Foveal microvasculature features of surgically closed macular hole using optical coherence tomography angiography

Changes in vascular density in the macula after pars plana vitrectomy for idiopathic macular hole with macular peeling and one type of flap

BACKGROUND AND AIMS

The aim of this study was to evaluate changes in vascular density in the macula after pars plana vitrectomy for idiopathic macular hole (IMD) with macular peeling and flap.

METHODS

A prospective study of 35 eyes in 34 patients who had undergone standard surgery. Evaluated parameters were best-corrected visual acuity (BCVA), intraocular pressure (IOP), central macular thickness (CRT), macular volume (TMV) and vascular density of the superficial and deep capillary plexus. The follow-up period was one year.

RESULTS

We divided the total group into two: temporal and circular flap and total group. We compared the values after surgery with the preoperative values. In the total group, BCVA increased from 48.38 to 71.44 letters (P≤0.05). IOP changed from 15.24 to 14.76 mmHg (P>0.05). CRT decreased from 432.27 to 323.64 µm (P≤0.05). TMV changed from 0.26 to 0.25 mm3 (P>0.05). The vascular density of the superficial plexus decreased from 32 to 28% (P≤0.05). The intercapillary space of the superficial plexus increased from 68 to 72% (P≤0.05). The vascular density of the deep plexus increased from 17 to 23%. The intercapillary space of the deep vascular plexus decreased from 83 to 77%. Changes in vascular density and intercapillary space of the deep plexus were statistically significant for certain months after operations (P≤0.05). There were no significant differences between subgroups.

CONCLUSION

The superficial plexus vascular density is almost the same in the temporal flap and in the foveal-sparing flap is decreased, and the deep plexus vascular density increased statistically significantly during the follow-up period after surgery.

Retinal displacement after surgery for idiopathic macular hole

AIM

To review and summarize the mechanism hypothesis, influencing factors and possible consequences of macular retinal displacement after idiopathic macular hole (IMH) surgery.

METHODS

PubMed and Web of Science database was searched for studies published before April 2023 on "Retinal displacement", "Idiopathic macular holes", and "Macular displacement".

RESULTS

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.

CONCLUSION

As a subclinical phenomenon, the clinical significance of postoperative macular displacement cannot be underestimated as it may affect the recovery of anatomy and function.

A cross-sectional study of macular displacement after macular hole surgery with ILM peeling in patients with idiopathic macular hole

PURPOSE

To examine the retinal displacement and change in mean superficial foveal avascular zone (FAZ) after successful closure of macular hole (MH) with vitrectomy with internal limiting membrane peeling (ILM) and gas tamponade.

METHODS

A total of 45 patients with idiopathic MH who underwent 23G pars plana vitrectomy with ILM peeling and tamponade with 20% SF6/14% C3F8 were included. Follow-up visits were performed at 2, 4, and 8 weeks. OCT and OCT-A scans were performed along with detailed ocular examination. Distance between optic disc and an easily identifiable vascular bifurcation nasal and temporal to fovea, FAZ, was noted. Chi-square test (categorical data) and Mann-Whitney U test and t tests for other parameters were performed for statistical analysis.

RESULTS

The mean displacement (µm) of an easily identifiable vascular bifurcation in the nasal quadrant was 96.58 ± 36.55 at 8 weeks and in the temporal quadrant was 273.07 ± 85.51 at 8 weeks. The change was statistically significant in the temporal quadrant (P = <0.001). The mean BCVA changed from a minimum of 0.08 at the preoperative timepoint to a maximum of 0.23 at 8 weeks (P = <0.001). The mean FAZ area (mm²) decreased from a maximum of 0.37 at the preoperative timepoint to a minimum of 0.19 at 8 weeks (p = <0.001).

CONCLUSION

The retina in the temporal quadrant is displaced significantly more than nasal quadrant after successful closure of macular hole. The mean superficial FAZ also decreases suggesting a centripetal movement of the foveal tissue postoperatively.

Foveal microvascular features following inverted flap technique for closure of large macular holes

PURPOSE

To describe the anatomical and functional outcomes following use of the inverted flap technique (IFT) to close idiopathic macular holes (MH) of diameter greater than 400 μm. To compare the changes in the macular microvascularization following surgery in operated and healthy fellow eyes.

