vertical meridian were also measured. En face displacement was calculated as optical flow of consecutive images. RESULTS: Average best-corrected visual acuity improved from 0.28 ± 0.08 logarithm of Minimum Angle of Resolution at T0 to 0.16 ± 0.25 at T6 ( P = 0.05), best-corrected visual acuity improvement correlated with best corrected visual acuity (BCVA) at T0 ( P < 0.001). Vertical metamorphopsia decreased from 1.33° ± 0.70° at T0 to 0.82° ± 0.69° at T6 ( P < 0.05). Foveal thickness reduced from 453 ± 53 µ m at T0 to 359 ± 31 µ m at T6 ( P < 0.05) and reduction correlated with best-corrected visual acuity improvement ( P < 0.05). Foveal layers decreased ( P < 0.05) in all cases. The mean en face deformation was 155.82 ± 50.17 µ m and mostly occurred in the first month: T0-T1 displacement was 83.59 ± 30.28 µ m, T1-T3 was 36.28 ± 14.45 µ m, while T3-T6 was 39.11 ± 22.79 µ m ( P < 0.001) on average. Perifoveal and parafoveal deformation correlated with optical coherence tomography foveal thickness reduction at all time intervals (1, 3, and 6 months: P < 0.01). CONCLUSION: Epiretinal membrane peeling affects all retinal layer thickness and results in new force balance across the entire retina and tangential displacement. Both en face and in-depth changes correlate with visual function.

DO DAILY ACTIVITIES AFFECT GAS TAMPONADE‒RETINA CONTACT AFTER PARS PLANA VITRECTOMY?: A Computational Fluid Dynamics Study.

PURPOSE: To calculate the retinal surface alternatively in contact with gas and aqueous because of fluid sloshing during daily activities such as ocular saccade, turning the head, standing up, and being a passenger of a braking car. METHODS: Fluid dynamics of aqueous and gas tamponade was reproduced using computational methods using the OpenFOAM open-source library. The double-fluid dynamics was simulated by the volume of fluid method and setting the contact angle at the aqueous-gas-retina interface. RESULTS: Sloshing increased the retinal surface in contact with aqueous by 13% to 16% regardless of fill rate and standing up determined the largest area of wet retina, followed by car braking, head rotation, and ocular saccade ( P < 0.001). All activities except the ocular saccade determined a significant increase in the surface of retina in contact with the aqueous ( P < 0.005). Car braking induced the highest shear stress (6.06 Pa); standing up determined the highest specific impulse and saccade the lowest. CONCLUSION: Daily activities instantaneously reduce the amount of retina consistently in contact with gas tamponade and increase shear stress giving aqueous a potential access to the subretinal space regardless of patients' compliance.

The Role of Subretinal Injection in Ophthalmic Surgery: Therapeutic Agent Delivery and Other Indications.

Subretinal injection is performed in vitreoretinal surgery with two main aims, namely, the subretinal delivery of therapeutic agents and subretinal injection of fluid to induce a controlled and localized macular detachment. The growing interest in this technique is mainly related to its suitability to deliver gene therapy in direct contact with target tissues. However, subretinal injection has been also used for the surgical management of submacular hemorrhage through the subretinal delivery of tissue plasminogen activator, and for the repair of full-thickness macular holes, in particular refractory ones. In the light of the increasing importance of this maneuver in vitreoretinal surgery as well as of the lack of a standardized surgical approach, we conducted a comprehensive overview on the current indications for subretinal injection, surgical technique with the available variations, and the potential complications.

Mutations associated with hypokalemic periodic paralysis: from hotspot regions to complete analysis of CACNA1S and SCN4A genes.

