Blastocyst-like Structures in the Peripheral Retina of Young Adult Beagles.

In this immunohistological study on the peripheral retina of 3-year-old beagle dogs, excised retina specimens were immunostained with antibodies against nestin, Oct4, Nanog, Sox2, CDX2, cytokeratin 18 (CK 18), RPE65, and YAP1, as well as hematoxylin and DAPI, two nuclear stains. Our findings revealed solitary cysts of various sizes in the inner retina. Intriguingly, a mass of small round cells with scant cytoplasms was observed in the cavity of small cysts, while many disorganized cells partially occupied the cavity of the large cysts. The small cysts were strongly positive for nestin, Oct4, Nanog, Sox2, CDX2, CK18, and YAP1. RPE65-positive cells were exclusively observed in the tissue surrounding the cysts. Since RPE65 is a specific marker of retinal pigment epithelial (RPE) cells, the surrounding cells of the peripheral cysts were presumably derived from RPE cells that migrated intraretinally. In the small cysts, intense positive staining for nestin, a marker of retinal stem cells, seemed to indicate that they were derived from retinal stem cells. The morphology and positive staining for markers of blastocyst and RPE cells indicated that the small cysts may have formed structures resembling the blastocyst, possibly caused by the interaction between retinal stem cells and migrated RPE cells.

Possible roles of anti-type II collagen antibody and innate immunity in the development and progression of diabetic retinopathy.

The pathogenesis of both diabetic retinopathy (DR) and rheumatoid arthritis (RA) has recently been considered to involve autoimmunity. Serum and synovial fluid levels of anti-type II collagen antibodies increase early after the onset of RA, thus inducing immune responses and subsequent hydrarthrosis and angiogenesis, which resemble diabetic macular edema and proliferative DR (PDR), respectively. We previously reported that DR is also associated with increased serum levels of anti-type II collagen antibodies. Retinal hypoxia in DR may induce pericytes to express type II collagen, resulting in autoantibody production against type II collagen. As the result of blood-retinal barrier disruption, anti-type II collagen antibodies in the serum come into contact with type II collagen around the retinal vessels. A continued loss of pericytes and type II collagen around the retinal vessels may result in a shift of the immune reaction site from the retina to the vitreous. It has been reported that anti-inflammatory M2 macrophages increased in the vitreous of PDR patients, accompanied by the activation of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a key regulator of innate immunity. M2 macrophages promote angiogenesis and fibrosis, which might be exacerbated and prolonged by dysregulated innate immunity.

Chronologic Analysis of Tear Dynamics on Blinking Using Quantitative Manometry in Healthy Humans.

PURPOSE: To analyze the tear dynamics during blinking by measuring the inner pressure of the upper lacrimal drainage system. METHODS: This observational study involved 11 healthy bi- or tricenarian volunteers. Direct manometry was performed using a fiber optic pressure sensor inserted into the conjunctival sac, upper/lower canaliculus (5 mm from punctum), and inferior lacrimal sac (15 mm from punctum) during both involuntary and intentional tight blinking. Pressure was measured 200 times/second during 3 separate blinks and then chronologically analyzed. RESULTS: In all subjects of all locations during both types of blinking, the inner pressures during the stationary eyelid closing/opening were positive/approximately zero, while a positive/negative pressure spike was observed during the eyelid closing/opening movement. The averages of the maximum pressure in the spike during the intentional tight blinking (tPmax: mm Hg) in the conjunctival sac, upper/lower canaliculus, and lacrimal sac were 8.00, 12.39/12.93, and 10.59, respectively, while for the minimum (tPmin: mm Hg), the pressures were -3.18, -3.91/-3.43, and -3.31, respectively. The tPmax and tPmin in the lacrimal duct were positively correlated with that of the conjunctival sac, which suggested synchronism of the drainage system. However, the tPmax in the canaliculus was significantly higher than that of the conjunctival sac, which suggested that tears do not flow from the conjunctival sac into the lacrimal duct during eyelid closure. CONCLUSIONS: The upper lacrimal drainage system functions as one united lumen in the lacrimal pump. The positive /negative pressure spike is essential for the lacrimal pump to efficiently eject/aspirate the tear from the lacrimal/conjunctival sac.

Adjustable Medial Epicanthoplasty Using a Rotational Flap for Epiblepharon Repair.

