Thickness of retinal layers in the foveas of children with anisometropic amblyopia

Purpose

To use highly precise spectral-domain optical coherence tomography (SD-OCT) to determine whether there were structural abnormalities in the layers of different regions of the fovea in children with anisometropic amblyopia.

Methods

Eighteen children (mean age 7.8 years old; range 5–11 years) with unilateral anisometropic amblyopia and 18 age-matched control subjects participated. Foveal thickness was measured with an enhanced depth imaging system, SD-OCT and segmented into layers using custom developed software. The thickness of each layer of the fovea was compared among amblyopic eyes, fellow eyes and control eyes with optical magnification correction for axial length and statistical correction for age and sex.

Results

The total thickness and each intra-ocular layer of the central fovea were the same for each group. However, the amblyopic eyes were significantly thicker than the normal control eyes in 2 of 4 quadrants of the peripheral retina. Exploring intra-retinal layers in these two quadrants, the nasal nerve fiber layer (NFL) and inferior inner nuclear layer (INL)were significantly thicker in amblyopic eyes than in control eyes (p = 0.01 and 0.012, respectively, by ANCOVA).

Conclusion

The SD-OCT data revealed marginal differences in some foveal layers at peripheral locations and indicated that structural differences might exist between individuals with amblyopia and visually normal control subjects. However, the differences were scattered and represented no identifiable pattern. More studies with large samples and precise locations of the retinal layers must be performed to extend the present results.

Structural analysis of retinal photoreceptor ellipsoid zone and postreceptor retinal layer associated with visual acuity in patients with retinitis pigmentosa by ganglion cell analysis combined with OCT imaging

The aim of this study was to examine changes in photoreceptor ellipsoid zone (EZ) and postreceptor retinal layer in retinitis pigmentosa (RP) patients by ganglion cell analysis (GCA) combined with optical coherence tomography (OCT) imaging to evaluate the structure-function relationships between retinal layer changes and best corrected visual acuity (BCVA). Sixty-eight eyes of 35 patients with RP and 65 eyes of 35 normal controls were analyzed in the study. The average length of EZ was 911.1 ± 208.8 μm in RP patients, which was shortened with the progression of the disease on the OCT images. The average ganglion cell-inner plexiform layer thickness (GCIPLT) was 54.7 ± 18.9 μm in RP patients, while in normal controls it was 85.6 ± 6.8 μm. The GCIPLT in all quarters became significantly thinner along with outer retinal thinning. There was a significantly positive correlation between BCVA and EZ (r = -0.7622, P < 0.001) and GCIPLT (r = -0.452, P < 0.001). Therefore, we assess the retinal layer changes from a new perspective in RP patients, which suggests that EZ and GCIPLT obtained by GCA combined with OCT imaging are the direct and valid indicators to diagnosis and predict the pathological process of RP.

Visual Acuity Is Correlated with the Area of the Foveal Avascular Zone in Diabetic Retinopathy and Retinal Vein Occlusion

PURPOSE

To determine if the area of the foveal avascular zone (FAZ) is correlated with visual acuity (VA) in diabetic retinopathy (DR) and retinal vein occlusion (RVO).

DESIGN

Cross-sectional study.

PARTICIPANTS

Ninety-five eyes of 66 subjects with DR (65 eyes), branch retinal vein occlusion (19 eyes), and central retinal vein occlusion (11 eyes).

METHODS

Structural optical coherence tomography (OCT; Spectralis, Heidelberg Engineering) and OCT angiography (OCTA; Avanti, Optovue RTVue XR) data from a single visit were analyzed. FAZ area, point thickness of central fovea, central 1-mm subfield thickness, the occurrence of intraretinal cysts, ellipsoid zone disruption, and disorganization of retinal inner layers (DRIL) length were measured. VA was also recorded. Correlations between FAZ area and VA were explored using regression models. Main outcome measure was VA.

