Browsing by Author "Akafo, S.K."

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A cross-over trial comparing once daily levobunolol with once and twice daily timolol.
(European Journal of Ophthalmology, 2005) Akafo, S.K.; Thompson, J.R.; Rosenthal, A.R.
The intraocular pressure (IOP) lowering efficacy of once-daily levobunolol 0.5% was compared with timolol 0.5% twice-daily and timolol 0.5% once-daily in 20 chronic open angle glaucoma and 5 ocular hypertensive patients. The design used was a randomised double blind cross-over trial with three periods each of 8 weeks separated by 2 weeks of no treatment. We found that following levobunolol a two week washout was not sufficient for the IOP to return to its original baseline level suggesting that levobunolol is a longer acting drug than timolol. Adjusting for this carryover effect, we found on significant difference in the IOP lowering effect among the three regimes (p = 0.53). Reduced cost, less ocular discomfort and better compliance are the main potential advantages of the once daily treatments.
Development of membrane-based tests for the detection of urinary antigens and antibodies in human toxoplasmosis: preliminary studies in Ghanaian patients.
(preliminary studies in Ghanaian patients, 2005) Ayi, I.; Akao, N.; Bosompem, K.M.; Akafo, S.K.; Clarke, J.; Nyador, L.; Apea-Kubi, K.A.; Fujita, K.
Two membrane-based ELISA systems were used in detecting Toxoplasma antigens and anti-Toxoplasma antibodies in urine samples collected from 54 ophthalmology (22 suggestive active and 32 suggestive past infection) patients and 26 pregnant women attending obstetrics/gynaecology clinic (OGP), suspected of toxoplasmosis by eye examination, past medical records and questionnaire, respectively, in Ghana from mid-February to April 2002. The antigen detecting ELISA was able to demonstrate antigen in 100% (22/22) ophthalmology (active infection) and 62.5% (20/32) ophthalmology (past infection) patients, and 42% (11/26) of OGP which included 3 that were sero-negative prior to and during this study, giving an overall prevalence of 66.3% (53/80). The urinary antigen positive samples also included 6 that were negative for both the Dye Test (DT) and latex agglutination test (LAT). Antigen was not detected in the urine of 22 normal (sero-negative for antibodies to Toxoplasma) individuals. The membrane-based urinary antibody detecting sandwich ELISA also detected anti-Toxoplasma antibodies in 100% (22/22) of ophthalmology (active infection) and 81.3% (26/32) of ophthalmology (past infection) patients, a total of 89% (48/54); and 80.8% (21/26) of OGP with an overall prevalence of 86.3% (69/80), including 7 ophthalmology patients' samples that were sero-negative for both DT and LAT. Antibody sero-positivity of the samples was determined by DT as 87% (47/54) in ophthalmology patients and 73.1% (19/26) in pregnant women, LAT as 85.2% (46/54) and 65.4% (17/26), and an overall prevalence as 82.5% (66/80) and 78.8% (63/80), respectively. The membrane-based ELISA systems appear promising but need to be investigated further for its efficacy as reliable diagnostic tests.
GALC deletions increase the risk of primary Open-Angle Glaucoma: The role of mendelian variants in complex disease
(Public Library of Science, 2013) Liu, Y.; Gibson, J.; Wheeler, J.; Kwee, L.C.; Santiago-Turla, C.M.; Akafo, S.K.; Lichter, P.R.; Gaasterland, D.E.; Moroi, S.E.; Challa, P.; Herndon, L.W.; Girkin, C.A.; Budenz, D.L.; Richards, J.E.; Allingham, R.R.; Hauser, M.A.
DNA copy number variants (CNVs) have been reported in many human diseases including autism and schizophrenia. Primary Open Angle Glaucoma (POAG) is a complex adult-onset disorder characterized by progressive optic neuropathy and vision loss. Previous studies have identified rare CNVs in POAG; however, their low frequencies prevented formal association testing. We present here the association between POAG risk and a heterozygous deletion in the galactosylceramidase gene (GALC). This CNV was initially identified in a dataset containing 71 Caucasian POAG cases and 478 ethnically matched controls obtained from dbGAP (study accession phs000126.v1.p1.) (p = 0.017, fisher's exact test). It was validated with array comparative genomic hybridization (arrayCGH) and realtime PCR, and replicated in an independent POAG dataset containing 959 cases and 1852 controls (p = 0.021, OR (odds ratio) = 3.5, 95% CI -1.1-12.0). Evidence for association was strengthened when the discovery and replication datasets were combined (p = 0.002; OR = 5.0, 95% CI 1.6-16.4). Several deletions with different endpoints were identified by array CGH of POAG patients. Homozygous deletions that eliminate GALC enzymatic activity cause Krabbe disease, a recessive Mendelian disorder of childhood displaying bilateral optic neuropathy and vision loss. Our findings suggest that heterozygous deletions that reduce GALC activity are a novel mechanism increasing risk of POAG. This is the first report of a statistically-significant association of a CNV with POAG risk, contributing to a growing body of evidence that CNVs play an important role in complex, inherited disorders. Our findings suggest an attractive biomarker and potential therapeutic target for patients with this form of POAG.
Homogeneous immunoglobulins in Ghanaians living in Accra, Ghana.
(African Journal of Medicine & Medical Sciences, 2004) Oyeyinka, G.O.; Ofei, V.; Maddy, S.Q.; Duah, O.A.; Akafo, S.K.; Aquaye, J.K.; Dosoo, D.K.