ABSTRACT: This report aimed to introduce the new adjustable rotational skin flap for epicanthoplasty in combination with traditional epiblepharon repair by the modified Hotz procedure. This retrospective study involved 25 consecutive patients with superficial punctate keratitis secondary to epiblepharon complicated with epicanthal fold who underwent the combined surgery between 2019 and 2020. The mean patient age was 11.4 years in this study with a median follow-up was 8months (range, 3-12months). The rationale of the surgery was to release vertical tension of the eyelids by dissecting dense connective tissue beneath the epicanthal fold and to form a new medial canthus using a rotational skin flap supplied by the redundant the upper and/or lower eyelid skin excised during the epiblepharon repair. Postsurgical resolution ofsuperficial punctate keratitis and patient satisfaction was achieved in all patients. Additionally, there were no complications, and no revisional surgery was required in all patients for a median 8 months follow-up period. Utilizing a rotational skin flap during epiblepharon repair is a useful adjunct during epicanthoplasty surgery. This modification is well tolerated and allows for intraoperative adjustment, whereas minimizing scarring and allowing for improved tissue relaxation.

Retinal venous pressure is decreased after anti-VEGF therapy in patients with retinal vein occlusion-related macular edema.

PURPOSE: The pathomechanism leading to retinal vein occlusion (RVO) is unclear. Mechanical compression, thrombosis, and functional contractions of veins are discussed as the reasons for the increased resistance of venous outflow. We evaluated changes in the retinal venous pressure (RVP) following intravitreal injection of anti-vascular endothelial growth factor (VEGF) agent to determine the effect on RVO-related macular edema. METHODS: Twenty-six patients with RVO-related macular edema (16 branch RVOs [BRVOs] and 10 central RVOs [CRVOs], age 72.5 ± 8.8 years) who visited our hospital were included in this prospective study. Visual acuity (VA), intraocular pressure (IOP), central retinal thickness (CRT) determined by macular optical coherence tomography, and RVP measured using an ophthalmodynamometer were obtained before intravitreal injection of ranibizumab (IVR) and 1 month later. RESULTS: Comparison of the BRVOs and CRVOs showed that VA was significantly improved by a single injection in BRVOs (P < 0.0001; P = 0.1087 for CRVOs), but CRT and RVP were significantly decreased without significant difference in IOP after the treatment in both groups (P < 0.0001). CONCLUSION: The anti-VEGF treatment resulted in a significant decrease in the RVP, but the RVP remained significantly higher than the IOP. An increased RVP plays a decisive role in the formation of macula edema, and reducing it is desirable.

Decreased Presence of Mast Cells in the Bursa Premacularis of Proliferative Diabetic Retinopathy.

INTRODUCTION: We previously reported that the intravitreal activities of chymase and tryptase were more increased in the patients with macular hole (MH) and epiretinal membrane (ERM) than in those with proliferative diabetic retinopathy (PDR) and that the source of these serine proteases might be mast cells in the bursa premacularis (BPM). The purpose of this study was to compare the density of mast cells in BPM samples obtained from MH, ERM, and PDR patients. METHODS: BPM and vitreous core samples were first collected during vitrectomy from eyes afflicted with vitreoretinal diseases (MH: 6 eyes, ERM: 3 eyes, and PDR: 9 eyes), and then were stained with hematoxylin, toluidine blue, antibodies against chymase and tryptase, and a terminal deoxynucleotidyl transferase dUTP nick end labeling assay kit. RESULTS: Hematoxylin nuclear staining showed fewer positive-staining cells in the BPM samples obtained from PDR patients than in those obtained from MH and ERM patients. Toluidine blue staining of the BPM revealed metachromasia in the mast cells of the patients with MH and ERM, but not those of the patients with PDR. In addition, immunostaining using anti-chymase and anti-tryptase antibodies showed that the BPM samples were more intensely stained than the vitreous core samples from the patients with MH and ERM and that both tissue samples were poorly stained in the patients with PDR. The apoptotic cells were more frequently observed in the BPM samples from patients with MH than in those from patients with PDR. CONCLUSIONS: These findings indicated that lower activities of chymase and tryptase in the vitreous of PDR patients appeared to be attributable to the decreased presence of mast cells in the BPM. The lack of mast cells in the BPM might be related to the pathogenesis of PDR.

Rituximab Monotherapy for Compressive Optic Neuropathy With Giant Ocular Adnexal Mucosa-Associated Lymphoid Tissue lymphoma.

