Research Articles (Ophthalmology)
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- ItemAbnormal serum lipoprotein levels as a risk factor for the development of human lenticular opacities(Clinics Cardiv Publishing, 2003-04) Meyer, D.; Parkin, D.; Maritz, F. J.; Liebenberg, P. H.Aim: To determine whether an association exists between the different plasma lipoprotein constituents and the prevalence of lenticular opacities in dyslipidaemic subjects. Methods: Adult patients (n = 115) of both genders were included if their fasting total serum cholesterol concentrations exceeded the 95th percentile of normal or their serum low-density lipoprotein (LDL) : high-density lipoprotein (HDL) ratios exceeded 5. Patients were excluded if they suffered from any condition known to cause, or predispose them to, elevated lipoprotein levels or lenticular opacification. Lenticular changes were assessed by means of a slit-lamp through the fully dilated pupil. Results: An extremely strong association (p < 0.0001) was found to exist between HDL cholesterol levels and the development of lens opacities. Below an HDL-C level of 1.5 mmol/l subjects had a seven-fold higher calculated probability of falling in the lens opacity subgroup than those with HDL-C levels above 1.5 mmol/l [odds ratio = 7.33 (95% CI = 2.06–26.10; p = 0.001)]. An equally strong association was found between high (>5) LDL:HDL ratios and the development of lens opacities (p < 0.0003). The risk of falling into the cataract subgroup if the individual’s LDL:HDL ratio exceeded 5 was 2.35 (95% CI = 1.09–5.04; p = 0.014). Conclusions: This study strongly suggests that an association exists between low levels of HDL cholesterol and high LDL:HDL ratios on one hand and the development of adult lens opacification on the other.
- ItemAnti-allergic ophthalmic drugs in general practice : which, why and when?(Medpharm Publications, 2013) Mohamed, N.; Smit, D. P.Ocular allergies present in many different guises. They may vary from self-limiting episodes of acute allergic conjunctivitis, to potentially sight-threatening chronic conditions, such as vernal keratoconjunctivitis. This article provides a brief description of the different ocular allergic conditions to aid accurate diagnosis. It also focuses on the different types of anti-allergic ophthalmic preparations and how to employ them in a logical, stepwise management strategy to obtain optimal results, while minimising exposure to potent drugs with potentially serious side-effects.
- ItemAnti-infective ophthalmic preparations in general practice(Medpharm Publications, 2012) Smit, DerrickOcular infections may be bacterial, viral, fungal or parasitic in aetiology. Pharmacological preparations are available to treat infections that are caused by these groups of organisms. The majority of these preparations are intended for topical administration, although some systemically administered agents may be needed to treat or prevent specific ocular infections. This article discusses the different anti-infective options that are available to general practitioners to treat infections caused by each aetiological group. It also discusses the role that is played by povidone-iodine and antibiotic-steroid combinations to manage eye infections. A summary of all these drugs is provided in table form for easy reference.
