Biomedical subjects

D T Tan

Publications and source records attributed to D T Tan.

At least 37 records · Page 2Linked to original sources

PubMed2000

Suppression of TGF-beta signaling in both normal conjunctival fibroblasts and pterygial body fibroblasts by amniotic membrane.

PURPOSE: When used as an alternative substrate following bare sclera removal of pterygium and other ocular surface diseases, amniotic membrane transplantation can reduce scarring on the reconstructed conjunctival surface. This study was carried out to determine if the amniotic membrane (AM) suppresses the expression of the TGFb signaling system in cultured normal conjunctival (HCF) and pterygial body fibroblasts (PBF). METHODS: HCF and PBF were cultured on AM and plastic wells in serum-containing and serum-free DMEM with or without TGF-beta1. Total RNA was extracted and subjected to Northern hybridization with probes of TGF-beta1, b2 and b3; TGF-beta receptors (TGF- beta R) type I, II and III; a-smooth muscle actin (alpha-SM), b1-integrin, CD44, fibroblast growth factor receptor 1 (FGF-R1/ flg) and platelet-derived growth factor receptor b (PDGFR-beta); and GAPDH as a loading control. MTT assay was used for cell proliferation. RESULTS: Amniotic membrane markedly suppressed the transcript expression of TGF-beta2, b3 and all three types of TGF-beta receptors by both fibroblasts as compared to their cultures on plastic surface. In addition, expression of CD44 transcript was also markedly suppressed while that of b1 integrin, a-SM actin, and FGFR1/flg was mildly suppressed. In contrast, expression of TGF-beta1 and PDGFR-beta remained largely unchanged. The cell proliferation of HCF and PBF grown on AM was also significantly suppressed. CONCLUSIONS: Amniotic membrane matrix uniquely suppresses TGF- beta signaling in both types of fibroblasts. It may also suppress signaling via CD44, b1 integrin and FGFR1/flg. As a result, the phenotype may become less mitogenic, contractile and fibrogenic. These data support in part why amniotic membrane transplantation has an anti-scarring effect for conjunctival surface reconstruction.

Actins↗

PubMed2000

Flow cytometry measurements of DNA content in primary and recurrent pterygia.

PURPOSE: To evaluate DNA content and cellular proliferation rates in primary and recurrent pterygia. METHODS: Matched pterygium and superior conjunctiva tissue were obtained in 36 eyes of 36 patients undergoing pterygium excision with conjunctival autografting (24 primary pterygia, 12 recurrent pterygia). Epithelial and fibrovascular layers were separated for analysis. Matched superior conjunctiva obtained at the time of surgery were used as controls. Samples were prepared according to Thompson's method, and flow cytometry was performed with a Becton-Dickinson FACScan. Analysis of histograms and calculations of cell percentages in cell cycle phases were carried out using CellFit software (version 2.0). Mean proliferation indices (MPIs) were compared using the Wilcoxon matched-pair signed-rank test. RESULTS: The MPI of pterygium fibrovascular tissue (13.4) was significantly higher than the MPI of pterygium epithelium (3.1; P = 0.0001). The MPI of pterygium fibrovascular tissue was also significantly higher than that of superior conjunctival fibrovascular tissue (6.0; P = 0.0001). There was no difference in MPI values between pterygium epithelium and superior conjunctival epithelium (3.55; P = 0.12). The MPI of fibrovascular tissue from recurrent pterygium (73.75) was significantly higher than the MPI of fibrovascular tissue from primary pterygium (7.3; P = 0.003). CONCLUSIONS: The finding of high levels of cellular proliferation in the subepithelial fibrovascular layer of pterygium confirms that pterygium is a disorder of excessive cellular proliferation and that the fibrovascular layer is the site of cellular proliferation. Markedly raised levels of cellular proliferation in recurrent pterygium tissue suggest a clinical correlation between fibrovascular tissue upregulation and pterygium recurrence after surgery.

Adult↗

PubMed1999

Amniotic membrane transplantation for symptomatic bullous keratopathy.

