Biomedical subjects

C H Low

Publications and source records attributed to C H Low.

At least 37 records · Page 2Linked to original sources

PubMed1997

Perforated leiomyosarcoma of Meckel's diverticulum.

Two cases of perforated leiomyosarcoma of Meckel's diverticulum are presented. There are only 59 cases reported in current literature, including 4 perforations. Although the condition is rare, leiomyosarcoma is the commonest tumour of Meckel's diverticulum. Its clinical presentation include abdominal pain, intestinal bleeding, abdominal mass, intestinal obstruction and less commonly, acute perforations. Both our cases presented with perforations which is unusual. Despite this late presentations both were resectable and both had no distant or local metastasis. One of our patients was 89 years old at presentation and has been disease-free 3 years after resection. The other patient was 69 years old and has also been disease-free.

Aged↗

PubMed1996

Analysis of photorefractive keratectomy patients who have not had PRK in their second eye.

BACKGROUND AND OBJECTIVE: Excimer laser photorefractive keratectomy (PRK) is performed at the Singapore National Eye Centre (SNEC) with a minimum period of 3 months between first and second eye treatment. During this period, iatrogenic anisometropia may occur, which can lead to significant visual disability. We analyzed the reasons why some patients delayed or did not receive PRK treatment to their second eye. The reasons for originally electing PRK, and the expectations these patients had, were also studied. PATIENTS AND METHODS: Between January 1992 and September 1993, 341 patients underwent PRK at SNEC. Of these, 86 (25.2%) did not receive PRK to their fellow eye within 1 year of follow-up and were recruited into the study. Data were collected retrospectively using a standardized questionnaire, and objective clinical data were obtained from the case records. Sixty-eight patients (79%) responded. RESULTS: Fifty-one patients (14.9%) had not undergone PRK at the conclusion of the study (mean follow-up = 31 months). Of these, 36 were due to dissatisfaction with the results of the procedure. Symptoms relating to hypermetropia (15 patients) and symptoms of glare and halos were the main reasons which discouraged patients from receiving PRK in their fellow eye. Seventeen of the 51 patients (33.3%) who did not have PRK performed in the second eye were overcorrected to hypermetropia, as opposed to 9 out of 255 patients (3.5%) who had PRK in the second eye (P < 0.001, chi-square test). Seventy-five percent of the patients who did not undergo PRK in the second eye expected postlaser unaided vision to be equal to prelaser best corrected vision; however, only 23% of these patients achieved this. CONCLUSION: Hypermetropia, glare and halos are significant causes of patient dissatisfaction after PRK. Patients who request PRK should be advised against harboring unrealistically high expectations for the procedure.

Adult↗

PubMed1996

Case report--ocular rosacea.

Rosacea is an uncommon disease of the eye and facial skin. Ocular rosacea is often undiagnosed by the ophthalmologist especially when skin manifestations are not evident yet. Early diagnosis and treatment is important to decrease morbidity of this potentially blinding disease. A case of ocular rosacea in a 14-year-old Chinese girl is reported. Our patient presented with chronic non-specific keratoconjunctivitis. Only much later did the characteristic corneal and facial skin lesions appear. She responded to guttae prednisolone, oral and guttae tetracycline. This case illustrates the difficulty of early diagnosis when ocular manifestations precede those of the skin. We believe this is the first case of ocular rosacea reported in Singapore.

Adolescent↗

PubMed1996

Problems of refraction after photorefractive keratectomy.

