Cone Outer Segment Tips Research Articles

Retinal displacement after surgery for idiopathic macular hole.

To review and summarize the mechanism hypothesis, influencing factors and possible consequences of macular retinal displacement after idiopathic macular hole (IMH) surgery. PubMed and Web of Science database was searched for studies published before April 2023 on "Retinal displacement", "Idiopathic macular holes", and "Macular displacement". Recently, more academics have begun to focus on retinal displacement following idiopathic macular holes. They found that internal limiting membrane (ILM) peeling was the main cause of inducing postoperative position shift in the macular region. Moreover, several studies have revealed that the macular hole itself, as well as ILM peeling method, will have an impact on the result. In addition, this phenomenon is related to postoperative changes in macular retinal thickness, cone outer segment tips line recovery, the occurrence of dissociated optic nerve fiber layer (DONFL) and the degree of metamorphopsia. As a subclinical phenomenon, the clinical significance of postoperative macular displacement cannot be underestimated as it may affect the recovery of anatomy and function.

Retinal response to light exposure in BEST1-mutant dogs evaluated with ultra-high resolution OCT

Mutations in BEST1 cause an autosomal recessive disease in dogs where the earliest changes localize to the photoreceptor-RPE interface and show a retina-wide micro-detachment that is modulated by light exposure. The purpose of this study was to define the spatial and temporal details of the outer retina and its response to light with ultra-high resolution OCT across a range of ages and with different BEST1 mutations. Three retinal regions were selected in each eye: near the fovea-like area, near the optic nerve, both in the tapetal area, and inferior to the optic nerve in the non-tapetal area. The OS+ slab thickness was defined between the peak near the junction of inner and outer segments (IS/OS) and the transition between basal RPE, Bruch membrane, choriocapillaris and proximal tapetum (RPE/T). In wildtype (WT) dogs, two tapetal regions showed additional hyperscattering OCT peaks within the OS+ slab likely representing cone and rod outer segment tips (COST and ROST). The inferior non-tapetal region of WT dogs had only one of these peaks, likely ROST. In dogs with BEST1 mutations, all three locations showed a single peak, likely suggesting optical silence of COST. Light-dependent expansion of the micro-detachment by about 10 um was detectable in both tapetal and non-tapetal retina across all ages and BEST1 mutations.

The role of optical coherence tomography biomarkers in predicting the outcome of epiretinal membrane removal surgery

Epiretinal membrane (ERM) is a common condition that can cause visual impairment. ERM removal surgery is an effective treatment option, but predicting postoperative visual outcomes is challenging. Imaging modalities, particularly optical coherence tomography (OCT), have emerged as valuable tools for preoperative evaluation and predicting surgical outcomes. This presentation focuses on the role of preoperative OCT biomarkers in estimating postoperative vision improvement after ERM removal surgery. Such biomarkers include the disorganization of retinal inner layers (DRIL), the presence of ectopic inner foveal layer (EIFL), the cotton ball sign, the cone outer segment tips (COST) line, the photoreceptor outer segment (PROS) length, the inner retina irregularity index, and the presence of posterior vitreous detachment (PVD).DRIL refers to the abnormal appearance of the inner retinal layers on OCT, and has been found to be associated with poorer postoperative visual outcomes in ERM removal surgery. Significant EIFL has also been associated with poorer visual outcomes after surgery. The cotton ball sign, which appears as a hyper‐reflective area in the inner nuclear layer, has been found to be associated with increased difficulty in ERM removal and poorer visual outcomes. These biomarkers suggest that a greater degree of retinal disorganization and irregularity may lead to more challenging surgeries and poorer visual outcomes.In contrast, the presence of intact COST line and normal PROS length have been associated with better visual function. PVD, which represents separation of the vitreous from the retina, has been shown to be associated with less surgical trauma and better postoperative outcomes. The inner retina irregularity index, which measures the extent of disorganization of the inner retinal layers, has also been found to correlate with the changes in metamorphopsia and quality of vision after surgery.These biomarkers have the potential to improve the accuracy of preoperative evaluation and prediction of surgical outcomes in ERM removal surgery. By identifying patients with a greater degree of retinal disorganization and irregularity, we can anticipate more challenging surgeries and poorer visual outcomes. Conversely, patients with minimal COST line defects, normal PROS length and full PVD may have better postoperative visual outcomes.In summary, preoperative OCT findings can help predict postoperative visual outcomes in ERM removal surgery. The use of imaging modalities and specific biomarkers can provide useful insight in management decisions, case selection, and timing of surgery.

