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Biomedical subjects

Walter J Stark

Publications and source records attributed to Walter J Stark.

26 records · Page 2Linked to original sources

Gene expression in donor corneal endothelium.

OBJECTIVE: To report gene expression profiles of normal human corneal endothelium with microarray analysis and serial analysis of gene expression (SAGE). METHODS: Corneal endothelium was removed from normal human corneas obtained from eye banks. Total RNA was isolated and SAGE analysis was performed. The same RNA source was used to construct a complementary DNA library that was hybridized to microarrays containing 12 558 transcripts. RESULTS: A total of 9530 SAGE tags were sequenced, representing 4724 unique tags. Microarray analysis identified 542 distinct transcripts. A database of human corneal endothelial gene expression was compiled. Of the SAGE tags, 1720 matched known genes, 478 corresponded to expressed sequence tags, and 2526 had no known match to public databases. The 5 most abundantly expressed SAGE tags were cytochrome c oxidase subunit II, adenosine triphosphate synthase F(0) subunit 6, carbonic anhydrase XII, 12S ribosomal RNA, and ferritin, heavy polypeptide 1. Thirty-four percent of the transcripts (n = 1616) were specific to the corneal endothelium, when compared with other publicly available SAGE libraries. The 5 most abundant unique tags were keratin 12, angiopoietinlike factor, annexin A8, and 2 tags with no match to the database. Many endothelial pump function enzymes were confirmed, including several plasma membrane Na( +)/K(+) adenosine triphosphatases and a recently reported bicarbonate transporter. CONCLUSIONS: Corneal endothelial gene expression profiles by the current analysis provide an understanding of endothelial metabolism, structure, and function; enable comparisons to diseased endothelium; and provide baseline data that may lead to the discovery of novel endothelial genes.

Aged↗

Surgical management of anterior chamber epithelial cysts.

PURPOSE: To review management strategies for treatment of anterior chamber epithelial cysts. DESIGN: Retrospective review of consecutive interventional case series. METHODS: Charts of patients treated for epithelial ingrowth over a 10-year period by a single surgeon were reviewed. Cases of anterior chamber epithelial cysts were identified and recorded, including details of ocular history, preoperative and postoperative acuity, intraocular pressure (IOP), and ocular examination, type of surgical intervention, and details of further procedures performed. RESULTS: Seven eyes with epithelial cysts were identified. Patient age ranged from 1.5 to 53 years at presentation. Four patients were children. In four eyes, cysts were secondary to trauma, one case was presumably congenital, one case developed after corneal perforation in an eye with Terrien's marginal degeneration, and one case developed after penetrating keratoplasty (PK). Three eyes were treated with vitrectomy, en bloc resection of the cyst and associated tissue, fluid-air exchange and cryotherapy. The last four eyes were treated with a new conservative strategy of cyst aspiration (three cases) or local excision (one keratin "pearl" cyst), and endolaser photocoagulation of the collapsed cyst wall/base. All epithelial tissue was successfully eradicated by clinical criteria; one case required repeat excision (follow-up, 9 to 78 months, mean 45). Two eyes required later surgery for elevated IOP, two for cataract extraction and one for repeat PK. Final visual acuity ranged from 20/20 to hand motions, depending on associated ocular damage. Best-corrected visual results were obtained in the more conservatively managed eyes. CONCLUSIONS: Anterior chamber epithelial cysts can be managed conservatively in selected cases with good results. This strategy may be particularly useful in children's eyes, where preservation of the lens, iris, and other structures may facilitate amblyopia management.

Adult↗

Combined phacoemulsification, intraocular lens implantation, and vitrectomy for eyes with coexisting cataract and vitreoretinal pathology.

