Should we be paying more attention to corneal neovascularization?
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Corneal Neovascularization↗
Biomedical subjects
Alan Sugar
Publications and source records attributed to Alan Sugar.
Corneal reshaping: is it a good alternative to refractive surgery?
PURPOSE OF REVIEW: To review current literature on overnight corneal reshaping and present this mode of vision correction in its current state. RECENT FINDINGS: Overnight corneal reshaping uses specially designed rigid gas-permeable contact lenses. It is effective in temporarily reducing or eliminating low to moderate myopia. This nonsurgical mode of vision correction allows for good unaided vision during waking hours. There are reports of young patients experiencing serious adverse events, particularly bacterial and Acanthamoeba keratitis while using these lenses, although incidence rates are unknown. SUMMARY: Overnight corneal reshaping is an alternative to refractive surgery and must continue to be studied and monitored to establish its safety.
Contact Lenses, Hydrophilic↗
Characterization of human phagocyte-derived chitotriosidase, a component of innate immunity.
Man has been found to produce highly conserved chitinases. The most prominent is the phagocyte-derived chitotriosidase, the plasma levels of which are markedly elevated in some pathological conditions. Here, we report that both polymorphonuclear neutrophils (PMNs) and macrophages (m) are a source of chitotriosidase. The enzyme is located in specific granules of human PMNs and secreted following stimulation with granulocyte macrophage colony-stimulating factor (GM-CSF). In addition, GM-CSF induces expression of chitotriosidase in m that constitutively secrete the enzyme and partly accumulate it in their lysosomes. Studies with recombinant human chitotriosidase revealed that the enzyme targets chitin-containing fungi. These findings are consistent with earlier observations concerning anti-fungal activity of homologous plant chitinases and beneficial effects of GM-CSF administration in individuals suffering from invasive fungal infections. In conclusion, chitotriosidase should be viewed as a component of the innate immunity that may play a role in defence against chitin-containing pathogens and the expression and release of which by human phagocytes is highly regulated.
Cells, Cultured↗
Mutations in TCF8 cause posterior polymorphous corneal dystrophy and ectopic expression of COL4A3 by corneal endothelial cells.
Posterior polymorphous corneal dystrophy (PPCD, also known as PPMD) is a rare disease involving metaplasia and overgrowth of corneal endothelial cells. In patients with PPCD, these cells manifest in an epithelial morphology and gene expression pattern, produce an aberrant basement membrane, and, sometimes, spread over the iris and nearby structures in a way that increases the risk for glaucoma. We previously mapped PPCD to a region (PPCD3) on chromosome 10 containing the gene that encodes the two-handed zinc-finger homeodomain transcription factor TCF8. Here, we report a heterozygous frameshift mutation in TCF8 that segregates with PPCD in the family used to map PPCD3 and four different heterozygous nonsense and frameshift mutations in TCF8 in four other PPCD probands. Family reports of inguinal hernia, hydrocele, and possible bone anomalies in affected individuals suggest that individuals with TCF8 mutations should be examined for nonocular anomalies. We detect transcripts of all three identified PPCD genes (VSX1, COL8A2, and TCF8) in the cornea. We show presence of a complex (core plus secondary) binding site for TCF8 in the promoter of Alport syndrome gene COL4A3, which encodes collagen type IV alpha 3, and we present immunohistochemical evidence of ectopic expression of COL4A3 in corneal endothelium of the proband of the original PPCD3 family. Identification of TCF8 as the PPCD3 gene provides a valuable tool for the study of critical gene regulation events in PPCD pathology and suggests a possible role for TCF8 mutations in altered structure and function of cells lining body cavities other than the anterior chamber of the eye. Thus, this study has identified TCF8 as the gene responsible for approximately half of the cases of PPCD, has implicated TCF8 mutations in developmental abnormalities outside the eye, and has presented the TCF8 regulatory target, COL4A3, as a key, shared molecular component of two different diseases, PPCD and Alport syndrome.
Autoantigens↗
Regulation of eye banking and uses of ocular tissue for transplantation.