Long-Term Visual Outcomes in Patients With Idiopathic Epiretinal Membrane Surgery.

Our aim was to assess long-term outcomes following surgical repair of idiopathic epiretinal membrane (ERM) with pars plana vitrectomy (PPV) and membrane peel (MP). A retrospective study evaluated patients with idiopathic ERM who underwent surgical repair at a single academic tertiary center with five to nine years of postoperative follow-up, assessing preoperative characteristics, surgical techniques, best visual acuity (BVA), and optical coherence tomography biomarkers at various time points. The study involved 67 patients (72 eyes) with an average postoperative follow-up of 82.8 ± 18.8 months. Patients with cone outer segment tips integrity at initial presentation and 1-year follow-up and patients with external limiting membrane and ellipsoid zone integrity at 1-year follow-up were noted to have significantly better long-term visual acuity than those without. More than 85% of patients achieved a BVA > 70 seven years after surgical repair. Vitreoretinal surgery for idiopathic ERM resulted in improved anatomical recovery and sustained visual acuity gain over long-term follow-up. [Ophthalmic Surg Lasers Imaging Retina 2024;55:70-77.].

Poster Session: Optoretinography-based frequency characterization of the retinal response to a chirped flickering light.

In this contribution, we present experimental results of in vivo characterization of the photoreceptor's response to a chirped flickering white light stimulating the retina. We acquire the ORG signal with Spatio-Temporal Optical Coherence Tomography (STOC-T) setup, which combines both temporal and coherence gating to overcome limitations present in Full Field Fourier Domain Optical Coherence Tomography. From the acquired volumes, we extract the changes in optical path length (OPL) between the inner and outer photoreceptor junction (ISOS) and the cone outer segment tips (COST). We perform the measurements for frequencies ranging from 5 Hz to 50 Hz. The chirped flickering facilitates significantly shorter data acquisition time. We present results of in vivo measurement from three volunteers. Our results show that we can measure OPL changes between ISOS and COST occurring in response to a chirped flickering stimulation in a reproducible manner and resolve the amplitude of the response in the function of flicker frequency.

Diurnal functional and anatomical changes in X-linked retinoschisis

BackgroundTo investigate the changes in macular cystic schisis (MCS) and sensitivity during the day in X-linked retinoschisis (XLRS) patients.MethodsTreatment-naïve patients with genetically verified XLRS underwent best-correlated visual acuity (BCVA) testing with ETDRS charts, spectral domain optical coherence tomography, and microperimetry (MP) twice a day, at 9 a.m. and 4 p.m., to measure changes in central retinal thickness (CRT), macular volume (MV), average threshold (AT), and fixation stability parameters (P1 and P2).ResultsAt baseline, the BCVA of the 14 eyes of 8 patients amounted 0.73 (± 0.23) LogMAR. Between timepoints, the BCVA increased in 3.21 letters (p = .021), the AV improved in 1.84 dB (p = .03, 9.73%), the CRT decreased in 24.43 µm (p = .007, − 4.05%), and the MV dropped in 0.27 µm3 (p = .016, − 2.68%). P1 and P2 did not variate. The collapse of the MCS led to the reduction of macula thickness. CRT at baseline correlated with the decrease of CRT (Spearman’s ρ: − 0.83 [p = .001]). Age and change of BCVA, CRT, and AV did not correlate among one another. Eyes with disrupted ellipsoid zone showed a more prominent change in CRT (p = .050). Photoreceptor outer segment length and integrity of the external limiting membrane and cone outer segment tips were not associated with BCVA, AT, or CRT variation.ConclusionEyes of treatment-naïve XLRS patients show diurnal macular thickness and function changes. Eyes with pronounced macular thickness show a greater reduction of the MCS. These results should be taken into consideration in upcoming clinical trials in XLRS.Trial registration numberInstitutional Review Board of the Hamburg Medical Chamber (Ethik-Kommission der Ärztekammer Hamburg): 2020–10,328.

Commentary: Indistinct retinal outer layers in the walls of idiopathic full thickness macular hole - A potential predictive biomarker for surgical outcomes.

Commentary: Indistinct retinal outer layers in the walls of idiopathic full thickness macular hole - A potential predictive biomarker for surgical outcomes.

Photoreceptor Manifestations of Primary Mitochondrial Optic Nerve Disorders.