OBJECTIVE: To determine whether amniotic membrane transplantation can be used to treat symptomatic bullous keratopathy displaying poor visual potential. METHODS: Amniotic membrane transplantation was performed at 5 centers on 50 consecutive eyes (50 patients) with symptomatic bullous keratopathy and poor visual potential. The underlying causes of bullous keratopathy included aphakia (9 eyes), pseudophakia (19 eyes), failed grafts (9 eyes), and others (13 eyes). RESULTS: During the follow-up period of 33.8 weeks (3-96 weeks) after amniotic membrane transplantation, 43 (90%) of 48 eyes with intolerable pain preoperatively became pain free postoperatively. Among the 5 eyes with residual pain, 3 received repeated amniotic membrane transplantation, 1 required a conjunctival flap for pain relief, and 1 had reduced pain. Epithelial defects in 45 (90%) of 50 eyes created and covered by amniotic membrane healed rapidly within 3 weeks. Only 4 eyes (8%) showed recurrent surface breakdown. Epithelial edema or bullae recurred in a smaller area in 5 eyes (10%) and pseudopterygium developed in 1 eye. CONCLUSION: Amniotic membrane transplantation can be considered as an alternative to conjunctival flaps in alleviating pain, promoting epithelial healing, and preserving cosmetic appearance in patients with symptomatic bullous keratopathy and poor visual potential.

Adult↗

PubMed1999

Conjunctival rotation autograft for pterygium. An alternative to conjunctival autografting.

OBJECTIVE: To determine the safety and efficacy of conjunctival rotation autografting (CRA) as an alternative to conventional conjunctival autograft after pterygium excision. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Consecutive patients seen at the Pterygium Clinic of the Singapore National Eye Centre who were thought to be unsuitable for conventional conjunctival autografting underwent a modified surgical procedure, which the authors describe as CRA. There were 51 rotation autografts performed on 45 eyes of 43 patients. INTERVENTION: In this procedure, the underlying fibrovascular pterygium tissue was removed and the original epithelium (with minimal subepithelial tissue included) replaced over the bare sclera with a 180 degrees rotation. Surgeries were performed by one surgeon (DT) from April 1995 to May 1996. MAIN OUTCOME MEASURE: Pterygium recurrence and complications of CRA were measured. RESULTS: The mean follow-up time was 12 months (range, 2-22 months). There were 46 primary and 5 recurrent pterygia. The indications for CRA were combined cataract and pterygium surgery (39.2%), double pterygia (31.4%), the need to preserve the superior conjunctiva (21.6%), and superior conjunctival scarring (7.8%). There were two recurrences (4% recurrence rate), one occurring at 4 months and the other occurring at 7 months after surgery. No significant complications were encountered. However, 50% of the grafts remained mildly injected for more than 3 months, and some remained injected for up to 13 months after surgery (average of 4 months). Pigmentary changes were also noted in six grafts (12%). CONCLUSION: Conjunctival rotation autografting is a useful technique of conjunctival grafting in cases in which it is not possible or desirable to use the superior conjunctiva as a donor source.

Adult↗

PubMed1999

Randomized clinical trial of a new dexamethasone delivery system (Surodex) for treatment of post-cataract surgery inflammation.