BACKGROUND: Excimer laser photorefractive keratectomy (PRK) is a refractive procedure to correct myopia that is gaining worldwide acceptance. PRK has been performed as an open-ended clinical trial since January 1992, and specific problems have been encountered in refracting PRK patients. METHODS: A review of all cases of PRK performed with at least 1-year follow-up was conducted. Nine hundred and seventy-one eyes with myopia ranging from -2.00 to -15.00 diopters had preoperative manifest and cycloplegic refraction, and postoperative refraction at 3 months after treatment. RESULTS: Refractive difficulty due to degradation of the retinoscopic reflex was encountered in patients who developed moderate to severe haze (seven eyes). Small ablation zones (5 mm) and decentered ablations also contributed to confusion in interpretation of the retinoscopic reflex. In addition, excessive accommodation, profound early myopic and hypermetropic shifts, postoperative irregular astigmatism and inaccurate autorefractometer readings contributed to difficulty in refraction. CONCLUSIONS: Laser ablation of the central cornea produces alterations in optical homogeneity of the cornea that may cause significant refractive difficulties. Refracting PRK patients requires careful and consistent refraction by an experienced refractionist, both before and after laser treatment.

Accommodation, Ocular↗

PubMed1995

Ureteric colic: value of initial investigations and the outcome.

During a one-year period (from April 1992 to April 1993), 294 patients with the complaint of ureteric colic seen at the Emergency Department of Tan Tock Seng Hospital were investigated with a plain X-ray of the kidney, ureter and bladder (KUB), urinary analysis (urine FEME) and subsequently intravenous urogram (IVU) at the outpatient clinic. The results showed that majority (73%) of the patients were male. Sixty percent of the cohort were in the age group 30-50 years. After evaluation, it was found that only 114 (39%) of the patients with ureteric colic had abnormal IVU. Among these patients, 99 were diagnosed to have calculus disease, 12 with urothelial tumours, 1 with renal cyst and 2 had no pathology detected. Nevertheless most (72%) of the patients did not require intervention. In addition, it was noted that if the KUB or urine FEME was positive, the chances that a urological pathology was present were 72% and 91% respectively. However, if both of them were negative, the chance that a pathology would not be present was 93%. This suggests that patient selection is very essential to avoid unnecessary investigations.

Adolescent↗

PubMed1995

Primary hyperparathyroidism: a case with severe skeletal manifestations.

Over the years, patients with primary hyperparathyroidism are often asymptomatic and diagnosis is suspected on the incidental finding of hypercalcaemia. We report a patient, a middle-aged man from northern Sumatra, with a florid but uncommon presentation of severe bone pains and bilateral femoral neck fractures. He was found to have a solitary parathyroid adenoma which was successfully removed surgically. Postoperatively, the patient had severe symptomatic hypocalcaemia that required aggressive replacement therapy with calcium, magnesium and active vitamin D. He was well clinically and had significant improvement of biochemical indices on follow-up at 3 months. This report is followed by a review on the management of this condition.

Adenoma↗

PubMed1994

Evaluation of non-surgical treatment of benign oesophageal stricture.

Benign oesophageal stricture is a disabling problem associated with oesophageal surgery, injection sclerotherapy and patients with reflux problems. Fortunately, mechanical dilatation has emerged as an effective treatment of choice. In recent years, balloon dilatation appears to have gained popularity because of its efficacy and safety. This study of 43 patients compares manual dilatation with balloon dilatation. Twenty-one patients underwent manual dilatation with either Eder-Puestow or Gum Elastic dilators. There were 4 failures which were then treated successfully with balloon dilatation. Two other patients developed perforation and needed emergency surgery. Nine patients required 3 or more graduated dilatations within one month. Another group of 22 patients were treated successfully by balloon dilatation without any complications. Ten patients developed recurrent dysphagia and needed another repeat dilatation after an interval averaging 4.5 months. The results show quite conclusively that balloon dilatation is superior to manual dilatation.

Catheterization↗

PubMed1994

Emergency surgery for bleeding oesophageal varices.