PurposeTo compare the manifestations of photoreceptors (PRs) in three hereditary optic neuropathies affected by primary mitochondrial dysfunction and discuss whether the retinal ganglion cells (RGCs) or the PRs are preferentially affected.MethodsA retrospective analysis of patients with genetically confirmed diagnoses of optic neuropathies associated with mitochondrial dysfunction was performed. This cohort included Leber's hereditary optic neuropathy (LHON), autosomal dominant optic atrophy type 1 (OPA1), and optic atrophy type 13 (OPA13). Patient chart evaluations included clinical characteristics, best-corrected visual acuity (BCVA), fundus photography, spectral-domain optical coherence tomography (SD-OCT), electroretinogram (ERG), and visual evoked potential data.ResultsThis analysis included seven patients with LHON, six with OPA1, and one with OPA13 from a tertiary medical center. Thirteen of the 14 individuals were male. The average BCVA at diagnosis was 20/285 and 20/500 in the right and left eyes, respectively. Five of the seven patients with LHON, and three of the six patients with OPA1 also showed a mild amplitude reduction or delayed latency on light-adapted ERG and 30-Hz flicker responses; however, SD-OCT imaging did not show correlated PR abnormalities. Notably, a 7-year follow-up of a patient with OPA13 revealed degeneration of RGCs prior to the degeneration of PRs. Follow-up data also demonstrated continuous loss of cone outer segment tips on SD-OCT imaging.ConclusionsRGCs are, in general, affected by mitochondrial dysfunction, whereas variable PR dysfunction exists in patients with LHON and OPA1, especially with respect to the cone responses. Involvement of PRs is particularly evident in OPA13 after RGC degenerations.

OCT-based biomarkers for predicting treatment response in eyes with centre-involved diabetic macular oedema treated with anti-VEGF injections: a real-life retina clinic-based study

Background/aimsTo determine whether a combination of baseline and change in spectral domain-optical coherence tomography (SD-OCT)-based biomarkers can predict visual outcomes in eyes with diabetic macular oedema (DMO) treated with antivascular...

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

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

Analyses of the effects of persistent subretinal fluid on visual/anatomic outcomes according to the type of macular neovascularization during the relaxed treat-and-extend protocol in age-related macular degeneration patients

BackgroundTo analyze the long-term effects of persistent subretinal fluid (SRF) on visual/anatomic outcomes according to the type of macular neovascularization (MNV) during relaxed treat-and-extend regimen with anti-vascular endothelial growth factor (anti-VEGF) agents in age-related macular degeneration (AMD) patients.MethodsPatients with fovea-involving type 1 or type 2 MNV, treated with a relaxed treat-and-extend regimen for 2 years were retrospectively reviewed. Eyes with SRF observed more than three times per year were defined as the ‘persistent SRF (+) group’. To exclude the effects of IRF as much as possible, the eyes with persistent IRF were excluded. The effects of persistent SRF on the best-corrected visual acuity (BCVA), central subfield retinal thickness (CST), and changes in the photoreceptor layer (PRL) thickness and outer retinal bands (external limiting membrane, ellipsoid zone, and cone outer segment tip line) after anti-VEGF injection were analyzed for each MNV type.ResultsSeventy-seven eyes with type 1 MNV (44 eyes with persistent SRF) and 53 eyes with type 2 MNV (18 eyes with persistent SRF) were enrolled. Following a relaxed treat-and-extend regimen with anti-VEGF agents, BCVA and CST improved for each MNV type. In comparison between persistent SRF (+) and persistent SRF (−) group, there were no differences in the amount of change in BCVA and CST between the two groups for each MNV type during 2-year follow-up periods. In addition, there were no differences in the amount of reduction in PRL thickness and state of the outer retinal bands between the two groups for each MNV type.ConclusionsUsing a relaxed treat-and-extend regimen with anti-VEGF agents, persistent SRF did not have additional effects on visual and anatomic outcomes by 2 years, regardless of the MNV type.

Optical coherence tomography analyses based segmentation and relative intensity evaluation of outer retinal layers in patients affected with X-linked juvenile retinoschisis.

