Changes in pulse waveforms in response to intraocular pressure elevation determined by laser speckle flowgraphy in healthy subjects.

BACKGROUND: The influences of intraocular pressure (IOP) elevations on the pulse waveform in the optic nerve head (ONH) were evaluated using laser speckle flowgraphy (LSFG) in normal subjects. METHODS: This prospective cross-sectional study was conducted at the Nagoya University Hospital. An ophthalmodynamometer was pressed on the sclera to increase the IOP by 20 mmHg or 30 mmHg for 1 min (experiment 1, 16 subjects) and by 30 mmHg for 10 min (experiment 2, 10 subjects). The mean blur rate (MBR) and the eight pulse waveform parameters determined using LSFG were measured before, immediately after and during an IOP elevation, and after the IOP returned to the baseline pressure. RESULTS: A significant elevation in the IOP and a significant reduction in the ocular perfusion pressure (OPP) were found after applying the ophthalmodynamometer (both, P < 0.001). The blowout score (BOS) reduced significantly (P < 0.001), and the flow acceleration index (FAI; P < 0.01) and resistivity index (RI; P < 0.001) increased significantly immediately after increasing the IOP by 20 or 30 mmHg (experiment 1). The BOS reduced significantly (P < 0.001), and the FAI (P < 0.01) and RI (P < 0.001) increased significantly after the IOP elevation by 30 mmHg in both experiment 2 and 1. However, the BOS and RI recovered significantly at time 10 compared to that in time 0 (immediately after IOP elevation) during the 10-min IOP elevation (P < 0.001 and P = 0.008, respectively). CONCLUSIONS: In conclusion, the BOS, FAI, and RI of the pulse waveforms changed significantly with an acute elevation in the IOP. The change should be related to the larger difference between the maximum and minimum MBRs during the IOP elevation.

RELATIONSHIP BETWEEN ABNORMALITIES OF PHOTORECEPTOR MICROSTRUCTURES AND MICROVASCULAR STRUCTURES DETERMINED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN EYES WITH BRANCH RETINAL VEIN OCCLUSION.

PURPOSE: To determine whether the size of the foveal avascular zone (FAZ) is significantly correlated with the best-corrected visual acuity (BCVA) and to examine the relationship between the size and microstructural changes of the photoreceptors in eyes with a branch retinal vein occlusion. METHODS: The medical records of 69 eyes of patients (mean age, 64.6 ± 11.7 years) with a branch retinal vein occlusion were reviewed after the resolution of macular edema. All the patients underwent optical coherence tomography angiography for measurement of the FAZ area and spectral domain optical coherence tomography for determination of microstructural changes of the photoreceptors at the fovea. RESULTS: The superficial and deep FAZ areas in eyes with a branch retinal vein occlusion were 0.39 ± 0.36 mm and 0.63 ± 0.18 mm, respectively, and both were significantly larger than those observed in the fellow eyes (both, P < 0.001). The superficial FAZ area correlated with the posttreatment BCVA (r = 0.285, P = 0.027) but not with any parameters regarding the microstructures of the photoreceptors. Multivariate linear regression analysis showed that the pretreatment BCVA (ß = 0.519, P < 0.001) and integrity of the external limiting membrane (ß = -0.373, P = 0.001) were independent factors that significantly correlated with the posttreatment BCVA. CONCLUSION: There was no significant correlation between the FAZ area and microstructural parameters. However, the integrity of the external limiting membrane was significantly correlated with the posttreatment BCVA in eyes with a branch retinal vein occlusion.

One-Year Outcomes of 1 + pro re nata versus 3 + pro re nata Intravitreal Aflibercept Injection for Neovascular Age-Related Macular Degeneration.

PURPOSE: We compared 1-year outcomes of 1 + pro re nata (PRN) versus 3 + PRN of intravitreal aflibercept injection (IAI) for age-related macular degeneration (AMD). METHODS: Forty-two eyes with naïve AMD received 3 + PRN IAI treatment and 47 eyes with naïve AMD received 1 + PRN IAI treatment. Visual acuity (VA), central retinal thickness (CRT), and central choroidal thickness (CCT) and number of administered IAIs during 12 months were compared. RESULTS: VAs improved, and CRTs reduced significantly at any given month from baseline in both groups (p < 0.01, respectively). CCT reduced significantly at 3 months in the 3 + PRN group (p = 0.024) but not in the 1 + PRN group. The 1 + PRN group received fewer injections than the 3 + PRN group (p < 0.01). CONCLUSIONS: Aflibercept leads to equivalent VA and morphologic retinal improvement without administering 3 injections.