METHODS

Retrospective study of 24 patients who underwent vitrectomy and IFT for large MH closure. The main variables were closure pattern, best corrected visual acuity (BCVA) and recovery of the external limiting membrane (ELM) and ellipsoid zone (EZ). Foveal avascular zones (FAZ) and vessel and perfusion densities, obtained by OCT angiography scans, were compared with those in healthy fellow eyes.

RESULTS

Complete MH closure was achieved in 95.8% (23/24) of patients 6 months after surgery. There was a significant improvement in postoperative BCVA, from 1.0 to 0.4 logMAR (p < 0.001). The most frequent closure pattern was 1a (62.5%, 15/24), followed by 2c (12.5%, 3/24). The closure pattern was not correlated with height, minimum or maximum diameters or macular hole index (MHI) (p > 0.05). ELM and EZ recovery occurred in 87.5% and 83.3% of cases, respectively. FAZ were smaller in operated eyes than in the fellow eyes (p = 0.012). There were no differences in the vessel or perfusion densities between the operated and fellow eyes (p > 0.05).

CONCLUSIONS

Use of the inverted flap technique for large MH closure provides a high rate of functional and anatomical recovery. We observed a reduction in the FAZ following surgery, with no differences in the macular microvascularization parameters, suggesting that the technique is safe.

Comparison of long-term visual and anatomical outcomes between internal limiting membrane flap and peeling techniques for macular holes with a propensity score analysis

OBJECTIVES

To compare visual and anatomical outcomes between internal limiting membrane (ILM) flap (IF) and peeling (IP) techniques for full-thickness macular holes (FTMHs).

METHODS

A retrospective case series with propensity-score matching (PSM). Patients with a minimum 12 months follow-up were divided into IF and IP groups and matched based on FTMH size and preoperative best-corrected visual acuity (BCVA). BCVA and optical coherence tomography (OCT) findings were obtained to assess outer retinal layer integrity, foveal thickness, and foveal displacement.

RESULTS

Twenty-six eyes were included in each group after PSM. The IF group showed significantly greater BCVA after 1 month, its corresponding change from preoperative BCVA, proportions of eyes with ellipsoid zone defects <250 μm after 1 month, and interdigitation zone restoration after 6 and 12 months (P = 0.007, 0.038, 0.048, 0.025, and 0.023, respectively), as well as less foveal gliosis after 1, 3, 6, and 12 months (P = 0.020, 0.017, 0.050, and 0.024, respectively). In the IP group, the mean outer nuclear layer thickness significantly decreased at 3 (P = 0.019) and 12 months (P = 0.016) compared to 1 month, and the foveal displacement toward the optic disc was significant after 1, 3, 6, and 12 months (P = 0.049, 0.006, 0.001, and <0.001, respectively).

CONCLUSIONS

Compared to IP, IF promoted faster recovery of BCVA and outer retinal layers and was more protective against postoperative foveal thinning and displacement; hence, it should be considered for small and large FTMHs.

Optical Coherence Tomography Angiography in Macular Holes Autologous Retinal Transplant

In this paper, we compare the post-operative macular microvascular parameters (vascular density and foveal avascular zone) in eyes with refractory macular hole (MH) that underwent pars plana vitrectomy and autologous retinal transplant (ART) with the fellow unoperated eye. We conducted a retrospective case control study of six consecutive patients who underwent pars plana vitrectomy and ART with at least six months of post-operative follow-up. Pre-operatively, all eyes underwent SD-OCT (Spectral Domain Optical Coherence Tomography) examination. Post-operative OCT-A analyses included vascular density (VD) and the foveal avascular zone (FAZ) area. Six patients with a mean age of 63.7 ± 14.3 years were included. The mean follow-up was 24 months (range 6–30 months). The pre-operative BCVA (best-corrected visual acuity) was 0.99 ± 0.46 logMAR and 1.02 ± 0.23 logMAR at the last post-operative visit (p = 1.00). The mean MH diameter was 966 ± 620 µm. VD in the MH group was 28.1 ± 7.3% compared to 20.2 ± 2.9% in the fellow eyes group (p < 0.05). The mean post-operative FAZ area in the MH group was 109.8 ± 114.6 mm2 compared to 41.5 ± 10.4 mm2 in the control group (p < 0.05). In all six eyes, MH closure was obtained. The post-operative visual acuity did not improve after ART. Eyes with a closed MH showed a bigger FAZ with a higher VD compared to the fellow healthy eye.