OBJECTIVE: To evaluate the safety of Surodex Drug Delivery System (Oculex Pharmaceuticals, Inc., Sunnyvale, CA) containing dexamethasone 60 micrograms, for use in cataract surgery, and to compare its anti-inflammatory efficacy with conventional dexamethasone 0.1% eyedrops. DESIGN: Randomized, masked, and partially controlled trial. PARTICIPANTS: Sixty eyes of 60 Asian patients undergoing extracapsular cataract extraction with intraocular lens implantation were examined. Of these, 28 eyes of 28 patients served as control eyes. Patients were stratified for age and presence of diabetes mellitus. INTERVENTION: Surodex was inserted in the anterior chamber of 32 eyes at the conclusion of surgery. These eyes received placebo eyedrops four times a day after surgery for 4 weeks. Control eyes received neither Surodex nor a placebo implant but were prescribed conventional 0.1% dexamethasone eyedrops four times a day for 4 weeks. MAIN OUTCOME MEASURES: Anterior chamber cells and flare were clinically graded at the slit lamp. Anterior chamber flare was objectively assessed with the Kowa FM500 Laser Flare Meter (Kowa Co. Ltd, Tokyo, Japan) for up to 3 months after surgery. Intraocular pressure and corneal endothelial specular microscopy with morphometric cell analysis were performed for up to 1 year after surgery. RESULTS: Clinical slit-lamp assessment of anterior chamber flare and cells showed no difference between Surodex-treated eyes and dexamethasone eyedrop-treated eyes. Flare meter readings showed lower flare levels in the Surodex group at all postoperative visits compared with the dexamethasone eyedrop group. Flare reduction in the Surodex group reached statistical significance at days 4, 8, 15, and 30 after surgery. At 3 months, flare was reduced to preoperative levels in the Surodex group but was still raised in the dexamethasone eyedrop group. Five eyes in the dexamethasone eyedrop group required augmentation of steroids and were deemed therapeutic failures as opposed to one eye in the Surodex group. One patient in the dexamethasone eyedrop group developed postoperative open-angle glaucoma with profound visual field loss and optic disc cupping, resulting in hand movements vision. No significant difference in endothelial cell loss was noted between Surodex-inserted eyes and dexamethasone eyedrop-treated eyes for up to 1 year after surgery. CONCLUSIONS: Intraocular placement of a single Surodex is a safe and effective treatment method to reduce intraocular inflammation after cataract surgery. There was no statistical difference in efficacy between Surodex and 0.1% dexamethasone eyedrops in reducing intraocular inflammation, as measured by clinical methods, while Surodex was clearly superior to eyedrops in reducing aqueous flare as objectively assessed with the laser flare meter.

Aged↗

PubMed1999

Postoperative inflammation: extracapsular cataract extraction versus phacoemulsification.

PURPOSE: To quantitatively compare postoperative inflammation after extracapsular cataract extraction (ECCE) with that after phacoemulsification in an Asian population. SETTING: Singapore National Eye Center, Singapore. METHODS: In this prospective, randomized, double-masked clinical trial, patients having cataract surgery were randomized to receive ECCE (n = 16) or phacoemulsification (n = 18). Diabetics were excluded. Two surgeons performed both types of surgery and implanted a 6.0 mm optic intraocular lens. Inflammation was assessed qualitatively by slitlamp grading of cells and flare and quantitatively using the Kowa flare meter. One independent postoperative investigator performed the slitlamp examination and laser flare meter readings. RESULTS: The ECCE and phacoemulsification groups were comparable (P > .05) in age, sex, ethnicity, and preoperative flare levels. The combined slitlamp inflammatory scores (anterior chamber cells and flare) and mean laser flare meter readings showed the ECCE group had significantly higher mean flare measurements than the phacoemulsification group at days 4 (P = .0012), 8 (P = .0013), 15 (P = .0013), 30 (P = .0004), and 60 (P = .0164). Flare levels in the ECCE group returned to preoperative values by the second month; the phacoemulsification group achieved preoperative levels by 1 month. The clinical inflammatory assessment score correlated closely to the flare level readings. CONCLUSION: Phacoemulsification induced less inflammation than ECCE, with the difference most marked in the first month after surgery.

Aged↗

PubMed1999

Lamellar corneal autograft for corneal perforation.

BACKGROUND: Corneal perforation secondary to exteriorization of the haptic foot of the anterior chamber intraocular lens (IOL) is a rare complication in IOL surgery. CASE REPORT: A superior penetrating corneal defect developed in the right eye of a 74-year-old woman associated with exteriorization of the superior haptic of an anterior chamber IOL. METHODS: We describe the technique of repositioning and successful patching of the defect using a lamellar cornea-sclera rotational autograft. CONCLUSIONS: This technique is useful for small perforations when cornea donor tissue is not available.