High-dose intravenous pulse steroid therapy for optic disc swelling and subretinal fluid in non-arteritic anterior ischemic optic neuropathy.

Non-arteritic anterior ischemic optic neuropathy (NAION) is a disease with microvascular abnormality that causes acute optic disc swelling (ODS) and, in severe cases, subretinal fluid (SRF) accumulation. ODS causes compartment syndrome and subsequent axonal degeneration and loss of retinal ganglion cells by apoptosis. No treatment modalities have been effective, although some cases improved after the intake of oral systemic steroids. We reported a case of a 72-year-old man who was referred due to a visual defect in the right eye. At first presentation, visual acuity and visual field were disturbed; critical flicker frequency (CFF) was decreased; and optic coherence tomography (OCT) showed ODS and SRF. Microscopic examination revealed parapapillary hemorrhage and fluorescence angiography showed non-filling, temporal-superior choroidal lesion adjacent to the optic disc at an early phase. After high-dose intravenous steroid treatment, SRF and ODS were decreased, and completely resolved after 30 days. Visual acuity and CFF were improved, and visual field was enlarged. High-dose intravenous steroids could possibly resolve SRF and ODS and improve visual function of patients with NAION. Some cases in NAION improved visual acuity and visual function in natural course, more cases were needed to evaluate the efficiency.

NEAR-INFRARED REFLECTANCE IMAGING IN EYES WITH ACUTE ZONAL OCCULT OUTER RETINOPATHY.

PURPOSE: To investigate the confocal scanning laser ophthalmoscopic images obtained with near-infrared (IR) light in eyes with acute zonal occult outer retinopathy (AZOOR). METHODS: Observational case series. The medical records of 12 eyes of 10 patients with AZOOR were reviewed. Scanning laser ophthalmoscopic images obtained from the AZOOR eyes were compared with images obtained by spectral-domain optical coherence tomography, by fundus autofluorescence, and by an adaptive optics fundus camera. RESULTS: In 8 of 12 eyes, abnormal hyporeflective areas were detected in the IR images, and the other 4 eyes did not have specific abnormalities in the IR images. The boundaries of the abnormal hyporeflective areas corresponded with the border of the irregularity of photoreceptor inner segment ellipsoid band in the spectral-domain optical coherence tomography images. The cone mosaics of the adaptive optics fundus image were disrupted in the abnormal hyporeflective area of the IR image. However, the areas of fundus autofluorescence abnormalities did not coincide with the hyporeflective areas in the IR images. CONCLUSION: The presence of hyporeflective areas in the IR images of patients with AZOOR suggests impairment of the photoreceptors area. The IR images would be useful to evaluate eyes with AZOOR.

Surgical Videos with Synchronised Vertical 2-Split Screens Recording the Surgeons' Hand Movement.

PURPOSE: To improve the state-of-the-art teaching system by creating surgical videos with synchronised vertical 2-split screens. METHODS: An ultra-compact, wide-angle point-of-view camcorder (HX-A1, Panasonic) was mounted on the surgical microscope focusing mostly on the surgeons' hand movements. In combination with the regular surgical videos obtained from the CCD camera in the surgical microscope, synchronised vertical 2-split-screen surgical videos were generated with the video-editing software. RESULTS: Using synchronised vertical 2-split-screen videos, residents of the ophthalmology department could watch and learn how assistant surgeons controlled the eyeball, while the main surgeons performed scleral buckling surgery. In vitrectomy, the synchronised vertical 2-split-screen videos showed the surgeons' hands holding the instruments and moving roughly and boldly, in contrast to the very delicate movements of the vitrectomy instruments inside the eye. CONCLUSIONS: Synchronised vertical 2-split-screen surgical videos are beneficial for the education of young surgical trainees when learning surgical skills including the surgeons' hand movements.

Investigation of causative factors for unusual shape of macula in eyes with macula-off rhegmatogenous retinal detachment.

