Diagnosis and management of keratoconus by eye care practitioners in Kenya.

BACKGROUND: To explore current eye care practice in keratoconus diagnosis and management in Kenya. METHODS: An online questionnaire was distributed to ophthalmic clinical officers (OCO) and optometrists. RESULTS: A total of 203 responses were received from 52 OCOs and 151 optometrists with a response rate of 24.4% and 53.5% respectively. The majority reported having access to retinoscopes (88.5%; p = 0.48) and slit lamps (76.7; p = 0.14). Few practitioners had access to a corneal topographer (13.5%; p = 0.08) and rigid contact lens (CL) fitting sets (OCOs 5.8%, optometrists 33.8%; p < 0.01). One-third did not feel that retinoscopy (38.7%; p = 0.21), slit lamp findings (30.3%; p = 0.10) and corneal topography (36.6%; p = 0.39) are important investigations in keratoconus diagnosis. Corneal topography was not recommended in two-thirds of patients (59.0%; p = 0.33) with vernal keratoconjunctivitis (VKC). The majority counselled against eye rubbing in mild (73.6%; p = 0.90) VKC, 52.9% in moderate (p = 0.40) and 43.6% in severe (p = 0.24) cases. The majority prescribed spectacles in mild (90.2%; p = 0.95), 29% (p = 0.97) in moderate and 1.9% (p = 0.05) in severe cases. When the binocular best corrected visual acuity (BCVA) with spectacles was ≤ 6/18, 76.9% of OCOs and 58.9% of optometrists referred for CLs (p = 0.02). When binocular BCVA with CLs dropped to ≤ 6/18, 83.7% (p = 0.18) referred to the ophthalmologist for surgical intervention. Few OCOs fitted rigid CLs (15.4% OCOs, 51.0% optometrists; p = 0.01), majority referred to optometrists (82.7% OCOs, 43.7% optometrists; p < 0.01). Progression was monitored in 70.1% (p = 0.11) of mild, 50.9% (p = 0.54) moderate and 25.3% (p = 0.31) advanced cases. Few OCOs (15.4%) performed corneal cross-linking (CXL). A few respondents (5.4%; p = 0.13) did not know when to refer keratoconus patients for CXL. Co-management with ophthalmologists was reported by 58.0% (p = 0.06) of respondents. CONCLUSION: The results of this study highlight the need to map services for keratoconus patients, review current curricula and continuous education priorities for mid-level ophthalmic workers, develop guidelines for the diagnosis and management of keratoconus and improve interdisciplinary collaboration.

Barriers to the Diagnosis and Management of Keratoconus Among Optometrists in Kenya.

Background: Early diagnosis and management of keratoconus (KC) are important for limiting visual complications of the disease. This study aimed to explore the perspectives of optometrists on the barriers to effective diagnosis and management of KC in Kenya. Methods: An online questionnaire was distributed to optometrists in Kenya to collect data on barriers to the diagnosis and management of KC. Results: The majority (60.9%) of optometrists were confident in retinoscopy and subjective refraction. Fewer were confident in the use of keratometers (46.4%) and corneal topographers (24.9%) and in the fitting of rigid gas permeable (RGP) contact lenses (25.0%). The most commonly reported barriers to improving their knowledge and skills were, limited continuous professional development opportunities (87.4%), high costs of conferences (86.1%) and the lack of diagnostic tools (79.5%). Impediments cited to diagnosing and managing KC effectively were a lack of national guidelines (64.9%), patient education material (71.5%), equipment (58.9%) and RGP supply (68.2%) and cost (67.5%). Most commonly reported barriers related to patients were compliance (91.4%), affordability (90.7%), RGP discomfort (89.4%), willingness to pay (88.1%) and the lack of patient education about KC (87.4%). Conclusion: This study showed that the lack of national guidelines, essential equipment and adequate practitioner knowledge and skills were barriers to KC diagnosis and management. Regulation of optometric education and clinical practice, development of national guidelines for diagnosis and management of KC, up-skilling of practitioners and cost-effective solutions for equipment procurement and maintenance may improve both access to, and quality of, care to patients with KC.