PURPOSE OF STUDY--This case-series reviews patients who underwent emergency transgastric ligation or oesophageal transection for uncontrolled bleeding oesophageal varices despite initial conservative therapy with vasoactive drugs, balloon tamponade and injection sclerotherapy. The study seeks to identify factors determining outcome of surgery and the problems of transection surgery following endoscopic sclerotherapy. SELECTION OF STUDY SUBJECTS--One hundred and ninety-eight patients (median age 54.6 years) were treated for bleeding varices between 1981 and 1991. Of these, 36 (18%) required emergency surgery and they formed the cohort under study. OBSERVATIONAL METHODS AND MAIN FINDINGS--Twenty-three patients underwent transabdominal oesophageal devascularisation and oesophageal transection while 13 had transgastric ligation. Nine patients were graded Child-Pugh's A, 20 Child-Pugh's B and 7 Child-Pugh's C-mortality was 11%, 25% and 100% respectively. Of all the risk factors, the Child-Pugh's grade was the single most important factor determining outcome (Chi-square test; 2 degrees of freedom, p < 0.0005). The data also showed that patients who were transfused less than 3 litres of blood had a mortality of 18% compared to 55% for those requiring 3 or more liters (Fisher's exact test p = 0.0155). There was no difference in mortality between transgastric ligation and oesophageal transection when patients were evaluated according to the Child-Pugh's grade. The results indicate that oesophageal transection is to be recommended for better control of bleeding (0% vs 23% post procedure) but conversely is associated with higher anastomotic leakage rate (8.7% vs 0%). PRINCIPAL CONCLUSIONS--We conclude that the decision to operate on bleeding variceal patients should be made early as procrastination is detrimental to their surgical outcome. In view of the extremely poor results with Child-Pugh's C patients, emergency surgery is best offered to the Child's A and B cases.

Adolescent↗

PubMed1994

Gastric carcinoid: a rare form of gastrointestinal carcinoids. A report on three cases.

The stomach is an uncommon site for carcinoid tumors, the incidence of which is about 2% of all carcinoids. During a five-year period, from 1988 to 1992, three patients with gastric carcinoid tumors were diagnosed at the Tan Tock Seng Hospital, Singapore. Their ages ranged from 59 to 68 years, and all were male. Two patients were referred for investigation of anemia, and one patient presented with massive hematemesis and an advanced ulcerated tumor requiring emergency total gastrectomy. Of the other two patients, one had pernicious anemia with multiple carcinoid polyps, and the other had sessile carcinoid nodules. None of the patients had carcinoid syndrome. Two patients underwent gastrectomy, while the patient with polyps had an endoscopic polypectomy. Follow-up ranged from one to three years. Two patients remained well, but the patient who presented with an advanced tumor with serosal invasion and nodal involvement had hepatic recurrence and died two years after the diagnosis of recurrence.

Aged↗

PubMed1993

Three year results of radial keratotomy surgery at the National University Hospital, Singapore.

This paper presents the three year results of radial keratotomy (RK) surgery on 51 of the first 59 consecutive eyes at the National University Hospital in Singapore. Before surgery, uncorrected visual acuity was worse than 6/24 in all eyes with 33.3% worse than 6/60. The average pre-operative spherical equivalent (SE) was -4.56 Dioptres(D). Three years after surgery the mean SE was -0.66D, a change of 3.9D; and 72.5% of eyes were within 1D of emmetropia. 70.6% had uncorrected visual acuity of at least 6/12 with no eyes having worse than 6/60 visual acuity. Analysis based on levels of pre-operative myopia showed that the best visual and refractive results were obtained in patients with SE of -6D or less. None of the patients were troubled by complications such as glare, fluctuating vision, irritation and discomfort three years after surgery. Our results indicate that RK surgery is safe and effective through the three years and more following surgery.

Adult↗

PubMed1993

Excimer laser photorefractive keratectomy in Singapore--a new treatment modality for myopia.

