Spectral domain optical coherence tomography for higher precision in the evaluation of vitreoretinal adhesions in exudative age-related macular degeneration

Vitreomacular interface abnormalities in the Ghanaian African

BACKGROUND/OBJECTIVE

Describe vitreomacular interface abnormalities (VMIA) using spectral-domain optical coherence tomography (SD-OCT), and correlations with age-related macular degeneration (AMD) grade in Ghanaian Africans.

SUBJECTS/METHODS

Prospective, cross-sectional study of adults aged ≥50 years recruited in Ghana AMD Study. Participant demographics, medical histories, ophthalmic examination, digital colour fundus photography (CFP) were obtained. High-resolution five-line raster OCT, Macular Cube 512 × 128 scans, and additional line scans in areas of clinical abnormality, were acquired. SD-OCT VMI features classified by International Vitreomacular Traction Study Group system and relationships to AMD grade were evaluated.

OUTCOMES

VMIA prevalence, posterior vitreous detachment (PVD), vitreomacular adhesions (VMA), vitreomacular traction (VMT), epiretinal membranes (ERM), correlations with AMD grade.

RESULTS

The full Ghana AMD cohort included 718 participants; 624 participants (1248 eyes) aged ≥50 years (range = 50-101, mean = 68.8), 68.9% female were included in this analysis. CFP with OCT scans were available for 776 eyes (397 participants); 707 (91.1%) had gradable CFP and OCT scans for both AMD and VMI grading forming the dataset for this report. PVD was absent in 504 (71.3%); partial and complete PVD occurred in 16.7% and 12.0% respectively. PVD did not increase with age (p = 0.720). VMIA without traction and macular holes were observed in 12.2% of eyes; 87.8% had no abnormalities. VMIA was not significantly correlated with AMD grade (p = 0.819).

CONCLUSIONS

This provides the first assessment of VMIA in Ghanaian Africans. VMIA are common in Africans; PVD may be less common than in Caucasians. There was no significant association of AMD grade with VMIA.

Two-Year Follow-Up Study of Patients with Neovascular Age-Related Macular Degeneration Undergoing Anti-VEGF Treatment during the COVID-19 Pandemic

BACKGROUND

regular intravitreal anti-vascular endothelial growth factor (VEGF) treatment is crucial for patients with neovascular age-related macular degeneration (nAMD), and delayed treatment can exacerbate disease progression.

METHODS

we compared the outcomes of on-time versus delayed intravitreal anti-VEGF treatment for patients with nAMD. This study was conducted during the coronavirus disease 2019 (COVID-19) pandemic with a 2-year follow-up period. The best-corrected visual acuity (BCVA) and anatomical findings were evaluated before the pandemic, during the pandemic, and at 6-, 12-, 18-, and 24-months post-pandemic.

RESULTS

The delayed and on-time groups comprised 54 and 72 patients, respectively. After the pandemic, the injection interval increased by 0.65 ± 1.51 months (p = 0.003), with 22.2% of the patients in the delayed group switching to the treat-and-extended regimen (p < 0.001). The delayed group showed greater mean BCVA deterioration (p = 0.027) and central subfield thickness (p = 0.037) at 6 months and worse maximum subretinal fluid height (p = 0.022) at 18 months than the on-time group. No difference was observed between the groups in the second year.

CONCLUSION

the negative effects of delaying anti-VEGF treatment because of the COVID-19 pandemic can be ameliorated by changing the treatment regimen and shortening treatment intervals.

[Role of vitreous in the pathogenesis of neovascular age-related macular degeneration]

Age-related changes in vitreous molecular and anatomic morphology begin early in life and involve two major processes: vitreous liquefaction and weakening of vitreo-retinal adhesion. An imbalance in these two processes results in anomalous posterior vitreous detachment (PVD), which comprises, among other conditions, vitreo-macular adhesion (VMA) and traction (VMT). VMA is more common in patients with neovascular age-related macular degeneration (nAMD) than age-matched control patients, with the site of posterior vitreous adherence to the inner retina correlating with location of neovascular complexes. The pernicious effects of an attached posterior vitreous on age-related macular degeneration (AMD) progression involve mechanical forces, enhanced fluid influx and inflammation in and between the retinal layers, hypoxia leading to an accumulation of vascular endothelial growth factor (VEGF) and other stimulatory cytokines, and probably an infiltration of hyalocytes. It has been shown that vitrectomy not only mitigates progression to end-stage AMD, but existing choroidal neovascularization regresses after surgery. Thus, surgical PVD induction during vitrectomy or by pharmacologic vitreolysis may be considered in non-responders to anti-VEGF treatment with concomitant VMA.

