This review describes a scheme for diagnosis of glaucoma in population based prevalence surveys. Cases are diagnosed on the grounds of both structural and functional evidence of glaucomatous optic neuropathy. The scheme also makes provision for diagnosing glaucoma in eyes with severe visual loss where formal field testing is impractical, and for blind eyes in which the optic disc cannot be seen because of media opacities.

https://bjo.bmj.com/content/bjophthalmol/86/2/238.full.pdf

The definition and classification of glaucoma in prevalence surveys

Tissue sections from aggressive human intraocular (uveal) and metastatic cutaneous melanomas generally lack evidence of significant necrosis and contain patterned networks of interconnected loops of extracellular matrix. The matrix that forms these loops or networks may be solid or hollow. Red blood cells have been detected within the hollow channel components of this patterned matrix histologically, and these vascular channel networks have been detected in human tumors angiographically. Endothelial cells were not identified within these matrix-embedded channels by light microscopy, by transmission electron microscopy, or by using an immunohistochemical panel of endothelial cell markers (Factor VIII-related antigen, Ulex, CD31, CD34, and KDR[Flk-1]). Highly invasive primary and metastatic human melanoma cells formed patterned solid and hollow matrix channels (seen in tissue sections of aggressive primary and metastatic human melanomas) in three-dimensional cultures containing Matrigel or dilute Type I collagen, without endothelial cells or fibroblasts. These tumor cell-generated patterned channels conducted dye, highlighting looping patterns visualized angiographically in human tumors. Neither normal melanocytes nor poorly invasive melanoma cells generated these patterned channels in vitro under identical culture conditions, even after the addition of conditioned medium from metastatic pattern-forming melanoma cells, soluble growth factors, or regimes of hypoxia. Highly invasive and metastatic human melanoma cells, but not poorly invasive melanoma cells, contracted and remodeled floating hydrated gels, providing a biomechanical explanation for the generation of microvessels in vitro. cDNA microarray analysis of highly invasive versus poorly invasive melanoma tumor cells confirmed a genetic reversion to a pluripotent embryonic-like genotype in the highly aggressive melanoma cells. These observations strongly suggest that aggressive melanoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis.

Vascular Channel Formation by Human Melanoma Cells in Vivo and in Vitro: Vasculogenic Mimicry

Background Ocular trauma or disease may lead to severe corneal opacification and, consequently, severe loss of vision as a result of complete loss of corneal epithelial stem cells. Transplantation of autologous corneal stem-cell sources is an alternative to allograft transplantation and does not require immunosuppression, but it is not possible in many cases in which bilateral disease produces total corneal stem-cell deficiency in both eyes. We studied the use of autologous oral mucosal epithelial cells as a source of cells for the reconstruction of the corneal surface. Methods We harvested 3-by-3-mm specimens of oral mucosal tissue from four patients with bilateral total corneal stem-cell deficiencies. Tissue-engineered epithelial-cell sheets were fabricated ex vivo by culturing harvested cells for two weeks on temperature-responsive cell-culture surfaces with 3T3 feeder cells that had been treated with mitomycin C. After conjunctival fibrovascular tissue had been surgically removed from the ocular surfa...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa040455

Corneal reconstruction with tissue-engineered cell sheets composed of autologous oral mucosal epithelium.

An Integrated Hypothesis That Considers Drusen as Biomarkers of Immune-Mediated Processes at the RPE-Bruch's Membrane Interface in Aging and Age-Related Macular Degeneration

https://oftalmologiarafaelcaiado.files.wordpress.com/2012/04/anchor-study.pdf

Ranibizumab versus Verteporfin Photodynamic Therapy for Neovascular Age-Related Macular Degeneration: Two-Year Results of the ANCHOR Study

The blind and painful left eye of a 88-year-old woman was enucleated and examined by light and transmission electron microscopy. Three years earlier, after unilateral pseudoexfoliation syndrome with advanced open angle glaucoma of the left eye had been diagnosed, argon laser trabeculoplasty and pars plicata diathermy were performed. Light microscopy showed deposits of typical pseudoexfoliative material in the anterior segment and endothelialization of the chamber angle. By transmission electron microscopy we demonstrated pseudoexfoliative fibers not only at the typical intraocular locations and in the bulbar conjunctiva but also ultrastructurally identical material in hitherto not described extraocular locations such as extraocular rectus and oblique muscles, vortex veins and the optic nerve sheaths. Ultrastructurally, the fibers showed all the characteristic features of pseudoexfoliative material. Our findings are another strong indication that pseudoexfoliation syndrome is not a purely intraocular disorder but represents a more widespread disease.

