Refractive outcome in combined phacovitrectomy: Anterior segment changes and corrective factor for IOL power calculation improvement.

PURPOSE: To analyze differences in refractive outcome Δ (difference between postoperative and expected refractive error) and in anterior segment changes between cataract surgery patients and combined phacovitrectomy patients. We also aimed to provide a corrective formula allowing to minimise the refractive outcome Δ in combined surgery patients. METHODS: Candidates for phacoemulsification and combined phacovitrectomy (respectively PHACO and COMBINED groups) were prospectively enrolled in two specialised centres. Patients underwent best corrected visual acuity (BCVA) assessment, ultra-high speed anterior segment optical coherence tomography (OCT), gonioscopy, retinal OCT, slit lamp examination and biometry at baseline, 6 weeks postoperatively and 3 months postoperatively. RESULTS: No differences in refractive Δ, refractive error and anterior segment parameters were noted between PHACO and COMBINED group (109 and 110 patients respectively) at 6 weeks. At 3 months, COMBINED group showed a spherical equivalent of -0.29 ± 0.10 D versus -0.03 ± 0.15 D in PHACO group (p = 0.023). COMBINED group showed a significantly higher Crystalline Lens Rise (CLR), angle-to-angle (ATA) and anterior chamber width (ACW) and a significantly lower anterior chamber depth (ACD) and refractive Δ with all 4 considered formulas at 3 months. For IOL power lower than 15, a hyperopic shift was observed instead. CONCLUSIONS: Anterior segment OCT suggests anterior displacement of the effective lens position in patients undergoing phacovitrectomy. A corrective formula can be applied to IOL power calculation to minimize undesired refractive error.

Scleral Buckling Using Chandelier and Releasable Suture: A Useful Surgical Variant.

PURPOSE: To describe a surgical variant for scleral buckling technique using a chandelier and scleral releasable suture. METHODS: We collected retrospectively 20 eyes of 20 patients who underwent to scleral buckling for retinal detachment. In all cases, the surgeons performed the surgical variant of scleral buckling using a 27-gauge (G) chandelier as endoillumination and releasable 7.0 vicryl scleral suture. RESULTS: None of the operated eyes developed lens opacity or lens marks at the entrance site of the chandelier used during the surgery, and no cataract development was observed as well, during the follow-up. Retinal reattachment was achieved in 19 out of 20 eyes at the first surgery in the follow-up time of 6 months. CONCLUSION: The association of chandelier and releasable suture was a useful surgical variant when performing scleral buckling technique for retinal detachment. Complications like lens opacity or lens marks at the entrance site of the chandelier due to the use of chandelier itself can be greatly reduced, as well as complications due to vitreous prolapse from the sclerotomy by using releasable scleral suture.

Vitreoschisis and retinal detachment: New insight in proliferative vitreoretinopathy.

PURPOSE: To assess the occurrence of peripheral vitreoschisis-induced vitreous cortex remnants (p-VCRs) in primary rhegmatogenous retinal detachment (RD) and investigate whether the presence of p-VCRs results in a greater risk of RD recurrence, secondary to Proliferative Vitreoretinopathy (PVR) development after pars plana vitrectomy (PPV). METHODS: Patients who underwent PPV for primary rhegmatogenous RD between January 2016 and December 2018 were included. The presence of residual p-VCRs was confirmed intraoperatively using triamcinolone acetonide (TA). Patients with p-VCRs were divided into two groups: Group A comprised of patients who underwent PPV without p-VCR removal, while Group B included patients who underwent PPV with p-VCR removal. RESULTS: Four hundred-thirteen eyes with evidence of p-VCR were analyzed. Two-hundred-twenty-three eyes underwent PPV without VCR removal (Group A), while 190 eyes underwent PPV with p-VCR removal (Group B). Primary anatomical success was 91.5% in the Group A and 95.4% in the group B. Retinal re-detachment due to PVR occurred in 17 (7.6%) eyes in Group A and in four (2.1%) eyes in Group B within the first 3 months (p = 0.01). Among group A, in 11 eyes, there was a diffuse posterior PVR grade C, while six eyes were focal PVR grade C. In Group B, we observed four retinal re-detachment due to focal PVR grade C. CONCLUSION: The presence of p-VCRs seems to be associated with a higher incidence of PVR development and might also result in more complex RD recurrence, this suggests the need for more aggressive VCRs removal during the first surgery.