Aged↗

PubMed1999

Undernournishment and Yersinia enterocolitica enterocolitis alter intestinal contractility in the rabbit: role of smooth muscle contractile protein content.

Previous studies have demonstrated that the longitudinal smooth muscle of rabbits infected with Yersinia enterocolitica and undernourished because of reduced food intake exhibit a significantly reduced ability to develop tension in response to carbachol compared with pair-fed animals, which are uninfected but equivalently undernourished. To determine whether the alteration in smooth muscle contractility results from changes in cell number (hypo- or hyperplasia), or in contractile protein content or isoform distribution, New Zealand White rabbits (600 to 1000 g) were randomly assigned to one of three treatment groups: infected, pair-fed or control. Tissue contractility was measured, morphometric studies were performed and immunoassays were developed for the measurement of total actin, gamma-enteric and alpha-vascular isoactins, and myosin heavy chain. Consistent with what was found in previous reports, the contractility of longitudinal smooth muscle in response to carbachol was found to increase in pair-fed animals and to decrease in Y enterocolitica-infected animals. There was no significant change in the proportional thickness of the ileal longitudinal smooth muscle coat, and the number of cross-sectioned longitudinal smooth muscle cells/mm2 was not significantly different in infected, pair-fed or control tissues. Immunoassay indicated that the proportion of each specific contractile protein, relative to total protein content in the muscularis propria, was unaffected by Y enterocolitica infection or by pair-feeding. Thus, the alterations in intestinal longitudinal smooth muscle function observed after Y enterocolitica infection were concluded not to be associated with tissue hypo- or hyperplasia, or changes in the total content or isoform distribution of contractile proteins in the muscularis propria.

Analysis of Variance↗

PubMed1999

Contact lens wear after photorefractive keratectomy: comparison between rigid gas permeable and soft contact lenses.

PURPOSE: To determine if rigid gas permeable (RGP) or soft contact lenses can be successfully worn after photorefractive keratectomy (PRK) to correct residual refractive errors. METHODS: Patients with residual stable ametropia after PRK were fit with RGP or soft lenses. Manifest refraction, corneal topography, and keratometry were performed, and post-PRK corneal haze was graded during the study visits. Contact lens fit characteristics and comfort were assessed. Lens centration, visual quality, and ocular surface status were graded, and visual acuity with contact lenses was charted. RESULTS: Eighteen patients were recruited for RGP lens fitting. The mean refractive error post-PRK was +0.80 D +/- 2.03 (range: -3.50 to+3.00 D). The mean contact lens power was -3.90 D +/- 2.03 (range: 0 to -7.00 D), and the mean contact lens base curve was 7.88 mm +/-0.16. A significant positive tear film at the site of the central ablation was noted, contributing to excessive minus lens power in all cases. Despite mild to moderate lens instability and de-centration, 14 patients reported excellent visual quality with the lenses, and pre-PRK best-corrected acuity was achieved in all patients. Twenty-five percent (4 of 16) of the patients were able to wear the lenses all day. Eleven patients were recruited for soft contact lens fitting-five from the RGP trial. The mean refractive error post-PRK was -0.64 D +/- 2.01 (range: -3.50 to +1.75D). The mean contact lens power was -0.60 D +/- 2.07 (range: -3.75 to +2.5 D), and the mean contact lens base curve was 8.33 mm +/- 0.42. Eight patients were corrected with lenses to their pre-PRK best-corrected acuity, and nine patients reported excellent visual quality with the lenses. All the patients had excellent lens centration. Thirty-six percent (four of 11) of patients were wearing the lenses all day. CONCLUSIONS: Fitting RGP lenses after PRK results in good visual acuity but may be associated with mild to moderate lens instability and decentration. Soft contact lens fitting also results in good visual acuity. Soft lenses were better tolerated by the subjects in our study because of improved lens centration and stability.

Adult↗

PubMed1999

Excimer laser phototherapeutic keratectomy for recurrent corneal erosions.