- ItemAstute and safe use of topical ocular corticosteroids in general practice : practical guidelines(Health and Medical Publishing Group (HMPG), 2013-04) Janse van Rensburg, E.; Meyer, D.Corticosteroids are the most effective way to treat ocular inflammation. They relieve symptoms rapidly and often prevent permanent damage. These medications, however, must be used with caution, as use of steroid-containing topical drops can lead to serious side-effects. In situations where resources are limited it is often difficult to decide if steroids can be given safely. The purpose of this article is to briefly review the most important features of topical steroids and provide a practical and safe guideline for their use in general practice
- ItemBiomarkers as a predictor for diabetic retinopathy risk and management : a review(AOSIS, 2018) Phillips, Kevin C.; Clarke-Farr, Peter C.; Matsha, Tandi E.; Meyer, DavidBackground: The systemic and ocular manifestations of diabetes are an increasing burden on both private and public healthcare systems. The ability to accurately predict patient susceptibility and prognostic implications of the disease is essential to its optimal management and planning. Aim: The purpose of this paper was to review alternative biomarkers to those currently in use regarding the diagnosis and prognosis of diabetes and the ocular effects of the disease. Current biomarkers include Fasting Plasma Glucose (FPG), Oral Glucose Tolerance Test (OGTT) and Glycolated Haemoglobin (HbA1c). Methods: The research strategy comprised of a comprehensive literature review of articles from Mendeley, Cochrane and Elsevier with additional input from experts in the field serving as co-authors. Results: The review found that there are alternative biomarkers to those currently utilised. These include adiponectin, apolipoprotein B, C-reactive protein and ferritin. Fructosamine, while useful where whole blood is available, is unreliable as a diagnostic biomarker resulting in a 10% variation coefficient. Post-prandial glucose (PPG) measurement most closely predicted HbA1c. Conclusion: With prediction of risk for diabetes in individuals, a value combination, expressed as either a numerical score or a percentage, consisting of adiponectin, apolipoprotein B, C-reactive protein and ferritin, almost doubled the relative risk of contracting the disease. Eye care practitioners need to question diabetic patients about their FPG and HbA1c levels and encourage them to have the relevant tests regularly, including PPG. The importance of biomarkers should be emphasised and used as an educational tool to facilitate better diabetes management and treatment adherence.
- ItemCortical lens opacities in the young patient - an indication for a lipogram?(Health & Medical Publishing Group, 2001) Meyer, D.; Maritz, F. J.; Liebenberg, P. H.; Parkin, D. P.; Burgess, L. J.Aim. To determine the characteristics and prevalence of lenticular opacification in patients with underlying dyslipidaemia. Methods. Eighty patients of both genders and all ages (18 - 90 years) were enrolled in the trial if they met the inclusion criteria for dyslipidaemia. Patients were included if their fasting serum cholesterol and triglyceride concentrations were > 5.2 mmol/1 and > 2.3 mmol/1, respectively, when measured on three separate occasions over a 1-month period. Patients were excluded if they suffered from any condition known to cause or predispose them to elevated lipid levels or lenticular opacification. Lenticular changes were assessed by means of a slit-lamp through the fully dilated pupil and other physical signs were documented subsequent to thorough physical evaluation. Results. In addition to the classic clinic signs of dyslipidaemia, 31% of patients had cortical lens opacities. Cortical opacities were twice as prevalent as Achilles tendon thickening (16.3%) in our study, the second most prevalent sign of elevated lipid levels. In the subgroup of patients aged under 50 years, 55% had lenticular opacities, predominantly cortical (80%). Conclusions. Cortical lens opacification was the most prevalent sign of dyslipidaemia and it occurred at a relatively young age in our trial population in those patients who were affected. Cortical lenticular opacification should be regarded as an indication for blood lipid profile evaluation.
- ItemDealing with dry eye disease in general practice(Medpharm Publications, 2012) Smit, DerrickDry eye disease (DED) is a very common condition with significant morbitity. It is under-diagnosed by healthcare practitioners, since the presenting symptoms are often non-specific or misleading, and clinical signs may be subtle, or absent. To help overcome this problem, validated symptom questionnaires have been developed to aid the diagnosis, and grading of severity, of DED. Recent advances in the understanding of the multifactorial aetiology of this condition have also permitted the development of modalities aimed at treating specific underlying causes, rather than merely alleviating symptoms. An awareness of the causes and risk factors involved in this disease will assist the family practitioner in recommending lifestyle and dietary changes that, on their own, may provide sufferers with considerable symptomatic relief. A better understanding of the pathophysiology will, in turn, allow the family practitioner to make informed choices when prescribing initial treatment, and also guide the practitioner to know when to refer a patient for specialist management.
- ItemEfficacy of cryotherapy in retinoblastoma(Health & Medical Publishing Group, 1976) Molteno A. C. B.Five cases of retinoblastoma treated by freezing are reported. From these cases it appears that a single freeze thaw cycle will destroy all tumor and that with suitable instruments it is possible to destroy tumors involving up to 30% of the volume of the globe without causing blindness.