Prognostic factors associated with the course of vitreomacular traction in eyes with age-related macular degeneration

CLINICAL RELEVANCE

Vitreomacular traction(VMT) is a clinical syndrome that can cause decreased vision and may affect the treatment response in cases of age-related macular degeneration(AMD). Factors affecting the course of VMT in AMD cases will guide the clinician in terms of patient management.

BACKGROUND

The aim of this study was to determine the prevalence of VMT in patients with AMD, to evaluate the natural course of VMT, and to investigate factors associated with the prognosis of VMT in eyes with AMD.

METHODS

This retrospective case series was conducted with 55 eyes of 46 patients who were diagnosed as having AMD accompanying with VMT. Demographic data, complete ophthalmologic examination findings, type of AMD, receiving an intravitreal injection(IVI), number of IVIs, and the presence of complete spontaneous release were obtained from the medical records of the patients. The horizontal length of VMT(HLVMT), central macular thickness(CMT), the horizontal length of choroidal neovascularization(HLCNV) were evaluated from spectral-domain optical coherence tomography(SD-OCT) images.

RESULTS

Spontaneous release was observed in 7(28%) eyes of the exudative AMD group and 10(33.3%) eyes of the nonexudative AMD group. On the last visit, the HLVMT was increased in 22(40%) of the eyes and a decrease in HLVMT was observed in 8(14.5%) of the eyes. In the remaining 12(21.8%) eyes had unchanged HLVMT. In all eyes with CNV, the area of VMT corresponded in 100% with localization of the CNV complex. No significant difference was found between the eyes with spontaneous release and persistent traction in terms of the type of AMD, IVI, HLVMT, age, gender, and crystalline lens status.

CONCLUSION

In this study, VMT was observed at higher rates in eyes with exudative AMD compared to the eyes with nonexudative AMD. However, spontaneous release rates were found close to those with idiopathic VMT independently of the type of AMD, HLVMT, and IVI.

Vitreous Antioxidants, Degeneration, and Vitreo-Retinopathy: Exploring the Links

The transparent vitreous body, which occupies about 80% of the eye’s volume, is laden with numerous enzymatic and non-enzymatic antioxidants that could protect the eye from oxidative stress and disease. Aging is associated with degeneration of vitreous structure as well as a reduction in its antioxidant capacity. A growing body of evidence suggests these age-related changes may be the precursor of numerous oxidative stress-induced vitreo-retinopathies, including vision degrading myodesopsia, the clinically significant entoptic phenomena that can result from advanced vitreous degeneration. Adequate intravitreal antioxidant levels may be protective against vitreous degeneration, possibly preventing and even improving vision degrading myodesopsia as well as mitigating various other vitreo-retinopathies. The present article is, therefore, a review of the different antioxidant molecules within vitreous and the inter-relationships between vitreous antioxidant capacity and degeneration.

The vitreopapillary interface in healthy and glaucoma: posterior vitreous detachment in the vitreopapillary interface study

PURPOSE

To investigate the vitreopapillary interface (VPI) in health and glaucoma according to the different stages of posterior vitreous detachment (PVD) formation.

METHODS

Prospective single centre study including healthy subjects and glaucoma patients. PVD staging was performed with spectral domain optical coherence tomography. Gender, age, lens status and refractive error were assessed in both groups. Glaucoma patients additionally had a comprehensive ophthalmological investigation including intraocular pressure measurement, visual field testing and confocal imaging of the optic nerve head.

RESULTS

Data on 523 subjects (993 eyes) were included from the VPI study (clinicaltrials.gov NCT02290795) database (493 eyes of 258 healthy subjects and 500 eyes of 265 glaucoma patients). Healthy subjects were significantly younger than primary open angle glaucoma patients (59.7 ± 14.81 versus 70.0 ± 10.78 years, p < 0.001), but were otherwise matched for refractive error and gender. Significantly more glaucomatous eyes were pseudophakic (26.6% versus 5.1%). Including only phakic nonoperated eyes from subjects between 50 and 80 years old decreased the age difference between healthy and open angle glaucoma (64.1 ± 8.0 versus 65.9 ± 6.7 years, p = 0.051). Comparing these subgroups rendered similar average ages for PVD stages 0 and 4, in contrast to the significant older age for the glaucoma subgroup in stage 1 (64.1 ± 6.01 versus 61.4 ± 8.38 years, p < 0.001) and a trend towards significance in stage 3 (70.8 ± 69.8 versus 67.5 ± 5.92 years, p = 0.051).