Choriocapillary regional characteristics in idiopathic macular holes using optical coherence tomography angiography

PURPOSE

To evaluate the characteristics of vascular density (VD) of the retinal capillary plexuses in idiopathic macular hole (IMH), the fellow eye, and healthy control eyes by optical coherence tomography angiography (OCTA).

METHODS

A retrospective cases series study involving 20 unilateral eyes (20 patients) with IMH, the unaffected fellow eyes (n = 20) and 20 health controls, with age- and sex-matched, was conducted in Shanxi Eye Hospital from January 2019 to December 2021. VD of the retinal capillary plexuses measurements were obtained by OCTA.

RESULTS

Four quadrants of superficial capillary plexuses (SCP) in IMH eyes were not significant compared with that in the unaffected fellow eyes (all P > 0.05). The four quadrants of deep capillary plexuses (DCP) in IMH eyes were lower than that in the unaffected fellow eyes (all P < 0.05). Different regions retinal thickness in the IMH eyes was higher than that in the unaffected fellow eyes (all P < 0.05). a significant negative correlation between deep vessel density and retinal thickness in different quadrants among IMH eyes (all P < 0.05). Additionally, the correlation between the vascular density of SCP and retinal thickness was significant in macular fovea area (= 0.519, P = 0.019). <0.001.

CONCLUSIONS

The morphology of retina and choroid in idiopathic macular hole is different from that in fellow eye. The thickness of choroid in the fovea area of the unaffected eye also showed a decreasing trend. Taken together, the mechanism of macular hole may be further understood, that is, the decrease of choroid thickness may occur before the macular hole formation. It was verified again that the choroidal blood flow area in macular fovea of IMH patients was significantly lower than that in fellow eyes and healthy eyes.

Functional features in patients with idiopathic macular hole treatment via OCT angiography

To evaluate the optical coherence tomography (OCT) angiography features in patients with idiopathic macular hole (IMH) before and after vitrectomy. This prospective study included 25 patients diagnosed with IMH in Shanxi eye hospital from August 2019 to December 2021. The study was divided into 3 groups: IMH eyes, fellow eyes and normal eyes. All unilateral IMH eyes underwent vitrectomy. There were significant differences in superficial retinal blood flow density (SRBFD, P < .001) and choroidal blood flow density (CBFD) between IMH and healthy control eyes before operation (P < .05). There was significant difference in SRBFD between fellow eyes and normal eyes (P = .038). The changes of SRBFD and CBFD in IMH eyes before and after operation were statistically significant (P < .05). The CBFD at 6 months after operation is negatively correlated with LogMAR visual acuity, and the CBFD of the fellow eye is also negatively correlated with LogMAR visual acuity. The SRBFD and CBFD had no correlation with the diameter of macular hole before and after operation. SRBFD and CBFD increased after vitrectomy, indicating that the blood supply of retina and choroid were partially restored after vitrectomy. There was no correlation between SRBFD, CBFD and hole diameter, but there was correlation between choroidal blood flow and LogMAR visual acuity.

Morphological and Functional Features in Patients with Idiopathic Macular Hole Treatment

Purpose

To evaluate the multifocal electroretinogram (mfERG) and optical coherence tomography (OCT) angiography features in patients with idiopathic macular hole (IMH) before and after vitrectomy.

Patients and Methods

This prospective study was conducted at Shanxi Eye Hospital from January 2019 to December 2021. Twenty-five eyes of 25 patients with unilateral IMH, the unaffected fellow eyes, and 30 eyes of healthy patients were investigated. All unilateral IMH eyes underwent vitrectomy.

Results

The IMH eyes had significantly delayed latency (rings 2-5) of mfERG compared with the healthy control eyes, and the amplitude density of all rings of mfERG was reduced (P < 0.05). When comparing the mfERG components before surgery and at the follow-up, the amplitude density of IMH eyes (ring 1, 3, 4 and 5) was increased significantly (P < 0.05). The delayed implicit times of the second and fifth ring were significantly shortened compared with those of preoperative eyes (P < 0.05). The mean delayed implicit time of mfERG in six months after surgery was negatively correlated with visual acuity (r = -0.890, P = 0.043). Significant differences of superficial retinal blood flow density (SRBFD, P < 0.001) and choroidal blood flow density (CBFD) (P < 0.05) got via OCTA were found between IMH before surgery and healthy control eyes. SRBFD of the fellow eyes were significantly different with the healthy control eyes (P = 0.038). Statistically significance of SRBFD and CBFD changes in IMH eyes were found before and after surgery (P < 0.05).

