A pilot project of glaucoma in Barbados

Racial Disparities Affecting Black Patients in Glaucoma Diagnosis and Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Racial Disparities Affecting Black Patients In Glaucoma Diagnosis And Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Evaluation of flow of chorioretinal capillaries in healthy black and white subjects using optical coherence tomography angiography

This study compared macular capillary parameters between healthy black and white subjects using optical coherence tomography angiography (OCTA). We measured vessel density (VD) of superficial (SCP), intermediate (ICP), and deep (DCP) capillary plexuses and choriocapillaris blood flow area (BFA) of the fovea, parafovea and total 3 mm-diameter circular area centered on the fovea, as well as the foveal avascular zone (FAZ) parameters, controlling for axial length. Black subjects had lower foveal and parafoveal VD in the SCP (p = 0.043 and p = 0.014) and the ICP (p = 0.014 and p = 0.002). In the DCP, black subjects had a trend toward lower foveal and parafoveal VD. Black subjects had decreased choriocapillaris BFA in the total 3 mm area (p = 0.011) and the parafovea (p = 0.033), larger FAZ area (p = 0.006) and perimeter (p = 0.014), and a higher capillary density in a 300 μm wide region around the FAZ (FD-300) (p = 0.001). There was no significant difference in FAZ acircularity index. To our knowledge, this is the first report analyzing the three distinct retinal capillary plexuses and identifying differing baseline VD, choriocapillaris and FAZ parameters in healthy young black compared to white subjects. Larger studies are needed to validate these findings and better understand racial differences in vulnerability to ocular diseases.

A Review to Populate A Proposed Cost-Effectiveness Analysis of Glaucoma Screening in Sub-Saharan Africa

To populate a proposed cost-effectiveness analysis of glaucoma screening in Sub-Saharan Africa (SSA).A complete search was conducted on PubMed, Medline and African Journals Online (AJOL) to obtain relevant published articles, which were included in this review. All relevant articles on prevalence of glaucoma in SSA and among other African-derived populations, severity of glaucoma, cost of diagnosis and management, clinical effectiveness of glaucoma screening and treatment and the different glaucoma screening strategies in SSA were reviewed.Population screening interventions for glaucoma may be considered as follows: standalone screening for glaucoma, screening for glaucoma during cataract outreach, and screening incorporated with diabetic retinopathy image review using tele-ophthalmology. Our review suggests that cost of glaucoma treatment is relatively low with cost of medical treatment ranging from USD 273 to USD 480 per year/patient and surgical treatment cost of USD 283 per patient as with other developing countries. Compliance with medication is moderate to good in about 50% of glaucoma patients. Prevalence of glaucoma is much higher in SSA and almost 50% of glaucoma patients are blind in at least one eye at presentation in clinics (without outreach screening). Our review suggests a moderate sensitivity and specificity in identifying glaucoma with basic equipment (direct ophthalmoscope, contact tonometer and frequency doubling technology) during outreach screening although about a third or fewer take up glaucoma services in clinics.Our review provides the necessary information to conduct a cost-effective analysis of glaucoma screening in SSA using the decision Markov model.

A survey of ocular diseases in an isolated rural Haitian community: a retrospective evaluation

PURPOSE

To report the prevalence and incidence of ophthalmic pathology from a small, rural town in Haiti and to determine the leading causes of blindness in this population.

DESIGN

Retrospective study from 2002 to 2009. Data collected include visual acuity, intraocular pressure, and ocular and family history.

METHOD

The study was conducted in a single center--Hospital de Lascahobas, Lascahobas, Haiti. Patients were natives of Lascahobas and the surrounding areas. Treatments were dispensed as indicated or warranted.

RESULTS

A total of 3702 patients were seen and examined: 51.52% were male and 49.48% were female. Ages ranged from 6 months to 92 years (mean, 48.69 SD +/- 49.94). Uncorrected refractive error was the most common diagnosis (53.27%), followed by presbyopia (43.76%), hyperopia (34.03%), and myopia (22.21%). A total 981 patients (26.50%) were diagnosed with cataract. Three hundred twenty-three (32.93%) cataract surgeries were performed. The overall postoperative complications rate was 9.29%. A total of 706 patients (19.07%) were diagnosed with glaucoma: 23.65% were glaucoma suspect and 76.35% were diagnosed with open-angle glaucoma (POAG). Of those diagnosed with POAG, 35.06% had end-stage (absolute) glaucoma. The mean age at diagnosis was 52.56 SD +/- 8.2 years. The mean intraocular pressure was 24.07 and 25.60 mm Hg, and the mean cup to disc ratio of the right eye (OD) and the left eye (OS), respectively, was 0.67 and 0.72.

CONCLUSIONS

Glaucoma was the most common cause for blindness. The most common cause of correctable vision loss was uncorrected refractive error followed by cataract. Providing constant eye care in this region will most likely decrease the incidence of correctable and permanent vision loss.

