Use of the Three-dimensional Viewing System and Microscope Tilting to Extend the Peripheral Retinal View.

PURPOSE: To describe and evaluate the effectiveness of the microscope and lens tilting technique associated with the three-dimensional viewing system for improving the peripheral retinal view in noncontact lens vitreoretinal surgeries. METHODS: Prospective, single-center, single-surgeon, consecutive case series of 25 patients undergoing vitrectomy for macular surgeries with three-dimensional visualization system. At the end of each surgery, the microscope and the noncontact lens were rotated by 20° in a direction opposite to the rotation of the eye to extend the peripheral visual field. RESULTS: Microscope and lens tilting technique extended the edge of the peripheral viewing field relative to its position with the microscope untilted, by 1.72 mm (±0.37) for the superior retina and 1.93 mm (±0.42) for the inferior retina (P < 0.0001). The ora serrata was visualized in 33% and 0% of cases for the superior retina and 91% and 36% of cases for the inferior retina, in tilted and nontilted microscope positions, respectively (P < 0.01). CONCLUSION: Microscope and lens tilting could be useful to extend the peripheral visual field of view in retinal surgery. The three-dimensional system allowed to maintain surgeon comfort and posture during surgery.

Nestin contributes to laser choroidal and retinal neovascularization.

Purpose: Choroidal and retinal neovascularization plays an essential role in various ocular diseases. In this study, we examined the role of nestin in this process. Nestin is an intermediate filament protein known to play several roles, including as a marker of neural progenitor and proliferating endothelial cells. Methods: We used Brown Norway rats, in which choroidal and retinal neovascularization was induced using intraocular laser impacts. The role of nestin was examined using angiography, western blot from the second to the 14th day after laser impacts, and intraocular injection of nestin siRNA. The localization of the protein was specified by co-immunoreactivity with glial fibrillary protein (GFAP), glutamine synthetase (GS), and von Willebrand factor (vWF). Results: In the control retina, nestin was found principally in glial structures in the ganglion cell layer, as confirmed by nestin/GFAP immunolabeling. Two days after the laser impacts, the nestin expression extended to numerous radial processes at the site of the impacts. With Bruch's membrane ruptured, these processes penetrated into the choroid. Nestin immunolabeling remained high from the third to the seventh day but appeared reduced on the 14th day. The nature of these processes was not clearly defined, but co-immunolabeling with GFAP suggested that they were principally in activated Müller cells from the third day after the laser impacts. However, the co-immunoreactivity of nestin and GS, a marker of mature functional Müller cells, could be observable only from the seventh day. Nestin was also observed in some vascular cells, as demonstrated by the co-immunoreactivity of the protein with vWF in the choroid and retina. As observed on angiography, the numbers of choroidal and retinal blood vessels were significantly increased (principally on the seventh day) after the laser impacts. An intraocular injection of nestin siRNAs led to a significant decrease in the number of blood vessels. Conclusions: Our results confirmed the presence of nestin in glial (e.g., astrocytes), reactive Müller, and endothelial cells. They demonstrated their critical involvement in a rat model of retinal and choroidal neovascularization experimentally induced using ocular laser impacts.

A new CRB1 rat mutation links Müller glial cells to retinal telangiectasia.

We have identified and characterized a spontaneous Brown Norway from Janvier rat strain (BN-J) presenting a progressive retinal degeneration associated with early retinal telangiectasia, neuronal alterations, and loss of retinal Müller glial cells resembling human macular telangiectasia type 2 (MacTel 2), which is a retinal disease of unknown cause. Genetic analyses showed that the BN-J phenotype results from an autosomal recessive indel novel mutation in the Crb1 gene, causing dislocalization of the protein from the retinal Müller glia (RMG)/photoreceptor cell junction. The transcriptomic analyses of primary RMG cultures allowed identification of the dysregulated pathways in BN-J rats compared with wild-type BN rats. Among those pathways, TGF-ß and Kit Receptor Signaling, MAPK Cascade, Growth Factors and Inflammatory Pathways, G-Protein Signaling Pathways, Regulation of Actin Cytoskeleton, and Cardiovascular Signaling were found. Potential molecular targets linking RMG/photoreceptor interaction with the development of retinal telangiectasia are identified. This model can help us to better understand the physiopathologic mechanisms of MacTel 2 and other retinal diseases associated with telangiectasia.