The purpose of this paper was to review the Singapore National Eye Centre's (SNEC) experience with excimer laser phototherapeutic keratectomy (PTK) for treating recurrent corneal erosions (RCE). Thirty-five eyes of 32 patients who had PTK between 1992 and 1997 in SNEC were studied retrospectively. There was a history of previous ocular trauma in 15 eyes. Sixteen eyes had anterior corneal dystrophy. All had received conventional therapy without improvement in symptoms. The mean duration of symptoms prior to PTK was 19 months (range 1 to 71 months). PTK was performed with one of two 193 nm excimer lasers (Summit UV200LA, Summit Technology, Waltham, USA or Visx 20/20B, Visx Corp, Santa Clara, USA). An average of 30 laser pulses were delivered to Bowman's membrane after debridement of the corneal epithelium. The mean follow-up time was 12 months (range 0 to 56 months). Among those with adequate length of follow-up, 26/27 eyes (96%) were symptom-free for 3 months, 19/22 eyes (86%) were symptom-free for 6 months and 9/13 eyes (69%) were symptom-free for 1 year. Three eyes had repeat PTK. Mild corneal haze was seen in 3 eyes. No visually threatening complications were encountered. PTK is a safe and effective procedure for RCE refractory to conventional treatment.

Adult↗

PubMed1998

Effect of the prokinetic agent, erythromycin, in the Richardson ground squirrel model of cholesterol gallstone disease.

Impaired gallbladder motility and delayed intestinal transit contribute to cholesterol gallstone formation by impeding the enterohepatic circulation of bile salts and causing gallbladder stasis. The therapeutic value of erythromycin, a prokinetic motilin analog, was evaluated in an animal model of gallstone formation. Eighty ground squirrels were fed either a trace- (control) or a high- (1%) cholesterol diet. Half of each diet group received either erythromycin stearate or placebo orally twice daily for 4 weeks. Biliary lipid secretion and bile salt pool size were determined via common duct cannulation. Gallbladder contractile response to cholecystokinin (CCK) was studied in vitro. Intestinal transit was evaluated in vivo by 51Cr marker. In the placebo-treated group, fed the high- versus the trace-cholesterol diet, bile salt secretion decreased (trace-cholesterol + placebo, 21.0 +/- 1.8 nmol/min/g liver vs. high-cholesterol + placebo, 9.3 +/- 1.4 nmol/min/g liver), cholesterol saturation index (CSI) doubled (trace-cholesterol + placebo, 0.61 +/- 0.06 vs. high-cholesterol + placebo, 1.30 +/- 0.04), nucleation time shortened (trace-cholesterol + placebo, > 21 days vs. high-cholesterol + placebo, 6.4 +/- 1.0 days), cholesterol crystals formed, gallbladder contractility diminished, and intestinal transit was delayed (each P < .05). Erythromycin treatment of animals on the high-cholesterol diet restored gallbladder contractility and intestinal transit to control levels, increased bile salt secretion, reduced the total bile salt pool, lowered the cholesterol saturation of bile, lengthened the nucleation time, and so reduced crystal formation (each P < .05). Erythromycin enhances gallbladder motility and hastens intestinal transit, promoting more rapid enterohepatic cycling of bile salts. This increases bile salt secretion, improves cholesterol solubility, and reduces crystal development.

Animals↗

PubMed1998

High-pressure paint gun injury to the orbit and ocular adnexa.

High-pressure injection injury to the orbit and adnexa is a rare but potentially blinding type of trauma. Few cases of such injury have been reported in the literature. A 27-year-old Indian man accidentally injected paint material from a high-pressure nozzle gun into his left eye. Radiological investigation revealed the presence of paint material in the orbital tissues and the ethmoidal sinuses. The patient underwent two orbital surgeries to remove the paint material. He later developed signs suggestive of limbal stem cell failure and was treated with limbal stem cell autografting. He also has ophthalmoplegia with a compensatory anomalous head posture that was managed conservatively. We report the clinical course and outcome of this unfortunate patient to highlight the complexity of such an injury and the need for a multidisciplinary approach in its management.