Familial periodic paralyses (PPs) are inherited disorders of skeletal muscle characterized by recurrent episodes of flaccid muscle weakness. PPs are classified as hypokalemic (HypoPP), normokalemic (NormoPP), or hyperkalemic (HyperPP) according to the potassium level during the paralytic attacks. HypoPP is an autosomal dominant disease caused by mutations in the CACNA1S gene, encoding for Cav1.1 channel (HypoPP-1), or SCN4A gene, encoding for Nav1.4 channel (HypoPP-2). In the present study, we included 60 patients with a clinical diagnosis of HypoPP. Fifty-one (85%) patients were tested using the direct sequencing (Sanger method) of all reported HypoPP mutations in CACNA1S and SCN4A genes; the remaining 9 (15%) patients were analyzed through a next-generation sequencing (NGS) panel, including the whole CACNA1S and SCN4A genes, plus other genes rarely associated to PPs. Fifty patients resulted mutated: 38 (76%) cases showed p.R528H and p.R1239G/H CACNA1S mutations and 12 (24%) displayed p.R669H, p.R672C/H, p.R1132G/Q, and p.R1135H SCN4A mutations. Forty-one mutated cases were identified among the 51 patients managed with Sanger sequencing, while all the 9 cases directly analyzed with the NGS panel showed mutations in the hotspot regions of SCN4A and CACNA1S. Ten out of the 51 patients unresolved through the Sanger sequencing were further analyzed with the NGS panel, without the detection of any mutation. Hence, our data suggest that in HypoPP patients, the extension of genetic analysis from the hotspot regions using the Sanger method to the NGS sequencing of the entire CACNA1S and SCN4A genes does not lead to the identification of new pathological mutations.

THE PROPHYLAXIS OF FELLOW-EYE RETINAL DETACHMENT IN STICKLER SYNDROME: A RETROSPECTIVE SERIES.

PURPOSE: To evaluate retrospectively if scleral buckling combined or not to cryopexy reduces fellow-eye retinal detachment (RD) in Stickler syndrome patients who lost their first eye due to RD. METHODS: Retrospective review of 52 Stickler syndrome patients who received a 6-mm wide, 360° encircling scleral buckling. Thirty-nine (75%; Cryo + Group) also received cryo treatment, whereas the reminder 13/52 (25% Cryo - Group) did not. RESULTS: Average follow-up was 15.6 ± 2.41 years. Five patients (5/52; 9.6%) developed a retinal detachment 2.6 ± 0.55 years after prophylactic treatment, respectively, 0/39 patients in the Cryo + Group and 5/13 in the Cryo - Group (P < 0.001). All five RD eyes were successfully reattached through revised episcleral surgery and adjunctive cryo treatment. Postop refraction changed an average -1.9 ± 0.74 diopters and best corrected visual acuity at the end of follow-up was 20/25 (0.1 ± 0.07 logarithm of the minimum angle of resolution), not significantly different from the rest of sample population who did not develop RD in their fellow eye. CONCLUSION: Cryopexy significantly reduced the risk of RD in Stickler syndrome patients undergoing scleral buckling. If RD ensues, the presence of scleral buckling may ease surgical repair and improve final outcome.

A novel intraocular lens designed for sutureless scleral fixation: surgical series.

PURPOSE: To report a retrospective series of patients implanted with a novel hydrophilic acrylic single-piece intraocular lens (IOL) designed for sutureless scleral fixation (FIL-SSF Carlevale lens, Soleko, Italy) injectable through a 2.2-mm incision. METHODS: Seventy-eight patients with minimum 6-month follow-up were divided into 6 groups: dropped nucleus, luxated IOL, trauma, aphakia, IOL exchange, and Marfan's syndrome. Surgery included peritomy and scleral flap creation at 3 and 9 o'clock position. The IOL was then injected and grasped with 25G forceps through a hole created 2 mm posterior to the limbus underneath the sculped scleral flap. RESULTS: The study included 78 patients (mean age 71.9 ± 12.6 years) and average follow-up 10.2 ± 4.2 months. Average surgery duration was 69.4 ± 26.1 min and vision significantly improved from 0.86 ± 0.56 logMAR to 0.38 ± 0.42 logMAR at 6 months post-operative (p < 0.001). Intraoperative complications included corneal edema, retinal tears, and vitreous bleeding each in 2/78 patients (2.5%); 1/78 (1.3%) localized retinal detachment and 1/78 (1.3%) rupture of one T-shaped IOL harpoon. Post-operative complications included 4/78 (5.1%) cystoid macular edemas, 2/78 retinal tears, 2/78 retinal detachments, 2/78 developed ocular hypertension, and 1/78 corneal decompensation requiring DSAEK. CONCLUSION: The Carlevale lens is designed for sutureless intrascleral fixation and can be successfully used in a variety of indications including difficult trauma cases with good rehabilitation. An implant requires experience and delicate manipulation.