Anatomic Predictive Factors of Acute Corneal Hydrops in Keratoconus: An Optical Coherence Tomography Study.

PURPOSE: To define the optical coherence tomography (OCT) corneal changes predisposing to acute corneal hydrops among patients with advanced keratoconus. DESIGN: Retrospective cohort study. PARTICIPANTS: A total of 191 advanced keratoconic eyes from 191 patients with advanced keratoconus cases were studied. METHODS: Data collected from patients with advanced keratoconus cases were studied during a minimum period of 24 months of follow-up. High-resolution Fourier-domain corneal OCT (5 µm of axial resolution) and corneal topography were performed every 4 months during the follow-up. Several anatomic features at the keratoconus cone were analyzed with OCT, including epithelial and stromal thicknesses, the aspect of Bowman's layer, the presence of Vogt's striae, and stromal opacities. A comparative analysis between anatomic corneal features in eyes that developed corneal hydrops and those that did not develop this complication during the follow-up was performed. MAIN OUTCOME MEASURES: Evaluation of anatomic corneal changes at risk of developing a corneal hydrops on the basis of OCT findings. RESULTS: Eleven cases of corneal hydrops (5.8%) occurred in our series during a mean follow-up of 30 months (24-36 months). All of these patients were male and younger (23.7±5.9 years) than patients with no acute keratoconus (32.7±11.3 years). Increased epithelial thickening with stromal thinning at the conus and the presence of anterior hyperreflectives at the Bowman's layer level were significantly associated with corneal hydrops, whereas the presence of corneal scarring was a preventive factor. At the healing stage, a pan-stromal scar occurs, with a significant stromal thickening and cornea flattening. CONCLUSIONS: Increased epithelial thickening, stromal thinning at the keratoconus cone, anterior hyperreflectives at the Bowman's layer level, and the absence of stromal scarring are associated with a high risk of developing corneal hydrops. These aspects should be taken into account by the clinician in the evaluation of keratoconus eyes and in the planning of corneal keratoplasty.

VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING FOR TRACTIONAL AND NONTRACTIONAL DIABETIC MACULAR EDEMA: Long-term Results of a Comparative Study.

PURPOSE: To compare the long-term outcomes of vitreomacular surgery in eyes with nontractional diabetic macular edema (DME) with those from eyes with tractional DME. METHODS: Retrospective comparative study from 55 consecutive patients (73 eyes). Twenty eyes were operated on for tractional DME and 53 eyes for nontractional DME unresponsive to laser photocoagulation or triamcinolone intravitreal injections. The best-corrected visual acuity, the central macular thickness, and the surgical complications were analyzed. RESULTS: The mean follow-up duration was 5.3 ± 2.4 years for the group with traction and 4.4 ± 1.7 years for the group without traction (P = 0.13). At 3 years, the mean logarithm of the minimum angle of resolution best-corrected visual acuity had improved significantly from 0.78 to 0.58 for the group without traction and from 0.75 to 0.45 for the group with traction (P < 0.001). At the final visit, there was no significant difference between the 2 groups in regard to visual or central macular thickness improvement (P = 0.447 and P = 0.742, respectively). The incidence of surgical complications was not significant between the two groups. The preoperative best-corrected visual acuity was the only predictive factor for the final best-corrected visual acuity. CONCLUSION: The results of vitrectomy were not different in terms of anatomical and visual outcomes and surgical complications between eyes without tractional DME and eyes with tractional DME.

Fourier-domain optical coherence tomography imaging in keratoconus: a corneal structural classification.