- ItemEyelid problems in general practice(Medpharm Publications, 2012) Smit, Derrick P.General practitioners are often confronted with complaints regarding the eyelids. The author presents a number of clinical cases that illustrate common eyelid problems, and provides a discussion of each case to highlight the important features of the condition. Appropriate treatment for each condition is also covered. Many eyelid conditions are amenable to treatment from general practitioners, but those conditions requiring specialist management need to be identified, and referred appropriately.
- ItemFundus auto fluorescence and spectral domain ocular coherence tomography in the early detection of chloroquine retinopathy(AOSIS Publishing, 2015-08-21) Goodman, Megan B.; Ziskind, AriPurpose: To determine the sensitivity of spectral domain ocular coherence tomography (SD-OCT) and fundus auto fluorescence (FAF) images as a screening test to detect early changes in the retina prior to the onset of chloroquine retinopathy. Method: The study was conducted using patients taking chloroquine (CQ), referred by the Rheumatology Department to the Ophthalmology Department at Tygerberg Academic Hospital. Group A consisted of 59 patients on CQ for less than 5 years, and Group B consisted of 53 patients on CQ for more than 5 years. A 200 × 200 macula thickness map, 5-line raster SD-OCT on a Carl Zeiss Meditec Cirrus HD-OCT and FAF images on a Carl Zeiss Meditec Visucam 500 were recorded for 223 eyes. Images were reviewed independently, and then those of Groups A and B compared. Results: There were no statistically significant differences between Groups A and B. The criteria included the internal limiting membrane and the retinal pigment epithelium (ILM-RPE) thickness, interdigitation zone integrity (p = 0.891, df = 1, χ² = 0.1876), ellipsoid zone integrity (p = 0.095, df = 2, χ² = 4.699) and FAF image irregularities (p = 0.479, df = 1, χ² = 4995978). Conclusion: The inclusion of SD-OCT and FAF as objective tests into the prescribed screening guidelines does not appear to simplify the detection of subclinical injury in patients on chloroquine treatment.
- ItemHutchinson's sign as a marker of ocular involvement in HIV-positive patients with herpes zoster ophthalmicus(Health and Medical Publishing Group (HMPG), 2010) Van Dyk, M.; Meyer, D.Background. A positive Hutchinson's sign indicates an increased risk of ocular involvement in herpes zoster ophthalmicus (HZO). We examined the sensitivity of Hutchinson's sign as an indicator of ocular involvement in a consecutive series of patients presenting with HZO. Methods. We conducted a descriptive observational prospective study of patients ≥18 years old presenting with HZO and consenting to pre- and post-test counselling and HIV and CD4 testing. A full ophthalmological examination focused on the extent of ocular involvement, and the presence of Hutchinson's sign was confirmed by two clinicians. Results. Thirty-three patients were enrolled; 29 were HIV positive, of whom 18 (62%) had not been diagnosed with HIV prior to enrolment. Of the 29 HIV-positive patients, 21 (72%) were Hutchinson's sign positive (HSP), all of whom had intra-ocular involvement (95% confidence interval 88 - 100%). Of the 8 HIV-positive, Hutchinson's sign-negative (HSN) patients, 4 did and 4 did not display intra-ocular involvement. Neither the mean CD4 count nor the average age in the HSP group differed significantly from the HSN group. Conclusion. We confirmed that a Hutchinson's sign- and HIVpositive patient with HZO has a very high positive predictive value for intra-ocular involvement. Neither age nor CD4 count had predictive value for ocular involvement. Young adults presenting with HZO should be suspected of having HIV, and HIV-positive patients with HZO but HSN may still have ocular involvement. All patients with HZO should be seen by an ophthalmologist.