Conclusion

IMH eyes had a decreased amplitude density and a delayed implicit time in some regions. Additionally, SRBFD and CBFD were both increased after vitrectomy, which suggests that the blood supply of the retina and choroid is partially restored after vitrectomy.

Surgical Macular Hole Closure Without a Gas Tamponade

Purpose:

This work aims to evaluate the outcomes of a series of macular hole (MH) surgical procedures in patients who had pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peel and without gas tamponade.

Methods:

Patients from a retina specialty clinic who had MHs were identified for this interventional case series. Patients with small MHs were offered inclusion into the trial. Patients with larger MHs were excluded. They underwent standard 3-port PPV and ILM peel without gas or air to treat small MHs. The main outcomes that we measured were closure of MH and visual results.

Results:

Small MHs in 5 patients were managed with PPV and ILM peel alone. The average preoperative hole size at its narrowest width was 227 µm (range, 173-294 µm). Four of 5 patients (80%) had successful hole closure without a gas tamponade and improved vision; 1 patient did not have hole closure and was treated with an in-office gas bubble to close the hole. The average preoperative vision at 3 months was 20/80– (54 Early Treatment Diabetic Retinopathy Study [ETDRS] letters) and improved to 20/30–2 (73 ETDRS letters) in the 4 patients whose MHs were closed with surgery without a gas bubble. This was statistically significant ( P = .003). The hole that did not close initially without gas tamponade was the largest in the series.

Conclusions:

Patients with small MHs can be successfully treated with a vitrectomy and ILM peel alone without a gas tamponade.

Assessment of the degree of restoration of the retinal structure and chorioretinal blood flow after surgical treatment of large-diameter macular holes

The aim: to evaluate the restoration features of the structural relationships of the retina and chorioretinal blood fl ow after surgical treatment of large-diameter macular hole (MH) using a modifi ed technology.Material and methods. A prospective study of 14 patients (14 eyes), 13 women and 1 man, with medium-and large-diameter MH was conducted. The mean age of the patients was 67.7 ± 5.38 (55–80) years. The study included patients with endto-end MH of the 3rd–4th stage according to the classifi cation of J. Gass. All patients underwent surgical treatment of macular rupture according to the proposed method of inverted fl ap of the internal limiting membrane (ILM) and fi lling it into a “pocket” formed between the retina and the ILM.Optical coherence tomography (OCT) was performed along with traditional research methods. The obtained images were used to measure manually the parameters of retinal MH, the thickness of the choroid in the projection of the rupture and the fovea zone before the operation and 1, 3 and 6 months after the operation. In the angio-mode, the foveal avascular zone (FAZ) was evaluated, as well as the density of capillaries of the superfi cial and deep retinal plexus in four quadrants, with the exception of the central zone.Results. In all patients, it was possible to achieve MH blocking. Visual acuity in the eyes with MH varied from 0.02 to 0.3, while in the comparison group, the best corrected visual acuity was from 0.3 to 1.0 (p = 0.002). An increase in the diameter of large choroidal vessels, as well as a pronounced decrease in the diameter of the posterior short ciliary artery, attracted attention. However, despite the improvement in visual acuity, patients retained a signifi cant expansion of the FAZ, which by 6 months exceeded the FAZ area of the paired eye by 25.8 % (p = 0.01).Conclusion. The results obtained indicate that the achievement of an anatomicalreconstructive effect and even a moderate improvement in visual acuity during surgical treatment of macular holes by the modifi ed inverted flap technology of the internal limiting membrane does not determine the restoration of retinal perfusion in full.

Macular microvasculature differences in patients with macular hole after vitrectomy with internal limiting membrane removal or single-layered temporal inverted flap technique

PURPOSE

To compare the macular microvasculature differences in cases with idiopathic macular hole (MH) after vitrectomy when using internal limiting membrane (ILM) removal or temporal inverted ILM flap technique (IFT).

METHOD

A total of 34 patients were included, of whom 20 were treated vitrectomy with ILM removal (group 1), and 14 were treated with IFT (group 2). The OCTA (RTVue; Optovue, Fremont, CA) parameters, including foveal avascular zone (FAZ), vessel density (VD) ratios in superficial capillary plexus (SCP), and deep capillary plexus (DCP) were evaluated at baseline and 6 months follow-up. The VD measurements in DCP and inner retinal thickness (IRT) in temporal and nasal sectors were compared in subanalyses.