OBJECTIVE: To study corneal morphologic changes in a large keratoconic population and to establish a structural optical coherence tomography (OCT) classification. DESIGN: Cross-sectional, observational study. PARTICIPANTS: A total of 218 keratoconic eyes from 218 patients and 34 eyes from 34 normal subjects. METHODS: A Fourier-domain OCT system with 5-µm axial resolution was used. For each patient, 3 high-resolution scans were made across the keratoconus cone. All scans were analyzed by keratoconus specialists who were not given access to patients' clinical and topographic data, and who established an OCT classification. The reproducibility of the classification and its correlation with clinical and paraclinical characteristics of patients with keratoconus were evaluated. The OCT examinations were performed every 4 months to follow up structural corneal changes. MAIN OUTCOME MEASURES: Evaluation of the structural corneal changes occurring in keratoconus cases with various stages of severity based on OCT findings. RESULTS: Fourier-domain OCT classification containing 5 distinct keratoconus stages is proposed. Stage 1 demonstrates thinning of apparently normal epithelial and stromal layers at the conus. Stage 2 demonstrates hyperreflective anomalies occurring at the Bowman's layer level with epithelial thickening at the conus. Stage 3 demonstrates posterior displacement of the hyperreflective structures occurring at the Bowman's layer level with increased epithelial thickening and stromal thinning. Stage 4 demonstrates pan-stromal scar. Stage 5 demonstrates hydrops; 5a, acute onset: Descemet's membrane rupture and dilaceration of collagen lamellae with large fluid-filled intrastromal cysts; 5b, healing stage: pan-stromal scarring with a remaining aspect of Descemet's membrane rupture. The reproducibility of the classification was very high between the corneal specialist observers. Clinical and paraclinical characteristics of keratoconus, including visual acuity, corneal epithelium and stromal thickness changes, corneal topography, biomechanical corneal characteristics, and microstructural changes observed on confocal microscopy, were concordant with our OCT grading. CONCLUSIONS: Optical coherence tomography provides an accurate assessment of structural changes occurring in keratoconus eyes. These changes were correlated with clinical and paraclinical characteristics of patients. The established classification not only allows structural follow-up of patients with keratoconus but also provides insight into the pathogenesis of keratoconus and treatment strategies for future research.

Suprachoroidal electrotransfer: a nonviral gene delivery method to transfect the choroid and the retina without detaching the retina.

Photoreceptors and retinal pigment epithelial cells (RPE) targeting remains challenging in ocular gene therapy. Viral gene transfer, the only method having reached clinical evaluation, still raises safety concerns when administered via subretinal injections. We have developed a novel transfection method in the adult rat, called suprachoroidal electrotransfer (ET), combining the administration of nonviral plasmid DNA into the suprachoroidal space with the application of an electrical field. Optimization of injection, electrical parameters and external electrodes geometry using a reporter plasmid, resulted in a large area of transfected tissues. Not only choroidal cells but also RPE, and potentially photoreceptors, were efficiently transduced for at least a month when using a cytomegalovirus (CMV) promoter. No ocular complications were recorded by angiographic, electroretinographic, and histological analyses, demonstrating that under selected conditions the procedure is devoid of side effects on the retina or the vasculature integrity. Moreover, a significant inhibition of laser induced-choroidal neovascularization (CNV) was achieved 15 days after transfection of a soluble vascular endothelial growth factor receptor-1 (sFlt-1)-encoding plasmid. This is the first nonviral gene transfer technique that is efficient for RPE targeting without inducing retinal detachment. This novel minimally invasive nonviral gene therapy method may open new prospects for human retinal therapies.

Influence of sutureless 23-gauge sclerotomy architecture on postoperative intraocular pressure decrease: results of a multivariate analysis.