CIR-Based Device-Free People Counting via UWB Signals.

The outbreak of COVID-19 has resulted in many different policies being adopted across the world to reduce the spread of the virus. These policies include wearing surgical masks, hand hygiene practices, increased social distancing and full country-wide lockdown. Specifically, social distancing involves keeping a certain distance from others and avoiding gathering together in large groups. Automatic crowd density estimation is a technological solution that could help in guaranteeing social distancing by reducing the probability that two persons in a public area come in close proximity to each other while moving around. This paper proposes a novel low complexity RF sensing system for automatic people counting based on low cost UWB transceivers. The proposed system is based on an ordinary classifier that exploits features extracted from the channel impulse response of UWB communication signals. Specifically, features are extracted from the sorted list of singular values obtained from the singular value decomposition applied to the matrix of the channel impulse response vector differences. Experimental results achieved in two different environments show that the proposed system is a promising candidate for future automatic crowd density monitoring systems.

Macular hole closure patterns: an updated classification.

BACKGROUND: The classification of macular hole closure patterns (MHCPs) currently relies on time domain OCT allowing only "open" and "closed" statuses or is based on inner foveal contour shape. Both classification types give no information on retinal layer reconstitution. Novel sophisticated surgical techniques lead to previously unknown MHCPs, outdating existing classifications and urging new ones. The purpose of the present study is to introduce a new classification allowing proper description of all MHCPs resulting from newer surgeries and based on the restoration of retinal layers. METHODS: Retrospective analysis of patients undergoing MH surgery with five different surgical techniques was performed. MHCPs were classified according to spectral domain optical coherence tomography (SD-OCT). Type 0: open MH (0A: flat margin, 0B: elevated, 0C: oedematous); type 1: closed MHs (1A: reconstitution all retinal layers; 1B interruption of the external layers; 1C interruption of internal layers); type 2: MH closed with autologous or heterologous filling tissue interrupting the normal foveal layered anatomy (2A: filling tissue through all layers; 2B reconstitution of normal inner retinal layers; 2C reconstitution of normal outer retinal layers; 2D H-shaped bridging of filling tissue). RESULTS: Closure rate was 95.2% (241/253). Surgical technique and vision correlated to closure pattern (p < 0.001). Type 1 MHCPs had the best post-operative visual acuity (VA) compared with type 2 and type 0 (p < 0.001). MHCPs 1A and 1C performed better than all others. MHCP at months 1 and 3 changed in 42/254 (16.5%) and remained stable in 212/254 (83.5%). Improvement in vision was higher in eyes with shifting closure pattern (0.57 ± 0.33 vs 0.51 ± 0.48 logMAR; p 0.021). CONCLUSION: MHCP classification based on retinal layer restoration properly comprises post-operative anatomic morphologies. MHCPs correlate the surgical technique and post-operative visual outcomes.

Visual Defects and Ageing.