RESULTS

Mean age was 62.9±13.2 years. There was no difference in demographic and OCT-derived anatomic measurements between branch retinal vein occlusion and central retinal vein occlusion groups (all P ≥ 0.058); therefore, data from the 2 groups were pooled together to a single RVO group for further statistical comparisons. Univariate and multiple regression analysis showed that the area of the FAZ was significantly correlated with VA in DR and RVO (all P ≤ 0.003). The relationship between FAZ area and VA varied with age (P = 0.026) such that for a constant FAZ area, an increase in patient age was associated with poorer vision (rise in logarithm of the minimum angle of resolution visual acuity). Disruption of the ellipsoid zone was significantly correlated with VA in univariate and multiple regression analysis (both P < 0.001). Occurrence of intraretinal cysts, DRIL length, and lens status were significantly correlated with VA in the univariate regression analysis (P ≤ 0.018) but not the multiple regression analysis (P ≥ 0.210). Remaining variables evaluated in this study were not predictive of VA (all P ≥ 0.225).

CONCLUSIONS

The area of the FAZ is significantly correlated with VA in DR and RVO and this relationship is modulated by patient age. Further study about FAZ area and VA correlations during the natural course of retinal vascular diseases and following treatment is warranted.

Widefield OCT Findings of a Patient With Stellate Nonhereditary Idiopathic Foveomacular Retinoschisis

The authors report extensive peripheral retinoschisis in a patient with stellate nonhereditary idiopathic foveomacular retinoschisis (SNIFR) detected by widefield optical coherence tomography (OCT). A 64-year-old woman diagnosed with foveomacular retinoschisis 3 years prior presented for evaluation after being seen by multiple other retina specialists. Standard macular spectral-domain OCT (6 mm) revealed typical foveomacular schisis involving only the outer retina. However, widefield OCT (12 mm) revealed diffuse bilateral retinoschisis involving both inner and outer retinal layers in the macula and midperiphery. Widefield imaging is important to evaluate and monitor complex peripheral retinoschisis that may be otherwise undetectable using conventional techniques. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:774-777.].

Residual Foveal Cone Structure in CNGB3-Associated Achromatopsia

PURPOSE

Congenital achromatopsia (ACHM) is an autosomal recessive disorder in which cone function is absent or severely reduced. Gene therapy in animal models of ACHM have shown restoration of cone function, though translation of these results to humans relies, in part, on the presence of viable cone photoreceptors at the time of treatment. Here, we characterized residual cone structure in subjects with CNGB3-associated ACHM.

METHODS

High-resolution imaging (optical coherence tomography [OCT] and adaptive optics scanning light ophthalmoscopy [AOSLO]) was performed in 51 subjects with CNGB3-associated ACHM. Peak cone density and inter-cone spacing at the fovea was measured using split-detection AOSLO. Foveal outer nuclear layer thickness was measured in OCT images, and the integrity of the photoreceptor layer was assessed using a previously published OCT grading scheme.

RESULTS

Analyzable images of the foveal cones were obtained in 26 of 51 subjects, with nystagmus representing the major obstacle to obtaining high-quality images. Peak foveal cone density ranged from 7,273 to 53,554 cones/mm2, significantly lower than normal (range, 84,733-234,391 cones/mm2), with the remnant cones being either contiguously or sparsely arranged. Peak cone density was correlated with OCT integrity grade; however, there was overlap of the density ranges between OCT grades.

CONCLUSIONS

The degree of residual foveal cone structure varies greatly among subjects with CNGB3-associated ACHM. Such measurements may be useful in estimating the therapeutic potential of a given retina, providing affected individuals and physicians with valuable information to more accurately assess the risk-benefit ratio as they consider enrolling in experimental gene therapy trials. (www.clinicaltrials.gov, NCT01846052.).

Inner-Retinal Irregularity Index Predicts Postoperative Visual Prognosis in Idiopathic Epiretinal Membrane

PURPOSE

To investigate the correlation between the inner-retinal irregularity index and visual outcomes before and after idiopathic epiretinal membrane (ERM) surgery.

DESIGN

Retrospective cohort study.

METHODS

We analyzed 66 eyes of 66 patients with idiopathic ERM. Ophthalmic examinations included best-corrected visual acuity (BCVA) measurements, metamorphopsia assessment, and spectral-domain optical coherence tomography before surgery and 1, 3, and 6 months post-surgery. Correlations between the inner-retinal irregularity index, defined as the length ratio between the inner plexiform layer and retinal pigment epithelium, and visual outcomes before and after ERM surgery were evaluated and compared with the correlation between the central foveal thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness, interdigitation zone defect, and visual outcomes.