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Corneal Transplantation↗
Baseline donor characteristics in the Cornea Donor Study.
PURPOSE: The Cornea Donor Study (CDS) is an ongoing study that is being conducted to determine whether donor age is related to long-term corneal graft survival. Characteristics of the donor population have been evaluated with respect to donor age, endothelial cell density, and death to preservation interval. METHODS: Within the context of a prospective, double-masked, controlled trial, 1101 donor corneas were assigned without regard to donor age. RESULTS: Slit-lamp characteristics of the donor corneas showed little variation with donor age, except for the presence of corneal arcus. As death to preservation time decreased, fewer epithelial abnormalities and a lower frequency of stromal edema and Descemet folds were observed. There was little change in the mean of the endothelial cell density with donor age beyond age 60, despite variation. CONCLUSION: With respect to donor age, there was little difference in either the slit-lamp characteristics or endothelial cell density of the donor corneas. Fewer epithelial abnormalities were observed with shorter death to preservation time.
Adolescent↗
Overnight corneal reshaping versus soft disposable contact lenses: vision-related quality-of-life differences from a randomized clinical trial.
PURPOSE: The purpose of this article is to evaluate patients' visual acuity, symptoms, and perceptions of vision-related quality of life in a randomized crossover clinical trial of overnight corneal reshaping (OCR) and daily wear soft lenses (SCL). METHODS: Qualified subjects were randomly assigned to wear one mode of contact lens for 8 weeks and then, after a washout period, they wore the alternate mode for 8 weeks. On concluding each contact lens wear mode, subjects completed the NEI-RQL42 questionnaire. During the SCL mode, subjects wore lenses during their waking hours. During the OCR mode, subjects wore lenses only while sleeping. Soft lenses were Biomedics 55 2-week disposable lenses. OCR lenses were CRT lenses by Paragon. (Three subjects were fit with custom-designed OCR lenses in Boston XO material, manufactured by Art Optical.) LogMAR acuity was measured and slit lamp evaluation was performed at specified intervals during follow up. After completing both phases of the study, patients chose which mode they preferred. RESULTS: Of 81 enrolled patients, 65 completed both phases and 16 dropped out during the study. Significant differences (p<0.01) favoring SCL wear included better visual acuity and less trouble with glare. Significant differences (p<0.01) favoring OCR wear included less activity limitations, less trouble with symptoms, and less dependence on refractive correction. Of 65 completing both phases, 44 preferred the OCR lenses and 21 preferred the soft lenses. Subjects who preferred the OCR lenses were less myopic and had steeper K readings at baseline, and showed less difference between visual acuity during OCR wear and visual acuity with SCL. CONCLUSION: In subjects with mild myopia who experienced both SCL and OCR, better visual acuity and less glare resulted from SCL wear, whereas activity limitations, symptoms, and dependence on refractive correction were less troublesome with OCR wear. When the study was completed, 67.7% chose OCR lenses worn only while sleeping, whereas 32.3% preferred 2-week disposable soft lenses worn during the day as their preferred correction.
Adult↗
A locus for posterior polymorphous corneal dystrophy (PPCD3) maps to chromosome 10.
Posterior polymorphous corneal dystrophy (PPCD) is an autosomal dominant disorder characterized by corneal endothelial abnormalities, which can lead to blindness due to loss of corneal transparency and sometimes glaucoma. We mapped a new locus responsible for PPCD in a family in which we excluded the previously reported PPCD locus on 20q11, and the region containing COL8A2 on chromosome 1. Results of a 317-marker genome scan provided significant evidence of linkage of PPCD to markers on chromosome 10, with single-point LOD scores of 2.63, 1.63, and 3.19 for markers D10S208 (at (circumflex)theta = 0.03), D10S1780 (at (circumflex)theta = 0.00), and D10S578 (at (circumflex)theta = 0.06). A maximum multi-point LOD score of 4.35 was found at marker D10S1780. Affected family members shared a haplotype in an 8.55 cM critical interval that was bounded by markers D10S213 and D10S578. Our finding of another PPCD locus, PPCD3, on chromosome 10 indicates that PPCD is genetically heterogeneous. Guttae, a common corneal finding sometimes observed along with PPCD, were found among both affected and unaffected members of the proband's sib ship, but were absent in the younger generations of the family. Evaluation of phenotypic differences between family members sharing the same affected haplotype raises questions about whether differences in disease severity, including differences in response to surgical interventions, could be due to genetic background or other factors independent of the PPCD3 locus.