We aim to provide a description of the optical coherence tomography findings in the outer macula hyperreflective bands of our patients with X-linked juvenile retinoschisis. Also to categorize these changes and to quantitatively and qualitatively correlate their reflectivity levels with visual function. We manually segmented the borders, and depicted relative intensity of the inner segment ellipsoid band, and quantified the volume of edema. The average relative intensity of the ellipsoid zone, ISe band, for the control subject was 14.864, our patient's, with the mild disease was, 28.238 and 34.943 in OD and OS, respectively, and for the patient with severe disease was, 44.442 and 40.154 for OD and OS respectively. Thresholding showed a significant difference in edema volume between mild disease (~20%), and severe form (~50%). Relative intensity analyses are indicative of homogeneity variability. High standard deviation value illustrates the high dispersion of data values and is a safe marker of ellipsoid zone homogeneity. Data suggested that both anatomic and functional characteristic of outer macula hyperreflective bands were notably associated with the pathogenesis cascade in the photoreceptor cells. External limiting membrane line disruption is initiated by the volume of macular edema and followed by disorganization of the three lines in a stepwise pattern, first at the ellipsoid zone, followed by the cone outer segment tips zone and finally at the External limiting membrane.

Three-dimensional composition of the photoreceptor cone layers in healthy eyes using adaptive-optics optical coherence tomography (AO-OCT).

To assess the signal composition of cone photoreceptors three-dimensionally in healthy retinas using adaptive optics optical coherence tomography (AO-OCT). Study population. Twenty healthy eyes of ten subjects (age 23 to 67). Procedures. After routine ophthalmological assessments, eyes were examined using AO-OCT. Three-dimensional volumes were acquired at 2.5° and 6.5° foveal eccentricity in four main meridians (superior, nasal, inferior, temporal). Cone densities and signal compositions were investigated in four different planes: the cone inner segment outer segment junction (IS/OS), the cone outer segment combined with the IS/OS (ISOS+), the cone outer segment tips (COST) and full en-face plane (FEF) combining signals from all mentioned cone layers. Additionally, reliability of a simple semi-automated approach for assessment of cone density was tested. Main outcome measures. Cone density of IS/OS, IS/OS+, COST and FEF. Qualitative depiction and composition of each cone layer. Inter-rater agreement of cone density measurements. Mean overall cone density at all eccentricities was highest at the FEF plane (21.160/mm2), followed by COST (20.450/mm2), IS/OS+ (19.920/mm2) and IS/OS (19.530/mm2). The different meridians and eccentricities had a significant impact on cone density, with lower eccentricity resulting in higher cone densities (p≤.001), which were highest at the nasal, then temporal, then inferior and then superior meridian. Depiction of the cone mosaic differed between all 4 layers regarding signal size and packing density. Therefore, different cone layers showed evident but not complete signal overlap. Using the semi-automated technique for counting of cone signals achieved high inter-rater reliability (ICC > .99). In healthy individuals qualitative and quantitative changes in cone signals are found not only in different eccentricities and meridians, but also within different photoreceptor layers. The variation between cone planes has to be considered when assessing the integrity of cone photoreceptors in healthy and diseased eyes using adaptive optics technology.

Factors Associated with the Clinical Course of Vitreomacular Traction.

Background To analyze the optical coherence tomography (OCT) characteristics as well as the clinical and demographic features to investigate their possible role to the course of vitreomacular traction syndrome. Methods The inclusion criteria were vitreomacular adhesion with traction causing distortion of the retinal architecture, with or without the presence of an epiretinal membrane, regardless of the size of the adhesion; age >18 years; follow-up of at least three months; and adequate quality OCT scan. Measurements of foveal thickness, average macular thickness, macular volume, maximum vertical and horizontal vitreomacular adhesion, nasal and temporal angles of traction, hyaloid hyperreflectivity, the presence of an epiretinal membrane (ERM), and cone outer segment tips detachment were obtained. Results 150 eyes were included in the analysis. 36 eyes (24%) developed complete resolution at the last visit, 19 eyes (12.7%) formed a full-thickness macular hole, and 95 eyes (63.3%) showed no resolution of the traction. Better BCVA at the first visit was associated with an increased likelihood of resolution of the VMT, but increasing age, CMT, and BCVA in the end of the follow-up was associated with a reduction in the likelihood of resolving. Of the other variables that were studied, no statistical significant predictors were identified. Conclusions Better BCVA in the first visit was associated with an increased likelihood of resolution of the VMT that occurred in 24% of our cases. Other factors such as the vertical area of adhesion and the angle of adhesion were not identified as prognostic factors affecting the clinical course of the disease.

Three-dimensional assessment of para- and perifoveal photoreceptor densities and the impact of meridians and age in healthy eyes with adaptive-optics optical coherence tomography (AO-OCT).

