Factors influencing the reliability of measurements in eyes with full-thickness macular holes: are we measuring incorrectly?

PURPOSE: The calliper function is used for manual measurements of full thickness macular holes (FTMHs). We aimed to investigate whether a reproducible difference could be detected beyond interobserver variability between two commonly used manufacturers in their manual calliper facility in spectral domain optical coherence tomography (OCT) for metrics related to FTMH. METHODS: This is a non-interventional, retrospective, observational study. Two independent observers examined 8 eyes (16 OCT) scans and 128 measurements (minimal linear diameter (MLD), basal diameter and hole height on both sides) of FTMHs, taken on Heidelberg Spectralis and Topcon Triton (OCT machines). The interobserver agreement and OCT machine agreement of measurements were analysed by Bland-Altman plots and intraclass correlation coefficient (ICC) analysis. Spectralis and Triton had 125 µm and 50 µm horizontal b-scan spacing, respectively. RESULTS: Overall, we report high absolute agreement in interobserver (ICC 0.991 (95% CI 0.985 to 0.995, p<0.001)) and OCT machine (ICC 0.993 (95% CI 0.987 to 0.996, p<0.001)) variability. Lower horizontal resolution in Triton compared with Spectralis leads to interobserver variability, in smaller horizontal measurements. Lower horizontal scanning density in Spectralis lead to relatively large interobserver variation if different reference scans were chosen, and consistently smaller MLD measurements than Triton. Vertical measurements without 1:1 scaling lead to inaccurate exaggerated oblique vertical measurements. Calliper function appears otherwise identically calibrated. CONCLUSIONS: We report excellent interobserver and OCT machine agreement in measurements. However, the paper shows several factors that could influence the reliability of measurements acquired in eyes with FTMHs, such as the dimension of the hole as well as different image resolution, density scanning protocols or vertical scaling of the OCT machines viewing platform.

Novel Method to Measure Volumes of Retinal Specific Entities.

Objectives: The aim of this study is to describe and validate an optical-coherence-tomography (OCT)-based method to easily calculate specific volumes, addressing the limitations of current OCT software in automating volumetric analysis for specific entities in retinal pathologies. Methods: After manually drawing the specific entity on linear OCT scans using the calliper function and automated measurement of its area, the following formula was used for volumetric calculation: Volume [mm3] = ∑area [mm2] × OCT-scan distance [mm]. Retinal volume (RV) was measured by two independent observers in eyes with a normal foveal profile (NFP) and was compared with the automated measurements performed by the OCT software (Engineering GmbH, Heidelberg, Germany); the same process was repeated for the volume of the foveal cavity (FC) or foveoschisis (FS) in eyes with lamellar macular holes (LMHs). Power calculations were conducted to ensure adequate sample size. The measurements were re-acquired after six weeks. Intra- and inter-observer variability as well as comparison to automated RV calculations were analysed. Results: This study included a total of 62 eyes divided into two groups: the NFP (30 eyes) and LMH (32 eyes) groups. The Bland-Altman plots showed a high degree of agreement in both groups for inter-observer and intra-observer agreement. In addition, in the NFP group, a high degree of agreement was demonstrated between human observers and the OCT software (Spectralis). Conclusions: An easy, reliable, and widely applicable method to calculate volumes is described and validated in this paper, showing excellent inter- and intra-observer agreement, which can be applied to any entity requiring a specific study in the context of retinal pathologies.

Volumetric Biomarkers of Visual Outcome after Surgical Repair in Lamellar Macular Holes.