The Role of OCT Angiography in the Assessment of Epiretinal Macular Membrane.

BACKGROUND: The aim of this observational study is to assess pre- and postoperative retinochoroidal vascular changes in patients undergoing epiretinal macular membrane (ERM) surgery by using optical coherence tomography angiography (OCTA). MATERIALS AND METHODS: 23 eyes affected by ERM and those which underwent phacovitrectomy associated with ERM peeling were enrolled. They were evaluated using structural OCT and OCTA before surgery and at 1, 3, and 6 months postoperatively. RESULTS: We found a statistically significant (p < 0.05) increase in the superficial capillary plexus vessel density (VD) from baseline to the 6-month follow-up. We observed a large increase in both the perfusion density (PD) and the VD of the deep capillary plexus between baseline and the 6-month follow-up (p < 0.001). A significant decrease in the VD and PD of the choriocapillaris (CC) from baseline to the 1st month and a significant increase in CC perfusion density at the 6-month follow-up compared to the preoperative value were revealed. The FAZ area and perimeter after surgery significantly increased during the follow-up (p < 0.001) at baseline retinal and choroidal plexi with a lower PD or VD correlated with worse visual acuity (p < 0.05 for all plexi). At baseline and at the 1-month follow-up, a significant correlation was found with the FAZ area and the FAZ perimeter: a smaller FAZ area or a smaller FAZ perimeter was correlated to a lower visual acuity. Before surgery, negative correlations (p < 0.05) were found between the Govetto ERM stages and perfusion density of the SCP and the DCP and between the Govetto stages and vessel density of the DCP. CONCLUSIONS: In our study, OCTA detected vascular alterations induced by the presence of the ERM, allowing several correlations with functional data. In these patients, OCTA may be useful to add new potential surgical prognostic factors.

Dexamethasone/Netilmicin Eye Drops and Eye Gel for the Treatment of Ocular Inflammation After Micro-Incisional Vitreoretinal Surgery.

PURPOSE: To evaluate the effect of dexamethasone/netilmicin (dexa/net) fixed combination in the treatment of ocular inflammation after sutureless micro-incisional vitreoretinal surgery (MIVS). PATIENTS AND METHODS: This multicenter, open, randomized, active-controlled, parallel-group, clinical trial was run in 6 sites in Italy. Treatment started the day of surgery and continued 4 times daily for 14 days. Patients were 1:1 randomized to dexa/net (eyedrops solution and eye gel) or dexamethasone/tobramycin (dexa/tobra) eyedrops suspension and ointment. Viscous formulations (gel or ointment) were used alone during the early post-operative phase; afterwards, a combination of eye drops during daytime and viscous formulations at bedtime was adopted. The primary efficacy parameter evaluated was bulbar conjunctival hyperemia. Additional efficacy and safety parameters (palpebral conjunctival hyperemia, anterior chamber flare and cells, symptoms of ocular discomfort and ocular tolerance, adverse events and intraocular pressure) were also evaluated. Control visits were performed at day 1, day 4 and day 14 after surgery; the endpoint of the study was set at 14±2 days after surgery. RESULTS: A complete resolution of bulbar conjunctiva hyperaemia at the study end point was reached in 92.9% of patients treated with dexa/net and 75.0% of those treated with dexa/tobra (p=0.02, Fisher's exact test). No differences were observed between treatments for other efficacy parameters. Statistically significant differences in favour of dexa/net (p< 0.0001, ANOVA) were observed for most of subjective tolerance variables examined (blurred vision, foreign body sensation, stickiness, burning) starting day 1 after surgery when only the viscous formulations were used. No increase in intraocular pressure or adverse events was observed during the study. CONCLUSION: The combination dexa/net is safe and effective in the treatment of post-operative inflammation following sutureless MIVS. In particular, the use of eye gel formulation is characterized by a great tolerability.

Morpho-Functional Evaluation of Full-Thickness Macular Holes by the Integration of Optical Coherence Tomography Angiography and Microperimetry.