- ItemIntra-ocular concentration-time relationships of subconjunctivally administered gentamicin(Health & Medical Publishing Group, 1991) Van Rooyen, M. M. B.; Coetzee, J. F.; Du Toit, D. F.; Van Jaarsveld, P. P.Eighty-nine patients scheduled for cataract removal or lens implantation were divided randomly into three groups. Each received 5, 10 or 20 mg gentamicin subconjunctivally at times varying between 0,2 and 19 hours pre-operatively. At surgery a sample of aqueous humour was obtained and analysed for gentamicin concentration. The data for each group were subjected to non-linear regression analysis to fit an open one-compartment pharmacokinetic model with first-order kinetics. A statistically acceptable fit was obtained. The average values of the pharmacokinetic parameters obtained from the single doses were used to simulate multiple-dose kinetics. The average target intra-ocular gentamicin concentrations and dosage interval were specified in the computer program, which subsequently allowed calculation of the dose required. This allowed the construction of a simple linear nomogram that can be used to read off the dose needed for handling specific clinical situations.
- ItemThe intraocular pressure-lowering properties of intravenous paracetamol(Dove Medical Press, 2016) Van Den Heever, Henning; Meyer, DavidAim: The aim of this paper was to investigate the intraocular pressure (IOP)-changing properties of a single standard dose of intravenous (IV) paracetamol and compare it to that of topical timolol, oral acetazolamide, and no treatment. Methods: A prospective, randomized, investigator-blind, parallel-group study was conducted in 73 eyes of 52 subjects. Subjects received a single dose of IV paracetamol (1 g), oral acetazolamide (250 mg), topical timolol (0.5%, one drop), or no treatment. Baseline IOP was measured, and the measurement was repeated at 1, 2, 4, and 6 hours after treatment. Results: Paracetamol reduced IOP from baseline by -10.8% (95% confidence interval [CI]: -4.9% to -16.8%, P=0.146) at 1 hour, -13.3% (95% CI: -8.3% to -18.4%, P=0.045) at 2 hours, -11.8% (95% CI: -5.5% to -18.4%, P=1.000) at 4 hours, and -23.9% (95% CI: -17.8% to -30.1%, P=0.006) at 6 hours after treatment. In the no-treatment group, the change was -2.9% (95% CI: +1.0% to -6.7%, P= referent) at 1 hour, -2.1% (95% CI: +2.9% to -7.2%, P= referent) at 2 hours, -7.6% (95% CI: -3.9% to -11.2%, P= referent) at 4 hours, and -6.9% (95% CI: -3.6% to -10.2%, P= referent) at 6 hours. Acetazolamide reduced IOP by -18.8% (95% CI: -12.7% to -24.8%, P=0.000) at 1 hour, -26.2% (95% CI: -18.2% to -34.2%, P=0.001) at 2 hours, -24.6% (95% CI: -16.9% to -32.3%, P=0.000) after 4 hours, and -26.9% (95% CI: -19.6% to -34.3%, P=0.000) 6 hours after treatment. Timolol reduced IOP by -31.2% (95% CI: -26.7% to -35.7%, P=0.000) at 1 hour, -27.7% (95% CI: -20.7% to -34.8%, P=0.000) at 2 hours, -28.7% (95% CI: -21.1% to -36.2%, P=0.000) at 4 hours, and -21.3% (95% CI: -13.4% to -30.0%, P=0.030) at 6 hours after treatment. The average change in IOP for the no-treatment group was -4.8% (95% CI: -2.6% to -6.9%, P= referent). It was -15.7% (95% CI: -9.3% to -22.1%, P=0.021) for paracetamol, -23.1% (95% CI: -16.4% to -29.8%, P=0.000) for acetazolamide, and -25.3% for the timolol group (95% CI: -19.4% to -31.2%, P=0.000). The maximal change in IOP for the no-treatment group was -9.2% (95% CI: -3.2% to -15.3%, P= referent). It was -25.9% (95% CI: -16.6% to -35.2%, P=0.009) for paracetamol, -33.8% (95% CI: -25.5% to -42.1%, P=0.000) for acetazolamide, and -36.8% (95% CI: -31.0% to -42.5%, P=0.000) for the timolol group. Conclusion: Intravenously administered paracetamol shows IOP-lowering properties over the first 6 hours after administration. Clinicians performing IOP measurements in patients who have received IV paracetamol in the preceding 6 hours should interpret these measurements with caution. Further studies are needed to investigate the IOP-changing properties of paracetamol.