Occurrence of pseudoexfoliative material in parabulbar structures in pseudoexfoliation syndrome.

Secondary corneal calcification involving the full thickness of the stroma is a rare potential complication of severe dry eye conditions, recurrent corneal ulcerations, chronic ocular inflammation, or multiple surgical procedures. We describe on a patient with unusual, hitherto unreported calcareous degeneration of the corneal stroma after topical steroid-phosphate therapy for chronic keratoconjunctivitis after Stevens-Johnson syndrome. The patient's serum levels of calcium and phosphorus were normal. Histopathologic and electron microscopic examination of the corneal button revealed mainly intracellularly located crystalline calcium deposits throughout all layers of the corneal stroma but sparing the Bowman layer. Energy-dispersive x-ray analysis confirmed the presence of calcium phosphate. The calcium deposits were closely associated with intracellular and pericellular accumulations of glycosaminoglycans. Our findings indicate that corneal stromal calcification may develop after topical steroid-phosphate medication, and suggest a possible role of alterations in the glycosaminoglycan metabolism of stromal keratocytes in the calcification process.

https://jamanetwork.com/journals/jamaophthalmology/articlepdf/412429/ecp90011.pdf

Corneal stromal calcification after topical steroid-phosphate therapy

Endothelium and pachymetry of clear corneal grafts 15 to 33 years after penetrating keratoplasty

To the Editor. —Current standard corneal transplantation techniques use circular, round, mechanical trephines either operated by hand or motor driven, under visual control through the operating microscope. The anatomic and functional results of this sight-improving procedure are acceptable. 1 The two major problems of the procedure are disturbing astigmatism and immunologic graft rejections. Excessive corneal astigmatism and optical irregularities are caused by incongruent cut surfaces of donor and patient corneas and disparities in corneal thickness. 1 Immunologic graft rejection occurs in 10% of avascular corneas and increases in frequency in vascularized corneas and as the diameter of the corneal graft increases. While for optical purposes it is desirable to have the corneal graft as large as possible, immunologic requirements aim for the opposite result. The ultraviolet excimer laser technique enables us to overcome the mechanical limitations of the trephination procedure and to produce noncircular trephinations. 2,3 We now introduce a

A new elliptical excision for corneal transplantation using an excimer laser.

Background/aims—“Orientation teeth” at the donor trephination margin and correspondent “notches” at the host margin facilitate graft orientation and avoid “horizontal torsion” induced by asymmetric suture placement. In this study the quality and reproducibility of these structures created by non-mechanical laser corneal trephination were compared using two laser emissions. Methods—The procedure was performed in 20 enucleated pigs’ eyes using open metal masks with eight “orientation teeth/ notches”(0.3 × 0.15 mm,base × height),an automated globe rotation device, and either a 193 nm ArF excimer laser or a Q switched 2.94 µm Er:YAG laser. “Teeth/ notches”were analysed by planimetry and scanning electron microscopy (SEM). Results—Mean size was 0.30 (0.027) × 0.16 (0.017) mm for “teeth” and 0.30 (0.035) × 0.15 (0.021) mm for “notches” (excimer), and 0.31 (0.022) × 0.16 (0.015) mm and 0.30 (0.031) × 0.14 (0.021) mm respectively (Er:YAG). Overall, variability of notches was higher than that of teeth. By SEM, comparable cut regularity and sustained ablation profile were observed with both lasers. However, the corneal surface at the cut edge appeared slightly elevated (<35 µm) in the Er:YAG group. Conclusion—Orientation teeth/notches resembling those obtained with the excimer laser can be created using the Q switched Er:YAG laser, with potential advantages of lower costs, convenient equipment size, and solid state safety.

https://bjo.bmj.com/content/bjophthalmol/83/9/1008.full.pdf

Gottfried O. H. Naumann

Papers

Occurrence of pseudoexfoliative material in parabulbar structures in pseudoexfoliation syndrome.

Corneal stromal calcification after topical steroid-phosphate therapy

Endothelium and pachymetry of clear corneal grafts 15 to 33 years after penetrating keratoplasty

A new elliptical excision for corneal transplantation using an excimer laser.

"Orientation teeth" in non-mechanical laser corneal trephination for penetrating keratoplasty: 2.94 µm Er:YAG v 193 nm ArF excimer laser