An adaptive optics optical coherence tomography (AO-OCT) system is used to assess sixty healthy eyes of thirty subjects (age 22 to 75) to evaluate how the outer retinal layers, foveal eccentricity and age effect the mean cone density. The cone mosaics of different retinal planes (the cone inner segment outer segment junction (IS/OS), the cone outer segment combined with the IS/OS (ISOS+), the cone outer segment tips (COST), and the full en-face plane (FEF)) at four main meridians (superior, nasal, inferior, temporal) and para- and perifoveal eccentricities (ecc 2.5° and 6.5°) were analyzed quantitatively. The mean overall cone density was 19,892/mm2 at ecc 2.5° and 13,323/mm2 at ecc 6.5°. A significant impact on cone density was found for eccentricity (up to 6,700/mm2 between ecc 2.5° and 6.5°), meridian (up to 3,700/mm2 between nasal and superior meridian) and layer (up to 1,400/mm2 between FEF and IS/OS). Age showed only a weak negative effect. These factors as well as inter-individual variability have to be taken into account when comparing cone density measurements between healthy and pathologically changed eyes, as their combined effect on density can easily exceed several thousand cones per mm2 even in parafoveal regions.

Predicting response of ischemic central retinal vein occlusion to bevacizumab injections: 1year follow-up.

To identify baseline optical coherence tomography (OCT) factors in ischemic central retinal vein occlusion (CRVO) that predict response to bevacizumab injections. Patients underwent OCT at diagnosis and the central macular thickness, subretinal fluid width and height as well as the presence of intraretinal cysts were measured. The extent of disorganized retinal inner layers, outer plexiform layer (OPL), external limiting membrane, ellipsoid zone and cone outer segment tips (COST) was recorded. Patients received three consecutive monthly injections of bevacizumab followed by pro re nata treatment. Overall 32 eyes of 32 patients aging 69.4 ± 12.7years were included. In univariate correlational analyses baseline OPL disruption (- 41, p = 0.02), EZ disruption (r = - 0.36, p = 0.05) and COST disruption (r = - 0.37, p = 0.04) correlated with deterioration in BCVA at 1year. Partial least squares demonstrated that the factors most largely associated with deterioration in BCVA were COST disruption and OPL disruption followed by EZ disruption, while worst vision at baseline was associated with improvement in vision. In patients with ischemic CRVO treated with bevacizumab, BCVA improvement at 1year can be partially predicted from baseline OCT measurements by the extent of COST, OPL and EZ disruption.

Comparison of SDOCT Scan Types for Grading Disorganization of Retinal Inner Layers and Other Morphologic Features of Diabetic Macular Edema.

PurposeTo assess grading reproducibility of disorganization of the retinal inner layers (DRIL) and other morphologic features of diabetic macular edema (DME) across spectral domain optical coherence tomography (SDOCT) instruments and scan types.MethodsA cross-sectional study enrolled participants with current or recent center-involved DME. In group A (27 eyes), we obtained two Cirrus scans (512 × 128 macular cube [Cube] and high-definition five-line raster [HD 5-Line]) and two Spectralis scans (high-resolution [HR] and high-speed [HS]). In group B, 26 eyes underwent HR scans and Optovue AngioVue (OP) 3 × 3-mm scans. All scans were graded for type and extent of DRIL, intraretinal cysts, cone outer segment tip visibility, and subretinal fluid (SRF).ResultsIn the total cohort, mean central subfield thickness was 342.9 ± 83.4 µm. Intraclass correlations were high for DRIL extent across the four different imaging settings (HR vs. HS, r = 0.93; HR vs. Cube, r = 0.84, HR vs. HD 5-Line, r = 0.76, HR vs. OP, r = 0.87) and ranged from good to excellent for intraretinal cyst and SRF area. There were significantly smaller mean normalized differences between HR/HS scans versus HR and all other scan modalities (HR/HS vs. HR/Cube, P = 0.02; HR/HD 5-Line, P = 0.0005; HR/OP, P < 0.0001).ConclusionsOur data suggest that the reproducibility for SDOCT parameters of DRIL and intraretinal cysts was high across all five SDOCT scan types; thus, evaluation of DRIL is feasible using multiple SDOCT models in eyes with DME.Translational RelevanceDME morphological changes can be evaluated on multiple SDOCT devices with good reproducibility, allowing clinicians and researchers flexibility in DME assessment for clinical care and research.