BACKGROUND: Myopia is a national epidemic in Singapore. Photorefractive Keratectomy (PRK) for the treatment of myopia using the Argon Fluoride Excimer Laser commenced in January 1992 at the Singapore National Eye Centre. METHODS: An open, prospective, non randomised clinical trial to assess the efficacy, predictability, stability, and safety of PRK for the correction of myopia between -2.0 to -6.0 dioptres. RESULTS: One hundred and fifty-five eyes of one hundred and thirty-five patients underwent PRK between January and September 1992, of which thirty-one had completed at least six months of follow-up. Twenty-nine of the thirty-one patients (93.5%) achieved an unaided visual acuity of at least 6/12. Twenty-six patients (83.9%) were within 1 dioptre of emmetropia. There was an initial over-correction in all patients which regressed to a plateau at around three or four months. Corneal haze did not pose a significant problem. Three patients had ocular hypertension, and another developed a mild allergic reaction to the antibiotic-steroid ointment. CONCLUSIONS: Excimer Laser Photorefractive Keratectomy is a very effective, fairly predictable, stable and safe surgical method for the treatment of myopia.

Adult↗

PubMed1992

Relative risks of complications in giant and nongiant gastric ulcers.

There are two divergent views regarding giant gastric ulcers. Traditionally, they have been regarded as a virulent disease prone to massive hemorrhage, intractability, and perforation. Recently, an entirely opposing viewpoint has developed that considers them no different from ordinary gastric ulcers. In this study between 1984 and 1989, 62 patients with giant ulcers (greater than or equal to 3 cm) were compared with 476 benign gastric ulcer patients to evaluate their relative risks of ulcer complications. The results showed that giant ulcers are more prone to severe hemorrhage (44% versus 27%; chi 2 test: p less than 0.009) but not more prone to free perforation. Penetration into contiguous organs occurred more frequently with giant gastric ulcers (45% versus 10%; chi 2 test: p less than 0.0001). The risk of the presence of microscopic malignancy in the macroscopically benign-looking giant ulcer is significantly greater than in the nongiant type (13% versus 3%; Fisher's exact test: p = 0.0013). The data showed that patients with giant gastric ulcers are more at risk for the development of life-threatening complications and, hence, more likely to require surgery.

Humans↗

PubMed1992

Breast carcinoma-in-situ: an emerging problem in Singapore.

Breast carcinoma-in-situ constitutes 4.1% of 707 breast cancers diagnosed between 1988 and 1990. Among these 30 patients, intraductal carcinoma-in-situ (DCIS) outnumbers lobular carcinoma-in-situ (LCIS) by 9-fold. They are mostly symptomatic - 87% present as breast lumps and/or nipple discharge, with 52% of lumps exceeding 2cm size. Three patients were detected by screening mammography and it is expected that more breast carcinoma-in-situ will be detected through mammographic screening. Two-thirds of the patients had mastectomy while the rest had lesser procedures. The different surgical procedures and adjuvant therapy instituted for the patients are reflections of the differing opinions regarding optimum therapy for carcinoma-in-situ and the differing rationale for DCIS and LCIS lesions.

Adult↗

PubMed1992

Computed tomography for oesophageal carcinoma: its value to the surgeon.

Between January 1988 and June 1991, 75 patients with carcinoma of the oesophagus or gastro-oesophageal junction were evaluated by computed tomography (CT). Fifty of these patients underwent operation, allowing 48 cases to have a detailed surgical and pathological verification of CT features. For thoracic oesophageal tumours the accuracy of CT was 59% for fat plane status, 86% for aortic contact, 81% for tracheobronchial tree compression and 66% for direct local invasion. CT was 69% accurate for identifying lymph nodes, of which only 38% contained metastatic deposits. For gastro-oesophageal junction tumours, CT was 74% accurate for fat plane status and 90% accurate for direct local invasion. Accuracy for detecting lymph node involvement was 63%, metastatic tumour being present in 91% of these nodes. By pathological staging, only 15% of all resections could be considered potentially curative. The value of CT was found to be in predicting a palliative or curative resection, and in warning the surgeon about possible infiltration of specific mediastinal or abdominal structures that would be encountered during operative dissection.