Adult↗
Cataract surgery in patients with nanophthalmos: results and complications.
PURPOSE: To evaluate the results and complications of cataract surgery in patients with nanophthalmos. SETTING: University hospital practice. METHODS: The records of consecutive patients with nanophthalmos who had cataract surgery from 1978 through 2002 were reviewed for ocular diagnoses, corneal diameter, keratometry, axial length, retinal-choroidal-scleral thickness determined by echography, ocular surgeries, visual acuity, and complications. RESULTS: Eight patients (6 women, 2 men) with a mean age of 59 years were reviewed. Four patients were not previously diagnosed with nanophthalmos; increased retinal-choroidal-scleral thickness (mean 2.41 mm) confirmed the diagnosis. Twelve eyes had cataract extraction with posterior chamber intraocular lens (IOL) implantation, 11 by phacoemulsification and 1 by extracapsular cataract extraction, and 4 eyes had lamellar scleral resections. Additional surgeries included glaucoma laser treatment (8 eyes), cyclocryotherapy (2 eyes), trabeculectomy with scleral resection (1 eye), trabeculectomy combined with phacoemulsification (1 eye), and neodymium:YAG laser capsulotomy (4 eyes). No eye lost vision; however, complications included severe iritis, broken IOL haptic with vitreous loss, posterior capsule opacity, choroidal hemorrhage, phthisis, and aqueous misdirection. CONCLUSIONS: Results indicate that echography should be used to assess retinal-choroidal-scleral thickness in eyes that are hyperopic and at risk for narrow-angle glaucoma. Thickening may confirm the diagnosis of nanophthalmos and allow careful preoperative assessment and appropriate operative procedures in these high-risk eyes. With advances in cataract, glaucoma, and uveal effusion treatments, surgical results in patients with nanophthalmos are improving.
Adult↗
Correction of spherical myopia with a single 150-degree intrastromal corneal ring segment.
A 47-year-old woman with an uncorrected visual acuity (UCVA) of 20/70 and a refraction of -1.50 +0.75 x 75 in the right eye had 2 0.25 mm intrastromal corneal ring segments (Intacs) inserted uneventfully through a superior incision. The patient was hyperopic 2 years later with a refraction of +0.50 +0.75 x 25 and was intolerant of spectacles. She also complained of temporal glare. Twenty-seven months after insertion, the temporal ring segment was removed. Four months later, the UCVA was 20/20; with a refraction of plano +0.50 x 35, the visual acuity was 20/15. Topography showed corresponding regular astigmatism, and the patient's glare had resolved. Removal of 1 Intacs segment may be an option in cases of overcorrection after ring insertion for myopia.
Corneal Stroma↗
LASIK for hyperopia, hyperopic astigmatism, and mixed astigmatism: a report by the American Academy of Ophthalmology.