Changes of outer retinal thickness with increasing age in normal eyes

AIM: To comprehensively investigate the relationship between outer retinal layer thickness and age in normal eyes. METHODS: One hundred normal eyes of 100 subjects who underwent spectral-domain optical coherence tomography (SD-OCT) were included in this retrospective study. The distances between the external limiting membrane (ELM) line and the photoreceptor inner segment/outer segment (IS/OS) line (ELM-IS/OS), the IS/OS line and the cone outer segment tips (COST) line (IS/OS-COST), the COST line and the retinal pigment epithelium (RPE) complex (COST-RPE) and the full retinal thickness (RT) were measured at the fovea and on four quarters. The relationship between thickness and age or sex was then analysed. CONCLUSION: In normal eyes, the RT thickness on the nasal quarter and the ELM-IS/OS thickness were significantly and negatively correlated with age. The IS/OS-COST and COST-RPE thicknesses were not significantly correlated with age or sex.

An anomalous foveal OCT-sign after posterior capsule rupture in cataract surgery: Complicated cataract surgery maculopathy.

To report a series of novel optical coherence tomography (SD-OCT) foveal abnormalities, that we called "T-sign," that were noticed after a complicated cataract surgery with posterior capsule rupture and vitreous loss. Retrospective case series of persistent foveal changes that incurred after anteroposterior vitreo-foveal traction secondary to phacoemulsification in presence of posterior capsule rupture. The study included three eyes of three patients that incurred in complicated cataract surgery and intraoperative vitreo-foveal traction. During 8-month follow-up period peculiar abnormalities in fundus examination and in OCT scans were reported in all cases. Phacoemulsification in presence of posterior capsule rupture could induce a vitreo-foveal strain that could be transmitted to the cone outer segment tips (COST line) and inner-outer segment (IS/OS) junction. This focal stress is liable for "T-sign," a persistent SD-OCT abnormality that induce a visual impairment and a slight metamorphopsia in the fixation point. All over the world, more than 9.5 million cataract surgeries are completed each year.1 During surgery, many intraoperative complications could occur, and capsule rupture with vitreous loss is a frequent event. Phacoemulsification in presence of a wide posterior capsule rupture and vitreo-macular adhesion could induce a typical modification of the foveal structure and a permanent visual impairment.

ATTENUATION OUTER RETINAL BANDS ON OPTICAL COHERENCE TOMOGRAPHY FOLLOWING MACULAR EDEMA: A Possible Manifestation of Photoreceptor Misalignment.

Macular edema is a common retinal disease which may leave important anatomical and functional sequelaes. Directional fundus imaging consists of comparing on- and off-axis images to reveal angle-dependent reflectance properties of fundus structures, which may be related to misaligned photoreceptors. Here, we analyzed directional optical coherence tomography (OCT) and flood-illumination adaptive optics ophthalmoscopy images to detect evidence of misaligned photoreceptors following macular edema. Transversal, observational study. Nine patients having recovered a normal macular profile after macular edema due to retinal vein occlusion were included. For each patient, a reference OCT scan (i.e., with the incident beam normal to the fovea) was acquired, and off-axis scans were then acquired by laterally shifting the entry pupil. In addition, in four of these eyes, directional adaptive optics ophthalmoscopy documented the directional variations of cone metrics. Included patients comprised two women and seven men (age range, 19-76 years). Reference OCT scans showed patchy attenuation of the cone outer segment tips and to a lesser extent of the inner segment/outer segment lines in all, but two eyes; these. Increased intensity of the cone outer segment tips and inner segment/outer segment lines could be observed on off-axis scans. Accordingly, fusion images showed 66% average reduction of the length of cone outer segment tips attenuation. In two cases, although reference scans showed continuity of outer bands, focal attenuation was evidenced in off-axis images. Directional adaptive optics ophthalmoscopy imaging showed a strong directional variability of cone counts in these areas, ranging from near absence to roughly two-third of reference values. In each case, directional variations of cone counts paralleled those of the reflectance of outer bands. After macular edema, focal attenuations of the inner segment/outer segment and of the cone outer segment tips lines may be present on OCT. These areas may show a strong directional variability by both OCT and adaptive optics ophthalmoscopy, suggesting that misaligned photoreceptor outer segments contribute to such features. The evaluation of outer retinal damage following macular edema should therefore take into account the optical Stiles-Crawford effect to disambiguate missing from misaligned cones.