RESUMEN
BACKGROUND: Plus disease, one of the most important prognostic indicators in retinopathy of prematurity (ROP), is designated as present or absent. A grading system based on comparison with standard, high-quality color photographs may be useful to more accurately describe the spectrum of vascular dilation and tortuosity preceding plus disease, but it is of practical value only if it has prognostic significance. We hypothesized that grading of "pre-plus" vascular changes can identify eyes at risk for progression to vision-threatening ROP. METHODS: Video clips of posterior pole images captured at the examination closest to 33 weeks' postconceptional age of 32 infants screened during an 18-month period were randomized. Two masked examiners viewed and graded the images in comparison with standard photographs representative of 5 distinct grades of retinal vascular dilation and tortuosity. A case-control design was used to compare the incidence of progression to stage 3 ROP, development of plus disease, and requirement of laser treatment between infants with normal posterior poles and those judged to have early dilation and tortuosity insufficient for plus disease. RESULTS: Of the 8 patients with mild vascular dilation and tortuosity insufficient for plus disease, 5 (63%) eventually required laser treatment, 4 (50%) later developed stage 3 ROP, and 5 (63%) progressed to plus disease. Of the 24 patients with normal posterior poles, none required laser treatment, 2 (8%) developed stage 3 ROP, and none progressed to plus disease. The group with mild vascular dilation and tortuosity had a significantly higher incidence of progression to laser treatment (P =.0003), stage 3 ROP (P =.027), and plus disease (P =.0003). CONCLUSIONS: Early vascular dilation and tortuosity judged insufficient for plus disease have prognostic significance in the early course of ROP. A grading system that uses standard, high-quality color photographs representing the spectrum of "pre-plus" vascular changes has potential utility in both the clinical and research settings.
Asunto(s)
Vasos Retinianos/patología , Retinopatía de la Prematuridad/patología , Estudios de Casos y Controles , Progresión de la Enfermedad , Humanos , Recién Nacido , Terapia por Láser , Oftalmoscopía , Pronóstico , Retinopatía de la Prematuridad/cirugía , Índice de Severidad de la Enfermedad , Grabación en VideoRESUMEN
PURPOSE: To report visually disabling postkeratoplasty astigmatism occurring 12 years after a corneal transplant for keratoconus apparently caused by pellucid marginal corneal degeneration (PMD). METHODS: A 33-year-old woman had had a corneal transplant for keratoconus in her left eye. Twelve years later, she was referred for evaluation and management of increasingly blurred vision due to marked postkeratoplasty astigmatism. RESULTS: The donor cornea protruded over a region of thinning, anterior to and concentric with a thinned inferior wound. Videokeratoscopy showed +18.35 D of astigmatism in the 34 degree meridian and inferior corneal steepness surrounding the region of inferior flatness. CONCLUSION: To our knowledge, this is the first case of apparent PMD occurring after corneal transplantation for keratoconus. The presence of subtle biomicroscopic and keratoscopic signs of PMD prior to corneal transplantation for keratoconus may affect the planned surgical approach.
Asunto(s)
Córnea/cirugía , Enfermedades de la Córnea/etiología , Queratocono/cirugía , Queratoplastia Penetrante/efectos adversos , Adulto , Astigmatismo/etiología , Recuento de Células , Córnea/patología , Enfermedades de la Córnea/patología , Enfermedades de la Córnea/cirugía , Topografía de la Córnea , Endotelio Corneal/patología , Femenino , Humanos , Agudeza VisualRESUMEN
Rek (retina-expressed kinase) has been identified as a putative novel receptor-type tyrosine kinase of the Axl/Tyro3 family with a potential role in neural cell development. rek clones were isolated from a chick embryonic brain cDNA library with a DNA probe obtained by reverse transcriptase-polymerase chain reaction of mRNA from Müller glia-like cells cultured from chick embryonic retina. Sequence analysis indicated that Rek is a protein of 873 amino acids with an extracellular region composed of two immunoglobulin-like domains followed by two fibronectin type III domains with eight predicted N-glycosylation sites. Two consensus src homology 2 domain binding sites are present in the cytoplasmic domain, suggesting that Rek activates several signal transduction pathways. Northern analysis of rek mRNA revealed a 5.5-kilobase transcript in chick brain, retina, and kidney and in primary cultures of retinal Müller glia-like cells. Rek protein was identified by immunoprecipitation and immunoblotting as a 140-kDa protein expressed in the chick retina at embryonic days 6-13, which corresponded to the major period of neuronal and glial differentiation. Transfection of rek cDNA into COS cells resulted in transient expression of a putative precursor of 106 kDa that autophosphorylated in immune complex protein kinase assays. Overexpression of rek cDNA in mouse NIH3T3 fibroblasts resulted in activation of the 140-kDa rek kinase and induction of morphologically transformed foci. These properties indicated that Rek has oncogenic potential when overexpressed, but its normal function is likely to be related to cell-cell recognition events governing the differentiation or proliferation of neural cells.