Imaging appearance of subependymoma: A rare tumor of the cord.

Subependymoma of the cord are rare tumors with very few cases described in the literature. They represent a diagnostic dilemma as far as imaging and histopathology is concerned. They are biologically benign with low proliferative index, hence postoperative prognosis is very good. We present a case of a 42-year-old male patient with an intramedullary Subependymoma located within the central canal of thoracic region cord. On imaging with T1-weighted and T2-weighted sequences it mimicked syringohydromyelia, however, on heavily T2-weighted images the tumor located within the central canal could be delineated. The tumor was excised with complete recovery.

A comparative study of clinico-radiological spectrum of tuberculosis among HIV seropositive and HIV seronegative patients.

BACKGROUND: A study to determine the prevalence of human immunodeficiency virus (HIV) infection among tuberculosis patients and to compare the clinico-radiological spectrum of tuberculosis among HIV seropositive and seronegative patients was carried out in the Department of TB and Chest Diseases, CSM Medical University, Lucknow (Uttar Pradesh), India. METHODS: A total of 1105 radiologically and/or bacteriologically confirmed patients of tuberculosis were screened for HIV infection during the years 1995 to 1997 and from 2000-2001. RESULTS: Out of a total 1105 patients screened, 31(2.8%) were found to be HIV seropositive. Tuberculin positivity was less among HIV seropositive patients as compared to HIV seronegative patients (22.6% vs 76.4%; p < 0.001). There was no statistically significant difference in sputum smear positivity for acid-fast bacilli (AFB) among HIV seropositive and seronegative patients. Among HIV seropositive patients, mid and lower zone involvement, exudative lesions and mediastinal lymphadenopathy was more common as compared to the seronegative patients. CONCLUSION: HIV seropositivity rates among tuberculosis patients was 2.8 percent. The presentation of tuberculosis was more often atypical among these patients.

Intracystic tetracycline therapy for hypofunctioning cystic thyroid nodules.

OBJECTIVES: Hypofunctioning benign cystic thyroid nodules are a common occurrence in iodine deficient region. There are reports of resolution of recurrent thyroid cysts with tetracycline instillation. Hence we conducted a study in 20 patients with hypofunctioning benign cystic thyroid nodules to document response to intracystic instillation of tetracycline as a primary modality of treatment. METHODS: Twenty patients were thoroughly investigated for the presence of malignancy clinically, radiologically and cytologically. One milliliter of tetracycline was instilled under ultrasonographic guidance. Response to therapy was assessed clinically and ultrasonographically at one, three, six and 12 months. RESULTS: Study group comprised of five male and 15 female patients with mean age 30 +/- 8 years. Initial mean volume of nodules was 15 +/- 7 ml (6 to 27 ml), which was decreased to 3 +/- 3 ml at one month, 2 +/- 3 ml at three months, and 1 +/- 2 ml at six months. Maximum number of patients (75%) responded within three months, however two patients required reaspiration and reinstallation of tetracycline. Ultrasonography revealed fibrotic scar as thick wall with internal echodensities in six patients (30%) six month after sclerotherapy. There was high rate of patient satisfaction, as cosmetically tetracycline did not leave any scar, which was unavoidable with surgery. Six patients (30%) reported mild pain after injection, and one patient developed redness at the site of injection. CONCLUSIONS: Intracystic tetracycline sclerotherapy is highly effective as primary mode of treatment in hypofunctioning benign cystic thyroid nodule in selected group of patients not at high risk of malignancy.

Limbal stem cell deficiency: concept, aetiology, clinical presentation, diagnosis and management.

Defects in renewal and repair of ocular surface as a result of limbal stem cell deficiency are now known to cause varying ocular surface morbidity including persistent photophobia, repeated and persistent surface breakdown and overt conjunctivalisation of the cornea. Ocular conditions with abnormalities of ocular surface repair include pterygium, limbal tumours, aniridia, severe scarring following burns, cicatricial pemphigoid and Stevens-Johnson Syndrome, sequelae of mustard gas exposure and Herpes simplex epithelial disease, radiation keratopathy, contact lens induced keratopathy, neuroparalytic keratitis and drug toxicity. Restoring ocular health in these eyes has traditionally been frustrating. An understanding of these intricate cell renewal and maintenance processes has spurred the evolution in recent years of new treatment methods for several blinding diseases of the anterior segment; many more exciting modalities are in the offing. However, there is inadequate awareness among ophthalmologists about the current principles of management of ocular surface disorders. The purpose of this article is to help elucidate the important principles and current treatment methods relevant to ocular surface disorders.