CONCLUSION

The VPI study is a large clinical trial investigating the VPI in health and glaucoma. A subset of glaucoma patients seems to experience stages 1-3 of PVD formation at older age compared to healthy subjects.

Influence of the Vitreoretinal Interface on the Treatment with Anti-VEGF for Exudative Age-Related Macular Degeneration

PURPOSE

To investigate the influence of the vitreoretinal interface on the outcomes of different ranibizumab regimens for exudative age-related macular degeneration.

METHODS

We conducted a retrospective subanalysis of 2 prospective clinical trials. Patients were treated with ranibizumab for 12 months according to 3 different regimens: pro-re-nata (PRN), treat and extend (T&amp;E), and monthly. Vitreoretinal interface was assessed for absence (group ON) or presence (group OFF) of posterior vitreous detachment (PVD).

RESULTS

We included 64 eyes from 64 patients. Visual improvement was poorer for group ON (0.3 ± 10.7 letters) than for group OFF (9.2 ± 13.3; p = 0.007). A significant difference in letters of improvement between groups was observed in the PRN cohort (ON: -5.0 ± 12.9; OFF: 11.4 ± 11.9; p = 0.003), but not in the cohorts with monthly (ON: 5.7 ± 7.8; OFF: 7.9 ± 15.2; p = 0.735) or T&amp;E (ON: 4.3 ± 4.3; OFF: 7.8 ± 11.1; p = 0.424) treatment.

CONCLUSION

The negative impact of absence of PVD is regimen dependent, with monthly dosing providing similar outcomes to PVD patients. In the absence of PVD (group ON), PRN should be avoided, and T&amp;E might be an alternative.

ASSOCIATION BETWEEN THE VITREOMACULAR INTERFACE AND OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS IN WET AGE-RELATED MACULAR DEGENERATION

PURPOSE

To study the effect of the vitreomacular interface on various wet age-related macular degeneration (AMD) characteristics including the size and type of choroidal neovascularization (CNV), choroidal thickness, and activity of the CNV.

METHODS

This was a retrospective observational cross-sectional study. The study included 43 patients (51 eyes) with treatment-naive age-related macular degeneration. Twenty-six patients with wet AMD in one eye and dry AMD in the other eye were included in a paired-eye analysis. Patients underwent optical coherence tomography examination using Heidelberg Spectralis (spectral domain optical coherence tomography) at presentation to determine the type of CNV and the vitreomacular status. In addition, various parameters were measured including the choroidal thickness and horizontal width and vertical height measurements of the CNV.

RESULTS

There was no correlation between the height, width, activity or type of the CNV, and the presence or absence of vitreomacular adhesion. The mean choroidal thickness (using enhanced depth imaging) in cases with vitreomacular adhesion was 272.57 μm compared with 197.32 μm in cases with no vitreomacular adhesion, a statistically significant difference (P = 0.003). In the paired-eye study (21 patients), there was no significant difference between the eyes with wet AMD and dry AMD with regard to vitreomacular status or the choroidal thickness. In a subgroup analysis, patients with Type 1 CNV had a significantly higher percentage of vitreomacular adhesion compared with the other eye with dry AMD (P = 0.034).

CONCLUSION

In conclusion, the vitreomacular interface does seem to be associated with an increased choroidal thickness in cases of wet AMD. Furthermore, the association between the vitreomacular interface and wet AMD is more significant for Type 1 CNV.

Vitreous hyper-reflective dots in pseudophakic cystoid macular edema assessed with optical coherence tomography

Purpose

This study compares the presence of vitreous hyper-reflective dots (VHDs) detected with optical coherence tomography (OCT) between eyes with pseudophakic cystoid macular edema (CME) and those with no CME after cataract surgery. In addition, we evaluated the impact of VHDs on the responsiveness of pseudophakic CME to cortisone treatment.

Setting

Department of Ophthalmology, Medical University of Graz, Austria.

Design

Retrospective, monocenter case-controlled study.