PURPOSE: To evaluate the factors affecting the postoperative intraocular pressure (IOP) decrease in 23-gauge (23-G) sutureless vitrectomy, including incision architecture evaluated by anterior segment spectral-domain optical coherence tomography (SD-OCT). METHODS: A prospective cohort study of 43 patients who underwent primary transconjunctival 23-G pars plana vitrectomy. All sclerotomy wounds were imaged 1 day after surgery using the anterior segment module of SD-OCT (OCT Spectralis, Heidelberg Engineering, Heidelberg, Germany). 23-G sclerotomy architecture, preoperative and postoperative medical data were also prospectively collected. RESULTS: Multivariate logistic regression analysis, with backward elimination, found that surgery duration (adjusted OR = 9.17, p = 0.020) and loss of wound apposition (adjusted OR = 15.12, p = 0.022) were risk factors for significant postoperative IOP decrease (≥3 mmHg) 1 day after surgery; while age, gender, myopia, and gas tamponade were not risk or protective factors for postoperative IOP decrease. CONCLUSIONS: In 23-G pars plana vitrectomy, the early postoperative decrease in IOP is mainly influenced by surgery duration and the self-sealing nature of the sclerotomy. The IOP decrease was not influenced by the presence or the absence of gas tamponade.

Epiretinal membrane recurrence: incidence, characteristics, evolution, and preventive and risk factors.

BACKGROUND: To evaluate the incidence, evolution, clinical characteristics, possible risk factors or preventive factors, and visual outcomes of epiretinal membrane (ERM) recurrence. METHODS: Retrospective study of 440 consecutive patients (440 eyes) who underwent pars plana vitrectomy for ERM. The internal limiting membrane (ILM) was peeled in 266 cases, with the help of indocyanine green in 27 cases and brilliant blue in 45 cases. Cases of symptomatic ERM recurrence were reoperated. RESULTS: The incidence of ERM recurrence was 5% (22/440), and 2% of the patients were reoperated (9/440). Epiretinal membrane recurrence was symptomatic in 9 cases (41%) and asymptomatic in 13 cases (59%). ILM peeling was the only factor preventing ERM recurrence (adjusted odds ratio = 0.33, P = 0.026). The use of staining dyes did not prevent recurrence (adjusted odds ratio = 0.35, P = 0.338). In the case of ERM reproliferation, the absence of ILM peeling, the existence of ERM on the fellow eye, and poor visual acuity before surgery seemed to be associated with a high risk of symptomatic recurrence and reoperation. The mean duration for follow-up was 3.5 ± 1.7 years. CONCLUSION: ILM peeling not only reduces the likelihood of reproliferation of ERM but also seems to improve the visual prognosis of recurrent ERMs. The use of dyes did not reduce the rate of recurrence compared with when ILM was peeled without dyes.

Use of Digital Methods to Optimize Visualization during Surgical Gonioscopy.

Purpose: The aim of this study was to evaluate the efficacy of digital visualization for enhancing the visualization of iridocorneal structures during surgical gonioscopy. Methods: This was a prospective, single-center study on a series of 26 cases of trabecular stent implantation performed by the same surgeon. Images were recorded during surgical gonioscopy, and before stent implantation, with standard colors and with the optimization of various settings, principally color saturation and temperature and the use of the cyan color filter. Subjective analyses were performed by two glaucoma surgeons, and objective contrast measurements were made on iridocorneal structure images. Results: The surgeons evaluating the images considered the optimized digital settings to produce enhanced tissue visibility for both trabecular meshwork pigmentation and Schlemm's canal in more than 65% of cases. The mean difference in the standard deviation of the pixel intensity values was 37.87 (±4.61) for the optimized filter images and 32.37 (±3.51) for the standard-color images (p < 0.001). The use of a cyan filter provided a good level of contrast for the visualization of trabecular meshwork pigmentation. Increasing the color temperature highlighted the red appearance of Schlemm's canal. Conclusions: We report here the utility of optimized digital settings including the cyan filter and a warmer color for enhancing the visualization of iridocorneal structures during surgical gonioscopy. These settings could be used in surgical practice to enhance the visualization of the trabecular meshwork and Schlemm's canal during minimally invasive glaucoma surgery.