A rare case of compressive optic neuropathy due to giant mucosa-associated lymphoid tissue lymphoma in the orbit was presented. A 87-year-old woman was aware of a slow progressive left ocular proptosis for 10 years and presented after becoming aware of a sudden progression of the proptosis accompanying visual disturbance over the previous 2 months. Orbital imaging and a biopsy of the tumor revealed a mucosa-associated lymphoid tissue lymphoma occupying her left orbit compressing and stretching the left optic nerve. Considering her age and the additional adverse effects of external beam radiation therapy to her damaged optic nerve, rituximab monotherapy was utilized. The intervention resulted in almost complete regression without any serious adverse effect, with left eye best-corrected visual acuity improving from 12/200 to 16/20. Rituximab monotherapy can be one of the first-choice treatment options for mucosa-associated lymphoid tissue lymphoma, especially in cases with the critical damage in the optic nerve.

Involvement of Anoikis in Dissociated Optic Nerve Fiber Layer Appearance.

Dissociated optic nerve fiber layer (DONFL) appearance is characterized by dimpling of the fundus when observed after vitrectomy with the internal limiting membrane (ILM) peeling in macular diseases. However, the cause of DONFL remains largely unknown. Optical coherence tomography (OCT) findings have indicated that the nerve fiber layer (NFL) and ganglion cells are likely to have been damaged in patients with DONFL appearance. Since DONFL appearance occurs at a certain postoperative period, it is unlikely to be retinal damage directly caused by ILM peeling because apoptosis occurs at a certain period after tissue damage and/or injury. However, it may be due to ILM peeling-induced apoptosis in the retinal tissue. Anoikis is a type of apoptosis that occurs in anchorage-dependent cells upon detachment of those cells from the surrounding extracellular matrix (i.e., the loss of cell anchorage). The anoikis-related proteins ßA3/A1 crystallin and E-cadherin are reportedly expressed in retinal ganglion cells. Thus, we theorize that one possible cause of DONFL appearance is ILM peeling-induced anoikis in retinal ganglion cells.

Expression of Lymphatic Markers in the Berger's Space and Bursa Premacularis.

We previously reported that the bursa premacularis (BPM), a peculiar vitreous structure located above the macula, contains numerous cells expressing markers of lymphatic endothelial cells, such as podoplanin and LYVE-1. Herein, we examined the expression of lymphatic markers in the Berger's space (BS), BPM, and vitreous core (VC). BS, BPM, and VC specimens were selectively collected in macular hole and epiretinal membrane patients during vitrectomy and were then immunostained with antibodies for podoplanin, LYVE-1, and fibrillin-1 and -2. By visualization using triamcinolone acetonide, the BS was recognized as a sac-like structure with a septum located behind the lens as well as BPM. Those tissues adhered to the lens or retina in a circular manner by means of a ligament-like structure. Immunostaining showed intense expression of podoplanin and LYVE-1 in the BS. Both BS and BPM stained strongly positive for fibrillin-1 and -2. The VC was faintly stained with antibodies for those lymph-node markers. Our findings indicate that both BS and BPM possibly belong to the lymphatic system, such as lymph nodes, draining excess fluid and waste products into lymphatic vessels in the dura mater of the optic nerve and the ciliary body, respectively, via intravitreal canals.

Significant correlations between photopic negative response, afferent pupillary defect, and mean defects of visual fields in asymmetric optic nerve disorders.

PURPOSE: The photopic negative response (PhNR) is a negative wave following the b-wave of the photopic electroretinogram (ERG). The PhNR originates from the retinal ganglion cells (RGCs), and it can be used to assess the function of RGCs noninvasively and objectively. The purpose of this study was to determine whether the relative amplitudes (affected/normal eye) of the PhNR are significantly correlated with the degree of the relative afferent pupillary defect (RAPD) in eyes with unilateral or asymmetrical damage of the optic nerve. METHODS: The PhNRs of the full-field photopic ERGs were measured. In addition, videopupillography and automated perimetry were performed on 27 cases with asymmetrical optic nerve disorders including glaucoma. The differences of these assessments were expressed by the relative amplitudes of the PhNRs of the two eyes, the neutral density (ND) filter required to equate the amplitudes of the pupillary light reflexes between the two eyes, and differences of the mean defects (ΔMDs) of the sensitivities of the Humphrey visual fields. The correlations between these values were determined by linear regression analyses. RESULTS: The relative PhNR amplitudes were significantly and negatively correlated with the ΔMDs (R2 = 0.58, P = 0.0001). In addition, the relative PhNR amplitudes were moderately but significantly and positively correlated with the RAPDs (R2 = 0.36, P = 0.002). CONCLUSION: The relative amplitudes of the PhNR of the affected eyes to the contralateral eyes indicate an asymmetric alteration of the RGCs, and they can be used to monitor the physiology of the RGCs objectively.