- ItemLong tube implants in the management of glaucoma(Health & Medical Publishing Group, 1976) Molteno, A. C. B.; Straughan, J. L.; Ancker, E.; Molteno, A. C. B.; Straughan, J. L.; Ancker, E.The design, surgical insertion and results of a plastic draining implant for severe glaucoma are reported. The need for pharmacological control of bleb inflammation is stressed and the favourable long term outlook for patients with such implants is discussed.
- ItemManagement of chemical ocular injuries – what every GP should know(Health and Medical Publishing Group (HMPG), 2013-04) Meyer, D.; Jansen van Rensburg, J.
- ItemModified neurosyphilis in the Cape Peninsula(Health & Medical Publishing Group, 1978) Joyce-Clarke, N.; Molteno, A. C. B.A prospective study of 148 cases of neurosyphilis revealed that 85 patients exhibited a modified 'forme fruste' of the disease. A high proportion of these patients had evidence of activity in the cerebrospinal fluid, while 6 patients have developed features which are diagnostic of neurosyphilis. During the study a significant number of active seronegative cases were diagnosed and 11 patients have deteriorated on treatment.
- ItemThe new challenge of corneal transplantation in South Africa(Health and Medical Publishing Group (HMPG), 2007-07) Meyer, DavidModern corneal transplantation is internationally accepted as highly successful and cost effective. The avascularity of the cornea puts it in a relatively immune-privileged position, and complications due to graft rejection can be handled more effectively than in other solid organs. Modern microsurgery, which has the ability to manage postoperative astigmatism, has turned corneal transplant surgery into a most gratifying procedure as far as visual acuity is concerned. Corneal graft survival is often lifelong, with most patients not needing topical or systemic immunosuppression for longer than several months postoperatively. Patients are frequently given a new lease on life after sight-restoring corneal transplantation.
- ItemA new system of refraction for use by the general practitioner(Health & Medical Publishing Group, 1977) Molteno, A. C. B.; Molteno, T. E. S.A rapid, simple and economical method of refraction with a circular slide rule is descriptionbed.
- ItemOculomotor nerve palsy precipitating acute angle-closure glaucoma : a case report(Health & Medical Publishing Group, 1989) Mouton, D. P.; Meyer, D.A case of acute angle-closure glaucoma precipitated by oculomotor nerve palsy in a patient with shallow anterior chambers is reported. The different ways in which a palsy of the oculomotor nerve can influence the intra-ocular pressure are discussed.
- ItemThe organisation of an ophthalmological service for diabetics in a teaching hospital(Health & Medical Publishing Group, 1987) Mouton, D. P.; Gill, A. J.; Van Rooyen, M. M.A new system of ophthalmological evaluation of diabetic patients in a teaching hospital has been devised. All the patients attending the diabetic clinic were screened by ophthalmologists. Any patient with a problem was then referred to a diabetic ophthalmology clinic where a full evaluation was done and treatment given where necessary. In an 18-month period 1,015 new ophthalmological diabetic patients were screened. Of these patients 13.6% had background retinopathy, 8.4% pre-proliferative retinopathy and 3.4% proliferative retinopathy, while 8.6% had maculopathy. These results show that even in a teaching hospital a significant percentage of patients already have pre-proliferative or even proliferative retinopathy when seen by an ophthalmologist for the first time. The importance of organising an ophthalmological service for the diabetic patient is stressed.