Paracentral retinal holes occurring after macular surgery: incidence, clinical features, and evolution.

AIM: To describe the incidence, clinical features, and evolution of paracentral retinal holes occurring after macular surgery. METHODS: A retrospective non-randomized study of 909 patients operated on for either a macular hole (MH, n = 400 patients) or an epiretinal membrane (ERM, n = 509 patients) between 2004 and 2009. Six patients (0.6%) developed a paracentral macular hole after surgery. Their clinical, auto-fluorescence, and optical coherence tomography (OCT) characteristics as well as their visual outcomes were studied. RESULTS: The mean age of patients was 70 years. Paracentral holes occurred approximately 5 weeks after surgery (with a range of 2-12 weeks). All patients were asymptomatic. Five patients underwent ILM peeling during initial surgery. Paracentral retinal holes were located superiorly to the fovea in three cases and temporally in the other three cases. Mean pre-operative BCVA was 20/200 and mean post-operative BCVA was 20/40. The eye where the eccentric MHs were closest to the fovea (inferior to 1 optic disc area) had the poorest final visual acuity. Autofluorescence imaging showed a bright fluorescence in paramacular holes. On OCT images, they were shown to be flat full-thickness holes. No treatment was attempted. No rhegmatogenous complications or choroidal neovascularization occurred in any of the patients. Mean follow-up was 2 years. CONCLUSIONS: In summary, paracentral MHs are uncommon complications which can occur at the site where ILM peeling has been initiated or completed. Except for the closest holes to fovea, they have good visual prognosis and do not require any treatment underlining the importance of initiating the ILM peeling as far as possible from the fovea.

Early corneal pachymetry maps after cataract surgery and influence of 3D digital visualization system in minimizing corneal oedema.

PURPOSE: To describe the early topography of corneal swelling occurring after cataract surgery and to evaluate the impact of the three-dimensional (3D) digital visualization system in minimizing corneal oedema. METHODS: Prospective observational, single-centre, consecutive case series of 134 patients undergoing cataract surgery performed by the same surgeon, with either 3D or conventional visualization systems. Eyes were assigned to two groups based on their anterior chamber depth (group ACD ≤3 mm and group ACD >3 mm). Optical coherence tomography was performed to evaluate postoperative corneal swelling. RESULTS: Three corneal swelling profiles were identified on the first postoperative day type 1, limited corneal oedema near peripheral corneal incisions; type 2, dome-shaped corneal swelling spreading from the principal corneal incision and reaching the paracentral cornea; type 3, continuous oedema spreading from the principal incision to central cornea, with a generalized oedema predominating in the upper part of the cornea. On the first day after surgery, in group ACD ≤3 mm, visual acuity was significantly better in patients undergoing surgery with 3D visualization (0.023 vs 0.072 logMar, p = 0.014) with reduced central corneal thickening 17.3 µm (±3.2) in comparison with conventional visualization 44.0 µm (±9.3) (p = 0.0082). In group ACD >3 mm, no significant association was found between the use of the 3D system and pachymetry changes and early visual rehabilitation. On day 21 after surgery, no significant differences in corneal pachymetry values were observed between the two surgical approaches in both groups. CONCLUSIONS: We describe early postoperative corneal map profiles providing insight into the pathogenesis of postoperative corneal swelling and possible prevention strategies. By improving visualization of the narrow surgical space in patients with shallow anterior chambers, the 3D system could help to minimize postoperative corneal oedema.

Facilitating Role of the 3D Viewing System in Tilted Microscope Positions for Cataract Surgery in Patients Unable to Lie Flat.