Adult↗

PubMed1998

Altered migrating myoelectrical complex in an animal model of cholesterol gallstone disease: the effect of erythromycin.

BACKGROUND: The ground squirrel on a high cholesterol diet exhibits prolonged intestinal transit, a pathogenetic factor in cholesterol gallstone formation. AIMS: To examine the effect of a high cholesterol diet on the characteristics of the migrating myoelectrical complex (MMC) and the potential benefit of erythromycin. METHODS: Twenty four animals received either a trace (controls) or a 1% (high) cholesterol diet. After four weeks, five bipolar jejunal and terminal ileal electrodes were implanted. Seven days later, myoelectric activity was measured in conscious, fasted animals before and after treatment with erythromycin. Biliary lipid composition was assessed. RESULTS: Compared with controls, animals fed the high cholesterol diet exhibited a prolonged MMC cycle period (70 (6) versus 83 (3) minutes; p<0.05), whereas MMC migration velocity and the proportions of the MMC represented by phases I, II, and III were unchanged. Oral erythromycin significantly shortened the MMC cycle period in animals on the control and high cholesterol diet by 59% and 54% respectively, and increased the proportion of the cycle period occupied by phase III of the MMC in both dietary groups. Gall bladder bile became saturated with cholesterol and crystals developed in nine of 12 animals on the high cholesterol diet; controls had none. CONCLUSION: Animals fed a high cholesterol diet had a prolonged MMC cycle period. This, along with diminished gall bladder motility, impairs the enterohepatic cycling of bile salts and reduces their hepatic secretion, contributing to the formation of abnormal bile. Erythromycin initiated more frequent cycling of the MMC. Its therapeutic value in cholesterol gallstone formation warrants further evaluation.

Animals↗

PubMed1998

Anaphylaxis-induced alterations in intestinal motility: role of extrinsic neural pathways.

The roles of mast cells and extrinsic and vagal neural pathways in the anaphylaxis-induced alterations in motility observed at sites remote from antigen exposure were explored. Rats were sensitized to egg albumin (EA) and prepared with 1) electrodes to monitor intestinal myoelectric activity, 2) an isolated intestinal loop, and 3) either intact vagal innervation or a subdiaphragmatic vagotomy. Fasting myoelectric activity was recorded before and after challenge of the jejunum in continuity or the isolated loop with EA or BSA. Intestinal segments and the brain stems were processed for mast cell identification (intestine) or Fos immunoreactivity (brain stem). EA but not BSA challenge of the jejunum or the isolated loop induced altered motility at both sites and diarrhea. Granulated mast cells were significantly reduced at the site local to but not remote from challenge. Vagotomy did not inhibit antigen-induced alterations in motility or diarrhea. The number of Fos-immunoreactive nuclei in vagal sensory or motor nuclei was not significantly altered by vagotomy. Thus antigen challenge of sensitized animals causes mast cell degranulation only at the site of direct challenge but alters motility at sites local and remote from challenge. The remote response requires intact extrinsic but not necessarily vagal neural pathways.

Anaphylaxis↗

PubMed1998

Refractive change following pterygium surgery.

PURPOSE: We conducted a prospective study of patients with primary pterygia to analyze surgically-induced astigmatic changes following pterygium surgery and their relation to pterygium morphology and size. METHODS: One hundred twenty-three eyes of 123 adult patients with primary pterygia were evaluated. Pterygium was graded according to morphology and the extent of corneal encroachment. Manifest refraction was performed preoperatively and at 1, 3, and 6 months postoperatively. Patients underwent either the bare sclera technique of pterygium excision or conjunctival grafting. Surgery was performed by one surgeon. Olsen's method of vector decomposition was used to analyze surgically-induced astigmatism. RESULTS: The mean magnitude of preoperative astigmatism was 0.99 D, with vector decomposition revealing a relative flattening of the cornea in the horizontal meridian. Astigmatism of 1.00 D or more was seen when the pterygium exceeded 3.5 mm beyond the limbus. Postoperatively, a steepening of the cornea in the horizontal meridian was demonstrated, the magnitude of which was related to pterygium size (P = 0.0001). ANOVA testing showed no significant difference (P > 0.05) when pterygia were divided according to morphology. CONCLUSIONS: This study confirms that pterygium excision induces a reversal of pterygium-related corneal flattening. A strong correlation was also found between the horizontal extent of pterygium encroachment and astigmatic change following surgery.