Surface modification and bioconjugation of anti-CD4 monoclonal antibody to magnetic nanoparticles as a highly efficient affinity adsorbent for positive selection of peripheral blood T CD4+ lymphocytes.

Magnetic activated cell sorting (MACS) is a straightforward and time-saving procedure for isolation of different healthy functional cells. The present study aimed for the developing of a new MACS-based platform for isolation of peripheral blood T CD4+ lymphocytes. For this goal, first: Fe3O4 magnetic nanoparticles (MNP) were prepared by co-precipitation of Fe (III) and Fe (II) ions and then coated by SiO2 shell, followed by the grafting of N-(phosphonomethyl) iminodiacetic acid (PMIDA) on the surface of fabricated MNP, Fe3O4@SiO2@PMIDA were formed. These MNP were further tested for their ability to bind CD4 T lymphocytes. Through conjugation of the anti-CD4 monoclonal antibody on the surface of Fe3O4@SiO2@PMIDA MNP. The newly developed immunomagnetic particles efficiently isolated T CD4+ lymphocytes from whole blood with high purity Therefore, our MNP afford an efficient tool for the cell separation process and further present the dramatic potential to be applied to other areas of biomedical application.

Sonochemical synthesis of pyrido[2,3-d:6,5-d']-dipyrimidines catalyzed by [HNMP]+[HSO4]- and their antimicrobial activity studies.

In this study, the one-pot four-component reaction of aromatic aldehyde, 2-thiobarbituric acid, ammonium acetate in the presence of a catalytic amount of [H-NMP]+[HSO4]- under ultrasonic irradiation in water is reported. In the present procedure, the pyrido[2,3-d:6,5-d']dipyrimidine derivatives were purely produced as valuable products. The process proved to be simple, environmentally friendly, efficient and high to excellent yielding. Moreover, some of the synthetic compounds were investigated and revealed important antimicrobial activity of prepared products.

Facile fabrication of nickel immobilized on magnetic nanoparticles as an efficient affinity adsorbent for purification of his-tagged protein.

In the present research, an efficient, convenient, and inexpensive method for the one-pot synthesis of Fe3O4@Histidine is developed. Histidine is readily loaded on magnetic nanoparticles by one step and simple method without any supplemental linkers. In the structure of Fe3O4@Histidine, histidine covalently immobilized on the surface of Fe3O4, magnetic nanoparticles are able to trap Ni2+ ions through a strong interaction between nickel and histidines in protein tag. Two coordination sites of nickel are occupied with ligand on the surface of magnetic nanoparticles and four coordination sites have been remained that these sites will be occupied with histidine tag of recombinant protein A. The functionalized nanoparticles were spherical and well separated with an average diameter around 30nm. The obtained magnetic nanoparticles have a saturation magnetization of about 54emu/g. Fe3O4@Histidine-Ni was used to enrich and purify 6×histidine-tagged recombinant protein-A directly from the mixture of lysed cells. It has been found that Ni(II)-immobilized Fe3O4@Histidine magnetic nanoparticles present negligible nonspecific protein adsorption and high His-tag protein binding capacity The average binding capacity (MW 42k Da), is 700±25µg·mg-1 (protein/Fe3O4@Histidine-Ni).

Nickel-Salen supported paramagnetic nanoparticles for 6-His-target recombinant protein affinity purification.

