A study of central corneal thickness in glaucoma and nonglaucoma patients in a West African population.

PURPOSE: To compare central corneal thickness (CCT) in high-tension glaucomatous eyes and nonglaucomatous eyes with normal intraocular pressure (IOP) and to determine if there is any correlation between CCT and severity of glaucoma, as indicated by vertical cup-to-disc ratio. METHODS: A case-control study that involved 506 subjects at the Korle-Bu Teaching Hospital, Accra, Ghana, from August 2006 to July 2007. The cases were patients with (high tension and IOP more than 21 mm Hg) primary open-angle glaucoma, and the controls were patients with normal IOP (less than 21 mm Hg) and no evidence of glaucoma. The main outcome measures were CCT, as measured by ultrasonic pachymetry (model DGH 55 pachmate), and vertical cup-to-disc ratio. RESULTS: Five hundred six subjects were recruited: 253 cases (506 eyes) and 253 controls (505 eyes). The mean CCT of the right eye for the glaucoma cases was 524.28 µm [95% confidence interval (CI), 4.44; SD, 36.85] and for the controls was 530.00 µm (95% CI, 4.56; SD, 35.75). The mean CCT of the left eye for the glaucoma cases was 524.70 µm (95% CI, 4.48; SD, 36.20) and for the controls was 531.06 µm (95% CI, 4.40; SD, 35.52). The relation between CCT and cupping determined by Pearson correlation coefficient yielded values of -0.09 and 0.01 for the right and left eyes, respectively. CONCLUSION: There was no significant difference between mean CCT of cases and controls in the right eye (P = 0.08), but there was a weakly significant difference in the CCT of the left eye (P = 0.05). Also, there was no correlation between cup-to-disc ratio and CCT.

Retinopathy in severe malaria in Ghanaian children--overlap between fundus changes in cerebral and non-cerebral malaria.

BACKGROUND: In malaria-endemic areas, reliably establishing parasitaemia for diagnosis of malaria can be difficult. A retinopathy with some features unique to severe malaria with a predictive value on prognosis, has been described. Detection of this retinopathy could be a useful diagnostic tool. This study was designed to determine the diagnostic usefulness of retinopathy on ophthalmoscopy in severe malaria syndromes: Cerebral malaria (CM) and non-cerebral severe malaria (non-CM), i.e. malaria with respiratory distress (RD) and malaria with severe anaemia (SA), in Ghanaian children. Secondly, to determine any association between retinopathy and the occurrence of convulsions in patients with CM. METHODS AND SUBJECTS: A cross-sectional study of consecutive patients on admission with severe malaria who were assessed for retinal signs, at the Department of Child Health, Korle-Bu Teaching Hospital, Accra, from July to August 2002 was done. All children had dilated-fundus examination by direct and indirect ophthalmoscopy. RESULTS: Fifty-eight children aged between six months and nine years were recruited. Twenty six(45%) had CM, 22 with convulsion; 26(45%) had SA and six(10%) had RD.Any retinopathy was seen in: CM 19(73%), SA 14(54%), RD 3(50.0%), CM with convulsion 15(68%) and CM without convulsion 4(100%). Comparison between CM versus non-CM groups showed a significant risk relationship between retinal whitening and CM(OR = 11.0, CI = 2.2- 56.1, p = 0.001). There was no significant association with papilloedema(OR = 0.9, CI = 0.3 - 3.0, p = 0.9), macular whitening(OR = 1.6, CI = 0.5 - 4.8, p = 0.4), macular haemorrhage(OR = 0.28, CI = 0.03 - 2.7 p = 0.2), retinal haemorrhage(OR = 1.9, CI = 0.6 - 5.6, p = 0.3), vessel abnormality(OR = 1.9, CI = 0.6 - 6.1, p = 0.3) and cotton wool spots(OR not calculated, p = 0.08).Tortuous and engorged retinal veins, not previously described as a feature of CM, was the most common vascular abnormality(15/58 = 26%) and was detected even in the absence of papilloedema. CONCLUSION: Retinal whitening, a sign suggestive of retinal ischaemia, was significantly more common in CM than in non-CM syndromes. However, the high prevalence of any retinopathy in the latter suggests that the brain and the retina may be suffering from ischaemia in both CM and non-CM.