Serum screening for homogeneous immunoglobulins (H-Ig) was done on 149 apparently healthy Ghanaians (aged 17-95 years) and 73 sick subjects who presented at the Korle-Bu Teaching Hospital from October 1999 to September 2000. Sera were screened by agarose gel electrophoresis and those with equivocal results were confirmed by immunoelectrophoresis. Immunoglobulin classes (IgG, IgA and IgM) and Bence Jones proteinuria were measured and determined by single radial immunodiffusion method and heating respectively. Total protein, albumin, calcium, uric acid, urea and creatinine were estimated on ACE chemistry autoanalyser. The laboratory profile of 5 Ghanaians with a picture of multiple myeloma and one with monoclonal gammopathy of undetermined significance drawn from the sick subjects (6 of 73) are presented. None of the 149 healthy subjects studied in three age groups (17-40; 41-64 and dollar 65 years) had H-Ig, and their serum IgG, IgA, IgM, urea, creatinine, uric acid, calcium, total protein and albumin levels were within the normal range. H-Ig were present in sera of 6 out of the 73 sick subjects (8.2%); 5 of them (4 males, 1 female) presented a picture of multiple myeloma. Three of these 5 patients had IgG, and the others IgA paraproteinaemia. All 5 patients had immunoparesis which was absent in the 6th patient (a male) who also had IgA paraproteinaemia (< 10 g/L), active bone marrow with < 2% mature plasma cells and no renal involvement. Results of bone marrow examination supported a diagnosis of multiple myeloma in the 3 patients with IgG paraproteinaemia, but were not available for the other two. Bence-Jones proteinuria was found in 2 (both with IgG paraproteinaemia) of 4 patients (50%) available for testing. Renal involvement was indicated in the 5 patients with a picture of multiple myeloma as urea and creatinine levels were significantly raised.
Investigation of known genetic risk factors for primary open angle glaucoma in two populations of African ancestry
(Investigative Ophthalmology and Visual Science, 2013-08) Liu, Y.; Hauser, M.A.; Akafo, S.K.; Qin, X.; Miura, S.; Gibson, J.R.; Wheeler, J.; Gaasterland, D.E.; Challa, P.; Herndon, L.W.; Ritch, R.; Moroi, S.E.; Pasquale, L.R.; Girkin, C.A.; Budenz, D.L.; Wiggs, J.L.; Richards, J.E.; Ashley-Koch, A.E.; Allingham, R.R.
Purpose. Multiple genes have been associated with primary open angle glaucoma (POAG) in Caucasian populations. We now examine the association of these loci in populations of African ancestry, populations at particularly high risk for POAG. Methods. We genotyped DNA samples from two populations: African American (1150 cases and 999 controls) and those from Ghana, West Africa (483 cases and 593 controls). Our analysis included 57 single nucleotide polymorphisms (SNPs) in five loci previously associated with POAG at the genome-wide level, including CDKN2B-AS1, TMCO1, CAV1/CAV2, chromosome 8q22 intergenic region, and SIX1/SIX6. We evaluated association in the full datasets, as well as subgroups with normal pressure glaucoma (NPG, maximum IOP ≤21 mm Hg) and high pressure glaucoma (HPG, IOP >21 mm Hg). Results. In African Americans, we identified an association of rs10120688 in the CDNK2B-AS1 region with POAG (P = 0.0020). Several other SNPs were nominally associated, but did not survive correction for multiple testing. In the subgroup analyses, significant associations were identified for rs10965245 (P = 0.0005) in the CDKN2B-AS1 region with HPG and rs11849906 in the SIX1/SIX6 region with NPG (P = 0.006). No significant association was identified with any loci in the Ghanaian samples. Conclusions. POAG genetic susceptibility alleles associated in Caucasians appear to play a greatly reduced role in populations of African ancestry. Thus, the major genetic components of POAG of African origin remain to be identified. This finding underscores the critical need to pursue large-scale genome-wide association studies in this understudied, yet disproportionately affected population. © 2013 The Association for Research in Vision and Ophthalmology, Inc.
Long-term post trabeculectomy intraocular pressures
(Acta Ophthalmologica, 2009) Akafo, S.K.; Goulstine, D.B.; Rosenthal, A.R.
Eighty-one eyes which had had trabeculectomy with a mean follow-up period of 9.2 years (range 7 to 10 years) were studied retrospectively for their subsequent pattern of intraocular pressure. Of 43 chronic open-angle glaucoma eyes, 29 (67%) had their pressures maintained below 21 mmHg by trabeculectomy alone over a 7–10-year period. On the other hand, 25 of 38 (65%) eyes with other types of glaucoma required an average of 1.5 different antiglaucoma medications post-op for the control of their intraocular pressures. Fifteen of 69 (22%) phakic eyes required cataract extraction at a mean of 5.1 years post-op. Two of 43 (5%) chronic open-angle glaucoma eyes suffered blinding complications attributable to the procedure. Seventeen percent: of eyes gained visual field at a mean of 7% of the pre-op field per year following trabeculectomy. Fifty percent lost field at a mean rate of 2.3% per year.
Serum immunoglobulin (IgG, IgA and IgM) levels in adult Ghanaians
(Ghana Medical Journal, 2003-06) Oyeyinka, G.O.; Maddy, S.Q.; Duah, O.A.; Asare-Anane, H.; Akafo, S.K.; Ansah, J.K.