Tonometry in normal and scarred corneas, and in postkeratoplasty eyes: a comparative study of the Goldmann, the ProTon and the Schiotz tonometers.

PURPOSE: Clinical comparison of intraocular pressure (IOP) measured with the Goldmann applanation tonometer (GAT), the ProTon tonometer (PT), and the Schiotz tonometer (ST), in normal eyes, eyes with scarred corneas and postkeratoplasty eyes. MATERIAL AND METHODS: The IOP readings with GAT, PT, and ST were compared in 125 eyes with normal corneas (Group A), 17 eyes with scarred corneas (Group B), and in 21 postkeratoplasty eyes (Group C). The data were statistically analysed at 95% confidence interval; linear regression analysis and paired t-test were done. RESULTS: The mean differences and their standard deviation [SD] between GAT and PT readings, and GAT and ST readings respectively were: [1] in Group A: -0.23 [SD 2.75] mmHg and +0.24 [SD 3.18] mmHg respectively; [2] in Group B: -1.8 [SD 12.67] mmHg and -4.5 [SD 9.95 mmHg; and [3] in Group C: +0.24 [SD 8.72] mmHg and -0.12 [SD 8.7] mmHg. They were not statistically significant. In Group A the 95% confidence interval between GAT and PT readings was -5.27 mmHg to 5.73 mmHg, and between GAT and ST readings, -6.12 mmHg to 6.59 mmHg. Ninety six [77%] eyes with the PT and 84 [69%] eyes with ST measurements were within 3 mmHg of GAT pressure. The correlation coefficients [r] for PT and ST were 0.93 [P = 0.0000] and 0.88 [P = 0.0000] respectively. In Group B 95% confidence interval between GAT and PT readings was -27.17 mmHg to 23.51 mmHg, and between GAT and ST measurement, -24.37 mmHg to 15.44 mmHg. The correlation coefficients [r] for the PT and ST were 0.112 [P = 0.660] and 0.630 [P = 0.006] respectively. In group C, the 95% confidence interval between GAT and PT measurements was -17.20 mmHg to 17.67 mmHg, and between GAT and ST measurements, -17.51 mmHg to 17.27 mmHg. The correlation coefficients [r] for the PT and the ST were 0.780 [P = 0.0000] and 0.740 [P = 0.0001] respectively. CONCLUSIONS: In clinical practice PT appears to have a higher level of accuracy than ST in normal corneas. In scarred corneas and post-penetrating keratoplasty eyes, because of high SD for mean differences and wide confidence interval of 95%, both PT and ST are inaccurate in measuring IOP as compared to GAT in such eyes.

A case of familial euthyroid hyperthyroxinemia--thyroid hormone resistance syndrome?

We describe a case of euthyroid hyperthyroxinemia in whom clinical and laboratory investigations strongly supported the diagnosis of generalised thyroid hormone resistance.

Clinical pattern of recurrent herpes simplex keratitis.

PURPOSE: To document the clinical pattern in recurrent herpes simplex disease. METHODS: Eyes with clinically documented pattern of corneal manifestation on more than one occasion were analysed. For each eye recruited, the clinical pattern of the disease at each recurrence of herpes simplex corneal disease, age, disease-free intervals, triggering factors, laterality and steroid abuse were noted and evaluated. RESULTS: For an average follow up of 6.9 years, a recurrence rate of 0.6 episodes per year was observed. Disease-free intervals of 75.7 months for epithelial herpes simplex disease was considerably longer than the 21.3 months observed for stromal disease. Clinical pattern of recurrence was of the same type following first episode of disciform keratitis, epithelial keratitis and endothelitis in 84%, 72.7%, and 75% of the eyes respectively. CONCLUSION: Herpes simplex disease often recurs in the same manifest clinical pattern as the first episode. This clinical evidence provides additional support for the potential role of herpes simplex biotypes in determining manifestation of clinical disease pattern.

Cornea stress test--evaluation of corneal endothelial function in vivo by contact lens induced stress.