Glaucoma patient receipt of information and instruction on how to use their eye drops

Objectives

The objectives of the study are: (a) to describe the sources of glaucoma patient's medication information and instruction, and (b) to examine the influence of patient characteristics on the sources of medication information and instruction obtained.

Setting

Four geographically distinct ophthalmology practices in the US.

Method

A survey assessing receipt of information and instruction on how to use eye drops was completed by 324 patients. Multivariable logistic and ordinal regression were used to analyse the data.

Key findings

Fifteen per cent of patients stated that no-one gave them information about their glaucoma medications, and 20% of patients stated that no-one showed them how to use their glaucoma medications. Ophthalmologists were the individuals most likely and ophthalmic technicians were the second-most likely to give the patients information and instruction on how to use their medications. Fourteen per cent of patients stated that pharmacists gave them information about their eye drops. Patients very rarely reported pharmacists or primary care physicians showing them how to use their glaucoma medications. Fourteen per cent of patients reported going to the internet for information. Younger patients were significantly more likely to receive information about glaucoma and glaucoma medications from the internet than older patients.

Conclusion

Patients are receiving information about glaucoma medications from numerous sources, yet almost one out of five glaucoma patients reported receiving no instruction on the instillation of their eye drops. Pharmacists have the opportunity to educate glaucoma patients about using their medications by giving them information and showing them how to administer the medications correctly.

Self-reported prevalence and factors associated with nonadherence with glaucoma medications in veteran outpatients

OBJECTIVE

The purpose of the current study was to determine the self-reported prevalence of and factors associated with nonadherence with glaucoma medications in veteran outpatients.

METHODS

This survey study was conducted at a Veterans Affairs (VA) clinic. A survey was administered to patients with glaucoma. We calculated the percentage of self-reported adherence with glaucoma medications in each patient. Logistic regression was used to assess whether patient characteristics and difficulties with using glaucoma medications were related to patients' reporting that they were <100% adherent with their glaucoma medications in the previous week.

RESULTS

The survey was completed by 141 patients (men, 91.5%; mean [SD] age, 70.22 [11.60] years [range, 37-93 years]; black race, 45.4%; white race, 44.0%; "other" or data unavailable, 10.6%). Nonwhite patients were significantly less adherent in the previous week than were white patients (27.0% vs 11.3%; P < 0.05). A total of 67.4% patients reported > or =1 difficulty in using their glaucoma medications. The 3 most commonly reported difficulties were "drops fall on cheek" (29.1%), "too many drops come out" (20.6%), and "hard to read print" (17.0%). A total of 19.1% of patients self-reported using <100% of their glaucoma medications in the previous week. The number of difficulties reported was significantly associated with reporting being <100% adherent in the previous week (P<0.05).

CONCLUSION

In this small sample of VA patients with glaucoma, adherence to glaucoma medications could be improved, especially among those who reported difficulties using their medications and those who were nonwhite.

Causes of visual impairment and common eye problems in Northwest American Indians and Alaska Natives

OBJECTIVES

Little information exists regarding the causes of visual impairment and the most common eye problems in American Indians/Alaska Natives.

METHODS

We randomly sampled American Indians/Alaska Natives older than 40 years from 3 tribes within the Northwest region.

RESULTS

We found a higher prevalence of visual impairment and normal-tension glaucoma, as well as a lower prevalence of ocular hypertension, in American Indians/Alaska Natives compared with previous results in other racial/ethnic groups.

CONCLUSIONS

American Indians/Alaska Natives have a need for vision correction. Future interventions in American Indians/Alaska Natives should include providing spectacles for refractive error, detecting glaucoma, and preventing visual impairment from age-related maculopathy and cataracts.

A randomised controlled feasibility trial of vitrectomy versus laser for diabetic macular oedema

AIM

(1) To evaluate whether vitrectomy is preferable to further macular laser in improving visual acuity and resolving retinal thickening in patients with diabetic macular oedema (DMO) despite previous laser and no macular traction. (2) To determine the feasibility of further trials in this population in terms of magnitude of comparative clinical effect, rate of recruitment, and loss to follow up.

METHODS

A randomised controlled feasibility study. Patients with DMO and a visual acuity of 0.3 logMAR (6/12) or worse after one or more macular laser treatments were randomised on a 1:1 basis to either pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling or further macular laser. Patients with a posterior vitreous detachment, biomicroscopic evidence of retinal traction, or a taut thickened posterior hyaloid (TTPH) were excluded. Primary outcome measures were (1) best corrected logMAR visual acuity, (2) mean central macular thickness on optical coherence tomography, and (3) rate of recruitment and loss to follow up. Analysis was on an intention to treat basis.