Many diseases are related to age, among these neurodegeneration is particularly important. Alzheimer's disease Parkinson's and Glaucoma have many common pathogenic events including oxidative damage, Mitochondrial dysfunction, endothelial alterations and changes in the visual field. These are well known in the case of glaucoma, less in the case of neurodegeneration of the brain. Many other molecular aspects are common, such as the role of endoplasmic reticulum autophagy and neuronal apoptosis while others have been neglected due to lack of space such as inflammatory cytokine or miRNA. Moreover, the loss of specific neuronal populations, the induction of similar mechanisms of cell injury and the deposition of protein aggregates in specific anatomical areas are very similar events between these diseases. Intracellular and/or extracellular accumulation of protein aggregates is a key feature of many neurodegenerative disorders. The existence of abnormal protein aggregates has been documented in the RGCs of glaucomatous patients such as the anomalous Tau protein or the ß-amyloid accumulations. Intra-cell catabolic processes also appear to be common in both glaucoma and neurodegeneration. They also help us to understand how the basis between these diseases is common and how the visual aspects can be a serious problem for those who are affected.

Comparison of United States and International Ophthalmic Drug Pricing.

PURPOSE: To compare United States and international drug pricing for commonly prescribed intravitreal and topical ophthalmic medications. DESIGN: Cross-sectional observational study. METHODS: For 25 commonly used ophthalmic medications (3 intravitreal, 22 topical), we obtained 2017 third quarter United States average wholesale price (AWP), drug acquisition cost, or consumer pricing through United States government health insurance plans (Veterans Affairs [VA], Medicaid, Medicare Part B, and Medicare Part D) and commercial drug plans (CVS Caremark and Navitus Health Solutions), online pricing without insurance through a large United States warehouse retailer (Costco), and international drug pricing through government-sponsored health plans in Italy, Spain, Turkey, Canada, and Japan. MAIN OUTCOME MEASURES: Drug acquisition costs and consumer pricing of ophthalmic drugs through various payment systems. All prices were converted to United States dollars. RESULTS: For intravitreal medications in the United States, aflibercept and ranibizumab were priced similarly to each other and were more expensive than dexamethasone implants. Pricing of aflibercept and ranibizumab through government health insurance plans in Italy, Spain, Turkey, Canada, and Japan were less expensive by as much as 84.3% compared with the United States. For topical medications in the United States, pricing varied significantly both across different classes of medications and also between nonbranded and branded medications. Drug acquisition costs through the VA and Medicaid were inexpensive on average, but pricing through a hospital-employee drug insurance plan offered the smallest range (between $2.35 and $60.00). In all 5 non-United States countries studied, each topical medication with the exceptions of cyclosporine emulsion and difluprednate was less than $100, and 94.4% of topical medications in these countries had a nonbranded or branded option that was less than $50. CONCLUSIONS: In the United States, for topical more than intravitreal medications, significant price variation exists across both different drug pricing systems and different medications. Price differentials between nonbranded and branded medications can be significant. Internationally, topical medications exhibited a more limited and lower price range compared with drug pricing in the United States.

Folding the internal limiting membrane flap under perfluorocarbon liquid in large, chronic and myopic macular holes.

PURPOSE: The purpose of the present paper is to describe a surgical technique aimed at creating multiple layers of Internal Limiting Membrane (ILM) using Perfluorocarbon Liquid (PFCL) in order to favour the closure of large, chronic and myopic Macular Holes (MH). METHODS: Thirty patients belonging to 3 subgroups: large (> 500 µm), chronic (> 12 months) and myopic (> - 9 diopters), MHs, underwent surgery and completed 6 months follow-up. The ILM was engaged and peeled 360° around the MH, hinged to the rim and folded over the hole. A PFCL bubble spanning the vascular arcades was then injected and the ILM is grasped repeatedly to fold the distal edge towards the MH centre, creating multiple ILM layers over the MH. RESULTS: MH closed in 26/30 cases (86.6%) with no significant difference among subgroups. Vision improved 2.57 ± 1.56 Snellen lines from LogMAR 1.50 ± 1.19 to 1.19 ± 1.32 (p < 0.01). Ellipsoid Zone (EZ) interruption width reduced from 1129 ± 439 µm to 258 ± 507 µm (p < 0.001) and correlated to pattern of MH closure, post-BCVA and line improvement (p < 0.001 in all cases). DISCUSSION: The use PFCL allows multiple ILM layers and resulted in a high closure rate. Pattern of MH closure differs from those previously described leaving a plug of ILM tissue that interrupts retinal architecture often only in the inner layers. PFCL gravity and hydrophobicity displace aqueous while the intensely polar opposite faces of the ILM attract each other. The folded ILM plugs MH and bridges the gap and may help glial cell proliferation and migration.