PURPOSE: To determine the factors significantly associated with anterior protrusion of the macula in eyes with a macula-off rhegmatogenous retinal detachment (RRD) and to determine the relationship between the intraretinal cystoid cavities (ICCs) and the anterior protrusion and function of the fovea. STUDY DESIGN: Retrospective cross-sectional study. METHODS: Sixty-nine eyes of 69 patients with successfully reattached macula-off RRD were retrospectively analyzed. Six radial spectral-domain optical coherence tomographic (OCT) images were used to evaluate the effects of the ICCs on detached macula and to measure the angle of the retina at the macula as a parameter to evaluate the anterior protrusion of the detached retina. The findings were compared to other parameters. RESULTS: The mean angle of the retina at the macula was 143.1 ± 15.9° with a range of 108 to 172°. Preoperatively, 51 eyes (74%) had ICCs in the inner nuclear layer and/or the outer plexiform layer and Henle fiber layer complex, but none was present after surgery. Multivariate regression analyses revealed that the angle of the retina was significantly associated with the presence of ICCs (ß = -0.637, P<0.001) and the height of subretinal fluid (ß = -0.256, P = 0.005). Eyes with ICCs had poorer preoperative vision (P<0.001), narrower angle of the retina (P<0.001), and thicker subretinal fluid (P<0.001) than eyes without cavities. CONCLUSIONS: The anterior protrusion in eyes with macula-off RRD is associated with the presence of ICCs. The presence of ICCs can affect preoperative function and morphology but does not affect postoperative function and morphology.

Elevated retinal artery vascular resistance determined by novel visualized technique of laser speckle flowgraphy in branch retinal vein occlusion.

We aimed to investigate the increase in resistivity of the retinal artery in the branch retinal vein occlusion (BRVO)-affected area, and to visualize it. Thirty-two eyes of 32 patients with BRVO were measured by laser speckle flowgraphy (LSFG). The retinal artery and vein running to the BRVO-affected area and vertically symmetrical vessels in the unaffected area were examined. We applied the LSFG parameter beat strength over mean blur rate (BOM), calculated using a similar method to the pulsatility index used in Doppler flowmetry to evaluate resistivity of the vessels. Our results showed that the BOM map could clearly visualize the increase of resistivity in the retinal artery as a two-dimensional map. The BOM of the arteries in the affected area was significantly higher than that of the unaffected area (P = 0.001). Multiple regression analysis showed that the ratio of BOM in retinal arteries of the affected area to the unaffected was significantly associated with the extent of retinal hemorrhage (ß = 0.447, P = 0.009). In conclusion, the index of resistivity of the retinal artery in the BRVO-affected area was higher and could be visualized in a two-dimensional map. These findings and techniques would contribute to elucidate the pathophysiology of BRVO.

Association of changes of retinal vessels diameter with ocular blood flow in eyes with diabetic retinopathy.

We investigated morphological changes of retinal arteries to determine their association with the blood flow and systemic variables in type 2 diabetes patients. The patients included 47 non-diabetic retinopathy eyes, 36 mild or moderate nonproliferative diabetic retinopathy (M-NPDR) eyes, 22 severe NPDR (S-NPDR) eyes, 32 PDR eyes, and 24 normal eyes as controls. The mean wall to lumen ratio (WLR) measured by adaptive optics camera was significantly higher in the PDR groups than in all of the other groups (all P < 0.001). However, the external diameter of the retinal vessels was not significantly different among the groups. The mean blur rate (MBR)-vessel determined by laser speckle flowgraphy was significantly lower in the PDR group than in the other groups (P < 0.001). The WLR was correlated with MBR-vessel (r = - 0.337, P < 0.001), duration of disease (r = 0.191, P = 0.042), stage of DM (r = 0.643, P < 0.001), systolic blood pressure (r = 0.166, P < 0.037), and presence of systemic hypertension (r = 0.443, P < 0.001). Multiple regression analysis demonstrated that MBR-vessel (ß = - 0.389, P < 0.001), presence of systemic hypertension (ß = 0.334, P = 0.001), and LDL (ß = 0.199, P = 0.045) were independent factors significantly associated with the WLR. The increased retinal vessel wall thickness led to a narrowing of lumen diameter and a decrease in the blood flow in the PDR group.

Correlation between blood flow on optic nerve head and structural and functional changes in eyes with glaucoma.

The purpose of this study was to determine the significance of the correlations between blood flow on the optic nerve head (ONH) using the mean blur rate (MBR) determined by laser speckle flowgraphy and the visual field loss determined by perimetry and the structural alterations by optical coherence tomography in eyes solely with open-angle glaucoma. There were significant differences in the circumpapillary retinal nerve fiber layer thickness (cpRNFLT), and the MBR-tissue, at the different stages of glaucoma (ANOVA, P < 0.001). Univariate linear regression analyses indicated that the mean deviations (MD) were significantly correlated with both the MBR-tissue (r = 0.661, P < 0.001) and the cpRNFLT (r = 0.279, P = 0.005). Logistic regression analyses showed that the MD was significantly correlated with the MBR-tissue (P < 0.001) and the cpRNFLT (P < 0.001). The MBR-tissue was found to be the factor that can best predict the MD based on the Akaike information criteria (P < 0.001). Stepwise multiple logistic regression analyses showed that the MBR-tissue and the cpRNFLT were both risk factors that were significantly associated with the MD (Odds ratio;1.25 and 1.07, P < 0.001 and P < 0.001, respectively). These results indicate that the MBR-tissue was as important as the structural values in diagnosing and determining the prognosis of glaucoma.