Methods

Inclusion criteria for the study group and the control group were CME and no CME within 12 weeks following uneventful phacoemulsification in otherwise healthy eyes, respectively. VHDs (number and size) and the macular thickness were assessed with OCT. Furthermore, the number of peribulbar or intravitreal steroid injections was assessed.

Results

A total of 284 eyes from 267 patients were analyzed, among which 119 met the inclusion criteria for the study (n = 63) and the control group (n = 56). VHDs were observed in 54 (85.7%) study eyes and 21 (37.5%, p = 0.013) control eyes. The number of VHDs was 3.9±3.4 in the study group and 0.7±1 in the control group (p<0.001). The size of the VHDs was 33.5±9.1 μm and 36.6±17.9 μm in the study and control groups, respectively (p = 0.978). Overall, the number of VHDs correlated with central subfield thickness (r = 0.584, p<0.001), cube volume (r = 0.525, p<0.001), and postoperative best-corrected visual acuity (BCVA) (r = -0.563, p<0.001). The number of VHDs did not correlate with the frequency of peribulbar or intravitreal steroid injections.

Conclusion

VHDs occurred more often in eyes with CME than in eyes without CME following cataract surgery. In addition, the number of VHDs had an impact on the extent of macular thickening and subsequently postoperative BCVA. No correlation was found between the number of VHDs and the frequency of required peribulbar or intravitreal steroid injections.

Prevalence of Vitreoretinal Interface Abnormalities on Spectral-Domain OCT in Healthy Participants over 45 Years of Age

PURPOSE

To assess the prevalence of vitreoretinal interface abnormalities in a general population of healthy adults ≥45 years of age.

DESIGN

Cross-sectional study carried out at 17 ophthalmology services throughout Spain.

PARTICIPANTS

Between September 2015 and March 2016, all consecutive healthy persons aged ≥45 years who were accompanying patients to ophthalmology services were invited to take part in the study. Exclusion criteria were known retinal disease, uveitis, history of ocular trauma or previous intraocular surgery (including cataract surgery and intravitreal injections), severe myopia (>-6 dioptres), and poor ocular media transparency.

METHODS

Spectral-domain OCT or swept-source OCT was performed on all participants. Diseases of the vitreomacular interface were classified according to the OCT-based anatomic classification system of the International Vitreomacular Traction Study Group. All pathologic and borderline images as well as doubtful cases were evaluated blindly in a central reading center.

MAIN OUTCOME MEASURES

Prevalence of vitreomacular interface abnormalities (vitreomacular traction epiretinal membrane, lamellar hole).

RESULTS

The study included 2257 participants with a mean age of 59.5 years (range 45-90), and a total of 4490 eyes (right eyes 2242, left eyes 2248). Vitreoretinal interface abnormalities were detected in 70 eyes, with a prevalence of 1.6%. Vitreomacular adhesion was observed in 1317 eyes (29.3%). Results of spectral-domain OCT or swept-source OCT examination were unrevealing in 3103 eyes. Vitreoretinal interface abnormalities were found in 61 participants, with a prevalence in the study population of 2.7%. Vitreomacular traction was observed in 14 participants (0.6%), epiretinal membrane in 44 (1.9%), and lamellar macular hole in 3 (0.1%). The prevalence of both vitreomacular traction and epiretinal membrane increased significantly with age. The presence of vitreoretinal interface abnormalities was unrelated to concomitant diabetes mellitus or hypertension.

CONCLUSIONS

An important percentage of healthy participants from the general population ≥45 years of age showed vitreoretinal interface abnormalities. Screening with OCT is advisable at any first routine consultation or preoperative assessment, particularly in older participants.

Effects of Vitreomacular Traction on Ranibizumab Treatment Response in Eyes with Neovascular Age-related Macular Degeneration

PURPOSE

To investigate the effects of vitreomacular traction (VMT) on ranibizumab treatment response for neovascular age-related macular degeneration (AMD).

METHODS

A retrospective review of 85 eyes of 85 patients newly diagnosed with neovascular AMD was conducted. Patients were eligible if they had received more than three consecutive monthly ranibizumab (0.50 mg) treatments and ophthalmic evaluations. Patients were classified into a VMT (+) group or VMT (-) group according to optical coherence tomography imaging. Best corrected visual acuity and central retinal thickness (CRT) measurements were obtained at three and six months after initial injection.