OBJECTIVE: To describe LASIK for hyperopia, hyperopia with astigmatism, and mixed astigmatism and to examine the evidence to answer questions about the safety and efficacy of the procedure. METHODS: A literature search conducted for the years 1968 to 2002 retrieved 118 citations. During review and preparation of this article, an additional 2 articles were included. The panel members selected 36 articles for the panel methodologist to review and rate according to the strength of evidence. A level I rating is assigned to properly conducted, well-designed, randomized clinical trials; a level II rating to well-designed cohort and case-control studies; and a level III rating to case series, case reports, and poorly designed prospective and retrospective studies. RESULTS: This assessment describes 5 nonrandomized interventional trials (level II), 3 nonrandomized comparative trials (level III), and 20 noncomparative case series (level III). Additionally, 6 single-case reports (level III) were included because they reported relevant complications, and 2 theoretical analyses (level III) were also considered. This assessment does not compare studies because many variables such as range of hyperopia, follow-up periods, lasers, microkeratomes, techniques, and surgeon experience have not been controlled. CONCLUSIONS: For low (<3 diopters [D]) to moderate (3-5 D) hyperopia, results from published studies (levels II and III evidence) have shown that LASIK is effective and predictable in achieving very good to excellent uncorrected visual acuity, achieving postoperative refractions within 1 D of emmetropia, and is safe in terms of minimal loss of best-corrected spectacle vision. Although there are fewer data for hyperopic astigmatism, the results available seem to mirror the data for low to moderate hyperopia (levels II and III evidence). The postoperative results for both uncorrected vision and safety are less compelling, as greater amounts of hyperopia are treated (>4 to 5 D). Utilizing hyperopic LASIK for the treatment of consecutive hyperopia and astigmatism is also effective, although the ability to reduce hyperopic astigmatism after radial keratotomy is limited. Although a variety of ablation profiles can be used to treat mixed astigmatism, very good visual results have been reported (levels II and III evidence). Serious adverse complications leading to permanent visual loss are possible but, fortunately, very rare. There are insufficient data to compare one laser system with another or one ablation profile with another.
Academies and Institutes↗
Iris-sutured posterior chamber intraocular lens implantation during penetrating keratoplasty.
PURPOSE: To evaluate the clinical indications and postoperative results of iris-sutured posterior chamber intraocular lens implants performed during penetrating keratoplasty. METHODS: Medical records were retrospectively reviewed for preoperative indications and postoperative results of 342 consecutive patients (366 eyes) who underwent iris suturing of a posterior chamber intraocular lens implant during penetrating keratoplasty over a 9-year period. RESULTS: Mean follow-up was 36 months. The principal indications for corneal transplantation were pseudophakic and aphakic bullous keratopathy. Mean postoperative best spectacle-corrected visual acuity was better than preoperatively at all measured time points (P < 0.0001) and improved from 20/474 preoperatively to 20/85 at 1 year. Nine eyes (7.7%) with known preoperative glaucoma required escalation of therapy by medication or surgery to control the intraocular pressure. Seventy-two eyes (29%) without known preoperative glaucoma required treatment of elevated intraocular pressure. Seventy-nine eyes (28%) without known preoperative cystoid macular edema were additionally diagnosed. Mean endothelial cell counts declined throughout the study time frame. Corneal donor rejection episodes occurred in 36 (9.8%) eyes, with the majority having a single episode. Overall, 27 (7.4%) eyes had known graft failure at last follow-up. Two eyes (0.5%) were enucleated following wound disruption. CONCLUSIONS: These long-term results of iris-sutured posterior chamber intraocular lens implants performed during penetrating keratoplasty suggest acceptable visual acuity, graft survival, and complication rates. They are similar to published retrospective and prospective results of flexible open-loop anterior chamber and transsclerally-sutured posterior chamber intraocular lens implants placed during penetrating keratoplasty.
Adult↗
Overnight corneal reshaping versus soft daily wear: a visual quality of life study (interim results).
PURPOSE: To evaluate patients' perceptions of visual quality of life differences in a crossover study with two different modes of contact lens wear: overnight corneal reshaping (OCR) lenses and daily-wear soft lenses. METHODS: Qualified subjects wore one mode of contact lens for 8 weeks and then completed the National Eye Institute RQL-42 questionnaire. After a washout period, subjects wore the alternate mode for 8 weeks followed by the questionnaire. During soft lens mode, subjects wore lenses during their waking hours. During the overnight corneal reshaping mode, subjects wore lenses only while sleeping. Soft lenses were Biomedics 55 2-week disposable lenses. OCR lenses were Corneal Refractive Therapy (CRT) lenses by Paragon. Subjects were randomly assigned to wear soft contact lenses or OCR lens first. After completing both phases of the study, patients were asked to choose which mode they preferred. RESULTS: Interim results show that of 74 subjects enrolled, 45 have completed both phases; 14 have dropped out of the study; and 15 are still in process. Of the 45 subjects completing both phases, 32 have chosen to continue with the CRT lenses, and 13 have chosen to stay with the soft lenses. Logarithm of the minimum angle of resolution visual acuity was 0.06 (20/20) for soft contact lenses and 0.11 (20/25) for CRT lenses. RQL-42 scoring for overall satisfaction was 81.33 for OCR lenses and 74.67 for soft lenses. CONCLUSIONS: Although overall satisfaction scores and vision were comparable between the two modes, 71% of the subjects elected to stay with CRT lenses. In this study of patients who experienced both modes of lens wear, 71% chose OCR lenses.