Vitreo-macular interface disorders in retinitis pigmentosa.

PURPOSE: To investigate the prevalence and progression of vitreo-macular interface disorders (VMID) phenotypes and their natural history in retinitis pigmentosa (RP). METHODS: A total of 257 eyes of 145 RP patients with VMID were retrospectively evaluated. Patients were divided according to the VMID subtypes into epiretinal membranes (ERMs), vitreo-macular traction (VMT) group, and macular hole (MH). Serial eye-tracked spectral-domain optical coherence tomography (SD-OCT) and best-corrected visual acuity (BCVA) changes were analyzed for a mean follow-up of 36.95 months. The status of posterior vitreous cortex was also considered. A control group of 65 eyes belonging to 65 RP patients with no macular changes was also recruited. RESULTS: VMID and control groups had the same baseline BCVA (0.50 vs 0.44 LogMAR) and did not differ in terms of phakic status. Different VMID groups had similar BCVA at baseline (p = 0.98). ERM represented the most prevalent disorder (207/257 eyes, 80.5%), followed by 35/257 (13.6%) VMT, and 15/257 Lamellar MH (LMH) eyes (5.8%). There were no cases of full thickness MH. Throughout the 36.9 months of follow-up, BCVA decreased an average 0.09 LogMAR from 0.31 to 0.4 in VMID patients and 0.01 in controls. VMID subgroup analysis showed a significant BCVA decrease in ERM patients (- 20.29%, p < 0.001), while VMT and LMH did not change significantly. Foveal thickness also remained stable over time. Complete PVD was present in 11 eyes in ERM, VMT, and LMH. CONCLUSIONS: Our study confirms the high prevalence of VMID in RP patients; however, only ERMs determined a significant loss of vision over 24 months. The high prevalence of VMID in RP patients suggests that macular alteration other than edema represents part of disease spectrum.

Does the Bursa Pre-Macularis protect the fovea from shear stress? A possible mechanical role.

Purpose of present study is to evaluate whether the Pre-Macular Bursa (PMB) modifies Wall Shear Stress (WSS) at the retinal surface during saccadic movements. We created a mathematical model consisting of 25,000 grid cells and simulated a horizontal saccade spanning 50° in 0.17s, both in absence and in presence of the PMB. Wall Shear Stress SS was computed throughout the retinal surface and the posterior pole was divided into 3 Zones comprising 400 nodes each: Zone 1 (radius 3.5 mm; 0°-17°) corresponding to the PMB area; Zone 2 (concentric annular area 5 mm in radius; 22°) and Zone 3 (concentric annular area 5.5 mm; 28°). The PMB reduced WSS significantly at the macula and increased it in the immediate surroundings. Average WSS in Zone 1 was 1.53 ±â€¯1.01 (max 4.23 Pa) with PMB Vs 6.94 ±â€¯9.23 (max 35.83 Pa) without. Zone 2 WSS was 9.39 ±â€¯10.33 (max 48.36 Pa) with PMB Vs 6.95 ±â€¯9.40 (max 38.60 Pa) without Zone 3 WSS was 8.41 ±â€¯10.03 (max 43.16 Pa) with PMB Vs 6.88 ±â€¯9.42 (max 39.43 Pa) without (p < 0.001 in all cases). The PMB significantly reduces WSS over the retinal surface underlying the bursa region; conversely, WSS slightly increases it in the immediate neighboring areas.