BACKGROUND: We investigate novel OCT parameters, based on the volumetric analysis of lamellar macular holes (LMHs), as prognostic indicators for visual outcomes after surgery. METHODS: LMHs were divided into degenerative LMHs (D-LMHs) and ERM-foveoschisis (ERM-FS). Pre-operative clinical, OCT linear and volumetric parameters were collected. Volumes were obtained using the OCT automatic segmentation, such as central retinal volume (CRV) and outer nuclear layer (ONL) volume, or using a novel method to calculate volumes of specific LMH entities like epiretinal proliferation (ERP), foveal cavity (FC) in D-LMH and schitic volume (SV) in ERM-FS. Univariate and multivariate linear regression analysis evaluated the factors predictive for post-operative best-corrected visual acuity (BCVA). RESULTS: We included 31 eyes of 31 patients (14 D-LMH,17 ERM-FS). A pre-operative BCVA ≤ 0.48 logMAR was a predictor for achieving ≤0.30 logMAR at final follow-up. A lower pre-operative BCVA (p = 0.008) and the presence of ERP (p = 0.002) were associated with worse visual outcomes post-surgery. Moreover, novel pre-operative OCT parameters significantly associated with worse post-operative BCVA, such as increased FC volume (p = 0.032) and lower CRV (p = 0.034) in the D-LMH subtype and lower CRV (p < 0.001) and ERP volume (p < 0.001), higher SV (p < 0.001) and foveal ONL volume (p < 0.001) in the ERM-FS subtype. CONCLUSIONS: Novel volumetric OCT parameters can be prognostic indicators of visual outcome following surgery in LMHs.

SF 6 COMPARED WITH C 2 F 6 FOR INFERIOR RHEGMATOGENOUS RETINAL REPAIR : The Manchester Pseudophakic Retinal Detachment Study.

PURPOSE: To compare SF 6 relative with C 2 F 6 in the anatomical and functional outcomes following pars plana vitrectomy for uncomplicated primary pseudophakic rhegmatogenous retinal detachment with inferior causative breaks. METHODS: This is a retrospective, comparative study on eyes with pseudophakic rhegmatogenous retinal detachment with inferior causative breaks that had small-gauge pars plana vitrectomy repair using SF 6 and C 2 F 6 tamponade between 2011 and 2020 at a tertiary centre in the United Kingdom. Primary outcome was single surgery anatomical success, and the secondary outcome was best-corrected visual acuity. Propensity score matching, using preoperative findings as covariates to account for relevant confounders, was performed. RESULTS: From 162 pseudophakic rhegmatogenous retinal detachment eyes with inferior causative breaks, the median (interquartile range) follow-up was 82 (52-182) days. The single surgery anatomical success was 156 (96.3%) overall: 47 of 47 (100.0%) and 109 of 115 (94.8%) in the SF 6 and C 2 F 6 groups, respectively ( P = 0.182). Relative to the SF 6 group, the C 2 F 6 group had a higher mean number of tears (SF 6 : 3.1[2.0], C 2 F 6 : 4.5[2.7], P = 0.002) and greater retinal detachment extent (SF 6 : 5.3[2.9], C 2 F 6 : 6.2[2.6] clock hours, P = 0.025). Following propensity score matching analysis, 80 eyes were matched with 40 in each group to homogenize preoperative factors. No significant difference was found in single surgery anatomical success and best-corrected visual acuity between the groups following propensity score matching. CONCLUSION: Primary pars plana vitrectomy with gas tamponade leads to a high single surgery anatomical success rate in uncomplicated pseudophakic rhegmatogenous retinal detachment with inferior causative breaks with no additional benefit associated with long-acting tamponade when comparing C 2 F 6 with SF 6 .

THE LONG-TERM RECOVERY OF VISION IN PSEUDOPHAKIC MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENTS.

PURPOSE: To assess the long-term visual recovery in uncomplicated macula-off pseudophakic rhegmatogenous retinal detachment treated with pars plana vitrectomy and gas tamponade in the absence of other visual comorbidities. METHODS: Single-center retrospective longitudinal study on eyes with macula-off pseudophakic rhegmatogenous retinal detachment successfully treated with pars plana vitrectomy between 2011 and 2020 and with at least 2 follow-ups (FU), first gas-free FU (first-FU) and a final-FU, were included. Patients with subsequent ocular surgery or comorbidities affecting best-corrected visual acuity were excluded. The duration between operation date and final-FU was calculated (total days FU) and split into total days quintiles-1: ≤57, 2: >57 and ≤77, 3: >77 and ≤152, 4: >152 and ≤508, and 5: >508 days. Multivariable regression was performed with logMAR gain between the first and the final-FU as the dependent variable. RESULTS: In 209 eyes, the authors report association with increase of logMAR gain between the first and the final-FU, with reducing clock hours of pseudophakic rhegmatogenous retinal detachment ( P = 0.041) and relative to the total days Quintile 1. Mean (SD) logMAR gain between the first and the final-FU was 0.02 (0.07) in the first quintile, increasing to 0.14 (0.13) ( P < 0.001) by the fifth quintile on multivariable regression. For patients not achieving 0.30 logMAR at the first-FU, this was attained at the final-FU with a sensitivity of 51.9% and specificity of 95.5% at a cut off ≤0.58 logMAR at the first-FU (area under the curve 0.756 [95% confidence interval 0.664-0.848], P < 0.001). CONCLUSION: The authors report a significant time-dependent visual improvement after uncomplicated pars plana vitrectomy with gas tamponade for macula-off pseudophakic rhegmatogenous retinal detachment without visual confounders and provide important quantitative data for counselling patients with macula-off repair.