Adolescent↗
Clostridium sordellii endophthalmitis after suture removal from a corneal transplant.
PURPOSE: To report a case of endophthalmitis caused by Clostridium sordellii. METHODS: A 33-year-old man sustained a penetrating injury of the right eye that resulted in several ocular surgical procedures including pars plana vitrectomy, scleral buckling, scleral-sutured posterior chamber intraocular lens, and penetrating keratoplasty. More than 4 years after the penetrating injury he presented for examination with pain, photophobia, redness, decreased vision, and floaters in the right eye. Vitreous culture grew Clostridium sordellii. RESULTS: Following intravitreal injection of antibiotics, the patient's vision improved from 3/200 to 20/80 (baseline visual acuity) within 2 days. All signs of inflammation resolved without recurrence. CONCLUSIONS: Clostridium sordellii endophthalmitis may have a more benign course than the fulminant endophthalmitis typically seen with other Clostridium species.
Adult↗
Clinicopathologic correlation and genetic analysis in a case of posterior polymorphous corneal dystrophy.
PURPOSE: To evaluate the clinical history, histopathology, and genetics of posterior polymorphous corneal dystrophy (PPMD) in a woman with a prominent retrocorneal membrane. DESIGN: Observational case report and genetic analysis of her family, UM:139. METHODS: Records were reviewed from a case and associated family members. The diagnosis of PPMD was based on clinical examination, immunohistochemical staining, electron microscopy, and screening of genetic markers from regions previously reported to be associated with PPMD. RESULTS: Over 17 years, the proband with PPMD had 25 ocular procedures performed for glaucoma, cataract, cornea, retina, and postoperative problems. A prominent retrocorneal membrane grew onto the crystalline lens and intraocular lens (IOL). Histopathology revealed stratified epithelial-like cells on iris from an iridectomy and stratified corneal endothelium on a corneal button. Electron microscopy on the cornea revealed microvilli, tonofilaments, and desmosomes consistent with endothelial transformation, which was confirmed by positive anticytokeratin (CK) AE1/AE3 and CAM 5.2 immunoreactivity. Negative immunoreactivity in epithelium and positive in endothelium with anti-CK 7 supported the diagnosis of PPMD rather than epithelial downgrowth. Multiple relatives were affected with PPMD with apparent autosomal dominant inheritance, but surprisingly, the PPMD, congenital hereditary endothelial dystrophy 1 (CHED1) and CHED2 loci on chromosome 20 and the collagen, type VIII, alpha-2 (COL8A2) gene were excluded by linkage and haplotype analyses. CONCLUSIONS: We are unaware of previous PPMD reports describing the unusual feature of a retrocorneal membrane extending onto the crystalline lens and IOL. In addition, this family suggests another PPMD locus.
Biomarkers↗
Corneal decompensation after laser in situ keratomileusis in fuchs' endothelial dystrophy.