PURPOSE: To assess the utility of the 3D viewing system in tilted microscope positions for the performance of cataract surgery in challenging positions, for patients with difficulty remaining supine. METHODS: Prospective, single-center, single-surgeon, consecutive case series of patients undergoing surgery in an inclined position. RESULTS: 21 eyes of 15 patients who had undergone surgery at inclined positions at angles of 20° to 80°, with a mean angle of 47.62°. Surgeon comfort was considered to be globally good. The surgeon rated red reflex perception and the impression of depth as good and stable in all cases. The operating time was slightly longer for patients inclined at angles of more than 50°. On the first day after surgery, BSCVA was 20/25 or better in all cases. No ocular complications occurred in any of the interventions. CONCLUSIONS: Due to the ocular-free design of the 3D system, the surgical procedure and the positioning of the surgeon remained almost identical to that for patients undergoing surgery in a supine position, maintaining the safety of the standard surgical approach.

Use of Black-and-White Digital Filters to Optimize Visualization in Cataract Surgery.

PURPOSE: To evaluate the effect of a black-and-white (BW) filter on the optimization of visualization at each stage of cataract surgery. METHODS: Prospective, single-center, single-surgeon, consecutive case series of 40 patients undergoing cataract surgery with BW filter. Surgical images and videos were recorded with and without the BW filter at each stage of cataract surgery. Contrast measurements of surgical images and subjective analysis of video sequences were performed. RESULTS: The surgeons assessed the BW filter to optimize the tissue visibility of capsulorhexis contours, hydrodissection fluid wave perception, the contrast of instruments through a nucleus during phaco-chop, and subincisional cortex contrast through the corneal edema. Despite the higher contrasts' value obtained with BW filter images during nucleus removal, posterior capsular polishing and viscous removal, the surgeons subjectively reported no significant advantage of using a BW filter. Standard color images were found to be better for localizing the limbal area during incision and for nucleus sculpture to assess groove depth. CONCLUSIONS: In conclusion, we describe here the potential indications for BW filter use at particular stages in cataract surgery. A BW filter could be used, with caution, in cases of poor visualization.

25-, 23-, and 20-gauge vitrectomy in epiretinal membrane surgery: a comparative study of 553 cases.

PURPOSE: To compare the safety and functional outcomes of 25-gauge and 23-gauge (G) micro-incision vitrectomy surgery (MIVS) instrumentation with the standard 20-G vitrectomy system in the treatment of epiretinal membranes (ERM). METHODS: A retrospective comparative study of 553 consecutive cases with epiretinal membrane who underwent pars plana vitrectomy. Twenty-gauge, 25-gauge and 23-gauge vitrectomy was performed respectively in 347, 91, and 115 eyes. Surgery duration, visual acuity improvement, intraocular pressure variation, intraoperative and postoperative complications were analyzed. RESULTS: The mean surgical time in the 23-G group and in the 25-G group was shorter than in the 20-G group (P < 0.001). Visual improvement was higher 8 days postoperatively in the 25-G group than in the 20-G and 23-G groups (P = 0.035), but not at 6 weeks postoperatively (P = 0.186). In the 20-G group, the IOP increased significantly on the first day postoperatively (P < 0.001), while in the 23-G group, the IOP decreased on the first day postoperatively (P = 0.073). In the 25-G group, the IOP did not change significantly (P = 0.807). The incidence of complications was not statistically significant between the three groups. Retinal breaks were significantly related to the induction of posterior vitreous detachment, independent of the system gauge. CONCLUSION: In ERM surgery, 23-G and 25-G (MIVS) systems are as safe and effective as the 20-G system, and significantly reduce surgical time. Although the 25-G system provides an earlier visual improvement, the 23- and 25- gauge systems are comparable, and the selection will depend on the surgeon's preference.

CFH exerts anti-oxidant effects on retinal pigment epithelial cells independently from protecting against membrane attack complex.