RESULTS

19 patients were randomised to PPV and 21 to further macular laser. The mean baseline logMAR visual acuity was 0.65 (SD 0.28) for the group randomised to PPV and 0.60 (0.23) for the group randomised to laser. The mean change in best corrected visual acuity of the vitrectomy group was deterioration by 0.05 logMAR, while in the control group the mean change was an improvement of 0.03 logMAR. The median (interquartile range) baseline central macular thickness was 403 (337, 492) for the group randomised to PPV and 387 (298, 491) for the controls randomised to laser. The median change in central macular thickness from baseline to review in the vitrectomy group was a thinning by 73 mum (20%) and by 29 mum (10.7%) in the control laser group. This single centre was able to recruit 40 patients in 18 months with follow up of 82% at 1 year.

CONCLUSION

A randomised controlled trial was found to be potentially feasible in this population, the rate of recruitment was however slow and one in five patients were lost to follow up because of death and ill health. These data provide little evidence in terms of visual acuity and macular thickness of any benefit of vitrectomy over further macular laser in patients with an attached hyaloid, DMO despite previous laser, and no clinically evident macular traction or TTPH.

Prevalence of glaucoma in Ponza, Italy: a comparison with other studies

The purpose of this study was to determine the prevalence of glaucoma in Ponza, Italy. The design was a population-based prevalence survey of residents of Ponza aged 40 years or older. There were 1,296 official residents identified by a house-to-house census, of whom 1,226 were identified as eligible for the study. Of these, 1,034 individuals (449 males and 585 females), or 84.3% of the eligible population, participated in the ophthalmological examination. A two-stage method was adopted to identify cases of glaucoma. All subjects underwent a standardized initial examination. Glaucoma suspects and 50% of non-suspects were referred to a definitive examination which included visual field testing. Patients were defined as glaucoma cases if they presented abnormal visual fields and at least one of the following: high 10P, large or asymmetric cup-to-disc ratio. In addition to typical glaucomatous visual field defects such as paracentral scotoma, nasal step, arcuate scotoma and temporal and/or central islands fields, a visual field defect was identified as a decrease in sensitivity greater than 6 db in at least one location of the central 10 degrees, two locations of the central 20 degrees or three locations of the central 30 degrees. Prevalence rates of 2.51% of Primary Open Angle Glaucoma (1.72%-3.66%, CI 95%), 0.97% of Primary Closed Angle Glaucoma (0.53%-1.77%, CI 95%) and 0.29% of secondary glaucoma were found. Moreover, 2.13% of probable POAG (1.41%-3.20%, CI 95%) and 6.00% of High Intraocular Pressure (4.71%-7.61%, CI 95%) were found. The prevalence rates of POAG found in the Ponza Ophthalmological Survey are consistent with the results of other studies. Minor differences are most likely due to the different criteria adopted in the assessment of glaucomatous visual field damage.

The Hong Kong vision study: a pilot assessment of visual impairment in adults

PURPOSE

The Hong Kong Adult Vision Pilot Study is a population based study of the distribution and determinants of eye disease in a random sample of the Chinese population age 40 and over. The present pilot study identifies the extent and causes of visual loss using methods developed in the United States and Australia. The pilot study uses the prevalence data to estimate the sample size necessary to predict the size of an effect a larger study may detect and the confidence with which that effect may be considered and the standard deviation of the Hong Kong population. The smallest detectable odds ratios were calculated based on known risk factor prevalence rates of the pilot study.

METHODS

Hong Kong Chinese residents aged 40 and over in 2 random cluster sites were identified by private household census. The examinations were performed at one location and included, health history and habits, presenting and best corrected LogMar vision, Humphrey visual field and IOP measurement, dilated slit lamp, fundus examination, fundus photography and echography.

RESULTS

In the two test sites, 355 people were examined of the 441 eligible residents (81% response). 76.6% of the population reported a change in vision in the last 10 years; 45% had not sought examination. 4.54% had vision less than 20/60. This was caused by: myopic choroidal degeneration (31%), cataract (19%), cataract + ARM (19%), ARMD (19%), glaucoma (6%), and corneal disease (6%). Vision loss increased significantly with age. Vision loss was more common in older women than in older men. The prevalence rates calculated from the pilot study data were used, requiring a relative precision of 95% and +/- 20% confidence interval of the prevalence rates, indicate that a sample size of 2500 would be a good number for a larger study.

CONCLUSIONS

The methods developed in the United States and Australia for completing eye disease prevalence studies are applicable in Hong Kong. Vision loss is increasingly common in older people and the percent of visual impairment in Hong Kong is higher than studies in the US and Australia. As the population ages demands on the health care systems will increase. The results from this pilot warrant continuation of the study. Efforts must be directed toward prevention of visual loss.