PURPOSE: To report corneal decompensation after laser in situ keratomileusis (LASIK) in a patient with Fuchs' endothelial dystrophy. METHODS: Observational case report. RESULTS: A 47-year-old woman with cornea guttata without symptoms or findings of corneal edema had uneventful LASIK for -5.50 -0.50 x 150 in the right eye and -4.00 -1.25 x 170 in the left eye. Postoperatively, she developed corneal edema, with significant loss of best-corrected visual acuity in both eyes. Preoperative corneal thickness was 587 microm in the right eye and 549 microm in the left eye, measured by ultrasound pachymetry. These readings were 550 and 560 microm on day 67 postoperatively. Endothelial cell counts showed means of 1209 and 1661 cells/mm2 in the right and left eyes, respectively. CONCLUSION: Caution is suggested when considering LASIK in eyes with severe cornea guttata.
Cell Count↗
Photorefractive keratectomy for treatment of flap complications in laser in situ keratomileusis.
PURPOSE: To present the results of photorefractive keratectomy (PRK) for treatment of laser in situ keratomileusis (LASIK) flap complications. METHODS: Compilation of case reports through solicitation on Kera-net, an Internet surgery discussion site. RESULTS: PRK was performed on 13 patients from 2 weeks to 6 months after LASIK flap complications. The technique used for the PRK varied. Epithelial removal was performed using no-touch phototherapeutic keratectomy (PTK) in six of the 13 patients and manual debridement in the other seven patients. A dilute solution of 20% ethanol was used to facilitate manual debridement in five of the seven patients. In two of these five patients, the epithelium was replaced as in laser-assisted subepithelial keratomileusis (LASEK). A solution of 0.02% mitomycin C was used after laser ablation to prevent haze formation in three patients. After an average 7 months of follow-up, uncorrected visual acuity was 20/20 in six patients, 20/25 in four patients, and 20/30 in two patients. The visual acuity in one patient was 20/80, purposely left undercorrected for monovision. Best spectacle-corrected visual acuity was 20/20 in 10 of 13 patients. Three patients were 20/25, losing one line of best spectacle-corrected visual acuity. On slit-lamp examination, at last follow-up appointment, stromal haze was graded from trace to none in all patients. CONCLUSIONS: Photorefractive keratectomy is a safe and effective technique for treatment of patients with LASIK flap complications.
Adult↗
Laser in situ keratomileusis for myopia and astigmatism: safety and efficacy: a report by the American Academy of Ophthalmology.
OBJECTIVE: This document describes laser in situ keratomileusis (LASIK) for myopia and astigmatism and examines the evidence to answer key questions about the efficacy and safety of the procedure. METHODS: A literature search conducted for the years 1968 to 2000 retrieved 486 citations and an update search conducted in June 2001 yielded an additional 243 articles. The panel members reviewed 160 of these articles and selected 47 for the panel methodologist to review and rate according to the strength of evidence. A Level I rating is assigned to properly conducted, well-designed, randomized clinical trials; a Level II rating is assigned to well-designed cohort and case-control studies; and a Level III rating is assigned to case series and poorly designed prospective and retrospective studies, including case-control studies. RESULTS: The assessment describes randomized controlled trials published in 1997 or later (Level I evidence) and more recent comparative and noncomparative case series (Level II and Level III evidence), focusing on results for safety and effectiveness. It is difficult to extrapolate results from these studies that are comparable to current practices with the most recent generation lasers because of the rapid evolution of LASIK technology and techniques. It is also difficult to compare studies because of variations in the range of preoperative myopia, follow-up periods, lasers, nomograms, microkeratomes and techniques, the time frame of the study, and the investigators' experience. CONCLUSIONS: For low to moderate myopia, results from studies in the literature have shown that LASIK is effective and predictable in terms of obtaining very good to excellent uncorrected visual acuity and that it is safe in terms of minimal loss of visual acuity. For moderate to high myopia (>6.0 D), the results are more variable, given the wide range of preoperative myopia. The results are similar for treated eyes with mild to moderate degrees of astigmatism (<2.0 D). Serious adverse complications leading to significant permanent visual loss such as infections and corneal ectasia probably occur rarely in LASIK procedures; however, side effects such as dry eyes, night time starbursts, and reduced contrast sensitivity occur relatively frequently. There were insufficient data in prospective, comparative trials to describe the relative advantages and disadvantages of different lasers or nomograms.
Academies and Institutes↗