PREDICTIVE FACTORS FOR DEVELOPMENT OF NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: A Spectral-Domain Optical Coherence Tomography Study.

PURPOSE: To investigate the risk factors predictive for the development of neovascular age-related macular degeneration (NVAMD) by means of spectral-domain optical coherence tomography. METHODS: Retrospective study of 73 eyes graded Stage 2 and Stage 3 according to the AMD International Grading System with minimum follow-up of 24 months. Drusenoid pigment epithelial detachment, hyperreflective foci, external limiting membrane, inner ellipsoid band, and retinal pigment epithelium integrity were analyzed at baseline and last follow-up. Binary logistic regression model analyzed significant predictors of neovascular conversion. RESULTS: The discontinuity of external limiting membrane, inner ellipsoid band, and retinal pigment epithelium bands were significantly more prevalent in the NVAMD group at baseline and last follow-up (P < 0.001). Hyperreflective foci represented the single most important predictor of neovascular conversion (Exp [B], 15.15; P = 0.005) as confirmed by Kaplan-Meier curve (P = 0.002). Drusenoid pigment epithelial detachment width was significantly greater in NVAMD group than control subjects at baseline and last follow-up (P < 0.001), and its delta value also resulted a significant neovascular predictor (Exp [B], 0.99; P = 0.04). CONCLUSION: Hyperreflective foci significantly increase the risk of NVAMD progression. The delta width of drusenoid pigment epithelial detachment also predicts disease progression, integrating the stratification of NVAMD progression risk.

Macular hole closure patterns associated with different internal limiting membrane flap techniques.

PURPOSE: To compare the anatomic and functional outcome of two variants of the inverted internal limiting membrane (I-ILM) flap technique for idiopathic macular holes (IMH) larger than 400 µm. METHODS: Twenty-seven consecutive patients undergoing PPV for IMH were randomly assigned to different variants of I-ILM technique: the Cover group included 14 patients in which the I-ILM was folded upside-down over the MH as a single layer while the Fill group enrolled 13 patients in which the I-ILM was folded within the MH in multiple layers. RESULTS: MH closed in 12/14 Cover and in 13/13 Fill eyes (84.6 vs. 100%, p = 0.14; n.s.). Vision at 1 month was Snellen 0.44 ± 0.17 vs. 0.28 ± 0.21 (p = 0.05) and 0.48 ± 0.20 vs. 0.37 ± 0.25 (n.s.) at 3 months. IS/OS line interruption width was 463 ± 385 vs. 602 ± 210 µm, respectively, at 1 month (n.s.) and 602 ± 210 vs. 563 ± 209 µm at 3 months (n.s.). The Cover group showed outer retina cystic changes more often (p < 0.01). MH over 700 µm closed in 0/2 and in 2/2 cases, respectively, in the Cover and Fill groups (0.045). CONCLUSIONS: Cover and Fill I-ILM techniques allowed similar closure rates and post-operative vision at 3 months. The Cover group showed better anatomical restoration and vision at 1 month while the Fill technique might be more efficient in closing larger MHs.

Ocular perfusion pressure control during pars plana vitrectomy: testing a novel device.

PURPOSE: To study the efficacy of a novel device intended to control infusion pressure based on mean ocular perfusion pressure (MOPP) during pars plana vitrectomy (PPV). METHODS: An arm blood pressure cuff connected to a vitrectomy machine calculated mean arterial pressure (MAP), while a pressure sensor close to the infusion trocar measured intraocular pressure (IOP). MOPP was calculated in real time in 36 consecutive patients undergoing PPV, who were divided into two groups. The device lowered IOP every time that calculated MOPP fell below 30 mmHg in the Control ON group (18 patients), while no action was taken in the Control OFF group (18 patients). RESULTS: Baseline IOP and blood pressure were similar between groups. The Control ON group had significantly lower average intraoperative IOP (30.5 ± 2.1 vs. 35.9 ± 6.9 mmHg; p = 0.002) and higher MOPP (56.4 ± 5.9 vs. 49.7 ± 6.1 mmHg) than the Control OFF group. The Control ON group also spent less time at MOPP < 10 mmHg and < 30 mmHg: 0 vs. 3.40 ± 2.38 min (p < 0.001) and 9.91 ± 7.15 vs. 16.13 ± 8.12 min (p = 0.02), respectively. CONCLUSIONS: The MOPP control device effectively maintained lower IOP and higher MOPP throughout surgery. It also helped avoid dangerous IOP peaks and MOPP dips, allowing patients to spend less time at MOPP of < 10 and < 30 mmHg.