RESULTS

There was no significant difference in means of post-operative BCVA and FAZ between the two groups (p = 0.943, p = 0.760). The mean VDs of the DCP was significantly decreased at 6 months postoperatively in both groups (p < 0.001, p < 0.001). The mean post-operative temporal VDs of DCP were similar in the two groups, but the mean post-operative nasal VDs of the DCP was lower in group 1 than in group 2 (p = 0.005 and p = 0.03 for parafovea and perifovea, respectively). The mean temporal IRTs were similar in the two groups, but paranasal and perinasal IRTs were significantly thinner in group 1 than in group 2 (p < 0.001, p < 0.001). The mean post-operative VDs of parafoveal and perifoveal temporal and nasal quadrants in DCP significantly and positively correlated with the IRTs.

CONCLUSION

Single-layered temporal IFT causes fewer VD changes when compared to complete ILM removal, especially in the DCP.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FINDINGS BEFORE AND AFTER VITRECTOMY FOR MACULAR HOLES: Useful or Useless?

PURPOSE

To investigate the vascular remodeling of optical coherence tomography angiography in full-thickness macular hole surgery.

METHODS

This retrospective, observational case series included 33 eyes of 33 patients with a full-thickness macular hole who underwent epiretinal membrane removal. Data were collected on best-corrected visual acuity, structural B-scan optical coherence tomography, and optical coherence tomography angiography preoperatively and at 1, 3, and 6 months postoperatively. Optical coherence tomography angiography was used to assess the retinal vascular density (VD) of the superficial vascular plexus and deep vascular plexus (DVP). Vascular density was assessed using the Early Treatment Diabetic Retinopathy Study grid for the whole, inner, and outer grids.

RESULTS

A statistically significant correlation was found between the VD (whole, inner, and outer grids) of the superficial vascular plexus alone from baseline to 1-month postoperatively (P < 0.001). Similarly, VD was correlated from baseline to 1, 3, and 6 months postoperatively to the whole (P < 0.0005, F = 23.22), inner (P < 0.0005, F = 28.23), and outer Early Treatment Diabetic Retinopathy Study grids of DVP (P = 0.033, F = 3.49). The best-corrected visual acuity and VD were significantly correlated with the superficial vascular plexus and DVP at baseline and 6 months (P < 0.05, all correlations). The most significant correlation was observed at 6 months between best-corrected visual acuity and DVP in the whole, inner, and outer Early Treatment Diabetic Retinopathy Study grids (P < 0.001).

CONCLUSION

Superficial vascular plexus and DVP are affected by full-thickness macular holes, with the most significant effects being on the DVP. Full-thickness macular hole surgery leads to an improvement in the best-corrected visual acuity in many eyes and the restoration of the VD, especially of the DVP.

Changes in choroidal blood flow in patients with macular hole after surgery

INTRODUCTION

A macular hole (MH) is a defect that occurs in the retina and involves all layers. In this study, we aimed to investigate the preoperative and postoperative choriocapillaris blood flow (CBF) changes in patients with MH and the role of CBF in the pathogenesis of the disease using optical coherence tomography angiography (OCTA).

MATERIAL METHOD

This is a retrospective study examining eyes with MH. The study included 25 operated eyes of 25 patients and contralateral eyes of 18 patients. CBF and subfoveal choroidal thickness were examined using the OCTA images of the patients before surgery and at the first, third and sixth months after surgery.

RESULTS

The mean CBF value of the patients was 1.57±0.20 mm² preoperatively, 1.94±0.13 mm² at the postoperative first month, 1.98±0.12 mm² at the third month, and 2.00±0.10 mm² at the sixth month. The increases in the CBF values between the preoperative period and the postoperative measurements were statistically significant (p<0.0001 for all). In the preoperative period, the CBF value of the contralateral eyes was 2.07±0.10 mm². The preoperative CBF value of the contralateral eyes was higher compared to that of the eyes with MH (p<0.0001). There was no significant difference between the preoperative CBF value of the contralateral eyes and the postoperative sixth-month value of the eyes with MH (p = 0.065).