Correction to: Significant correlations between photopic negative response, afferent pupillary defect, and mean defects of visual fields in asymmetric optic nerve disorders.

The original publication of this paper contains mistakes.

A case of tractional retinal detachment associated with congenital retinal vascular hypoplasia in the superotemporal quadrant treated by vitreous surgery.

BACKGROUND: Here we report a case of traction retinal detachment (TRD) associated with congenital retinal vascular hypoplasia localized in the superotemporal quadrant that was treated with vitrectomy. CASE PRESENTATIONS: A 58 year-old female presented with a gradual decrease of visual acuity (VA) and distorted vision in her left eye. She had a past history of amblyopia in her left eye from early childhood, and a previous examination performed at a nearby hospital revealed that the corrected visual acuity (VA) in that eye was 0.15. Upon initial examination, no abnormal findings were observed in her right eye, yet optic-disc traction and macular rotation with a folded TRD extending superotemporally from the macular region was observed in her left eye. Fluorescein fundus angiography showed a retinal nonperfused area localized in the superotemporal quadrant surrounded by a retinal avascular area. The optic disc in her left eye was smaller than that in her right eye. Vitrectomy was performed to remove the proliferative membrane and created an artificial posterior vitreous detachment (PVD). Following surgery, the patient's corrected VA improved from 0.04 to 0.1. CONCLUSIONS: The present case was likely to be TRD caused by PVD in the presence of localized congenital retinal vascular hypoplasia secondary to optic-disc hypoplasia.

Valsalva retinopathy induced by handstand: a case report.

BACKGROUND: Valsalva retinopathy is known to occur as a sudden preretinal or sub-internal limiting membrane hemorrhage induced by a rapid rise in venous pressure following increased intrathoracic or intraabdominal pressure. Here we report a case of Valsalva retinopathy that was probably induced by straining that occurred due to following a handstand. CASE PRESENTATION: A 15-year-old boy became aware of decreased visual acuity in his left eye immediately after doing a handstand for approximately 10 s during physical education class, and subsequently visited a local clinic on the same day. Upon examination, a vitreous hemorrhage (VH) in the posterior pole of the fundus was found in his left eye, and he was subsequently referred to our department 7 days later. Upon examination, the VH around the optic nerve head of the left eye appeared to be resolved, and an oval-shaped sub-internal limiting membrane (sub-ILM) hemorrhage was found in the superonasal side of the optic nerve head. No abnormalities were observed in the macular area. Four months later, the sub-ILM hemorrhage was found to have spontaneously resolved. Subsequent fluorescein angiography examinations revealed no abnormal findings at the lesion site. CONCLUSIONS: In this patient, we hypothesize that the Valsalva retinopathy was induced by straining that occurred due to a handstand, and that the resultant sub-ILM hemorrhage progressed to VH.

Two cases of diabetic macular edema complicated by an atypical macular hole.

BACKGROUND: Here we report two patients who developed an atypical macular hole (MH) during the treatment course for diabetic macular edema (DME). CASE PRESENTATIONS: Patient 1 was a 73-year-old male. Optical coherence tomography (OCT) revealed perifoveal retinoschisis (RS) in addition to cystoid macular edema and serous retinal detachment (SRD) in his left eye, and that an MH had developed during the clinical course. A convex surface was formed at the MH margin toward the vitreous cavity, and granular shadows were observed in the fluid cuff. Intraoperative findings revealed a thin epiretinal macular membrane (ERM) around the MH. Patient 2 was a 79-year-old male. Although the patient underwent pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR) in both eyes, RS and a thin ERM in addition to SRD was observed in his left eye after surgery, and an MH developed during the clinical course. As in Patient 1, a convex surface was formed at the fluid cuff margin toward the vitreous cavity. CONCLUSIONS: Both patients had persistent DME, SRD, RS, and a thin ERM before the development of the MH. OCT revealed the formation of a convex surface at the MH margin toward the vitreous cavity, suggesting that the fragility of the layered structure of the retina combined with tangential retinal traction may have been involved in the atypical MH form.

Long-Term Follow-Up Changes of Central Choroidal Thickness Thinning after Repeated Anti-VEGF Therapy Injections in Patients with Central Retinal Vein Occlusion-Related Macular Edema with Systemic Hypertension.