Long-Term Safety and Efficacy of Pars Plana Vitrectomy for Uveitis: Experience of a Tertiary Referral Centre in the United Kingdom.

AIM: To evaluate the effectiveness of pars plana vitrectomy (PPV) without macular intervention on uveitis eyes with persistent vitreous inflammation/opacities in terms of visual acuity (VA), intraocular inflammation and macular profile. METHODS: We carried out a single-center retrospective study of patients with uveitic eyes that underwent PPV without intervention on the macula due to persistent vitreous inflammation/opacities. The primary outcome measures were best-corrected visual acuity (BCVA), intraocular inflammation and macular profile at 3, 12 and 24 months after surgery. RESULTS: Twenty-seven eyes of twenty-six patients were analyzed. Overall, 77.8% had an improvement of VA (55% by 0.3 LogMAR or more); 62.5% of patients had no intraocular inflammation, and the number of patients on systemic steroids and second-line immunosuppressives was reduced by 26% at 12 months; 87.5% of patients had resolution of macular oedema at 12 months. CONCLUSION: PPV for persistent vitreous inflammation/opacities is safe and effective, showing beneficial outcomes in terms of improvement of BCVA and the reduction in inflammation.

Expansile gas concentration in primary pseudophakic retinal detachment repair, effect on intraocular pressure and outcomes; the Manchester Pseudophakic Retinal Detachment Study.

PURPOSE: To investigate the effect of isovolumetric and expansile gas tamponade concentrations on single surgery anatomical success (SSAS) and day 1 intraocular pressure (IOPD1) following pars plana vitrectomy (PPV) for mild-moderate complexity primary pseudophakic rhegmatogenous retinal detachment (PRD). METHODS: We conducted a single-centre retrospective continuous and comparative study on eyes that had undergone small-gauge PPV using isovolumetric versus expansile gas for PRD repair between 2011 and 2020 at a single tertiary vitreoretinal centre in UK. We performed propensity score matching (PSM) using preoperative findings as covariates to account for relevant confounders. Significant risk factors such as proliferative vitreoretinopathy C or giant retinal tears were excluded. RESULTS: From 456 eyes, PSM analysis matched 240 eyes with 120 in each group. The median (interquartile range) follow-up was 96 (59 to 218) days. The SSAS was 229/240 (95.8%) overall; 115/120 (95.8%) and 114/120 (95.0%) in isovolumetric and expansile groups, respectively (p = 1.000). Relative to the isovolumetric group, the expansile group had lower proportion of eyes with IOP ≤ 21 mmHg (odds ratio, 95% confidence interval, 0.40 [0.23-0.68], p < 0.001); but significantly higher number of eyes with IOP ≥ 22 mmHg (2.53 [1.48-4.34], p < 0.001), ≥ 25 mmHg (2.77 [1.43-5.33], p < 0.001), ≥ 30 mmHg (2.90 [1.28-6.58], p = 0.006) and ≥ 40 mmHg (p = 0.029, isovolumetric: 0 [0%] vs expansile group: 6 [5%]). There was only one case of hypotony (≤ 5 mmHg) 1/240 (0.4%) which occurred in the expansile group. CONCLUSIONS: Expansile gas concentration does not impact SSAS but is associated with significantly raised IOPD1 with no reduction in hypotony rates following PPV for primary PRD.

The impact of 360-laser barricade on outcomes of vitrectomy for pseudophakic retinal detachment; The Manchester Pseudophakic Retinal Detachment Study.

