Vitreoschisis in Eales' disease: pathogenic role and significance in surgery

Posterior pole retinal breaks causing posterior pole retinal detachment in a middle-aged man with retinal vasculitis and moderate myopia

A 38-year-old man presented with sudden decreased vision in the right eye 3 years ago due to vitreous haemorrhage. During follow-up, right eye fundus showed evidence of vasculitis, non-perfusion areas and neovascularisation elsewhere. Systemic evaluation findings of positive Mantoux test, QuantiFERON Gold test and right apical pleuroparenchymal fibrosis observed on high-resolution CT of the chest were suggestive of postinfection probable tubercular aetiology. He was treated with oral steroids, antitubercular therapy, intravitreal bevacizumab and anterior retinal cryopexy, leading to resolution of vasculitis and vitreous haemorrhage. Later he developed peripheral retinal flap and posterior retinal breaks at 8-month and 11-month follow-up, respectively, which were managed by barrage laser. He maintained a stable visual acuity of 20/20, N6 for the next 2 years. He then presented with sudden decreased vision in the right eye (20/50, N10). Right eye fundus showed posterior pole retinal detachment with lifting of previously barraged posterior retinal breaks. He underwent vitreoretinal surgery with gas tamponade. Recent 1-month postoperative visit showed successful retinal reattachment and visual recovery of 20/20, N6.

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

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

The 88-kDa Eales' protein in serum is a complex of haptoglobin, complement C3, and galectin-1 as identified by liquid chromatography coupled mass spectrometry

PURPOSE

Eales' disease (ED), an enigmatic inflammatory disease, affects peripheral retinal veins and thereby vision in males. This study was aimed at identifying and deciphering the role of a novel 88-kDa protein reported in the serum and vitreous of patients with ED.

EXPERIMENTAL DESIGN

The purified 88-kDa protein was identified by UPLC coupled ESI-QTOF-MS. The identified proteins were quantified in the serum from 20 ED patients and controls (age and sex matched), respectively by ELISA. The interaction of these proteins was studied using co-immunoprecipitation, western blot, and MS analyses. N-glycosylation of protein was observed by MS and lectin blot.

RESULTS

The 88-kDa protein was identified to be a complex of haptoglobin, complement C3, and galectin-1. ELISA results showed a 1.5-fold increase in levels of haptoglobin (p = 0.008), with level of complement C3 unaltered and 1.2-fold decreased serum galectin-1 levels (p = 0.003) in ED patients compared to controls. Co-immunoprecipitation illustrated the interaction between haptoglobin and complement C3. Reduced sialylation and increased β-1, 6-N-acetyl-glucosamine branched N-glycans were observed in haptoglobin of ED patients.

CONCLUSION

The 88-kDa protein, a complex of haptoglobin, complement C3, and galectin-1, may play a potential role in ED pathogenesis while levels galectin-1 and haptoglobin may serve as potential biomarker of ED.

[Eales' disease]

The syndrome of recurrent vitreous hemorrhages in young men was described for the first time by Henry Eales in 1880. The association with a clinical manifestation of ocular inflammation was reported 5years later. Eales disease affects young adults who present with ischemic retinal vasculitis, with the peripheral retina most commonly affected. Most cases have been reported in South Asia. Although the etiology of this abnormality is unknown, it may be related to an immune sensitivity to Mycobacterium tuberculosis antigens. Its pathogenesis is related to extensive ischemia that affects the retina, secondary to an obliterative retinal vasculopathy with release of angiogenic factors of the VEGF type. Involvement of the retina is the hallmark of the disease, which manifests as follows: periphlebitis, retinal capillary ischemia most often affecting the periphery with secondary proliferative retinopathy and retinal and/or papillary neovascularization, recurrent vitreous hemorrhages and tractional retinal detachment. These complications are potentially blinding. The natural history of Eales disease varies, with temporary or permanent remission in some cases and continuous progression in others. Progression is often bilateral, which necessitates regular follow-up. The treatment of Eales disease depends on the stage of the disease and is not well defined. Observation only, pars plana vitrectomy surgery and/or intravitreal injections of anti-VEGF are recommended in cases of vitreous hemorrhage, associated with corticosteroids when retinal vasculitis is present. Laser pan-retinal photocoagulation is necessary when neovascularization is present.