PURPOSE: We investigated the thinning of central choroidal thickness (CCT) following intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) drugs to treat central retinal vein occlusion (CRVO)-related macular edema in patients with and without systemic hypertension (HT) to assess the influence of repeated anti-VEGF therapy and HT on the choroid in CRVO eyes. METHODS: We conducted a retrospective study involving 27 patients with CRVO-related macular edema from January 2014 to July 2017, with follow-ups exceeding 18 months. Visual acuity (VA), central retinal thickness (CRT), and CCT were evaluated before and after initial anti-VEGF drug treatment during follow-up. RESULTS: The mean follow-up period was 35.2 months. Seventeen (63.0%) patients had HT. At 1 month after treatment, VA had improved in 21 (77.8%) patients, and CRT had decreased in 25 (92.6%). At the final visit, 22 (81.5%) showed improved VA, 19 (70.4%) had resolved macular edema, and the CCT had gradually become thinner with additional drug injections in all the patients. Furthermore, the mean CCT in HT patients (209.0 µm) was significantly lower than in non-HT patients (256.1 µm), and the mean injections were 7.8 and 5.3, respectively (p = 0.2067). CONCLUSION: The CCTs were thinner in eyes with HT than in eyes without HT both before and after the repeated anti-VEGF injections.

Newly Designed Universal Trans-punctal Rigid Lacrimal Microendoscope.

PURPOSE: To report the development and clinical findings of a universal trans-punctal lacrimal microendoscope design. METHODS: In this study, we examined a unique and original "2-bend" (i.e., double-angle) rigid lacrimal microendoscope designed for universal applications for anatomical variations. The shape of endoscope was initially evaluated in 6 lacrimal systems of cadavers (4 Caucasian-cadaver lacrimal systems and 2 Asian-cadaver lacrimal systems). Second, a prospective clinical study involving 45 consecutive cases of nasolacrimal duct obstruction in Japanese patients was conducted to compare the facility and ease of use between the conventional single-bend type and our original 2-bend type trans-punctal lacrimal microendoscope for examination of the lacrimal drainage system. RESULTS: The findings in the cadaver study revealed that original 2-bend lacrimal microendoscope, which was designed double-angled 20°-30° at 10 and 30 mm from the tip of the scope, could more easily used to insert and image all lacrimal systems, while the conventional single-bent lacrimal microendoscope was difficult to insert in subset of patients with a prominent nasal process of the frontal bone. In the clinical trial, our findings showed that 26.7% of lacrimal systems could not be passed using the conventional single-bend design, while using the 2-bend design, all cases could successfully be investigated. CONCLUSIONS: The original 2-bend-design microendoscope was found to be effective and valuable for universal use in examination and evaluation of the lacrimal passage.

Endoscopic Evaluation of Lacrimal Mucosa With Indigo Carmine Stain.

PURPOSE: Histological investigation in the use of indigo carmine for detection of mucosal pathology in lacrimal microendoscopy. To investigate the histopathological correlation of staining found on lacrimal microendoscopy. METHODS: A prospective case series was conducted in patients with a history of nasolacrimal duct obstruction and dacryocystitis requiring treatment with dacryocystorhinostomy or dacryocystectomy. Prior to lacrimal surgery, all patients underwent endolacrimal evaluation using transpunctal lacrimal microendoscopy. Indigo carmine dye (0.2 mg/0.5 ml) was injected into the lacrimal system via the irrigation channel of the endoscope, and after copious irrigation, the differential mucosal staining was recorded. Histopathologic analysis of tissue samples of positively and negatively stained lacrimal sac mucosa collected after surgery was performed to investigate the correlation with the results of each endoscopic evaluation. RESULTS: Four patients underwent dacryocystorhinostomy and 2 patients underwent dacryocystectomy. Histopathology of positive-stained lacrimal sac mucosa corresponded to areas of the advanced fibrous stage of mucosal changes resulting from dacryocystitis, which showed atrophy of epithelium associated with the loss of goblet cells and subepithelium fibrous scarring. In contrast, areas of lacrimal mucosa that did not stain with indigo carmine were still in an active inflammatory stage of dacryocystitis preserving columnar epithelium with goblet cells. CONCLUSIONS: This study suggests that indigo carmine staining is a useful adjunct in lacrimal microendoscopy for accurately detecting areas of highly damaged fibrous lacrimal mucosa, as it allows for direct visualization of lacrimal mucosal pathology and can provide prognostic insight and guidance in regard to treatment options for patients with lacrimal drainage obstruction.Use of indigo carmine dye as an in vivo adjunct in lacrimal microendoscopy is useful for accurately detecting areas of highly damaged lacrimal mucosa.