RESULTS

One month after the third injection, mean visual acuity (VA) increases of 6.36 and 9.87 letters were observed in the VMT (+) and VMT (-) groups, respectively. The corresponding mean CRT values decreased by 70.29 µm and 121.68 µm, respectively. A total 41 eyes were identified as eligible for a subsequent fourth injection; 71.1% of patients (27 eyes) in the VMT (+) group but only 29.8% of patients in the VMT (-) group needed a subsequent fourth injection. Follow-up was extended to six months for 42 of the 85 enrolled patients (49.4%). The trends in VA and optical coherence tomography were found to be maintained at six-month follow-up.

CONCLUSIONS

VA and CRT appeared to be more improved after ranibizumab treatment in the VMT (-) group compared to the VMT (+) group. VMT might antagonize the effect of ranibizumab treatment in a subpopulation of AMD patients.

Influence of the vitreomacular interface on the efficacy of intravitreal therapy for uveitis-associated cystoid macular oedema

PURPOSE

To evaluate the effect of the vitreomacular interface (VMI) on treatment efficacy of intravitreal therapy in uveitic cystoid macular oedema (CME).

METHODS

Retrospective analysis of CME resolution, CME recurrence rate and monthly course of central retinal thickness (CRT), retinal volume (RV) and best corrected visual acuity (BCVA) after intravitreal injection with respect to the VMI configuration on spectral-domain OCT using chi-squared test and repeated measures anova adjusted for confounding covariates epiretinal membrane, administered drug and subretinal fluid.

RESULTS

Fifty-nine eyes of 53 patients (mean age: 47.4 ± 16.9 years) were included. VMI status had no effect on complete CME resolution rate (p = 0.16, corrected p-value: 0.32), time until resolution (p = 0.09, corrected p-value: 0.27) or CME relapse rate (p = 0.29, corrected p-value: 0.29). Change over time did not differ among the VMI configuration groups for BVCA (p = 0.82) and RV (p = 0.18), but CRT decrease was greater and faster in the posterior vitreous detachment (PVD) group compared to the posterior vitreous attachment (PVA) and vitreous macular adhesion (VMA) groups (p = 0.04). Also, the percentage of patients experiencing a ≥ 20% CRT thickness decrease after intravitreal injection was greater in the PVD group (83%) compared to the VMA (64%) and the PVA (16%) group (p = 0.027), however, not after correction for multiple testing (corrected p-value: 0.11).

CONCLUSION

The VMI configuration seems to be a factor contributing to treatment efficacy in uveitic CME in terms of CRT decrease, although BCVA outcome did not differ according to VMI status.

Effects of Vitreomacular Adhesion on Age-Related Macular Degeneration

Herein, we review the association between vitreomacular adhesion (VMA) and neovascular age-related macular degeneration (AMD). Meta-analyses have shown that eyes with neovascular AMD are twice as likely to have VMA as normal eyes. VMA in neovascular AMD may induce inflammation, macular traction, decrease in oxygenation, sequestering of vascular endothelial growth factor (VEGF), and other cytokines or may directly stimulate VEGF production. VMA may also interfere with the treatment effects of anti-VEGF therapy, which is the standard treatment for neovascular AMD, and releasing VMA can improve the treatment response to anti-VEGF treatment in neovascular AMD. We also reviewed currently available methods of relieving VMA.

Pharmacologic vitreolysis: New strategy for treatment of anomalous vitreo-macular adhesion

Persistent anomalous vitreo-macular adhesion (VMA) is a well-known factor, associated with a variety of sight threatening diseases - including macular hole, vitreo-macular traction syndrome, cystoid and diabetic macular edema, exudative age- related macular degeneration, myopic traction maculopathy and others. With the advent of optical coherence tomography our understanding of these pathologies and the ability of their early diagnosis has gone much far in the past two decades. The release of macular traction has been of exclusive surgical capability. Notwithstanding good results, vitrectomy is hampered by the inability of complete vitreo-retinal separation (i.e., smooth, bare internal limiting membrane), compulsory postoperative positioning in macular hole cases, surgical complications, and high costs. With aim to offer less invasive and safe treatment modality for anomalous VMA, investigators have made enormous progress in the past decade. Leading among the studied nonsurgical measures is the intravitreal application of pharmacologic agents for the induction of vitreo-retinal separation and vitreous liquefaction, a method termed pharmacologic vitreolysis. Several vitreolytic agents have been studied to date, the most potent among them proved to be plasmin. Recently, ocriplasmin (formerly known as microplasmin) - a more stable than plasmin recombinant product, proved to be safe and efficient in releasing VMA in large studies, and consequently received FDA approval. It’s role in clinical practice is now in the process of being determined. This paper aims to review and summarize the current knowledge and status of investigation on this new approach for the treatment of VMA.