PURPOSE: To investigate the anatomical and functional outcomes and specifically, the effect of 360-degree barrier-laser, in pars plana vitrectomy (PPV) for primary pseudophakic rhegmatogenous retinal detachment (PRD). METHODS: We conducted a single-centre retrospective, continuous and comparative study on eyes that had undergone PPV with focal-retinopexy (laser or cryotherapy) versus 360-laser for PRD repair between 2011-2020 at a single tertiary vitreoretinal centre in the UK. Primary outcomes were single surgery anatomical success (SSAS) rate and final postoperative visual acuity (VA). Multivariable regression covariates for primary re-detachment included age, gender, onset-of-detachment, pre-operative VA, ocular co-morbidities, macula-status, majority inferior (vs superior) PRD, number-of-tears and PRD extent (in clock-hours), 360-laser barricade, and perfluorocarbon liquid (PFCL) use. For VA gain, primary re-detachment was added as a covariate. RESULTS: We included 467 eyes with a mean follow-up of 388 (161) days. The SSAS was 444/467 (95.1%) overall, and 351/370 (94.9%) and 93/97 (95.9%) in focal-retinopexy and 360-laser groups, respectively (p = 0.798). Compared to the focal-retinopexy group, the 360-laser group had significantly worse post-operative VA but similar logMAR gain (p = 0.812). A multivariable binary logistic regression found that only PFCL use was linked with increased primary re-detachment (OR:5.32 [p = 0.048]) and 360-laser did not contribute to increased SSAS. A multivariable linear regression analysis showed that poor logMAR gain was significantly associated with better pre-operative logMAR, ocular co-morbidities, greater PRD extent, use of 360-laser and primary re-detachment. However, when excluding macula-off RD (n = 211), 360-laser was no longer significant (p = 0.088). CONCLUSIONS: Prophylactic 360-laser does not seem to impact on SSAS and functional outcomes following PPV for primary PRD.

New simulation software to predict postoperative corneal stiffness before laser vision correction.

PURPOSE: To develop a new virtual surgery simulation platform to predict postoperative corneal stiffness (Kc mean ) after laser vision correction (LVC) surgery. SETTING: Narayana Nethralaya Eye Hospital and Sankara Nethralaya, India; Humanitas Clinical and Research Center, Italy. DESIGN: Retrospective observational case series. METHODS: 529 eyes from 529 patients from 3 eye centers and 10 post-small-incision lenticule extraction (SMILE) ectasia eyes were included. The software (called AcuSimX) derived the anisotropic, fibril, and extracellular matrix biomechanical properties (using finite element calculation) of the cornea using the preoperative Corvis-ST, Pentacam measurement, and inverse finite element method assuming published healthy collagen fibril orientations. Then, the software-computed postoperative Kc mean was adjusted with an artificial intelligence (AI) model (Orange AI) for measurement uncertainties. A decision tree was developed to classify ectasia from normal eyes using the software-computed and preoperative parameters. RESULTS: In the training cohort (n = 371 eyes from 371 patients), the mean absolute error and intraclass correlation coefficient were 6.24 N/m and 0.84 (95% CI, 0.80-0.87), respectively. Similarly, in the test cohort (n = 158 eyes from 158 patients), these were 6.47 N/m and 0.84 (0.78-0.89), respectively. In the 10 ectasia eyes, the measured in vivo (74.01 [70.01-78.01]) and software-computed (74.1 [69.03-79.17]) Kc mean were not statistically different ( P = .96). Although no statistically significant differences in these values were observed between the stable and ectasia groups ( P ≥ .14), the decision tree classification had an area under the receiver operating characteristic curve of 1.0. CONCLUSIONS: The new software provided an easy-to-use virtual surgery simulation platform for post-LVC corneal stiffness prediction by clinicians and was assessed in post-SMILE ectasia eyes. Further assessments with ectasia after surgeries are required.

Safety Profile of Lutein- Versus Triamcinolone Acetonide-Based Vitreous Staining.