RESULTS

Inner-retinal irregularity index and central foveal thickness were significantly correlated with BCVA and metamorphopsia at each follow-up examination (all P < .05). The interdigitation zone defect correlated with BCVA at 3 and 6 months post-surgery (P < .001 and P < .015, respectively). However, GC-IPL thickness was not correlated with visual outcomes at any follow-up examination. The preoperative interdigitation zone defect was correlated with 6-month BCVA (P = .035) and the preoperative inner-retinal irregularity index was significantly correlated with the 6-month BCVA and marginally correlated with the 6-month metamorphopsia (P = .018 and P = .097, respectively).

CONCLUSION

The inner-retinal irregularity index was significantly correlated with visual outcomes before and after ERM surgery. This index can be used as a new surrogate marker for inner-retinal damage and a predictive prognostic marker in ERM.

Bilateral solar retinopathy. Autofluorescence and optical coherence tomography

CASE REPORT

A 33-year-old man referred decreased bilateral visual acuity for five years, with no history of interest. Military profession and probably previous sun exposure. Focal pigmented lesions in the macular area of the fundus were observed, with impairment of the photoreceptor layer in the fovea, observed by optical coherence tomography (OCT), in various sectors of the fovea.

DISCUSSION

Solar retinopathy is associated with professions at risk of sun exposure. The diagnosis is based on autofluorescence and macular OCT, that later will provide key data to establish the cause.

Progression of Macular Atrophy in Pattern Dystrophies

BACKGROUND AND OBJECTIVE

To quantify the progression of macular atrophy associated with pattern dystrophies (PD).

PATIENTS AND METHODS

Retrospective, observational study including patients with reticular PD and macular atrophy. A detailed ophthalmologic exam was performed, and progression of macular atrophy areas was evaluated on fundus autofluorescence frames using RegionFinder software, a semiautomated software embedded in Spectralis device (Heidelberg Engineering, Heidelberg, Germany).

RESULTS

We included 19 eyes of 12 patients. The median follow-up was 4.5 years (interquartile range [IQR]: 2.7-5.5). Three eyes (16%) had choroidal neovascularization. Atrophy involved foveal area in 21% (four of 19) of cases. Decreased vision occurred in three eyes (16%). The median atrophy progression rate evaluated by RegionFinder software was 0.101 mm(2)/year (IQR: 0.054-0.257).

CONCLUSION

The progression of macular atrophy in PDs appears to be relatively slow. Further studies are necessary to correlate the progression of atrophy in PDs with genetic data. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:652-658.].

Macular Thickness Following Strabismus Surgery as Determined by Optical Coherence Tomography

PURPOSE

To investigate macular changes following strabismus surgery by using optical coherence tomography (OCT).

METHODS

The authors prospectively evaluated 60 eyes of 30 patients undergoing unilateral extraocular muscle surgery. OCT measurements employing the fast macular thickness mapping protocol were performed 1 day prior to surgery and 1 day postoperatively. Postoperative macular changes in the study eye that was operated on (n = 30) were compared with the fellow control eye (n = 30, controls).

RESULTS

There was an increase in mean ± standard deviation central foveal thickness (CFT) in the operated eyes, from 201.63 ± 18.36 µm at baseline to 206.03 ± 22.73 µm postoperatively (P = .024). Preoperative and postoperative perifoveal outer temporal quadrant thicknesses were 220.10 ± 16.23 and 225.80 ± 14.78 µm, respectively (P = .009). There were no differences between preoperative and postoperative retinal thickness measurements for all measured areas in the control eyes. Eyes that underwent surgery involving the rectus muscles showed a trend toward a greater CFT increase compared with eyes that had oblique muscle surgery (P = .070).

CONCLUSIONS

The authors found subclinical increases in the foveal and perifoveal macular thicknesses following extraocular muscle surgery. These findings could be attributed to change in the mechanical forces caused by the new position of the extraocular muscles and transmitted via the sclera or, alternatively, to postoperative inflammation and alterations in the blood-retinal barrier. The clinical implications of these findings remain to be clarified.