LASER PROPHYLACTIC TREATMENT OF THE FELLOW EYE IN GIANT RETINAL TEARS: Long-Term Follow-up.

PURPOSE: To report the results of a retrospective study on prophylactic laser treatment versus observation of giant retinal tears (GRTs) fellow eyes. METHODS: One hundred and sixty consecutive charts of patients operated for GRT were included in this retroprospective study. Standard office visit included manifest and corrected refraction, intraocular pressure measurement, slit-lamp examination of the anterior and posterior segment with +90 diopter lens, and indirect ophthalmoscopy were performed at baseline and during follow-up period. RESULTS: Observation group included 62 and prophylactic laser treatment group 98 eyes. The incidence of retinal tears with localized preequatorial retinal detachment, GRTs with macula-ON retinal detachment, and GRTs with Macula-OFF retinal detachment were 3.2, 0, and 14.5%, respectively, during 43.5 ± 19.8 months of follow-up period in observation group and 11.2, 2, and 0%, respectively, in prophylactic laser treatment group during 37.2 ± 16.3 months of follow-up period. CONCLUSION: Prophylactic laser treatment of GRTs fellow eyes decreased the incidence of GRTs and limited the consequences of newly developed tears, lowering the occurrence of a macula-off retinal detachment with a consequent better final visual outcome respect to observation group.

AXIAL ROTATION VITRECTOMY: Back to the Future? the Fluidics of a Prototype Vitreous Cutter Probe.

PURPOSE: To characterize the fluidics of axial rotating vitreous cutter probe (RT) compared with the standard guillotine (regular blade), when tested in Balanced Salt Solution (Alcon Laboratories, Forth Worth, TX). METHODS: RT and regular blade (RB) cutter probes connected to the same vitrectomy console used a peristaltic pump. The authors measured instantaneous flow through aspiration tubing proximal to the handpiece, fluid velocity, and acceleration at the port by means of particle image velocimetry. RESULTS: Average flow at aspiration tubing of RT and RB did not vary significantly. Regular blade probes produced higher instantaneous flow fluctuation than RT at any considered cut rate (RB 1,600 6.4 ± 5.3 mL/minute; RB 3,000 11.8 ± 6.3 mL/minute; RT 1,600 0.9 ± 0.7 mL/minute, and RT 3,000 1.8 ± 0.8 mL/minute, respectively. P < 0.001 in all cases). Regular blade also yield significantly higher fluid velocity at cutter port compared with RT (RB 1,600 85.8 ± 70.1 mm/second; RB 3,000 81.6 ± 66.4 mm/second; RT 1,600 71.9 ± 40.3 mm/second; and RT 3,000 32.9 ± 20.8 mm/second. P < 0.001 in all cases). Fluid acceleration at the cutter port was higher when the RB was used (RB 1,600 26.85 ± 30.18 mm/second; RB 3,000 33.76 ± 34.09 mm/second; RT 1,600 24.01 ± 21.94 mm/second; and RT 3,000 16.62 ± 17.87 mm/second. P < 0.001 in all cases). CONCLUSION: RT blade design causes less instantaneous flow fluctuation within the aspiration tubing, and also lower fluid velocity and lower acceleration at the cutter port. Fluidics suggests a safer cutting action and a reduced risk of retinal incarceration.