PURPOSE: To report the preoperative, intraoperative, and postoperative outcomes of combining phacoemulsification and posterior chamber intraocular lens (IOL) implantation with pars plana vitrectomy in eyes with significant cataract and coexisting vitreoretinal pathology. DESIGN: Retrospective, consecutive, interventional case series. METHODS: Charts of patients undergoing combined procedures at the Wilmer Ophthalmologic Institute between March 1995 and May 2000 were reviewed. RESULTS: In all, 122 eyes of 111 patients were identified. Patient ages ranged from 27 to 89 years (mean 65). Forty-three eyes had diabetic retinopathy; 11 had undergone vitrectomy previously. Macular pathology (hole, membrane, choridal neovascularization) was present in 69 eyes. The most common indications for surgery were diabetic vitreous hemorrhage, macular hole, epiretinal membrane, and retinal detachment. In all cases, phacoemulsification and IOL implantation were performed before vitreoretinal surgery. Preoperative vision ranged from 20/30 to light perception and postoperative vision ranged from 20/20 to no light perception. In 105 patients vision improved, in 7 there was no change, and in 10 vision decreased. Postoperative complications included opacification of the posterior capsule, increased intraocular pressure, corneal epithelial defects, vitreous hemorrhage, retinal detachment and iris capture by the IOL. CONCLUSIONS: Combined surgery is a reasonable alternative in selected patients. Techniques that may simplify surgery and reduce complications include: careful, limited, curvilinear capsulorhexis; in-the-bag placement of IOLs; use of IOLs with larger optics; suturing of cataract wounds before vitrectomy; use of miotics and avoidance of long-acting dilating drops in patients with intravitreal gas; and use of wide-field viewing systems.

Adult↗

Long-term outcomes of combined penetrating keratoplasty with iris-sutured intraocular lens implantation.

PURPOSE: To evaluate the long-term outcomes of combined penetrating keratoplasty with iris-sutured posterior chamber intraocular lens implantation. PARTICIPANTS: Patients (264 eyes) with aphakic and pseudophakic bullous keratopathy. DESIGN: Retrospective case series. INTERVENTION: Penetrating keratoplasty combined with implantation of an iris-sutured posterior chamber intraocular lens performed by a single surgeon. METHODS: Data were gathered from the institutional database during a period of 10 years (1989-1999) and analyzed using customized software. MAIN OUTCOME MEASURES: Graft survival rate, visual acuity, and intraoperative and postoperative complications. RESULTS: Two-hundred fifty-two consecutive patients (264 eyes) were operated. Graft survival rates were 95% at 1 year, 89% at 2 years, and 81% at 5 years and were comparable to the results of previous corneal transplant studies. Among 180 patients (191 eyes) with a follow-up of at least 2 years (range, 2-11 years; mean, 5 years), the visual acuity at final follow-up visit, compared with preoperative visual acuity was improved in 72% of eyes (mean preoperative visual acuity, 20/250; mean postoperative visual acuity, 20/60). No intraoperative complications were encountered. CONCLUSIONS: Combined penetrating keratoplasty with iris-sutured posterior chamber intraocular lens implantation offers significant vision benefits in this patient group.

Adolescent↗

Serial analysis of gene expression in the corneal endothelium of Fuchs' dystrophy.