MACULAR BUCKLING WITH ANDO PLOMBE MAY INCREASE CHOROIDAL THICKNESS AND MIMIC SEROUS RETINAL DETACHMENT SEEN IN THE TILTED DISK SYNDROME

PURPOSE

Serous subfoveal detachment has been described in the literature as a complication that appears at the border of the staphyloma. Macular buckling induces a postoperative inward bulge that resembles the ridge of a staphyloma. We describe three patients who developed a serous subfoveal detachment after uneventful macular buckling. To our knowledge, this complication, that shares similarities with the staphyloma ridge detachment, has not been previously reported.

METHODS

The clinical records of all cases that underwent macular buckling at our clinic were reviewed.

RESULTS

Three patients developed a serous subfoveal detachment that could not be explained by choroidal neovascularization or polypoidal vascular choroidopathy. Along with the development of the subfoveal detachment, we observed an increase of the choroidal thickness beneath the fovea. This thickening, that tended to progress during the follow-up, resolved spontaneously after explantation of the buckle. The decrease in foveal thickness did also lead to resolution of the subfoveal detachment.

CONCLUSION

The development of the subfoveal detachment in our patients was closely associated with a focal increase of the choroidal thickness after the macular buckling. After the buckle was removed, the choroidal thickness went back to the normal prebuckling values and the detachment resolved in all three patients. This leads us to think that there is a close association between choroidal thickness and the serous subfoveal detachment.

Spectral-Domain Optical Coherence Tomography in Wagner Syndrome: Characterization of Vitreoretinal Interface and Foveal Changes

PURPOSE

To evaluate the spectrum of morphologic abnormalities in patients with Wagner syndrome by spectral-domain optical coherence tomography (SD OCT).

DESIGN

Retrospective comparative case study.

METHODS

Institutional study of patients entered into the French Vitreoretinopathy Study Group database. Twelve eyes of 9 patients from 3 unrelated families with genetically confirmed Wagner syndrome and 28 eyes from 15 age- and sex-matched healthy family controls were scanned by SD OCT. Morphology and layer thickness of the total retina, inner retinal layers, outer retinal layers, and photoreceptor layer at different degrees of eccentricity from the fovea were compared between the 2 groups.

RESULTS

A thick multilayered membrane adherent to the perifovea but completely detached from the fovea, thus forming a bridge over the foveal pit, was observed in 84% of eyes from patients with Wagner syndrome. At the equatorial area, SD OCT imaging allowed visualization of the architecture of an avascular vitreous veil with localized retinal traction. Most retinal layers were significantly thinner in patients with Wagner syndrome compared to the control group, except at the foveal center where abnormal persistence of 1 or more inner retinal layers could be observed.

CONCLUSION

SD OCT provides better structural insight into the range of retinal defects at the vitreoretinal interface and fovea, which is not only useful for improving diagnosis and management, but also for understanding the pathogenesis of Wagner syndrome.

Assessment of Foveal Microstructure and Foveal Lucencies Using Optical Coherence Tomography Radial Scans Following Macular Hole Surgery

PURPOSE

To evaluate the foveal microstructure using high-density (24-line) radial scans and their correlation with visual recovery following macular hole surgery.

DESIGN

Retrospective, consecutive, interventional case series.

METHODS

Forty-five eyes of 43 patients with ≥6 months follow-up following surgery were analyzed. Preoperative predictive measures evaluated included basal hole and minimum linear diameters. Outcome measures included best-corrected visual acuity (BCVA), postoperative foveal lucency horizontal and vertical size, external limiting membrane, and ellipsoid zone defect.

RESULTS

Mean basal hole diameter was 642 ± 330 μm and minimum linear diameter was 277 ± 161 μm. BCVA (logMAR) improved from 0.67 ± 0.23 to 0.31 ± 0.16 at 12 months (P < .001). Foveal lucency horizontal and vertical sizes (μm) improved from 97 ± 81 and 33 ± 18 at 1 month to 26 ± 33 and 19 ± 18, respectively (P < .05) at 12 months. External limiting membrane recovered in all cases at 1 month. Mean ellipsoid zone defect (μm) reduced from 136 ± 164 at 1 month to 32 ± 33 at 12 months (P < .05). Preoperative basal hole diameter correlated with horizontal foveal lucency size at all time points (P < .05). Horizontal foveal lucency size at 1 month correlated (P < .05) with BCVA at 6 and 12 months. Basal hole diameter ≥700 μm (71% sensitivity and 70% specificity) and minimum linear diameter ≥330 μm (71% sensitivity and 70% specificity) were predictive of foveal lucency development. Cataract surgery did not influence foveal lucency resolution and no holes reopened.