Age Related Macular Degeneration (AMD) is the first cause of social blindness in people aged over 65 leading to atrophy of retinal pigment epithelial cells (RPE), photoreceptors and choroids, eventually associated with choroidal neovascularization. Accumulation of undigested cellular debris within RPE cells or under the RPE (Drusen), oxidative stress and inflammatory mediators contribute to the RPE cell death. The major risk to develop AMD is the Y402H polymorphism of complement factor H (CFH). CFH interacting with oxidized phospholipids on the RPE membrane modulates the functions of these cells, but the exact role of CFH in RPE cell death and survival remain poorly understood. The aim of this study was to analyze the potential protective mechanism of CFH on RPE cells submitted to oxidative stress. Upon exposure to oxidized lipids 4-HNE (4-hydroxy-2-nonenal) derived from photoreceptors, both the human RPE cell line ARPE-19 and RPE cells derived from human induced pluripotent stem cells were protected from death only in the presence of the full length human recombinant CFH in the culture medium. This protective effect was independent from the membrane attack complex (MAC) formation. CFH maintained RPE cells tight junctions' structure and regulated the caspase dependent apoptosis process. These results demonstrated the CFH anti-oxidative stress functions independently of its capacity to inhibit MAC formation.

In vivo imaging of palisades of Vogt in dry eye versus normal subjects using en-face spectral-domain optical coherence tomography.

PURPOSE: To evaluate a possible clinical application of spectral-domain optical coherence tomography (SD-OCT) using en-face module for the imaging of the corneoscleral limbus in normal subjects and dry eye patients. PATIENTS AND METHODS: Seventy-six subjects were included in this study. Seventy eyes of 35 consecutive patients with dry eye disease and 82 eyes of 41 healthy control subjects were investigated. All subjects were examined with the Avanti RTVue® anterior segment OCT. En-face OCT images of the corneoscleral limbus were acquired in four quadrants (inferior, superior, nasal and temporal) and then were analyzed semi-quantitatively according to whether or not palisades of Vogt (POV) were visible. En-face OCT images were then compared to in vivo confocal microscopy (IVCM) in eleven eyes of 7 healthy and dry eye patients. RESULTS: En-face SD-OCT showed POV as a radially oriented network, located in superficial corneoscleral limbus, with a good correlation with IVCM features. It provided an easy and reproducible identification of POV without any special preparation or any direct contact, with a grading scale from 0 (no visualization) to 3 (high visualization). The POV were found predominantly in superior (P<0.001) and inferior (P<0.001) quadrants when compared to the nasal and temporal quadrants for all subjects examined. The visibility score decreased with age (P<0.001) and was lower in dry eye patients (P<0.01). In addition, the score decreased in accordance with the severity of dry eye disease (P<0.001). CONCLUSION: En-face SD-OCT is a non-contact imaging technique that can be used to evaluate the POV, thus providing valuable information about differences in the limbal anatomy of dry eye patients as compared to healthy patients.

Symmetry in early response to intravitreal ranibizumab in bilateral diabetic macular oedema.

PURPOSE: To study the symmetry in response to bilateral diabetic macular oedema (DME) treated with bilateral intravitreal injections of ranibizumab (IVR). METHODS: The charts of 36 eyes of 18 patients treated with a loading dose of three monthly IVR in both eyes were retrospectively reviewed. Favourable anatomical response was defined as a decrease by more than 10% in baseline central macular thickness (CMT), and favourable functional response was defined as an increase in visual acuity (VA) ≥5 letters. A symmetric response was defined as a similar anatomical and/or functional response in the first (FE) and second (SE) treated eyes. RESULTS: The VA improved significantly after ranibizumab treatment in both eyes (p < 0.01). A statistically significant positive correlation was found for the functional response to ranibizumab between the FE and the SE (R(2)  = 0.26, p = 0.03). The mean CMT decreased significantly in both eyes (p < 0.01). A strong positive correlation was observed between the anatomical response to ranibizumab in the FE and the SE (R(2)  = 0.37, p = 0.01). Symmetric favourable anatomical and functional responses were observed in 13 patients (72%). In two additional patients, an asymmetric functional response was observed despite a decrease in retinal thickness in both eyes. CONCLUSION: Symmetric anatomical and functional responses were observed in 72% of patients with DME after three initial IVR in each eye. This finding could be of clinical interest in the decision to treat the fellow eye, in a disease where a bilateral involvement is frequent.