Akito Hirakata

Correlation Between Foveal Cone Outer Segment Tips Line and Visual Recovery After Epiretinal Membrane Surgery

PURPOSE To determine whether there is a significant correlation between the integrity of the foveal microstructures and the best-corrected visual acuity (BCVA) after pars plana vitrectomy for epiretinal membrane (ERM) removal. METHODS This was a retrospective, interventional case series. Forty-six eyes of 45 patients with an ERM underwent vitrectomy. The foveal area was examined by spectral-domain-optical coherence tomography (SD-OCT) preoperatively and postoperatively. The correlation between the length of the photoreceptor cone outer segment tips (COST) line defect, the inner segment/outer segment junction (IS/OS) line defect, the external limiting membrane (ELM) line defect, and the BCVA was determined. RESULTS The length of the COST line defect was significantly correlated with the BCVA at postoperative 1, 3, 6, 9, and 12 months (P < 0.001 for all). Forward stepwise regression analyses showed that the postoperative BCVA was significantly correlated with the length of COST line defect (P < 0.001) but not with the IS/OS line and ELM line defects for up to 6 months. The preoperative length of the COST line defect was significantly correlated with the postoperative BCVA at 12 months (P = 0.005), but the lengths of the IS/OS line defect and ELM line defect were not. The factor that best predicted the postoperative BCVA was the length of the preoperative COST line defect (P = 0.04) but not the preoperative BCVA (P = 0.69). CONCLUSIONS The recovery of the foveal COST line defect is correlated with the BCVA after ERM surgery. The length of the preoperative COST line defect can predict the potential foveal function. (ClinicalTrials.gov number, NCT01549249.).

Ultrasound biomicroscopy for examination of the sclerotomy site in eyes with proliferative diabetic retinopathy after vitrectomy.

Purpose: We evaluated the capability of ultrasound biomicroscopy (UBM) to predict fibrovascular proliferation at sclerotomy sites in eyes with postoperative vitreous hemor‐rhage due to proliferative diabetic retinopathy (PDR). Methods: Ultrasound biomicroscopy was used for examining the sclerotomy sites in 13 eyes of 11 patients with PDR experiencing postoperative vitreous hemorrhage (PDR group). Thirty‐nine sclerotomy sites (all entry sites of each eye) were examined before reoperation, and the UBM images were compared with findings obtained during revision of the vitrectomy. Thirteen eyes of 13 patients undergoing vitrectomy for nondiabetic dis‐eases were used as controls and examined after vitrectomy. Results: The UBM images were classified into the following four categories: A, tent; B, spheroid; C, trapezoid; and N, none. The findings were distributed as follows in the PDR group: category A, 18%; B, 5%; C, 56%; and N, 21 %; and as follows in the control group: category A, 28%; B, 5%; C, 5%; and N, 62%. In the PDR group, 11 of 12 sclerotomy sites disclosing fibrovascular proliferation possessed the trapezoidal image. Mean length of trapezoidal base was 2.49 ± 0.97 mm and 1.51 ± 0.75 mm in the groups with and without fibrovascular proliferation, respectively (P < 0.01). The average relative reflectivity of the trapezoidal image against the sclera was 0.501 ± 0.169 in the fibrovascular proliferation group and 0.891 ± 0.183 in the fibrous ingrowth group (P < 0.01). Conclusion: Ultrasound biomicroscopy is useful in detecting fibrovascular proliferation at sclerotomy sites because a large and low‐reflecting trapezoidal UBM image is highly correlated to its presence.

Ultrastructural and immunohistochemical findings in five patients with vitreomacular traction syndrome.

Objective: To evaluate pathologic features of vitreomacular traction syndrome (VMT). Methods: Preretinal membranes removed from five patients during vitreous surgery for VMT syndrome were evaluated by electron microscopy (n = 4) and immunohistochemistry (n = 1). Results: Electron microscopic examination revealed large segments of internal limiting lamina (ILL) in three of the four cases. Other extracellular features included two types of abnormal collagen fibrils, determined to be type I and fibrous long‐spacing collagen. The myofibrocyte was the predominant cell type in all cases. Collagen types I, II. and III, as well as glial fibrillary acidic protein and vimentin, were identified by immunohistochemistry. Conclusions: Epiretinal membranes in eyes with VMT syndrome adhered tightly to the ILL with abnormal collagen and contractile elements that included myofibrocytes.

Long-term complications of hydrogel buckles.