CONCLUSION

The preoperative and postoperative third-month CBF values of the eyes with MH were found to be lower than those of the contralateral eyes, but there was no difference between the postoperative sixth-month CBF value of the eyes with MH and the preoperative CBF value of the contralateral eyes. We consider that the eyes with MH achieve similar CBF values to the contralateral eyes in an average of six months after successful surgery.

REGIONAL DENSITIES OF RETINAL CAPILLARIES AND RETINAL SENSITIVITIES AFTER MACULAR HOLE SURGERY WITH INTERNAL LIMITING MEMBRANE PEELING

PURPOSE

To measure the vascular density (VD) of the retinal capillary plexuses by optical coherence tomography angiography (OCTA) after surgery for an idiopathic macular hole.

METHODS

Retrospective, observational case series.Sixteen eyes of 16 patients with an idiopathic macular hole underwent vitrectomy with internal limiting membrane peeling. The VDs of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were determined by OCTA, and the retinal sensitivity (RS) and the inner retinal thickness (IRT) were measured before, and at 3, 6, and 12 months after the surgery. The VD, RS, and IRT were measured at the four parafoveal quadrants.

RESULTS

The mean age was 68.9 years. The VDs of the SCP and DCP were significantly correlated with the RS and IRT at 12 months postoperatively (all P < 0.001 for both SCP and DCP). The VDs of the SCP and DCP were higher, the RS more sensitive, and the IRT thicker in the nasal than the temporal quadrant at 12 months (P < 0.001, <0.001, =0.009, <0.001, respectively).

CONCLUSION

The significant correlation between the VDs of the SCP and DCP and the RS and IRT may be due to the nasal shift of the posterior retina.

Ultrastructural study of closed macular hole- preliminary application of a novel high magnification module combining with OCT

Background

As a novel high magnification module (HMM) combining with OCT (OCT-HMM) is able to detect the microstructure of retina, we apply it to explore the ultrastructure of the macula after closure of the idiopathic macular hole (IMH) by surgery.

Methods

This is an observational case series study in which patients with full-thickness IMHs who had undergone successful macular closure by vitrectomy and internal limiting membrane peeling and healthy subjects were recruited. After comprehensive ophthalmic examinations, the images of macular area were obtained and collected by professional operators using OCT-HMM. Then images were independently analyzed by 4 masked vitreoretinal specialists.

Results

A total of 24 IMH eyes and 42 healthy eyes were examined. HMM images were obtained in 10 IMH eyes. Among them, 4 eyes whose macula closed completely with recovery of photoreceptor layer presented a dark arc nasal to the fovea, oriented to the optic, and the notch of arc faced temporally. Six eyes in which the macula closed incompletely with photoreceptor cells loss revealed a dark ring with uneven bright spots inside. The other 14 eyes failed to obtain clear images by OCT-HMM. The contra lateral eyes of the patients and the healthy subjects’ eyes succeeded to obtain the HMM images which displayed evenly grey background thickly covered with tiny bright dots that was in similar size and evenly and widely distributed and there no dark arc or ring. OCT B-scan and IR images could be acquired in all of the IMH and healthy eyes.

Conclusion

The preliminary application of HMM has supplied us a brand-new insight into the microstructure of closed IMH. A dark arc sign could be detected with OCT-HMM in the macula which was functionally closed after surgery that was probably the healing mark on a microstructure photoreceptors level. Its existence and shape indicated that the functional closure followed by a retinal displacement mainly horizontally from temporal side to nasal side but not symmetric centripetally.

Secondary Vitrectomy with Internal Limiting Membrane Plug due to Persistent Full-Thickness Macular Hole OCT-Angiography and Microperimetry Features: Case Series

Purpose

To study the features in OCT-angiography and microperimetry in eyes with persistent full-thickness macular hole (FTMH) closed with the secondary plana vitrectomy (PPV) with autologous internal limiting membrane (ILM) plug.

Methods

Secondary PPV was performed with closing the persistent FTMH with ILM plug, C₃F₈ tamponade, and face-down positioning. Four patients were followed for 6 months with best corrected visual acuity (BCVA) measurement, SD-OCT and OCT-A, and microperimetry. The results were compared with the fellow eye; in two patients, it was the healthy eye, and in two remaining eyes, successfully closed FTMH after primary PPV.

Results

ILM flap was integrated in all cases with V-shape of closure, and atrophy was found in one case, with the largest diameter of FTMH. BCVA improved in two cases and remained the same in two cases. In OCT-A, the area of foveal avascular zone (FAZ) was larger, and foveal vessel density (FVDS) was smaller in eyes after secondary PPV in comparison to fellow eyes. In microperimetry, retinal sensitivity was lower in eyes after secondary PPV, and eccentric fixation was found in 2 of 4 patients.