Reliable and valid assessment of corneal endothelial function is a critical input for diagnosing, prognosticating and monitoring progression of disorders affecting corneal endothelium. In 123 eyes, corneal endothelial function was assessed employing data from the corneal hydration recovery dynamics. Serial pachometric readings were recorded on Haag-Striet pachometer with Mishima-Hedbys modification before and after two hours of thick soft contact lens wear. Percentage Recovery Per Hour (PRPH) was derived from raw data as an index of endothelial function. Assessed PRPH in pseudophakic corneal oedema and Fuchs' endothelial dystrophy eyes (35.9 +/- 9.8%) was significantly lower than normal controls (61.9 +/- 10.5%). On employing receiver operation characteristics curve analysis the tested results demonstrated high sensitivity (87%) and specificity (92%) for detection of low endothelial function at PRPH cut off of 47.5%. Using this PRPH cut off, 80% of Fuchs' endothelial dystrophy and 93.3% of pseudophakic corneal oedema eyes could be demonstrated to have low endothelial function. A total of 66.7% of diabetic eyes also demonstrated PRPH of lower than 47.5%. Clear corneal grafts demonstrated PRPH values of 24.6% to 73.0%. Of 6 corneal grafts that demonstrated initial PRPH of lower than 47.5%, 4 failed within 4 to 6 months. Our data demonstrated high sensitivity and specificity of this corneal stress test. PRPH index was useful in quantifying endothelial function in clinical disorders including diabetes mellitus. The index PRPH was demonstrated to be useful in monitoring and prognosticating outcome of corneal grafts.

Graded corneal sensitivity for screening of diabetic retinopathy.

Several alternative approaches to screen diabetics followed by referral of patients with retinopathy changes, are being investigated. The intent is to demonstrate usefulness of a cost effective, easy and valid screening test. We investigated in this report the efficacy of graded corneal sensitivity for screening presence of diabetic retinopathy. In 105 randomly chosen subjects with (70 subjects) and without (35 subjects) diabetes mellitus, corneal aesthesiometry and status of retinopathy was determined independently. Corneal sensitivity in subjects of diabetes mellitus without retinopathy (1.17 +/- 0.29 gm/mm2) was significantly different when compared to healthy controls (0.99 +/- 0.04 gm/mm2) (p < 0.01). Also corneal sensitivity in eyes with any type of retinopathy was significantly worse (1.94 +/- 1.33 gm/mm2) when compared to eyes without retinopathy. At a cut off value of 1.20 gm/mm2 the sensitivity and specificity of corneal hypoesthesia as a test to detect diabetic retinopathy was 86% and 74%, respectively. For detecting presence of proliferative diabetic retinopathy at a cut off value of 1.49 gm/mm2 the sensitivity and specificity were 89% and 80% respectively. These observations indicate that corneal hypoesthesia may be a reasonable indication of the presence of diabetic retinopathy and could be used to screen diabetic populations for retinopathy, after its validity is confirmed in larger studies.

Donor corneal tissue evaluation.

Proper evaluation of donor cornea is critical to the success of corneal transplantation. Attention must be paid to the cause of death and ocular condition as several general and ocular diseases constitute contraindications for donor corneal usage. Death to enucleation time should be noted. Gross examination and slit lamp biomicroscopy are mandatory for the evaluation of the donor eye while specular microscopy adds another useful dimension to information regarding donor cornea. This article provides a comprehensive review of all the aspects of donor corneal evaluation as practised today worldwide.

Thyroid hormones in diabetic ketoacidosis before and after therapy.

Fifteen IDDM patients were evaluated for thyroid hormone abnormalities before and after control of diabetes mellitus/ketoacidosis. Blood sugar mean +/- SEM mg/dl on admission was 430 +/- 20.3 and after therapy fasting and post prandial blood sugar values were 120 +/- 14.5 and 150 +/- 20.2 respectively. GHb mean +/- SEM % on admission was 15.2 +/- 0.36. Serum T3 mean +/- SEM ng/dl of 0.36 +/- 0.04 was in hypothyroid range and rT3 mean +/- SEM ng/ml 0.40 +/- 0.6 was significantly raised (P < 0.001) before therapy. After metabolic control both T3 and rT3 became normal. T4 concentration mean +/- SEM meg/dl of 5.5 +/- 0.7 was well within normal range before therapy and rose to mean +/- SEM mcg/dl 8.8 +/- 0.5 after therapy (P < 0.01). TSH response to TRH was blunted in uncontrolled state. It is concluded that peripheral changes in T3, T4 and rT3 (low T3, high rT3 and low or normal T4) occurred in uncontrolled diabetic state during ketoacidosis. TSH response to TRH was blunted due to suppression of hypothalamic pituitary thyroid axis which takes more than a week for complete recovery.