Surgical treatment for diabetic vitreoretinal diseases: a review

Over the past four decades, advancements in surgical instrumentations and techniques have significantly improved the postoperative anatomical and visual outcomes of patients with various diabetic vitreoretinal diseases. In particular, surgical interventions for previously serious and untreatable blinding proliferative diabetic retinopathy can now be performed, with much better results. The advents of micro incisional vitrectomy system with better visualization system like binocular indirect ophthalmomicroscope and state-of-the-art instrumentation revolutionized the era of diabetic vitrectomy. High-speed vitrectors, finer instruments, chromo-assisted vitrectomy and use of anti-vascular endothelial growth factors not only change the paradigm but also help achieve much better outcome after diabetic vitrectomies. In this review, we will discuss and summarize the indications, surgical considerations, surgical techniques, potential complications and outcomes of vitreoretinal surgery for diabetic eye diseases.

Vitreopapillary and vitreomacular traction in proliferative Eales' disease

Vitreoretinal interface alterations leading to vitreopapillary and vitreomacular traction in a 29-year case of proliferative Eales' disease is described for the first time. On fundus examination, an ellipsoid area of vitreomacular traction was noted temporal to the optic disc. A triangular-shaped infolding of the retina was observed superior to the fovea. Epiretinal membrane was seen temporal to the disc involving the macula. Imaging by spectral domain optical coherence tomography in the papillomacular bundle region revealed retinoschisis at the level of the outer nuclear layer and confirmed the presence of retinal infolding and epiretinal membrane in the macular area. Three-dimensional imaging documented vitreoretinal interface alterations exquisitely.

Cloning and characterization of human vitreous tissue-derived cells

PURPOSE

Previously, we established a porcine vitreous tissue-derived hyalocyte cell line (PH5) and investigated the regulation of hyaluronan synthesis in these cells by cytokines. The objective of the current study was to establish human vitreous tissue-derived cells and to compare their characteristics with those of PH5 cells.

METHODS

Human vitreous specimens from two patients were cultured in the presence of 10% foetal bovine serum and immortalized by infection with human papilloma virus 16 genes E6 and E7. We used reverse transcription polymerase chain reaction (RT-PCR) to analyse and compare the expression profiles for several genes in the human vitreous tissue-derived cells and PH5 cells. To investigate the regulation of hyaluronan production in response to cytokine stimulation, the expression of hyaluronan synthase isoforms was examined using RT-PCR, and hyaluronan production was measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Two types of cells, HV64 and HV65, were derived from human vitreous tissue. The HV64 and HV65 cell-doubling times were 58 r and 76 hr, respectively. The cells expressed messenger RNA (mRNAs) encoding collagen type I α1 (COL1A1), collagen type II α1 (COL2A1), CD11b, CD14, CD68, CD204 and CD206 but did not express mRNA for glial fibrillary acidic protein (GFAP). Cytokine stimulation did not induce the expression of hyaluronan synthase mRNA or the production of hyaluronan. In contrast, mRNAs for GFAP and hyaluronan synthase-2 were expressed in the porcine PH5 cells, and treatment with transforming growth factor-β1 and/or platelet-derived growth factor-BB induced the production of hyaluronan in PH5 cells.

CONCLUSION

The new human vitreous tissue-derived cells have macrophage-like characteristics and are different from our previously developed porcine hyalocyte cells. These human vitreous tissue-derived cells might be useful for studies of human intraocular diseases.

Vitreous substitutes: a comprehensive review

Vitreoretinal disorders constitute a significant portion of treatable ocular disease. Advances in vitreoretinal surgery have included the development and characterization of suitable substitutes for the vitreous. Air, balanced salt solutions, perfluorocarbons, expansile gases, and silicone oil serve integral roles in modern vitreoretinal surgery. Vitreous substitutes vary widely in their properties, serve different clinical functions, and present different shortcomings. Permanent vitreous replacement has been attempted with collagen, hyaluronic acid, hydroxypropylmethylcellulose, and natural hydrogel polymers. None, however, have proven to be clinically viable. A long-term vitreous substitute remains to be found, and recent research suggests promise in the area of synthetic polymers. Here we review the currently available vitreous substitutes, as well those in the experimental phase. We classify these compounds based on their functionality, composition, and properties. We also discuss the clinical use, advantages, and shortcomings of the various substitutes. In addition we define the ideal vitreous substitute and highlight the need for a permanent substitute with long-term viability and compatibility. Finally, we attempt to define the future role of biomaterials research and the various functions they may serve in the area of vitreous substitutes.