A survey of patients attending an eye clinic in Ghana.

To determine the motivation behind patients attending hospital eye services, 30 in-depth interviews were conducted in Accra, Ghana, using a semi-structured format. Patients were interviewed from five different populations. Discomfort in the eye was the main reason for attending the eye clinic. Patients had high expectations of the doctors and expected to be cured. Limitations such as money, time and travel restricted the frequency of visits. Patients were not generally against doctors seeking second opinions although some expressed disappointment at their doctor being unable to make an immediate diagnosis. The majority of patients were happy for the doctor to seek a second opinion via teleconsultation or any other method. Care needs to be taken to ensure patients return for the outcome of these opinions.

Variation in optineurin (OPTN) allele frequencies between and within populations.

PURPOSE: To evaluate the extent to which mutations in the optineurin (OPTN) glaucoma gene play a role in glaucoma in different populations. METHODS: Case-controlled study of OPTN sequence variants in individuals with or without glaucoma in populations of different ancestral origins and evaluate previous OPTN reports. We analyzed 314 subjects with African, Asian, Caucasian and Hispanic ancestries included 229 cases of primary open-angle glaucoma, 51 cases of juvenile-onset open-angle glaucoma, 33 cases of normal tension glaucoma, and 371 controls. Polymerase chain reaction-amplified OPTN coding exons were resequenced and case frequencies were compared to frequencies in controls matched for ancestry. RESULTS: The E50K sequence variant was identified in one individual from Chile with normal tension glaucoma, and the 691_692insAG variant was found in one Ashkenazi Jewish individual from Russia. The R545Q variant was found in two Asian individuals with primary open-angle glaucoma; one of Filipino ancestry and one of Korean ancestry. In addition to presenting OPTN allele frequencies for Caucasian and Asian populations that have been the subject of previous reports, we also present information for populations of Hispanic and black African ancestries. CONCLUSIONS: Our study contributes additional evidence to support the previously reported association of the OPTN E50K mutation with glaucoma. After finding an additional 691_692insAG OPTN variant, we can still only conclude that this variant is rare. Combined analysis of our data with data from more than a dozen other studies indicates no association of R545Q with glaucoma in most populations. Those same studies disagree in their conclusions regarding the role of M98K in glaucoma. Our analysis of the combined data provides statistically significant evidence of association of M98K with normal tension glaucoma in Asian populations, but not in Caucasian populations; however, the validity of this conclusion is questionable because of large differences in allele frequencies between and within populations. It is currently not possible to tell how much of the underlying cause of the allele frequency difference is attributable to demographic, technical, or ascertainment differences among the studies.

Audit of Web-based telemedicine in ophthalmology.

A Web-based service was set up to link subspecialist ophthalmologists with those seeking advice on particular clinical problems in ophthalmology. The service operated between countries, with centres in Malaysia, Ghana, Tanzania, South Africa and Gambia seeking advice from Moorfields Eye Hospital in the UK. It also operated within country, where a rural clinic in The Gambia sought advice from the central hospital on difficult cases or cases for possible referral. Provision of Web access and training in image capture and manipulation were undertaken in each participating centre. During the first 12 months, 132 cases were posted to the Website from five of the six centres participating. The rate of case referral rose to about 12-14 cases per month by the end of the study. Overall, 24% of referrals did not use images. In the first four months the response time was 13 days, and in the last four months it was three days. Most cases were answered with a single response from the specialist. The main problem was the amount of Internet down-time in each of the locations. The main benefit was safe and reliable access to specialist advice for practitioners.