Adult↗

PubMed1991

Diaphragmatic injuries: why are they overlooked?

Twenty-one cases of diaphragmatic tears (11 blunt and ten penetrating injuries) were reviewed retrospectively. Left-sided diaphragmatic ruptures predominated except for two patients with penetrating injuries and one patient with bilateral tears following blunt trauma. Significant associated injuries (injury severity score greater than 16) were present in 76% of cases: the most common being intra-abdominal visceral injuries of the stomach, spleen and liver. Initial hypotension (systolic pressure less than 100 mmHg) was present in seven patients and respiratory distress (rate greater than 30 per min and/or Pa,O2 less than 70 mmHg) was seen in eight cases. Correct preoperative diagnosis was made in six cases while 12 were only detected during operation. The other three cases were diagnosed late. A variety of reasons accounts for the tendency to overlook diaphragmatic injuries in trauma victims. First, it is an uncommon condition presenting to an unsuspecting clinician. Second, the paucity of pathognomonic clinical signs makes for a difficult diagnosis. Third, the diverting attention of life-threatening visceral injuries accounts for failure to identify patients with the few available clinical and radiological features.

Adolescent↗

PubMed1990

Spontaneous hematic cysts of the orbit presenting with acute proptosis. A report of three cases.

Three cases of spontaneous hematic cyst of the orbit are described. All cases presented with acute onset of proptosis, conjunctival chemosis, choroidal folds, restricted ocular movement, and optic nerve compression syndrome with very poor vision. A computed tomography scan demonstrated a cystic lesion situated in the upper part of the orbit. Exploration revealed a cyst containing chocolate-colored fluid. Visual recovery was complete in two of three cases. There was no definite history of trauma in all three cases. Chronic hematic cysts have been described recently, but cases with acute onset such as ours have not to our knowledge been described clearly.

Acute Disease↗

PubMed1990

Necrotising fasciitis in leukaemic children.

This is a report of necrotising subcutaneous infection in the perineum of three young girls with acute lymphoblastic leukaemia (ALL). This occurred during induction therapy when they were granulocytopenic. Pseudomonas aeroginosa was isolated from both blood and affected sites. With aggressive chemotherapy and extensive surgical debridement, two patients were salvaged but one perished from the septicaemia. Necrotizing Fasciitis is an uncommon progressive infection of the subcutaneous tissue. It occurs more frequently in adults following surgery or trauma and rarely arises spontaneously. In the paediatric literature, reports are few and mainly in healthy children occurring post-operatively. There was only one case of this occurring in a boy with Aplastic anaemia. Early recognition and aggressive therapy helps to improve the morbidity and mortality of this devastating condition.

Bacterial Infections↗

PubMed1989

Early gastric cancer in Singapore.

A study was carried out on 41 cases of early gastric cancer over a five year period (1983-1987) based on resected stomach specimens. Males (29) outnumbered females (12) by 2.4:1. Mean age was 63 years (Range 30-80 years), and there was an overwhelming Chinese preponderance (40, 97.6%). The indications for endoscopy were: dyspepsia (24, 58.5%), gastro-intestinal bleeding (14, 34.1%) and follow up of megaloblastic anaemia (3, 7.4%). The diagnosis of malignancy was unsuspected at endoscopy in 38 patients and the commonest finding was a chronic ulcer (35, 85.4%). Most of the lesions were located in the body (24, 58.5%) and along the lesser curvature (36, 87.8%). Depressed lesions (Type III and combined IIc + III) were the commonest macroscopic lesions. Intestinal type carcinoma was the commonest microscopic type (34, 82.9%). Submucosal infiltration was present in 19 (47.3%) and lymph node metastases in 4 (9.8%). There was only one death from carcinoma of the stomach (mortality 2.4%).

Adenocarcinoma↗