Vitreoschisis in macular diseases

OBJECTIVES

Vitreoschisis is a possible pathogenic mechanism in macular diseases. Thus, the vitreoretinal interface was evaluated in monkey eyes and patients with various macular diseases in search of vitreoschisis. It is hypothesised that vitreoschisis is present in macular holes (MH) and macular pucker (MP), but not in other maculopathies.

METHODS

Histopathology was studied in 14 monkey eyes and a vitrectomy specimen of a patient with macular pucker. Optical coherence tomography/scanning laser ophthalmoscopy (OCT/SLO) was performed in 239 eyes: 45 MH, 45 MP, 51 dry age-related macular degeneration (AMD), 53 non-proliferative diabetic retinopathy (NPDR) and 45 controls.

RESULTS

Immunohistochemistry demonstrated lamellae in the posterior vitreous cortex of 12/14 (86%) monkey eyes. With OCT/SLO, vitreoschisis was detected in 24/45 (53%) MH and 19/45 (42%) MP eyes, but in only 7/53 (13%) NPDR, 3/51 (6%) AMD and 3/45 (7%) control eyes (p<0.001 for all comparisons). Rejoining of the inner and outer walls of the split posterior vitreous cortex was visible in 16/45 (36%) MH eyes and 15/45 (33%) MP eyes. Histopathology of the MP specimen confirmed a split with rejoining in the posterior vitreous cortex.

CONCLUSIONS

Vitreoschisis was detected in half of eyes with MH and MP, but much less frequently in controls, AMD and NPDR patients. These findings suggest that anomalous PVD with vitreoschisis may be pathogenic in MH and MP.

Microplasmin intravitreal administration in patients with vitreomacular traction scheduled for vitrectomy: the MIVI I trial

PURPOSE

To evaluate the safety and preliminary efficacy of 4 doses and several exposure times of intravitreal microplasmin given before pars plana vitrectomy for vitreomacular traction maculopathy.

DESIGN

A multicenter, prospective, uncontrolled, dose-escalation, phase I/II clinical trial.

PARTICIPANTS

Sixty patients enrolled into 6 successive cohorts.

INTERVENTION

A single intravitreal injection of microplasmin at 1 of 4 doses (25, 50, 75, or 125 microg in 100 microl) administered either 1 to 2 hours, 24 hours, or 7 days before planned pars plana vitrectomy.

MAIN OUTCOME MEASURES

For safety, a complete ophthalmologic examination, fundus photography, fluorescein angiography, Humphrey visual fields, and electrophysiology; for efficacy, posterior vitreous detachment (PVD) induction as assessed by B-scan ultrasound and ease of PVD induction at the time of vitrectomy.

RESULTS

The use of microplasmin led to a progressively higher incidence of PVD induction on ultrasonography with increasing time exposure. A PVD before surgery was observed with 25 microg microplasmin in 0, 2, and 5 patients with increasing exposures (2 hours, 24 hours, 7 days). With increasing dose, a PVD before surgery was observed by ultrasound as follows: 25 microg, 0; 50 microg, 1; 75 microg, 2; 125 microg, 3. However, at surgery, with a 125-microg dose, these patients had a discontinuous layer of vitreous present on the retinal surface resulting from the induction of an anomalous PVD in the form of vitreoschisis. One retinal detachment developed shortly after administration of microplasmin. Two developed after surgery. There were no other safety concerns.

CONCLUSIONS

Results from this initial clinical trial evaluating intravitreal microplasmin show the drug to be well tolerated and capable of inducing a pharmacologic PVD in some patients. These results warrant evaluation of microplasmin in larger, controlled trials.

Surgical outcomes for vitrectomy in Eales' disease

AIM

To present and analyse the anatomical and functional outcomes for vitrectomy in Eales' disease.