(1) Objective: To use optical coherence tomography angiography (OCTA) and microperimetry (MP) to evaluate the correlation between retinal structure and function in patients with idiopathic, full-thickness macular holes (FTMHs) (2) Methods: This prospective, observational study included 11 eyes of 10 patients with FTMHs evaluated before surgery using OCTA and MP. MP sensitivity maps were superimposed and registered on slabs corresponding to superficial capillary plexus (SCP) and deep capillary plexus (DCP) on OCTA, and on the outer plexiform layer (OPL) and the Henle fiber layer (HFL) complex in en face OCT. On these maps, mean retinal sensitivity was calculated at 2° and 4°, all centered on the FTMH. Cystic cavity extension was assessed on the slab corresponding to the OPL + HFL complex in en face OCT and DCP in OCTA using the Image J software (Version 1.49v; National Institutes of Health, Bethesda, MD, USA); (3) Results: Absolute scotomas were observed corresponding to the FTMH. Additionally, rings of relative scotoma in the perilesional area were detected and correlated to the cystic spaces on en face OCT and OCTA. There was a significant correlation between reduced retinal sensitivity at 2° and 4° diameters around the FTMH and the extension of cystic areas (p < 0.01). There was a significant correlation between the extension of cystic cavities and BCVA (p < 0.01). (4) Conclusions: Morpho-functional analysis of FTMH using OCTA and MP, and the correlation between vascular abnormalities and impaired retinal sensitivity, may provide new, useful information. This integrated evaluation of FTMH may be useful to determine the function-structure correlation before and after vitreoretinal surgery, in order to gain a better understanding of the functional consequences induced by the morphological alterations, assessing outcomes in a more objective way, and potentially adding new surgical prognostic factors.

ULTRASOUND IN VITRECTOMY: An Alternative Approach to Traditional Vitrectomy Techniques.

PURPOSE: To study a prototype of an ultrasound-based vitrector, and to try to understand the physical phenomena underlying this new technology. METHODS: We tested the ultrasound-based vitrector prototype (UV) (ultrasonically-driven handpiece obtained from a modified version of the Alcon CONSTELLATION Vision System [Alcon]) using an automatic experimental setup. Balanced saline solution (BSS) and vitreous (from fresh postmortem enucleated porcine eyes) flow rates were analyzed using three different tips. RESULTS: In general, BSS solution flow rates increased with increasing aspiration levels and decreased when we used % US power. Vitreous flow rates were influenced by aspiration levels, % US power, and ultrasound-related phenomena: cavitation phenomenon and "jet streaming." CONCLUSION: Ultrasound-based vitrectomy may represent an important alternative to traditional vitrectomy. Such a tool, capable of liquefying and excising the vitreous body using ultrasound, could overcome all the limits of the guillotine-based technique (GV). Knowledge of the physical phenomena underlying ultrasound-based technology is a necessary prerequisite for further development of this new technology.

Patient-Specific iPSC-Derived Endothelial Cells Provide Long-Term Phenotypic Correction of Hemophilia A.

We generated patient-specific disease-free induced pluripotent stem cells (iPSCs) from peripheral blood CD34+ cells and differentiated them into functional endothelial cells (ECs) secreting factor VIII (FVIII) for gene and cell therapy approaches to cure hemophilia A (HA), an X-linked bleeding disorder caused by F8 mutations. iPSCs were transduced with a lentiviral vector carrying FVIII transgene driven by an endothelial-specific promoter (VEC) and differentiated into bona fide ECs using an optimized protocol. FVIII-expressing ECs were intraportally transplanted in monocrotaline-conditioned non-obese diabetic (NOD) severe combined immune-deficient (scid)-IL2rγ null HA mice generating a chimeric liver with functional human ECs. Transplanted cells engrafted and proliferated in the liver along sinusoids, in the long term showed stable therapeutic FVIII activity (6%). These results demonstrate that the hemophilic phenotype can be rescued by transplantation of ECs derived from HA FVIII-corrected iPSCs, confirming the feasibility of cell-reprogramming strategy in patient-derived cells as an approach for HA gene and cell therapy.

Femtosecond laser-assisted cataract in vitreoretinal surgery.