CONCLUSION

Using radial scans, 71% of eyes demonstrated a foveal lucency at 1 month, whose size correlated with visual recovery. Preoperative basal hole diameter was predictive of foveal lucency development and size.

[Association between optical coherence tomography findings and visual acuity of Behcet's disease-associated uveitis patients during remission stage]

OBJECTIVE

To study the relationship between the structure of macular central fovea and the best-corrected visual acuity (BCVA) during remission stage of Behcet's disease associated uveitis.

METHODS

Retrospective case series studies. The study covered 51 patients (79 eyes) during remission stage of Behcet's disease-associated uveitis from Peking Union Medical College Hospital in a three-year period from January 2012 to January 2015. There were 40 males, 11 females with the average age of 31.5 ± 6.9 years old (ranging from 18 to 46). All the patients received a complete set of ophthalmic examination, including BCVA, intraocular pressure, slit-lamp microscope, ophthalmoscope and frequency domain optical coherence tomography (OCT). All the eyes were divided into 4 groups according to central macular thickness (CMT) (the thick CMT group: CMT ≥ 130 µm; the thin CMT group: CMT < 130 µm) and the existence of ellipsoid zone. Group 1: thick CMT and ellipsoid (+); Group 2: thick CMT and ellipsoid (-); Group 3: thin CMT and ellipsoid (+); Group 4: thin CMT and ellipsoid (-). Sight disparity among multiple groups was tested with Kruskal Wallis, while the difference between two groups was tested with Mann-Whitney U test. Bonferroni correction was conducted when necessary.

RESULTS

The mean CMT was (151.4 ± 62.3) µm in all eyes (43 eyes in thick CMT group, 36 eyes in thin CMT group). According to grouping rule, there were 32 eyes in group 1, 11 eyes in group 2, 2 eyes in group 3 and 34 eyes in group 4. The BCVA of thick CMT group was better than that of thin CMT group (logMAR0.1 and logMAR1.0) (z = -6.88, P < 0.01). In addition, the BCVA of ellipsoid (+) group was better than the ellipsoid (-) group. (log MAR0.1 and log MAR1.0) (z = -6.60, P < 0.01).

CONCLUSION

Thick CMT and intact ellipsoid zone usually associated with relatively better BCVA in Behcet's disease-associated uveitis patients.

Optic Disc-Fovea Distance, Axial Length and Parapapillary Zones. The Beijing Eye Study 2011

Purpose

To measure the distance between the optic disc center and the fovea (DFD) and to assess its associations.

Methods

The population-based cross-sectional Beijing Eye Study 2011 included 3468 individuals aged 50+ years. The DFD was measured on fundus photographs.

Results

Readable fundus photographs were available for 2836 (81.8%) individuals. Mean DFD was 4.76 ± 0.34mm (median: 4.74 mm; range: 3.76–6.53mm). In multivariate analysis, longer DFD was associated with longer axial length (P<0.001; standardized correlation coefficient beta: 0.62), higher prevalence of axially high myopia (P<0.001; beta:0.06), shallower anterior chamber depth (P<0.001; beta:-0.18), thinner lens thickness (P = 0.004; beta: -0.06), smaller optic disc-fovea angle (P = 0.02; beta: -0.04), larger parapapillary alpha zone (P = 0.008; beta: 0.05), larger parapapillary beta/gamma zone (P<0.001; beta: 0.11), larger optic disc area (P<0.001; beta: 0.08), lower degree of cortical cataract (P = 0.002; beta: -0.08), and lower prevalence of age-related macular degeneration (P = 0.001; beta: -0.06). Bruch´s membrane opening-fovea distance (DFD minus disc radius minus parapapillary beta/gamma zone width) in non-glaucomatous eyes was not significantly (P = 0.60) related with axial length in emmetropic or axially myopic eyes (axial length ≥23.5 mm), while it increased significantly (P<0.001; r: 0.32) with longer axial length in eyes with an axial length of <23.5mm. Ratio of mean DFD to disc diameter was 2.65 ± 0.30. If the ratio of disc-fovea distance to disc diameter was considered constant and if the individual disc diameter was calculated as the individual disc-fovea distance divided by the constant factor of 2.65, the resulting calculated disc diameter differed from the directly measured disc diameter by 0.16 ±0.13 mm (median: 0.13 mm, range: 0.00–0.89 mm) or 8.9 ± 7.3% (median: 7.4%; range: 0.00–70%) of the measured disc diameter.