PURPOSE To investigate long-term complications of hydrogel buckles used in scleral buckling surgery for retinal detachment. METHODS Clinical records of 31 patients who underwent scleral buckle removal between April 1998 and April 2001 were reviewed. Removed buckles were examined by scanning electron microscopy (SEM). RESULTS Nineteen patients were men and 12 were women, with a mean age of 43 years. Initial scleral buckling surgery using hydrogel buckles had been performed between February 1988 and October 1995. Patients presented at a mean of 8.5 years postoperatively with complaints of symptoms such as foreign body sensation and diplopia, prompting buckle removal. Buckles from 28 eyes, left in place for 5.8 years or more, were discolored, friable, and swollen. Buckles from three eyes, left in place for 5.5 years or less, appeared grossly unaltered. One eye with buckle swelling associated with a large retinal cyst underwent buckle removal and vitrectomy. SEM of deteriorated buckles showed distortion of micropores when compared to grossly unaltered buckles and unused controls. CONCLUSIONS Severe deterioration of hydrogel buckles may occur when they are left in place for 5 years or longer and may cause adverse symptoms and rarely intraocular complications. This deterioration is associated with changes in the microstructural architecture of the hydrogel material.

Vitrectomy with or without internal limiting membrane peeling for each stage of myopic traction maculopathy.

Purpose: To evaluate the effect of vitrectomy on the best-corrected visual acuity (BCVA) and postoperative complications in highly myopic eyes with myopic traction maculopathy. Methods: The medical records of 71 eyes of 64 patients with myopic traction maculopathy and high myopia (⩽−8.0 diopters and axial length, ≥26.0 mm) were reviewed. Twenty-six eyes had only macular retinoschisis, 30 eyes had foveal detachment, and 15 eyes had macular hole. The BCVA and complications were studied in eyes that underwent vitrectomy with or without internal limiting membrane (ILM) peeling. Results: The postoperative BCVA at the final visit significantly improved in the macular retinoschisis and the foveal detachment groups (P = 0.003 and P = 0.010, respectively) but not in the macular hole group (P = 0.069). The BCVA in the macular retinoschisis group and the foveal detachment group with ILM peeling significantly improved at the final visit (P = 0.003 and P = 0.010, respectively). The BCVA at the final visit significantly correlated with age (P = 0.026) and ILM peeling (P = 0.034). A recurrence of tractional macular detachment developed more frequently in eyes without ILM peeling (P = 0.018). Conclusion: These results indicate that vitrectomy with ILM peeling can lead to improvement in vision in patients with macular retinoschisis or foveal detachment with visual impairments.

Retinoschisis associated with disc coloboma.

Editor,—Among a variety of optic disc anomalies, colobomas and optic nerve pits are known to be closely related.1 Previous studies2 have shown that retinal detachment in eyes with choroidal coloboma is often caused by retinal breaks within the coloboma. However, the pathogenesis of non-rhegmatogenous retinal detachment correlating with optic disc coloboma has not been well defined. Here, we report a case of optic disc and choroidal coloboma associated with an unusual form of macular detachment complicated by retinoschisis. ### CASE REPORT A 35 year old Japanese woman complaining of blurred vision in the left eye was referred to Kyorin University Hospital on 1 October 1996. Her best corrected visual acuity was 20/20 in the right eye and 20/200 in the left. Indirect ophthalmoscopy of the …

Binding, coupling, and mRNA subtype heterogeneity of α1-adrenergic receptors in cultured human RPE

In retinal pigment epithelium, apically applied epinephrine changes the conductance of specific ions which subsequently affects the membrane voltage and stimulates transepithelial fluid transport. In this investigation, myo-[3H]inositol radiotracer studies, radioligand binding with [125I]HEAT, and ribonuclease protection assays were performed to examine the coupling of this receptor to phosphoinositide hydrolysis and the specific mRNA subtypes expressed in cultured human retinal pigment epithelial cells. After labeling second to sixth passage cells with 3-muCi myo-[3H]inositol for 24 hr, epinephrine caused a dose- and time-dependent increase in [3H]inositol phosphate products (EC50 of 0.7 microM). This stimulation was antagonized by prazosin but not by propranolol. The effect of epinephrine was potentiated by the presence of the monoamine oxidase inhibitor, pargyline (10 microM). Pertussis toxin (1 microgram per well) attenuated the stimulatory effect of epinephrine. In the radioligand binding assays, [125I]HEAT binding sites varied among different cell lines, with a range of 44 to 200 fmol (mg protein)-1. Using a ribonuclease protection assay, alpha 1D and alpha 1B, but not alpha 1C, adrenergic mRNA subtypes were detected in cultured human cells. Collectively, these results show that the catecholamines act on a potentially heterogeneous population of alpha 1-adrenergic receptors coupled to phospholipase C by a pertussis toxin-sensitive G protein.