Adult↗

PubMed1997

Effect of pterygium morphology on pterygium recurrence in a controlled trial comparing conjunctival autografting with bare sclera excision.

OBJECTIVES: To compare success rates of conjunctival autografting and bare sclera excision for primary and recurrent pterygium in the tropics and to evaluate risk factors for pterygium recurrence. METHODS: A prospective, controlled clinical trial was performed in which 123 primary and 34 recurrent pterygia, matched for age and pterygium morphology, were randomized in 2 separate studies to receive either bare sclera excision or conjunctival autograft. The surgical procedures were performed by one surgeon and reviewed at 1, 3, 6, and 12 months after surgery by an independent observer. Pterygium morphology was clinically graded as atrophic, intermediate, or fleshy according to an assessment of pterygium translucency. Risk factors were assessed using likelihood ratio tests. Weibull curves were used to estimate recurrence rates allowing for the interval censoring. RESULTS: In the group with primary pterygium (mean follow-up, 15.1 months), 38 (61%) of the 62 cases of bare sclera excision (heretofore referred to as the bare sclera group) had pterygium recur in contrast with 1 (2%) of the 61 cases of conjunctival autograft (heretofore referred to as the conjunctival autograph group) (P<.001, likelihood ratio X2 test). Nontranslucency, or fleshiness of the pterygium, and not age was a significant risk factor for recurrence in the bare sclera group (P<.001, likelihood ratio X2 test). In the group with recurrent pterygium (mean follow-up, 13.2 months), 14 (82%) of the 17 bare sclera group had pterygium recur, while no recurrences occurred among 17 cases in the conjunctival autograft group. Nontranslucency was again a highly significant factor for recurrence (P<.001, likelihood ratio X2 test). CONCLUSIONS: Pterygium recurrence is related to pterygium morphology and fleshiness of the pterygium is a significant risk factor for recurrence if bare sclera excision is performed. Conjunctival autografting for primary and recurrent pterygium is effective in reducing pterygium recurrence compared with bare sclera excision.

Adult↗

PubMed1997

Abnormal expression of the p53 tumor suppressor gene in the conjunctiva of patients with pterygium.

PURPOSE: To determine whether pterygium is a disorder of abnormal growth by examining the expression of the p53 gene in the conjunctiva of patients with pterygium. METHODS: Immunostaining for abnormal expression of p53 was performed using mouse monoclonal antibody to human p53, pAb 240, on six eyes with primary pterygium and two eyes with recurrent pterygium. RESULTS: In three of the eight eyes with pterygium, specimens were positive for abnormal expression in the epithelium of the pterygium and in the superior bulbar conjunctiva. CONCLUSION: Abnormal p53 expression in the epithelium of primary and recurrent pterygium specimens suggests that pterygium is a growth disorder rather than a degeneration.

Antibodies, Monoclonal↗

PubMed1997

Harvesting a lamellar graft from a corneoscleral button: a new technique.

PURPOSE: To describe a new technique for harvesting a lamellar graft from a corneoscleral button in the absence of an artificial anterior chamber. METHODS: Two layers of sterile fine-weave fabric were wrapped tightly around a glass orbital implant. The corneoscleral button was sutured firmly at its scleral rim onto the fabric. The lamellar graft then was dissected in the regular fashion. RESULTS: The lamellar graft was successfully obtained. During the dissection, the donor cornea and its supporting fabric-covered glass ball were easily handled, and there was minimal risk of perforation of the posterior lamella of the donor cornea. CONCLUSION: This simple technique allows a lamellar graft to be easily obtained from a corneoscleral button without specialized and expensive equipment.

Cornea↗