Conclusions

DFD (mean: 4.76mm) increases with longer axial length, larger parapapillary alpha zone and parapapillary beta/gamma zone, and larger disc area. The axial elongation associated increase in DFD was due to an enlargement of parapapillary beta/gamma zone while the Bruch’s membrane opening-fovea distance did not enlarge with longer axial length. This finding may be of interest for the process of emmetropization and myopization. Due to its variability, the disc-fovea distance has only limited clinical value as a relative size unit for structures at the posterior pole.

A combination of retinal morphology and visual electrophysiology testing increases diagnostic yield in Parkinson's disease

BACKGROUND

Impaired vision and remodeled foveal pit have been demonstrated in Parkinson's disease (PD) patients using different techniques.

METHODS

Ten PD (20 eyes) and eight healthy controls (HC) subjects (16 eyes) were enrolled. Subjects were evaluated for N70 and P100 latencies using two-channel VEP with pattern reversal and on/off pattern; Contrast sensitivity (CS) using Pelli-Robson chart; macular thickness measured using Zeiss-HD optical coherence tomography (OCT).

RESULTS

PD patients had a significantly delayed N70 (reversal pattern) and P100 (on/off pattern), lower CS score, and decreased retinal thickness at temporal 1.5-2.5 mm from the foveola. N70 latency was negatively correlated with CS (R = -0.419, P = 0.01) and average GCL-IPL thickness (R = -0.529, P = 0.001). CS was positively correlated with parafoveal thickness (R = 0.490, P = 0.002). A combination of parafoveal thickness and CS score yielded an AUC of 0.784 for PD discrimination which increased to 0.844 when combined with N70 and P100 measures.

CONCLUSION

A combination of pattern reversal VEP latency, CS score, and inner retinal foveal thickness measures has a high diagnostic yield for PD.

Evaluation of Macular Function Using Pattern Electroretinogram in Idiopathic Epiretinal Membrane

PURPOSE

Pattern electroretinogram (PERG) in idiopathic epiretinal membrane (ERM) was investigated to find the correlation of the ganglion cell function with postoperative visual acuity.

DESIGN

This was a retrospective consecutive chart review.

METHODS

Medical records of 24 eyes that underwent vitrectomy and membrane peeling for idiopathic ERM were reviewed retrospectively. The amplitude and implicit time of P50 and N95 in preoperative PERG were analyzed to find correlation with visual acuity and foveal thickness. The ratio of the parameters in involved eyes to those in healthy fellow eyes was calculated for analysis.

RESULTS

Visual acuity (logarithm of the minimum angle of resolution) improved from 0.53 at baseline to 0.34 at 6 months (P = 0.003). Foveal thickness decreased significantly from 488.3 μm at baseline to 374.7 μm (P = 0.001). The preoperative N95 amplitude ratio was significantly correlated with visual acuity at 6 months after ERM removal (r = -0.423, P = 0.040), whereas the amplitude of P50 and implicit time of both waves showed no significant correlation with postoperative visual acuity. The implicit time ratio of P50 (r = 0.530, P = 0.008) and N95 (r = 0.436, P = 0.033) showed significant correlation with preoperative foveal thickness on optical coherence tomography.

CONCLUSIONS

N95 amplitude in PERG was a predictor of visual outcomes after ERM surgery. These results suggest the correlation of postoperative visual acuity with the function of the ganglion cell layer, which is the closest cell layer to be affected by ERM.

Changes in Inner and Outer Retinal Layer Thicknesses after Vitrectomy for Idiopathic Macular Hole: Implications for Visual Prognosis

Purpose

To investigate sequential post-operative thickness changes in inner and outer retinal layers in eyes with an idiopathic macular hole (MH).