Correlations between intraretinal cystoid cavities and pre- and postoperative characteristics of eyes after closure of idiopathic macular hole.

Intraretinal cystoid cavities have been detected at the edges of macular holes (MHs) but their clinical characteristics and their relationship to the MH variables have not been determined. We measured the areas of the intraretinal cystoid cavity in 111 eyes with MHs in the OCT images preoperatively. Our results showed that the intraretinal cystoid cavities were located in the Henle fiber layer-outer nuclear layer (HFL-ONL) complex in 106 eyes and in the inner nuclear layer (INL) in 89 eyes. All were resolved after the initial vitrectomy to close the MH. The mean area of the cystoid cavity was greater in the HFL-ONL complex (55.9 ± 42.7 × 103 µm2) than in the INL (9.1 ± 9.8 × 103 µm2; P < 0.001). The area of the cystoid cavities was significantly correlated with the basal MH size (r = 0.465,P < 0.001), the external limiting membrane height (r = 0.793, P < 0.001), and the maximum retinal thickness (r = 0.757, P < 0.001). The area of the cystoid cavities was significantly correlated with the preoperative best-corrected visual acuity (BCVA; r = 0.361, P < 0.001), but not with the postoperative BCVA or the integrity of any of the outer retinal microstructural bands. The presence of intraretinal cystoid cavities was related to some morphological characteristics, but not to the postoperative BCVA or the restoration of the outer retinal bands.

Differences in Blood Flow Between Superior and Inferior Retinal Hemispheres.

Purpose: To determine whether the blood flow in the superior retina is significantly different from that in the inferior retina, and to determine whether the posture affects the blood flow in the superior and inferior retina. Methods: The blood flow in the vessels around the optic nerve head was measured by laser speckle flowgraphy in the sitting position in 68 healthy subjects. The blood flow in the superior peripapillary retina was compared with that in the inferior peripapillary retina. The measurements of the blood flow were performed in the sitting position, and the effect of switching to a supine position was determined at 2, 4, 6, 8, 10, and 30 minutes after the switch. Results: The total relative flow volume (RFV)-all, RFV-artery, and RFV-vein were significantly greater in the superior retina than in the inferior retina (all P < 0.001). The mean diameter-all and mean diameter-artery in the superior retina were significantly larger than that in the inferior retina (all P < 0.05). The mean blur rate (MBR)-all, MBR-artery, and MBR-vein in the superior retina were also greater than that in the inferior retina (P < 0.001, P < 0.01, and P < 0.001, respectively). Although the ocular perfusion pressure was significantly changed with the postural alteration, the total RFV-all remained greater in the superior retina than in the inferior retina after the postural change. Conclusions: Clinicians need to be aware of the differences in the blood flow between the superior and inferior retinal peripapillary area when considering the mechanisms of retinochoroidal diseases.

Association between displacement and thickness of macula after vitrectomy in eyes with epiretinal membrane.

The purpose of this cross-sectional retrospective study was to determine the relationship between the retinal displacements and the retinal thickness in eyes with epiretinal membrane (ERM) after vitrectomy with internal limiting membrane (ILM) peeling. To accomplish this, we measured the retinal thickness using optical coherence tomography (OCT) and the retinal displacement using OCT angiography to obtain 3 mm × 3 mm en face images before, and 2, 4, and 8 weeks following the surgery from 20 eyes of 20 patients. The distance between the retinal vessel bifurcations and the fovea was significantly displaced centrifugally and asymmetrically in the 4 quadrants postoperatively (P < 0.001). The foveal avascular zone (FAZ) was significantly enlarged, and the central foveal thickness (CFT) and the inner nuclear layer (INL) thickness were significantly thinner postoperatively. The displacements were significantly correlated with the changes in the FAZ area (r = 0.717, P < 0.001), the CFT (r = - 0.702, P < 0.001), and the INL thickness (r = - 0.702, P < 0.001). In conclusion, the distance between the retinal bifurcations and the fovea was asymmetrically expanded after the surgery and was significantly correlated with the morphological changes. These results indicate that a horizontal macular contraction is correlated with vertical retinal contraction in the eyes with an ERM.