PURPOSE: To assess the safety and surgical results of femtosecond laser-assisted phacovitrectomy. METHODS: Fifteen patients over 50 years of age with coexisting vitreoretinal pathologies and cataract underwent combined femtosecond laser-assisted cataract extraction and sutureless 25-G and 27-G vitreoretinal surgery. RESULTS: The indication for surgery was macular hole in 6 patients, epiretinal membrane in 6, vitreous hemorrhage in 2, and retinal detachment in 1. The mean preoperative best-corrected visual acuity (BCVA) was 0.64 ± 0.23 logMAR and the mean postoperative BCVA was 0.19 ± 0.11 logMAR. In 4 patients with epiretinal membrane with corneal astigmatism of 3.35 ± 0.32 D as mean value, a toric intraocular lens (IOL) was implanted: mean residual refractive cylinder was 0.47 ± 0.23 D. Three months postoperatively, mean IOL rotation was 1.64 ± 0.28°. All patients improved their visual acuity. The intraoperative complications of femtosecond laser were 1 subconjunctival hemorrhage, 1 case of miosis, and 1 suction loss. The surgeon was able to maintain a clear view of the retina at all times. After surgery, a better fundus examination was possible with no capsular opacification. Mean follow-up was 6 months. CONCLUSIONS: Femtosecond laser cataract in vitreoretinal surgery appears a safe and effective technique with potential benefits: the precision and centration of the capsulorhexis may potentially reduce the risk of IOL prolapse into the anterior chamber in gas-filled eyes. Implantation of the toric IOL was effective in reducing preexisting corneal astigmatism and provided good rotational stability and refractive outcome.

STAINING-ASSISTED REMOVAL OF SILICONE OIL FOR THE IDENTIFICATION OF SUBCLINICAL PROLIFERATIVE VITREORETINOPATHY.

PURPOSE: Retinal detachment is a frequent complication after removal of silicone oil (ROSO). A retrospective study was conducted to determine whether staining-assisted removal of silicone oil (st-ROSO) allowed better identification and removal of proliferative vitreoretinopathy (PVR) processes compared with a conventional removal of silicone oil technique. METHODS: All individuals underwent pars plana vitrectomy (PPV) and silicone oil fill-in for complicated retinal detachments. In conventional removal of silicone oil (Group 1), no staining was used. In staining-assisted removal of silicone oil (Group 2), a mixture of trypan blue and brilliant blue G dyes was used to identify proliferative vitreoretinopathy and subclinical epiretinal membrane. RESULTS: After the first 3-month follow-up, 15.9% of patients (N = 608) developed a retinal detachment. Retinal detachment occurred in 22.8% of patients in Group 1 (n = 284) and 9.8% of patients in Group 2 (n = 324; P < 0.001). In Group 2, proliferative vitreoretinopathy removal was performed in 153 eyes (47.2%). CONCLUSION: The incidence of retinal redetachment was significantly lower after staining-assisted removal of silicone oil compared with a conventional technique. Staining-assisted removal of silicone oil allowed better identification and removal of proliferative vitreoretinopathy processes.

EFFECTS OF A MODIFIED VITRECTOMY PROBE IN SMALL-GAUGE VITRECTOMY: An Experimental Study on the Flow and on the Traction Exerted on the Retina.

PURPOSE: Thorough this experimental study, the physic features of a modified 23-gauge vitrectomy probe were evaluated in vitro. METHODS: A modified vitrectomy probe to increase vitreous outflow rate with a small-diameter probe, that also minimized tractional forces on the retina, was created and tested. The "new" probe was created by drilling an opening into the inner duct of a traditional 23-gauge probe with electrochemical or electrodischarge micromachining. Both vitreous outflow and tractional forces on the retina were examined using experimental models of vitreous surgery. RESULTS: The additional opening allowed the modified probe to have a cutting rate of 5,000 cuts per minute, while sustaining an outflow approximately 45% higher than in conventional 23-gauge probes. The modified probe performed two cutting actions per cycle, not one, as in standard probes. Because tractional force is influenced by cutting rate, retinal forces were 2.2 times lower than those observed with traditional cutters. CONCLUSION: The modified probe could be useful in vitreoretinal surgery. It allows for faster vitreous removal while minimizing tractional forces on the retina. Moreover, any available probe can be modified by creating a hole in the inner duct.