PURPOSE: To compare the gene expression profiles of normal human corneal endothelium with Fuchs' corneal endothelium, by using serial analysis of gene expression (SAGE). METHODS: Three pairs of normal human corneas were obtained from eye banks. Thirteen bisected Fuchs' corneal buttons were processed at the time of corneal transplantation. The endothelia of normal and Fuchs'-affected corneas were stripped, and total RNA was isolated. Serial analysis of gene expression (SAGE) was performed to identify and quantify gene transcripts. Genes over- and underexpressed by Fuchs' endothelium were limited to P < 0.01 by the method of Audic and Claverie. RESULTS: A total of 19,136 tags were identified with 9,530 from normal and 9,606 from Fuchs' endothelium. The expression of 18 transcripts was upregulated, and 36 transcripts were downregulated in Fuchs' endothelium compared with normal tissue. Upregulated transcripts included serum amyloid A1 and A2, metallothionein, and apolipoprotein D. Of the downregulated transcripts, 26 matched known genes, 3 matched expressed sequence tags (ESTs), and 7 were unknown to current databases. One downregulated transcript involved a newly reported bicarbonate transporter. Decreased transcripts related to antioxidants and proteins conferring protection against toxic stress were noted in Fuchs' versus normal endothelium including nuclear ferritin, glutathione S-transferase-pi, and heat shock 70-kDa protein. Nine different SAGE tags matching mitochondrial sequences accounted for 25% of the ESTs that were decreased in Fuchs' endothelium. CONCLUSIONS: SAGE analysis comparing normal to Fuchs' endothelium demonstrates diminished expression of mitochondrial, pump function, and antiapoptotic cell defense genes.

Aged↗

Endothelial dystrophy, iris hypoplasia, congenital cataract, and stromal thinning (edict) syndrome maps to chromosome 15q22.1-q25.3.

PURPOSE: To localize a gene causing a newly described autosomal dominant anterior segment dysgenesis characterized by corneal endothelial dystrophy, iris hypoplasia, congenital cataracts, and corneal stromal thinning (EDICT syndrome). DESIGN: Experimental study. METHODS: A set of microsatellite markers spanning the 22 human autosomes was used to perform linkage analysis on affected and unaffected individuals within a single family. RESULTS: Linkage analysis of the anterior segment dysgenesis endothelial dystrophy, iris hypoplasia, congenital cataract, and stromal thinning (EDICT) syndrome in this family revealed a logarithm of the odds (LOD) score of 2.71 on chromosome 15q22.1-25.3 between markers D15993 and D15S202. These results suggest a gene for EDICT syndrome lies in this chromosomal region. CONCLUSIONS: A LOD score of 2.71 suggests a novel locus associated with the newly described EDICT syndrome lies in a region of chromosome 15 between markers D15S993 and D15S202. Identification of the disease-causing gene in this region may yield insights into a broad range of disorders affecting the corneal stroma, endothelium, iris, and lens.

Adolescent↗

Surgical approaches to the management of epithelial cysts.

PURPOSE: The purpose of this study was to review management strategies for treatment of epithelial cysts. STUDY DESIGN: Retrospective consecutive interventional case series. METHODS: Charts of patients treated for epithelial ingrowth over a 10-year period by a single surgeon (J.A.H.) were reviewed. Cases of epithelial cysts were identified and the following data were recorded: details of ocular history, preoperative and postoperative visual acuity, intraocular pressure (IOP), ocular examination findings, type of surgical intervention, and details of subsequent procedures performed. RESULTS: Seven eyes with epithelial cysts were identified. Patients ranged in age from 1 1/2 years to 53 years at presentation. Three patients were children. Four cysts were due to trauma, one was presumably congenital, one developed after corneal perforation in an eye with Terrien's marginal degeneration, and one developed after penetrating keratoplasty. Three patients were treated with vitrectomy, en bloc resection of the cyst and associated tissue, fluid-air exchange, and cryotherapy. Four patients were treated with conservative strategy consisting of cyst aspiration (three cases) or local excision (one "keratin pearl" cyst) and endolaser photocoagulation of the collapsed cyst wall or base. In all cases, the epithelial tissue was successfully eradicated; one case required a second excision (follow-up, 9 months to 78 months; mean, 45 months). Two eyes required subsequent surgery for elevated IOP, two for cataract extraction, and one for a second penetrating keratoplasty. Final visual acuity ranged from 20/20 to hand motions, depending on associated ocular damage. Best visual results were obtained in the more conservatively managed eyes. CONCLUSION: Epithelial cysts can be managed conservatively in selected patients with good results. This strategy may be particularly useful in children, in whom preservation of the lens, iris, and other structures may facilitate amblyopia management.

Adult↗