Purpose: To assess the safety profile of a new lutein-based vitreous dye (LB-VD) formulation compared with various triamcinolone acetonide (TA) formulations with and without subsequent exposure to perfluorodecalin (PFD) in vitro. Methods: Human adult retinal pigment epithelial cells (ARPE-19) were treated with the following formulations: undiluted preserved TA (TA-BA), diluted preserved TA (D-TA-BA), preservative-free TA (TA-PF), and LB-VD. First, cell tolerability was evaluated with MTT, LDH, and ATPlite assays after 1, 5, and 30 minutes of exposure to each tested formulation. Then, cells were sequentially exposed to formulations and PFD. After 24 hours of exposure to PFD, cell tolerability was evaluated through MTT and ATPlite assays. Results: Among the formulations tested, LB-VD showed the highest levels of cell viability, cell metabolism, and cell proliferation and induced the lowest release of LDH, whereas the TA-based formulations demonstrated a cytotoxic effect on ARPE-19 cells in vitro. After subsequent 24-hour exposure to PFD, a greater reduction of cell viability was noted for all the formulations; however, this reduction was not significant only for the combination LB-VD-PFD, which was the best tolerated condition. Conclusions: LB-VD showed a better safety profile compared with all TA-based formulations, even when used in combination with PFD. Translational Relevance: In surgical practice, LB-VD may be preferred to TA-based formulations for vitreous staining in the light of its more favorable safety profile.

Choroidal Caverns in Stargardt Disease.

Purpose: To report choroidal caverns in patients affected by recessive Stargardt disease (STGD1) and to investigate its clinical features. Methods: Retrospective analysis of STGD1 patients recruited at the Regional Reference Center for Hereditary Retinal Degenerations at the Eye Clinic in Florence from 2012 to 2017. Patients included in the study underwent a complete ophthalmic examination including best-corrected visual acuity, color fundus photography, fundus autofluorescence, optical coherence tomography (OCT) and OCT angiography. Results: Eighty-six patients (172 eyes) were included in the study. Twenty-three eyes (13.3%) of 21 patients presented choroidal caverns. The total number of detected choroidal caverns was 63. Choroidal caverns were only present in patients with stage III and IV STGD. Interestingly, patients with choroidal caverns presented larger macular atrophy (20.53 ± 16.9 mm2 vs. 18.11 ± 20.39 mm2), worse visual acuity (1.03 ± 0.29 vs. 0.83 ± 0.26), and a thinner choroidal thickness (245.9 ± 88.7 vs. 266.0 ± 110.5 µm). Conclusions: Choroidal caverns are present only in the advanced stage of STGD1, and a possible degenerative origin of the finding has been hypothesized.

Xen Gel Stent as a minimally invasive option for intraocular pressure control after DSAEK: A case study.

PURPOSE: This case study describes the implantation of a Xen45 Gel Stent in a patient that had previously undergone Descemet stripping automated endothelial keratoplasty (DSAEK). Glaucoma might worsen after corneal transplant, and while medical treatment is the first-line therapy to achieve intraocular pressure (IOP) control, a surgical approach is required when medication does not reach the target IOP. METHODS: In 2017, the patient underwent treatment in both eyes with ocular hypotensive eye drops for pseudoexfoliative (PXF) glaucoma. In May 2017, DSAEK was performed on the right eye because of the presence of a pseudophakic bullous keratopathy. An increase in IOP, resistant to medical treatment, was observed after the corneal transplant. In November 2017, a Xen45 Gel Stent was implanted. RESULTS: The patient had a positive outcome with a Xen45 Gel Stent implant in surgical glaucoma treatment after DSAEK. The case demonstrated excellent postoperative IOP control, stable vision and a healthy ocular graft at short-term and long-term follow-ups. CONCLUSION: Studies with larger numbers of patients in this particular form of therapy are required. Nevertheless, Xen45 Gel Stent implantation appears to be a promising option in preventing or limiting glaucoma in patients who have previously undergone DSAEK. It is a brief, minimally invasive procedure with reduced postoperative inflammation, faster visual recovery and a lower risk of graft damage or hypotony, even in the case of PXF glaucoma.

The role of anterior segment optical coherence tomography in uveitis-glaucoma-hyphema syndrome.