In this research, a simple, efficient, inexpensive, rapid and high yield method for the purification of 6×histidine-tagged recombinant protein was developed. For this purpose, manganese ferrite magnetic nanoparticles (MNPs) were synthesized through a co-precipitation method and then they were conveniently surface-modified with tetraethyl orthosilicate (TEOS) in order to prevent oxidation and form high density of hydroxyl groups. Next, the salen ligand was prepared from condensation reaction of salicylaldehyde and 3-aminopropyl (trimethoxy) silane (APTMS) in 1:1 molar ratio; followed by complexation with Ni(OAc)2.4H2O. Finally, the prepared Ni(II)-salen complex conjugated to silica coated MNPs and MnFe2O4@SiO2@Ni-Salen complex nanoparticles were obtained. The functionalized nanoparticles were spherical with an average diameter around 70nm. The obtained MNPs had a saturation magnetization about 54 emu/g and had super paramagnetic character. These MNPs were used efficiently to enrich recombinant histidine-tagged (His-tagged) protein-A from bacterial cell lysate. In about 45min, highly pure His-tagged recombinant protein was obtained, as judged by SDS-PAGE analysis and silver staining. The amount of target protein in flow through and washing fractions was minimal denoting the high efficiency of purification process. The average capacity of the matrix was found to be high and about 180±15mgg-1 (protein/MnFe2O4@SiO2@Ni-Salen complex). Collectively, purification process with MnFe2O4@SiO2@Ni-Salen complex nanoparticles is rapid, efficient, selective and whole purification can be carried out in only a single tube without the need for expensive systems.

Characteristics of Keratoconic Patients Attending a Specialist Contact Lens Clinic in Kenya.

PURPOSE: To describe the characteristics of keratoconus (KC) patients seen in a contact lens clinic of a children's hospital in Kenya. RESULTS: A total of 254 patients' records were analyzed. Mean age at presentation to the clinic was 20.97 ± 11.13 year (range, 6-84 years) with 75% between the ages of 6 and 25 years. There was a preponderance of males (59.8%). Most patients were referred by an ophthalmologist. All patients were Africans. The most common complaints were blurred vision (50%), poor visual acuity with spectacles (33.5%), contact lens intolerance (11.8%), and other (unspecified). Most cases were severe (71%) followed by moderate (22.9%) and mild (6.2%). Mean BCVA was 0.24 ± 0.23 (6/11). An optical correction was provided in 98% of cases; 34.6% with spectacles, 31.1% with gas permeable lenses and the remaining with both. Referral for keratoplasty was warranted in 16.5%. CONCLUSION: This is the first study of KC conducted in Kenya. KC presented at a very early age and tended to be severe. Ophthalmologists were the main source of referral. The main presenting symptom was reduced vision. Optical correction was the most common management and the percentage of patients referred for surgery concurred with other studies.

Inorganic-organic hybrid silica based tin complex as a novel, highly efficient and recyclable heterogeneous catalyst for the one-pot preparation of spirooxindoles in water.

In the present study, a tin complex immobilized on silica gel as a novel, green, highly efficient and heterogeneous reusable catalyst was synthesized by grafting 2-amino benzamide onto the silica gel surface as a result of the reaction between isatoic anhydride and 3-aminopropyl-functionalized silica gel, followed by complexing with tin chloride. The resulting organic-inorganic hybrid material was evaluated in the one-pot three-component synthesis of spiro[indoline-pyrazolo[4',3':5,6]pyrido[2,3-d]pyrimidine]trione derivatives in water via the condensation reaction of isatins, barbituric acids, and 1H-pyrazol-5-amines. All the reactions were completed in short reaction times and all the products were obtained in high to excellent yields with high purity. In addition, the synthesized novel catalyst could be separated from the reaction mixture by simple filtration and can be reused up to seven runs without significant loss in activity.

A facile one-pot ultrasound assisted for an efficient synthesis of 1H-spiro[furo[3,4-b]pyridine-4,3'-indoline]-3-carbonitriles.

A convenient one-pot protocol was developed for the synthesis of 1H-spiro[furo[3,4-b]pyridine-4,3'-indoline]-3-carbonitrile derivatives. This reaction was carried out through a three component condensation reaction of isatins, malononitrile, and anilinolactones in the presence of a catalytic amount of Et3N as an inexpensive and available basic catalyst in THF under ultrasound irradiation. The products were obtained in high yields and short reaction times. The main advantage of this synthetic method is that the obtained products in ultrasonic irradiations are different from classical heating.