Methods

Retrospective case series. Twenty-four eyes of 23 patients who had received pars plana vitrectomy (PPV) for the closure of MH were included in the study. Spectral domain optical coherence tomography C-scan was used to automatically measure the mean thickness of the inner and outer retinal layers pre-operatively and up to 6 months following surgery. The photoreceptor outer segment (PROS) length was measured manually and was used to assess its relationship with best-corrected visual acuity (BCVA).

Results

Compared with the pre-operative thickness, the inner layers significantly thinned during follow-up (P = 0.02), particularly in the parafoveal (P = 0.01), but not perifoveal, area. The post-operative inner layer thinning ranged from the ganglion cell layer to the inner plexiform layer (P = 0.002), whereas the nerve fiber layer was unaltered. Outer layer thickness was significantly greater post-operatively (P = 0.002), and especially the PROS lengthened not only in the fovea but also in the parafovea (P < 0.001). Six months after surgery, BCVA was significantly correlated exclusively with the elongated foveal PROS (R = 0.42, P = 0.03), but not with any of the other thickness parameters examined.

Conclusions

Following PPV for MH, retinal inner layers other than the nerve fiber layer thinned, suggestive of subclinical thickening in the inner layers where no cyst was evident pre-operatively. In contrast, retinal outer layer thickness significantly increased, potentially as a result of PROS elongation linking tightly with favorable visual prognosis in MH eyes.

Fabrication of healthy and disease-mimicking retinal phantoms with tapered foveal pits for optical coherence tomography

Optical coherence tomography (OCT) has become a standard tool in ophthalmology clinics for diagnosing many retinal diseases. Nonetheless, the technical and clinical communities still lack a standardized phantom that could aid in evaluating and normalizing the many protocols and systems used for diagnosis. Existing retinal phantoms are able to mimic the thickness and scattering properties of the retinal layers but are unable to model the morphology of the foveal pit, particularly the tapering of the retinal layers. This work demonstrates a new fabrication procedure that is capable of reliably and consistently replicating the shape and tapered appearance of the retinal layers near the foveal pit using a combination of spin-coating and replica molding. We characterize the effects of using different mold sizes which enable us to achieve a range of pit dimensions. We also present a modified procedure to replicate two diseased states of the retinal tissue, such as retinal detachment and dry aged-related macular degeneration. The ability to create an anatomically correct foveal pit for healthy and disease-mimicking phantoms will allow for a new standard better suited for intra- and inter-system evaluation and for improved comparison of retinal segmentation algorithms

[Central retinal changes after ranibizumab injection for wet age-related macular degeneration]

AIM

to assess the dynamics of macular morphofunctional parameters in wet age-related macular degeneration after three injections of ranibizumab.

MATERIAL AND METHODS

A total of 76 patients with classic choroidal neovascular membrane were examined. The latter could be seen on optical coherence tomography scans before the treatment as an optically heterogeneous formation beneath the neurosensory epithelium. The point of fixation was located 2-10 degrees from the fovea according to microperimetry testing. Wedge-like reduction of light sensitivity down to 0-2 dB corresponded to the area of neovascularization.

RESULTS

Macular sensitivity improved from 7.24 ± 2.73 dB to 13.88 ± 1.94 dB (p < 0.05) after a course of three ranibizumab injections, the most significant changes taking place after the third one. The point of fixation moved somewhat back to the fovea after each injection. Morphological parameters of neovascular membranes gradually decreased: after the first injection the height went down to 20.29 ± 17.84 µm and the width--down to 1200 ± 300 µm on average, after the second one the height was 14.39 ± 9.83 µm, width--1000 ± 175 µm, after the third one the height and the width were 13.31 ± 8.13 µm and 900 ± 100 µm correspondingly (p < 0.05).

CONCLUSION

Antivascular therapy reduces the pathological effect of neovascular membrane throughout the whole treatment period. The dynamics of studied parameters are characterized by an apparent response to the first injection, which indicates the advisability of further treatment.