METHODS

This retrospective case series enrolled 63 patients (71 eyes) who underwent pars plana vitrectomy (PPV) for the complications of Eales' disease. Indications included nonclearing vitreous haemorrhage (VH) with/without epiretinal membranes in 49 (69%) eyes, and retinal detachments (RD) involving/threatening macula in 22 (31%). Additional procedures (scleral buckling; gas/oil tamponade) were performed at surgeon's discretion. Minimum follow-up was 6 months. The primary outcome measures were change in best-corrected visual acuity (BCVA) and posterior segment status.

RESULTS

The mean age of the patients was 29.6 years (range: 15-70 years); 60 were male (95%). Preoperatively, posterior vitreous detachment (PVD) existed in 28 (39.4%) eyes. Forty (56.3%) eyes underwent only PPV; the rest required additional surgical procedures (q.v.). The mean baseline BCVA (1/60) improved to 6/24 postoperatively (P<0.0001). Fifty-four eyes of 50 patients (76%) showed an improvement of > or =2 equivalent Snellen lines; six eyes (four patients) remained stable (+/-1 line); visual acuity worsened in 11 eyes (nine patients). The mean final BCVA was similar in eyes operated for VH and RD (P=0.08); but the magnitude of change from baseline was greater in the VH group (P=0.009). PVD had a borderline association with final BCVA (P=0.056); but did not influence the functional/anatomical improvement. Thirteen eyes required repeat interventions; 11 (15.49%) eyes experienced surgical failure.

CONCLUSIONS

Although surgical outcomes in Eales' disease depend on preoperative PVD/RD to some extent; good results are possible in the presence of incomplete PVD and tractional sequelae.

A comparative study of epiretinal membranes associated with Eales' disease: a clinicopathologic evaluation

AIM

To study the histopathologic features and clinical correlation of epiretinal membranes (ERM) obtained from patients of Eales' disease and compare with other vasoproliferative disorders.

METHODS

Retrospective analysis of epiretinal membranes submitted for histological evaluation between January 1995 and June 2001, from the patients of diabetic retinopathy and vascular occlusions (Group 1; vaso-occlusive disorders) and of Eales' disease (Group 2; vasoinflammatory disorders). Demographics, pre and postoperative visual acuity, and anatomic and histologic characteristics of membranes were studied. Histopathologic features and clinical outcomes were correlated between the groups. The results were analysed statistically by Student's t-test, Fisher's exact test and Kruskal-Wallis test.

RESULTS

This study consisted of 42 patients, 24 in Group 1 and 18 in Group 2. Patients in Group 2 (33.0+/-9.2 years) were significantly younger than the patients in Group 1 (49.9+/-7.6 years) (P< or =0.0001). Final visual acuity of >20/400 was attained in 79.2% (19/24) patients in Group 1 and 83.3% (15/18) in Group 2 (P=1.0). Inflammatory membranes were significantly associated with presumed Eales' disease (94.4 vs 0%) (P< or =0.0001) and fibrovascular membranes with Group 1 (70.8% vs 33.3%) (P=0.028). Mast cells and eosinophils were observed as special features in epiretinal membranes of patients with Eales' disease.

CONCLUSIONS

Histological features of ERM in Eales' disease are comparable to other vasoproliferative disorders except for features of inflammation. Presence of mast cells and eosinophils in epiretinal membranes of Eales' disease needs further investigation.

Eales disease--an update

Eales disease, first described by Henry Eales in 1880, remains an enigma. The disease, observed more commonly in the Indian subcontinent than in the rest of the world, occurs in young healthy adult males, initially presenting as retinal periphlebitis and later as retinal ischemia that may lead to vascular alterations and neovascularization. Recurrent vitreous hemorrhage with or without retinal detachment is the common sequelae. In recent years, immunological, molecular biological, and biochemical studies have indicated the role of human leukocyte antigen, retinal autoimmunity, mycobacterium tuberculosis genome, and free radical mediated damage in the etiopathogenesis of this disease. However, its etiology appears to be multifactorial. The management depends on the stage of the disease and consists of medical treatment with oral corticosteroids in the active inflammatory stage and laser photocoagulation in the advanced retinal ischemia and neovascularization stages. The results of vitreoretinal surgery have been found to be satisfactory in case of vitreous hemorrhage with or without retinal detachment.