PURPOSE: To describe features of uveitis-glaucoma-hyphema (UGH) syndrome, using Anterior Segment-Optical Coherence Tomography (AS-OCT) and Ultrasound Biomicroscopy (UBM) and to evaluate the diagnostic role of AS-OCT as an imaging technique alternative to UBM. DESIGN: Retrospective case series. METHODS: Four eyes of 4 patients with UGH syndrome were analyzed. All patients reported previous uncomplicated cataract surgery with in-the-bag implantation of single-piece-intraocular lens (IOL). They underwent at presentation complete ophthalmological examination and imaging with slit-lamp anterior segment photographs, UBM and AS-OCT. RESULTS: Although AS-OCT did not allow to visualize the structures behind the iris, it displayed a contact between IOL (plate and/or haptics) and iris and IOL tilting in 3 out of 4 eyes. AS-OCT directly detected the cause of UGH syndrome in one eye, 2 eyes required some expedients to display the iris chafing, like scans in mydriasis and/or patient's gaze direction change. AS-OCT did not allow to appreciate the IOL-iris contact (showed by UBM technique) only in one eye, probably due to the change of patient position from supine to sitting, and consequent anteriorization of iris diaphragm. Furthermore AS-OCT showed fine details, as capsular bag collapse and indirect signs of haptic malposition in 3 out of 4 eyes. CONCLUSION: AS-OCT is a non-invasive technique that allows to determine IOL position and IOL-uveal contact in selected cases of UGH syndrome. Considering AS-OCT and UBM advantages and limitations, AS-OCT should be used as first imaging modality when clinical diagnosis is uncertain. When UGH diagnosis cannot be verified using AS-OCT, UBM should be performed.

Outcome and genetic analysis of patients affected by retinal capillary hemangioblastoma in von Hippel Lindau syndrome.

Purpose: To describe genetic analysis, treatment results, and complications of patients affected by retinal capillary hemangioblastoma (RCH) in von Hippel Lindau (VHL) syndrome. Methods: We collected 17 patients with VHL syndrome, who underwent a molecular test and an ophthalmic evaluation at the Eye Clinic of the University Hospital of Florence from January 2005 to February 2020. We focused on eyes showing RCHs examined using color fundus photographs, fluorescein angiography, and optical coherence tomography. Results: Eight eyes of six patients (6/17; 35%) showed RCHs at the fundoscopic examination. All RCHs were treated with laser therapy. Three eyes underwent episcleral surgery, one eye showing vitreous hemorrhage received three intravitreal (IV) anti-VEGF injections and three cryotherapy procedures, and one eye underwent vitrectomy. In patients with RCHs, five were characterized by a truncating mutation of the VHL protein, and one patient showed a missense mutation. We have reported two VHL mutations not reported in literature. Conclusions: Patients with multiple RCHs, who developed RCH secondary effects, showed truncating mutations of the VHL protein. We recommend early screening and close monitoring, especially if RCHs are detected at presentation, for every patient with VHL syndrome independently of the results of the molecular test for a missense or a truncating mutation in VHL.

Outer nuclear layer relevance in visual function correlated to quantitative enface OCT parameters in Stargardt disease.

PURPOSE: To evaluate the correlation between Best Corrected Visual Acuity (BCVA) and the following parameters in Stargardt Disease (STGD): Central Retinal Thickness (CR-T), Central Outer Nuclear Layer Thickness (C-ONL-T), Areas of macular Photoreceptor loss (PHRa), and Retinal Pigment Epithelium (RPE) loss (RPEa). METHODS: A total of 64 eyes of 32 STGD patients were included in the study. All patients received a comprehensive ophthalmological examination, color fundus photographs, fundus auto-fluorescence imaging, and Optical Coherence Tomography (OCT). The CR-T and C-ONL-T were evaluated from standard SD-OCT scans. The PHRa and RPEa were calculated from enface OCT scans (sub RPE slab and photoreceptor slab). The collected OCT parameters were evaluated for possible association with BCVA. RESULTS: The mean macular PHRa and RPEa was 16.16 ± 13.36 and 12.05 ± 12.57 mm2 respectively. The mean CR-T measured 120.78 ± 41.49 µm while the mean C-ONL-T was assessed at 4.60 ± 13.73 µm. BCVA showed the highest correlation with the C-ONL-T (r = -0.72; p < 0.001) while there was no correlation with the CR-T (r = -0.17; p = 1.00). CONCLUSIONS: Enface OCT permits a rapid and precise quantitative evaluation of the macular PHR and RPE atrophy area in STGD. Nonetheless, the OCT parameter that showed the highest correlation with visual acuity in STGD was the ONL thickness.