Conclusion

Although the anatomical results of repeated surgeries of FTMH with ILM plug are favorable, visual function results may be limited. Secondary closure of FTMH with ILM plug may lead to atrophy, changes in the macular vasculature, and eccentric fixation. The trial is registered with NCT03701542.

Optical coherence tomography angiography using the black-and-white pixel binarization histogram software: a new technique for evaluating healing of macular holes in two surgical techniques

Background

Many factors can influence the functional outcomes of macular hole surgery and some studies have tried to describe anatomical features that could predict successful treatment. The purpose of this study is to describe a new technique for evaluating the healing of macular holes after two surgical techniques using a black-and-white pixel binarization histogram software by optical coherence tomography angiography and its potential functional implications.

Methods

This was a retrospective, observational case series of patients who presented with idiopathic full-thickness macular holes and underwent vitreoretinal surgery for successful macular hole closure using the internal limiting membrane peeling technique or the inverted peeling technique or the free internal limiting membrane flap technique. Optical coherence tomography angiography 3.0 × 3.0-mm scans were obtained postoperatively. The outer retina layer was analyzed separately; three different analyses were performed within a 3.0-mm-diameter area central circle, a 1.5-mm-diameter area, and a 0.5-mm-diameter area from the foveal center. The outer retinal layer images were evaluated by counting the number of black and white pixels. The inclusion criteria were patients with idiopathic macular holes who underwent ophthalmologic examinations and swept-source optical coherence tomography 1 week and 1 and 6 months postoperatively. The exclusion criteria were a traumatic macular hole or a history of eye trauma and a diagnosis of glaucoma or any other chronic ocular disease. The Mann–Whitney test was used to determine significance; P < 0.05 was considered significant.

Results

Ten eyes of 10 patients who underwent vitreoretinal surgery to treat a macular hole either with the conventional peeling technique (n = 5) or the inverted/free internal limiting membrane flap technique (n = 5) were included. In the peeling group, the percentage of white pixels ranged from 7.22% to 18.40% in the 0.5 × 0.5-millimeter area in the macular center; the mean postoperative logarithm of the minimum angle of resolution best-corrected visual acuity was 0.3 ± 0.2. In the inverted flap group, the percentage of white pixels ranged from 3.65% to 8.93% in the 0.5 × 0.5-millimeter area in the macular center; the mean logarithm of the minimum angle of resolution best-corrected visual acuity was 0.9 ± 0.4.

Conclusions

A simple method of optical coherence tomography angiography imaging analysis of the outer retina using a binarization technique of the black and white pixels was created and may have functional implications during the analysis of the healing process after macular hole surgery. We hypothesized that higher numbers of white pixels correspond to viable cellularity and better prognoses postoperatively.

Stereopsis After Unilateral Macular Hole Surgery with Internal Limiting Membrane Peeling

Purpose

We have shown distinct morphological changes of the foveal retina such as horizontally asymmetrical retinal thicknesses and displacements of the fovea toward the optic disc after successful idiopathic macular hole (MH) closure by MH surgery with internal limiting membrane (ILM) peeling. The purpose of this study was to determine whether these morphological changes will alter the stereoacuity.

Setting

This was a non-randomized, retrospective study conducted on patients who underwent MH surgery at the Matsumoto Dental University Hospital, Nagano, Japan.

Methods

Forty patients (22 women, 18 men) who underwent MH surgery with ILM peeling for a unilateral MH were studied. At >6 months after the PPV, the stereoacuity was measured with the Titmus stereotest (TST) and the TNO stereotest (TNO). The relationship between the stereoacuity and the age, MH size, best-corrected visual acuity (BCVA), foveal retinal thickness, and amount of nasal shift of the retina was determined.

Results

The mean postoperative BCVA was −0.05 ± 0.11 logarithm of the minimum angle of resolution (logMAR) units. The percentage of cases with good stereoacuity of ≤100 sec of arc was 87.5% with the TST and ≤240” was 90% with the TNO test. A better stereoacuity was significantly correlated with a younger age (r = 0.36, P <0.05; with TNO), smaller MH (r = 0.51, P < 0.001, with TST), better postoperative BCVA (r = 0.43 P <0.01 with TST; r = 0.49, P <0.01 with TNO), but not with the parafoveal retinal thickness or degree of nasal shift.