Impairment of Autophagy Causes Superoxide Formation and Caspase Activation in 661 W Cells, a Cell Line for Cone Photoreceptors, under Hyperglycemic Conditions.

Microvascular changes are the earliest adverse events in diabetic retinopathy, but recent studies have shown that oxidative stress induced by photoreceptors is associated with the development of the retinopathy. The purpose of this study was to determine the roles played by superoxides formed by photoreceptors under hyperglycemic conditions on autophagy. To accomplish this, we cultured 661 W cells, a transformed murine cone cell line, with 5.5 or 25 mM glucose in the presence or absence of 3 methyl adenine (3MA) or rapamycin. The superoxides were determined by flow cytometry using hydroethidine as a fluorescence probe. The autophagy activity was determined by changes in the expression of LC3B2 and P62 by immunoblotting. The degree of mitophagy was determined by the accumulation of mitochondria and lysosomes. Apoptotic changes of 661 W cells were determined by the caspase 3/7 activities. Our results showed higher levels of P62 and superoxides in cells cultured in 25 mM glucose than in 5.5 mM glucose. Addition of 3MA caused a significant increase of P62, superoxides, and caspase 3/7 activities in the 661 W cells cultured in high glucose but not in low glucose. These findings suggest that autophagy is important for the functioning and survival of 661 W cells under hyperglycemic conditions.

Effects of an Aquaporin 4 Inhibitor, TGN-020, on Murine Diabetic Retina.

PURPOSE: To investigate the effect of a selective aquaporin 4 (AQP4) inhibitor, 2-(nicotinamide)-1,3,4-thiadiazole (TGN-020), on the expression of vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS) production, as well as on the retinal edema in diabetic retina. METHODS: Intravitreal injections of bevacizumab, TGN-020, or phosphate-buffered saline (PBS) were performed on streptozotocin-induced diabetic rats. Retinal sections were immunostained for anti-glial fibrillary acidic protein (GFAP), anti-AQP4, and anti-VEGF. Protein levels of VEGF from collected retinas were determined by Western blot analysis. In addition, retinal vascular leakage of Evans Blue was observed in the flat-mounted retina from the diabetic rats in the presence or absence of TGN-020. Volumetric changes of rat retinal Müller cells (TR-MUL5; transgenic rat Müller cells) and intracellular levels of ROS were determined using flow cytometry analysis of ethidium fluorescence in the presence or absence of TGN-020 or bevacizumab under physiological and high glucose conditions. RESULTS: In the diabetic retina, the immunoreactivity and protein levels of VEGF were suppressed by TGN-020. AQP4 immunoreactivity was higher than in the control retinas and the expressions of AQP4 were co-localized with GFAP. Similarly to VEGF, AQP4 and GFAP were also suppressed by TGN-020. In the Evans Blue assay, TGN-020 decreased leakage in the diabetic retinas. In the cultured Müller cells, the increase in cell volumes and intracellular ROS production under high glucose condition were suppressed by exposure to TGN-020 as much as by exposure to bevacizumab. CONCLUSION: TGN-020 may have an inhibitory effect on diabetic retinal edema.

Involvement of the Retinal Pigment Epithelium in the Development of Retinal Lattice Degeneration.

Lattice degeneration involves thinning of the retina that occurs over time. Here we performed an immunohistological study of tissue sections of human peripheral retinal lattice degeneration to investigate if retinal pigment epithelium (RPE) cells are involved in the pathogenesis of this condition. In two cases of retinal detachment with a large tear that underwent vitreous surgery, retinal lattice degeneration tissue specimens were collected during surgery. In the obtained specimens, both whole mounts and horizontal section slices were prepared, and immunostaining was then performed with hematoxylin and antibodies against glial fibrillary acidic protein (GFAP), RPE-specific protein 65 kDa (RPE65), pan-cytokeratin (pan-CK), and CK18. Hematoxylin staining showed no nuclei in the center of the degenerative lesion, thus suggesting the possibility of the occurrence of apoptosis. In the degenerative lesion specimens, GFAP staining was observed in the center, RPE65 staining was observed in the slightly peripheral region, and pan-CK staining was observed in all areas. However, no obvious CK18 staining was observed. In a monkey retina used as the control specimen of a normal healthy retina, no RPE65 or pan-CK staining was observed in the neural retina. Our findings suggest that migration, proliferation, and differentiation of RPE cells might be involved in the repair of retinal lattice degeneration.