Correlation between preoperative factors and final visual acuity after successful rhegmatogenous retinal reattachment.

We evaluated the preoperative optical coherence tomographic (OCT) findings in eyes with macula-off rhegmatogenous retinal detachment (RRD) and determined the factors that were significantly correlated with the postoperative best-corrected visual acuity (BCVA). The length of the preoperative photoreceptors was defined as the distance between the external limiting membrane (ELM) and the outer end of the outer segments of the photoreceptors in the OCT images. The mean length of the photoreceptors was 102.8 ± 28.7 µm with a range of 20 to 159 µm in eyes with RRD. The length of the preoperative photoreceptors was not significantly correlated with the preoperative BCVA but it was significantly correlated with the postoperative BCVA (r = -0.353, P = 0.003). Multivariate regression analyses revealed that the length of the photoreceptors (ß = -0.388, P = 0.001) and the preoperative BCVA (ß = 0.274, P = 0.021) were the only independent factors that were significantly associated with the postoperative BCVA. The length of the preoperative photoreceptors was significantly correlated with the postoperative photoreceptor length (r = 0.486, P < 0.001). Longer preoperative photoreceptors were significantly correlated with longer postoperative photoreceptors and better BCVA after successful reattachment. These results suggest that the preoperative length of the photoreceptors can be good factor to use for predicting the final BCVA following successful reattachment of macula-off RRD.

Effect of intravitreal or sub-tenon triamcinolone acetonide injection at completion of vitrectomy on peripheral retinochoroidal thickness in eyes with proliferative diabetic retinopathy.

The effect of triamcinolone acetonide (TA) on the peripheral retinochoroidal thickness was determined after pars plana vitrectomy (PPV) with scatter photocoagulation in eyes with proliferative diabetic retinopathy. The peripheral retinochoroidal thickness was measured at 5 mm from the limbus in the four quadrants using anterior segment optical coherence tomography before, and 3 days, and 1 and 2 weeks after the surgery. The total peripheral thickness was significantly thicker than the baseline thickness after PPV alone (P < 0.001; 18 eyes), PPV combined with intravitreal TA injection (IVTA; P = 0.011; 19 eyes), and PPV combined with sub-tenon TA injection (STTA; P = 0001; 23 eyes). The total peripheral thickness in the PPV group at 3 days after surgery was significantly thicker than that of the PPV + IVTA (P = 0.015) and of the PPV + STTA groups (P = 0.016). Multiple linear regression analyses showed that the injection of TA by the two routes and the number of photocoagulation burns were significantly correlated with the total peripheral thicknesses at 3 days after the surgery. The results indicate that the PPV with large number of intraoperative scatter photocoagulation burns caused an increase in the total peripheral thickness and an administration of either IVTA and STTA can reduced the degree of thickening.

Influence of submacular fluid on recovery of retinal function and structure after successful rhegmatogenous retinal reattachment.

PURPOSE: To determine the influence of residual submacular fluid (SMF) on the recovery of function and structure of the retina after successful rhegmatogenous retinal detachment (RRD) reattachment. METHODS: We reviewed the medical records of all patients who had undergone successful RRD repair by scleral buckling (SB) surgery or by pars plana vitrectomy (PPV) from March 2011 to August 2014. Spectral-domain optical coherence tomographic images of the macular regions were used at 1, 2, 3, 6, 9, and 12 months following the surgery. The best-corrected visual acuities (BCVA) were evaluated at the same times. RESULTS: The eyes with a macula-off RRD that were treated by SB surgery had a significant higher incidence of residual SMF (52%) than those treated by PPV (6.8%; P <0.001). Nevertheless, the postoperative BCVA was significantly improved in the eyes that had undergone SB surgery (P = 0.007). The postoperative BCVAs were not significantly different between the groups in which the SMF was absorbed (12 eyes) and not absorbed (13 eyes) within 1 month after the SB surgery. The photoreceptor outer segment length and the presence of a foveal bulge were not significantly different between these two groups at 12 months. Multiple regression analyses showed that the presence of a foveal bulge (ß = 0.531, P = 0.001) and the duration of the retinal detachment before surgery (ß = 0.465, P = 0.002) but not the duration of the SMF were independent factors significantly correlated with the final BCVA. CONCLUSIONS: These results suggest that the postoperative residual SMF does not significantly disrupt the functional and structural recovery of eyes with macula-off RRD treated by SB surgery.