Choroidal Vascularity Index in CHM Carriers.

Purpose: To assess the choroidal structure using the Choroidal Vascularity Index (CVI) and analyse choroidal changes in choroideremia (CHM) carriers. Material and Methods: Female CHM carriers, genetically characterized, and a control group were recruited at the Eye Clinic of Careggi Teaching Hospital, Florence. The patients underwent a complete ophthalmic evaluation and retinal imaging. In particular, the Stromal Area (SA), Luminal Area (LA), Total Choroidal Area (TCA), CVI, and Subfoveal Choroidal Thickness (SFCT) were calculated for each eye using Optical Coherence Tomography (OCT) examinations. Results: Twelve eyes of 6 CHM carriers and 14 eyes of 7 age-matched controls were analysed. The mean SFCT was 270.9 ± 54.3µm in carriers and 281.4 ± 36.8µm in controls (p = 0.564); LA was 0.99 ± 0.25mm2 and 1.01 ± 0.13mm2 (p = 0.172); SA was 0.53 ± 0.09mm2 and 0.59 ± 0.07mm2 (p = 0.075), and TCA was 1.53 ± 0.34mm2 and 1.69 ± 0.19mm2 respectively (p = 0.146). Mean CVI measured 64.03 ± 3.98% in the CHM carriers and 65.25 ± 2.55% in the controls (p = 0.360). Conclusions: The CVI and CVI-related parameters (SA, LA, and TCA) do not differ between CHM female carriers and controls. These findings reveal a preserved choroidal vasculature in eyes with RPE impairment and support the primary role of RPE in the pathogenesis of CHM disease.

Microbubble technique in failed deep anterior lamellar keratoplasty: 2-year outcomes.

PURPOSE: To compare the long-term results of big-bubble technique and microbubble techniques to complete stroma dissection after failure of achieving a big-bubble. METHODS: A total of 35 eyes with keratoconus underwent lamellar keratoplasty with the big-bubble technique (15 eyes) or the microbubble technique (15 eyes). Conversion to penetrating keratoplasty was performed in 3 eyes of the big-bubble group and in 2 eyes of the microbubble group. Best-corrected visual acuity, corneal thickness, corneal astigmatism, and endothelial cell count were assessed preoperatively and at 12 and 24 months after surgery. RESULTS: Mean preoperative visual acuity was 0.29 ± 0.18 in the big-bubble group and 0.25 ± 0.15 in the microbubble group. Postoperatively, all patients showed a regular interface between donor and recipient tissue. At 24 months, mean best-corrected visual acuity was 0.84 ± 0.16 in the big-bubble group and 0.68 ± 0.17 in the microbubble group (p = 0.013), and mean central corneal thickness was 530 ± 39 µm in the big-bubble group and 545 ± 30 µm in the microbubble group. Astigmatism was 2.41 ± 1.29 D and 3.59 ± 1.48 D (p = 0.036), respectively, while endothelial cell density was 1,671 ± 371 in the big-bubble group and 1,567 ± 275 in the microbubble group. CONCLUSIONS: The microbubble technique appears to be a valid alternative as it was safe and provided good functional results.

Canaloplasty: Current Value in the Management of Glaucoma.

Canaloplasty is a nonpenetrating blebless surgical technique for open-angle glaucoma, in which a flexible microcatheter is inserted within Schlemm's canal for the entire 360 degrees. When the microcatheter exits the opposite end, a 10-0 prolene suture is tied and it is then withdrawn, by pulling microcatheter back through the canal in the opposite direction. Ligation of prolene suture provides tension on the canal and facilitates aqueous outflow. The main advantage of canaloplasty is that this technique avoids the major complications of fistulating surgery related to blebs and hypotony. Currently, canaloplasty is performed in glaucoma patients with early to moderate disease and combination with cataract surgery is a suitable option in patients with clinically significant lens opacities.