Effects of core vitrectomy in the treatment of age-related macular degeneration

PURPOSE

To investigate the clinical efficacy and safety of an additional core vitrectomy to the standard therapy in patients with exudative age-related macular degeneration (ARMD).

METHODS

In this prospective, controlled, single-centre study, 50 eyes of 50 patients (mean age: 74.1 ± 7.1; median 74 (69/78)) with ARMD were enrolled and randomized 1:1 to group 1 - core vitrectomy additional to three times injections of ranibizumab (3x Rbz) and Group 2 - 3x Rbz (control). 1 16 of 25 eyes in Group 1(64%) and 12 of 25 (48%) in Group 2 had a posterior vitreous detachment (PVD) prior to start of the study. Changes in best-corrected visual acuity (BCVA) using ETDRS charts, central macular thickness and macular volume (OCT) as well as the rate of reinjection with an OCT-based pro renata (PRN) protocol were monitored prospectively over 48 weeks. Forty-seven eyes completed follow-up at week 48.

RESULTS

In Group 1, 4 of 24 lost 1 line of BCVA (16.7%) and 3 of 24 lost 2 lines (12.5%), whereas 17 of 24 gained more than 1 line (70.8%) and improved in average by 9.8 letters. In Group 2, 3 of 23 remained stable and 20 of 23 gained more than or exactly 1 line (78.3%), resulting in 14.3 letters, with no loss of lines. Central macular thickness decreased by 85.58 μm (28.8%) in Group 1 and by 121.43 μm (32.68%) in Group 2 compared with baseline. In Group 1, four patients received three additional and two patients, two additional Rbz injections. In Group 2, three patients received three additional, three patients two and 12 patients one additional Rbz injections. This yielded in an average injection rate of 3.66 in Group 1 and 4.17 in Group 2 over 48 weeks. Posterior vitreous detachment (PVD) was identified in Group 1 in 16 of 24 (66.7%) and in Group 2 in 12 of 23 (52.2%) patients at baseline. At week 48, 6 of 8 (75%) of the patients in Group 1 with initial attached vitreous showed a vitreal detachment, whereas only 1 of 11 (9%) in Group 2 had a new occurred detachment of the vitreous. No systemic or ocular adverse events were noticed.

CONCLUSION

An initial core vitrectomy combined with a conventional ranibizumab injection regimen for exudative AMD patients was safe and lead to similar functional results with less intravitreal ranibizumab injections over 48 weeks.

Retinal pigment epithelium tear after vitrectomy for vitreomacular traction syndrome in an eye with retinal angiomatous proliferation

An 87-year-old Japanese man presented with retinal angiomatous proliferation (RAP) and a retinal pigment epithelium (RPE) detachment in his right eye. His decimal best-corrected visual acuity was 0.15 in the right eye, and optical coherence tomography (OCT) showed a vitreomacular adhesion in the right eye as well. After 3 monthly intravitreal injections of ranibizumab, the size and height of the RPE detachment was significantly reduced. The accumulated intra- and subretinal fluid also disappeared, but the vitreomacular traction remained. Pars plana vitrectomy was performed, and the posterior hyaloid was separated from the retina with a vitrectomy cutter without any intraoperative complications. Two months after the surgery, a large RPE tear was observed over the macular area. His visual acuity decreased to 0.06 and remained unchanged thereafter. We suggest that the small tear led to the larger RPE tear because vitreomacular traction was transmitted to the RPE through the fibrovascular tissue of the RAP during the creation of the hyaloid detachment. Because such an RPE tear has not been reported after vitrectomy for vitreomacular traction, surgeons need to pay special attention to this potential complication in eyes with vitreomacular traction and RAP.

Clinical applications of optical coherence tomography in the posterior pole: the 2011 José Manuel Espino Lecture - Part I

Optical coherence tomography (OCT) is now a standard of care in ophthalmology and is considered essential for the diagnosis and monitoring of many retinal diseases. One of the major advances obtained with OCT was the understanding of the pathophysiology of macular holes. Non-full-thickness macular holes have been revisited because high-resolution OCT images can detect a lamellar macular defect that is not always visible clinically, and surgery has been advocated by some authors. OCT can be valuable in determining the need for and/or timing of surgical intervention on epiretinal membranes or vitreomacular traction syndrome. In addition, we can use this technology as a predictive factor in the prognosis and follow-up of the most common posterior pole pathologies.