Evaluation of retinal damage induced by air/fluid exchange using a trypan blue inclusion test in rabbits.

PURPOSE To investigate whether retina damaged in the process of air/fluid exchange could be visualized in situ using trypan blue staining. METHODS Vitrectomy and air/fluid exchange with continuous air infusion for various periods of time was performed in adult pigmented rabbits, followed by injection of 0.4% trypan blue solution into the vitreous cavity. Retinal staining was evaluated intraoperatively under the operating microscope and by light microscopy after enucleation. RESULTS Intraoperative examination showed localized trypan blue staining of areas of the retina opposite the infusion cannula. Light microscopy of the same areas revealed intranuclear trypan blue inclusion in the retina. CONCLUSION Trypan blue staining allows for the immediate in situ evaluation of damage to the retina associated with air/fluid exchange and continuous air infusion in rabbit eyes.

Correlation between foveal interdigitation zone band defect and visual acuity after surgery for macular pseudohole.

Purpose: To determine the correlation between the integrity of the foveal microstructures and the best-corrected visual acuity (BCVA) after pars plana vitrectomy for a macular pseudohole. Methods: Thirty-one eyes of 31 patients with a macular pseudohole underwent vitrectomy with internal limiting membrane removal. The foveal area was examined by spectral domain optical coherence tomography preoperatively and postoperatively. The correlations between the BCVA and the lengths of the photoreceptor interdigitation zone (IZ), the ellipsoid zone, and the external limiting membrane band defects, and central foveal thickness were determined. Results: The BCVA improved significantly and the length of the IZ band defect decreased significantly after the surgery. Simple linear regression analyses showed that the BCVA was significantly correlated with the length of the IZ band defect preoperatively and also at 1 to 12 months postoperatively (P < 0.001 for all). The BCVA was not significantly correlated with the length of the ellipsoid zone, external limiting membrane band defect, and the central foveal thickness. Conclusion: The significant correlation between the length of the foveal IZ band defect and the BCVA preoperatively and postoperatively indicates that the foveal IZ band is related to the visual recovery in patients with macular pseudohole.

Differences of Intrasession Reproducibility of Circumpapillary Total Retinal Thickness and Circumpapillary Retinal Nerve Fiber Layer Thickness Measurements Made with the RS-3000 Optical Coherence Tomograph

Purpose To evaluate the intrasession reproducibility of various thickness parameters used to diagnose and follow-up glaucoma, in particular circumpapillary total retinal thickness (cpTR) provided by the RS-3000 optical coherence tomograph (OCT). Methods Fifty-three healthy eyes of 28 subjects underwent three consecutive imaging with the RS-3000 Advance OCT (NIDEK, Aichi,Japan) to evaluate the intrasession reproducibility of circumpapillary total retinal thickness (cpTR), circumpapillary retinal nerve fiber layer thickness (cpRNFL), macular ganglion cell complex thickness (mGCC) and macular total retina thickness (mTR) measurements. Intraclass correlation (ICC), coefficient of variation (CV) and reproducibility coefficient (RC) were calculated for each parameter. Results The ICC and CV values for mean cpTR and cpRNFL were 0.987 and 0.897, and 0.60% and 2.81%, respectively. The RC values for the mean cpTR and cpRNFL were 5.95 μm and 9.04 μm, respectively. For all cpTR parameters the ICC values were higher and both the CV and RC values were lower than those for the corresponding cpRNFL parameters. The ICC and CV values for superior mGCC, inferior mGCC, superior mTR and inferior mTR were 0.983, 0.980, 0.983 and 0.988, and 0.84%, 0.98%, 0.48% and 0.43%, respectively. The RC values for superior mGCC, inferior mGCC, superior mTR and inferior mTR were 2.86 μm, 3.12 μm, 4.41μm and 4.43 μm, respectively. Conclusions Intrasession reproducibility of cpTR, mGCC and mTR measurements made on healthy eyes was high. Repeatability of cpTR measurements was better than that of the corresponding cpRNFL measurements. These results suggest that future clinical investigations addressing detection of glaucoma and glaucomatous progression with the RS-3000 OCT may benefit from focusing on the cpTR parameters.