Conclusion

The postoperative stereopsis is relatively good in patients with better postoperative BCVA after MH surgery with ILM peeling, even though foveal morphological changes had occurred.

[Foveal avascular zone and OCT angiography. An overview of current knowledge]

BACKGROUND

The foveal avascular zone (FAZ) has often been analyzed under different aspects in the last decades, mainly by fluorescence angiography (FA); however, the novel technology of optical coherence tomography angiography (OCTA) enables a non-invasive examination, visualization and quantitative analysis of the FAZ, which has recently led to many new findings, especially in a multidisciplinary manner. This article provides an overview of the investigation of the FAZ using OCTA and the new findings that have been obtained using OCTA in recent years.

METHODS

This article is based on a comprehensive literature review.

RESULTS

In many studies a good reproducibility and repeatability of the FAZ measurements by OCTA could be proven, also by comparing different OCTA devices. In patients with ocular pathologies and systemic diseases, e. g. after retinal vein occlusion or retinal surgery and in patients with diabetes mellitus without diabetic retinopathy, differences to healthy control groups and correlations to visual function could be shown. Moreover, in patients with neurological diseases, such as Alzheimer's dementia, changes of the FAZ could be identified.

CONCLUSION

The OCTA is a non-invasive technology, which enables a reliable visualization and reproducible quantification of the FAZ. The size of the FAZ seems to be altered in different retinal and systemic diseases, which also may correlate with visual function; however, long-term studies evaluating the diagnostic value of these changes in the course of the disease are currently lacking.

An overview of optical coherence tomography angiography and the posterior pole

Optical coherence tomography angiography is a relatively new, noninvasive technology that has revolutionized imaging of the retinal and choroidal microvasculature. This technology is based on the detection of movement or changes that represent moving red cells in sequential optical coherence tomography scans. As with other established imaging technologies, it has unique benefits as well as certain disadvantages, which include a limited field of view and vulnerability to imaging artifacts. However, software and hardware improvements are continually evolving to mitigate these limitations. Optical coherence tomography angiography has been used to gain a better understanding of microvascular changes across a spectrum of ocular diseases including diabetic retinopathy, age-related macular degeneration, glaucoma, and retinal vein occlusions. In this article, we review algorithms and techniques commonly utilized in optical coherence tomography angiography systems and compare optical coherence tomography angiography to fluorescein angiography, the current gold standard for imaging the retinal vasculature. In addition, we provide an overview of important optical coherence tomography angiography findings in a variety of ocular diseases. Although the clinical role of this technology is still poorly defined, optical coherence tomography angiography has the potential to become an invaluable tool in the diagnosis and monitoring of vascular pathologies.

Inner Retinal Layer and Outer Retinal Layer Findings after Macular Hole Surgery Assessed by means of Optical Coherence Tomography

AIM

To summarize the spectrum of optical coherence tomography (OCT) and OCT angiography (OCTA) features after full-thickness macular hole (MH) repair surgery.

METHODS

A PubMed engine search was carried out using the terms "Macular Hole," "Optical Coherence Tomography," and "Optical Coherence Tomography Angiography." All reports published in English up to October 2018, irrespective of their publication status, were included. Tomographic signs analyzed were divided according to the involved portion of the retina in "inner retinal layers" and "external retinal layers." Despite predominantly involving the inner retinal layers, cystoid macular edema (CME) has been treated as a separate entity. Finally, report on vessel density (VD) changes and the foveal avascular zone (FAZ) area modifications have been included.

RESULTS

Different clinical findings can be observed on OCT of patients who underwent MH repair surgery. There is general consent that retinal thinning involving primarily the retinal nerve fiber layer and the ganglion cell layer takes place after surgery. In the postoperative period, the outermost retinal layers get progressively restored. Persistent defects in the ellipsoid zone or in the external limiting membrane correlate with worse postoperative visual outcome. OCTA has globally demonstrated that eyes after MH closure show a reduction in macular and paramacular VD and smaller FAZ areas, compared with control or fellow eyes.

CONCLUSION

Clinicians should be aware of the most common tomographic findings to properly manage each condition. In addition, significant advantages for the postoperative application of OCT and OCTA include noninvasiveness, rapid and simple execution, repeatability, and precise measurements.