Non-responders to treatment with antagonists of vascular endothelial growth factor in age-related macular degeneration

PURPOSE

Most of the publications on modern therapy of neovascular age-related macular degeneration focus on the effect of the treatment. The purpose of this study is to determine the frequency of non-responders to anti-vascular endothelial growth factor (anti-VEGF) treatment and find possible reasons for their failure to respond.

METHODS

The records of patients treated until the end of 2008 the first time with either bevacizumab or ranibizumab were reviewed. Based on the availability of measurable results and according to prior publications showing the effect of the therapy, loss of three lines of distance acuity, increase of retinal thickness or lesion size were identified as indicators of non-responders. Two of these three signs had to be present.

RESULTS

334 eyes of 283 patients were included; 74.55% received bevacizumab and 25.45% received ranibizumab. Overall 14.37% of the eyes were identified as non-responders (14.06% in the bevacizumab group and 15.29% in the ranibizumab group). Baseline distance acuity and vitreo-retinal adhesions were significantly correlated with non-responders. Correlations with age, gender, lesion type, other morphologic features, and the kind of anti-VEGF agent failed to be significant. 10.4% of the non-responders showed a delayed but good response to anti-VEGF treatment.

CONCLUSIONS

About 15% did not sufficiently respond to anti-VEGF treatment. Vitreo-retinal adherences were the only ophthalmologic factor which could be identified to be significantly correlated with insufficient response.

Progressive morphological changes and impaired retinal function associated with temporal regulation of gene expression after retinal ischemia/reperfusion injury in mice

Retinal ischemia/reperfusion (I/R) injury is an important cause of visual impairment. However, questions remain on the overall I/R mechanisms responsible for progressive damage to the retina. In this study, we used a mouse model of I/R and characterized the pathogenesis by analyzing temporal changes of retinal morphology and function associated with changes in retinal gene expression. Transient ischemia was induced in one eye of C57BL/6 mice by raising intraocular pressure to 120 mmHg for 60 min followed by retinal reperfusion by restoring normal pressure. At various time points post I/R, retinal changes were monitored by histological assessment with H&E staining and by SD-OCT scanning. Retinal function was also measured by scotopic ERG. Temporal changes in retinal gene expression were analyzed using cDNA microarrays and real-time RT-PCR. In addition, retinal ganglion cells and gliosis were observed by immunohistochemistry. H&E staining and SD-OCT scanning showed an initial increase followed by a significant reduction of retinal thickness in I/R eyes accompanied with cell loss compared to contralateral control eyes. The greatest reduction in thickness was in the inner plexiform layer (IPL) and inner nuclear layer (INL). Retinal detachment was observed at days 3 and 7 post- I/R injury. Scotopic ERG a- and b-wave amplitudes and implicit times were significantly impaired in I/R eyes compared to contralateral control eyes. Microarray data showed temporal changes in gene expression involving various gene clusters such as molecular chaperones and inflammation. Furthermore, immunohistochemical staining confirmed Müller cell gliosis in the damaged retinas. The time-dependent changes in retinal morphology were significantly associated with functional impairment and altered retinal gene expression. We demonstrated that I/R-mediated morphological changes the retina closely associated with functional impairment as well as temporal changes in retinal gene expression. Our findings will provide further understanding of molecular pathogenesis associated with ischemic injury to the retina.

Vitreomacular adhesion and neovascular age-related macular degeneration

We explore the hypothesis that vitreomacular adhesion (VMA) and vitreomacular traction (VMT) play a role in the pathogenesis and clinical course of neovascular ("wet") age-related macular degeneration (AMD). Several biological theories are offered to explain this possible association, including direct tractional force, altered vitreous oxygenation, altered diffusion coefficients of intravitreal molecules, and alterations in the pharmacokinetics of intravitreal drugs. Release of VMT may improve the clinical course of neovascular AMD, and a few case series suggest that vitrectomy can lead to both a functional and anatomic improvement. A large, randomized, controlled clinical trial is underway, investigating pharmacologic release of VMA in eyes with neovascular AMD.