Correlation Between the Dynamic Postoperative Visual Outcome and the Restoration of Foveal Microstructures After Macular Hole Surgery

PURPOSE

To analyze the long-term dynamic healing process of outer retinal changes for 1 year in patients who underwent a standard vitrectomy procedure for idiopathic macular hole (MH) repair.

DESIGN

Retrospective, consecutive, observational case series.

METHODS

Data were collected on 60 eyes of 56 patients (30 women, 26 men) that underwent successful pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling for idiopathic MH from January 2011 to December 2012. The age distribution ranged from 56 to 85 years (mean: 64 years). Forty eyes underwent combined phacoemulsification, PPV, ILM peeling, and intraocular lens implantation; 20 preoperative pseudophakic eyes underwent PPV and ILM peeling only. The main outcome measures included logMAR best-corrected visual acuity (BCVA) and macular microstructures determined by spectral-domain optical coherence tomography performed pre- and postoperatively during follow-up visits at 1, 3, 6, 9, and 12 months.

RESULTS

One month after surgery, 24 eyes (40%) showed normal external limiting membrane (ELM), 36 eyes (60%) showed normal ELM at 3 months, and 54 eyes (90%) showed normal ELM 12 months after surgery. Six eyes (10%) revealed a continuous ellipsoid zone (EZ) at 1 month, 18 eyes (30%) at 3 months, and 48 eyes (80%) at 12 months postoperatively. There were no eyes with a disrupted ELM in the presence of an intact EZ line. The eyes with intact ELM and/or intact EZ line showed better BCVA than eyes with defects in ELM or EZ line. On the contrary, glial cell presentation is significantly associated with worse postoperative BCVA. However, the presence of foveal cystoid change is not significantly associated with postoperative BCVA.

CONCLUSIONS

The ELM and EZ line at the fovea recovered and the presence of glial cells and cystoid space resolved gradually after surgery. The postoperative visual acuity was correlated with resolved glial cells and a restored ELM and EZ line.

Intravitreal Aflibercept for Macular Edema Secondary to Branch Retinal Vein Occlusion in Chinese Patients

PURPOSE

To investigate the short-term efficacy and safety of intravitreal aflibercept in a case series of patients from Taiwan, China, with macular edema secondary to branch retinal vein occlusion (BRVO).

METHODS

A total of 32 patients with macular edema associated with BRVO, without prior macular laser or other intervention, were enrolled consecutively from September 2013 to February 2015. The cases received single 2 mg injections of intravitreal aflibercept. Primary outcome measures included changes in central foveal thickness (CFT; 1 mm increments by spectral-domain optic coherence tomography) and best corrected visual acuity (BCVA), determined at 1, 2, and 3 months after the injection. Complications after injections were recorded. The changes in CFT and BCVA were compared with Wilcoxon sign-rank tests.

RESULTS

The CFT was significantly reduced and the BCVA was significantly improved at 1, 2, and 3 months after injection (all P < 0.05). Tomography findings revealed no recurrence within 3 months. No systemic thromboembolic events, elevated intraocular pressure, retinal detachment, or infectious endophthalmitis occurred following injection.

CONCLUSION

Single intravitreal aflibercept may be useful in treating macular edema associated with BRVO within 3 months. No adverse systemic or ocular effects were found in this case series.

Clinical Insights Into Foveal Morphology in Albinism

PURPOSE

A hallmark of albinism is foveal hypoplasia. However, literature suggests variable foveal development. This study evaluates the association between ocular phenotype and foveal morphology to demonstrate the broad structural and functional spectrum.

METHODS

Best-corrected visual acuity (BCVA), nystagmus, angle kappa, stereoacuity, iris transillumination, macular melanin presence, foveal avascular zone, and annular reflex were recorded in 14 patients with albinism. Spectral-domain optical coherence tomography provided macular images.

RESULTS

The clinical phenotype was broad, with BCVA varying from 20/20 to 20/100. Better BCVA was associated with a preserved foveal avascular zone, annular macular reflex, stereoacuity, and macular melanin. Imaging demonstrated a continuum of foveal development correlating with BCVA. Individuals with a rudimentary pit had normal inner and outer segment lengthening and better BCVA.

CONCLUSIONS

The spectrum of ocular structure and visual function in albinism is broad, suggesting a possible diagnosis of albinism in a patient with an even more normal clinical presentation.