The 'GIST' score: ranking glaucoma for genetic studies. Glaucoma Inheritance Study of Tasmania

The 'GIST' score was developed to facilitate linkage analysis of adult-onset primary open angle glaucoma (POAG) pedigrees in the Glaucoma Inheritance Study of Tasmania (GIST). Previous genetic linkage studies on juvenile open angle glaucoma pedigrees have relied upon an analysis of definitely affected individuals using the 'single best diagnosis' convention. Studies of adult-onset POAG have been complicated by limited numbers of unequivocally affected members identified even in very large pedigrees due to the later onset of the disease. Many members of the pedigree may have equivocal clinical features or are too young to show signs of the disease. The 'GIST score' is a numeric value between zero and one where zero is clinical certainty of absence of the disease and one is the definitive diagnosis of POAG. The score is developed by assigning relative weighting to key clinical features which results in a 'pedigee probability' of the diagnosis being present or absent in a member of a pedigree. Ranking of borderline and unaffected glaucoma subjects allows the laboratory more flexibility in the use of the members of the pedigree for linkage analysis. The score is not intended to have clinical usefulness in management of glaucoma.

Eye disease among ambulatory Jewish senior citizens in California

Knowledge of the epidemiology of eye disease among the elderly becomes increasingly important as our population ages. Leading causes of blindness in the elderly include age-related macular degeneration, open-angle glaucoma and cataract. Few studies have examined the prevalence of these blinding eye diseases among senior citizens. A retrospective review of vision screening examinations from 429 patients seen at the UCLA Mobile Eye Clinic in visits to a Jewish senior citizens' center was performed to examine the distribution of best recorded visual acuity and prevalence of eye disease in a group of ambulatory Jewish senior citizens. Best recorded visual acuity was > or = 20/40 in the better eye for 83.9% of the patients. The prevalence of age-related macular degeneration was 20.7%, and increased with increasing age (p < .00005). The prevalence of open-angle glaucoma was 6.3%. The prevalence of senile cataract was 59.0% and increased with increasing age (p < .00005). Despite the limitations imposed by a retrospective review of charts, our study provides an indication of the prevalence of blinding eye disease and distribution of visual acuity among ambulatory Jewish senior citizens in southern California. Except for the high prevalence of senile cataract, the prevalence data derived from this study are similar to other epidemiologic studies of eye disease in the elderly.

The African Caribbean Eye Survey: risk factors for glaucoma in a sample of African Caribbean people living in London

The purpose of the study was to estimate the prevalence of and risk factors for chronic glaucoma in a sample of African Caribbean people over 35 years of age living in the London Borough of Haringey. A cross-sectional voluntary sample of persons were subjected to detailed ophthalmic assessment including automated tangent screen suprathreshold visual field testing, applanation tonometry and stereoscopic disc evaluation in 50 community-based survey clinics over an 8 month period. Cases and suspects were referred to Moorfields Eye Hospital for more detailed assessment and confirmation of the diagnosis. Of 873 eligible persons examined (out of a total of 1022), 32 definite cases of glaucoma were identified, a prevalence of 3.9%; 42% of these had been previously diagnosed. Approximately 10% of the sample required further assessment and follow-up when ocular hypertensives and glaucoma suspects were included. An age-standardised comparison with the findings of the Roscommon survey revealed a relative risk for glaucoma for Haringey blacks compared with Irish whites of 3.7. Significant risk factors for glaucoma included age, African birthplace and darker skin colour. Neither diabetes nor hypertension reached significance. Despite the lack of a population base, this study provides strong evidence that the 4 times greater risk of glaucoma estimated for American blacks compared with whites applies equally to the United Kingdom population. Community-based facilities are required to raise awareness of the risk among this ethnic minority in this country and case-finding resources should be provided to meet local needs.

Reliability of intraocular pressure measurement with the Goldmann applanation tonometer in epidemiological studies

The reproducibility of intraocular pressure (IOP) measurement with the Goldmann applanation tonometer was investigated as part of a population-based epidemiological study. Sixty-two subjects were examined in a first measurement session. The IOP was measured three times consecutively in both eyes according to a fixed protocol. The mean standard deviation (SD) of these measurements was 0.8 mmHg. The mean intraobserver variation for the first measurement was 1.64 (SD 2.07) mmHg. For the median of the three measurements the intra-observer variation was 1.50 (SD 1.96) mmHg. The mean inter-observer values were 1.79 (SD 2.41) mmHg for the first measurement and 1.60 (SD 2.15) mmHg for the median measurement. The correlation coefficient between the median values of the three measurements of both observers was 0.81. No systematic differences were found between the two observers. Using the median value of three consecutive measurements reduced the inter-observer variation by 11% and the intra-observer variation by 9% compared with a single measurement.

Prevalence of age-related maculopathy. The Beaver Dam Eye Study

PURPOSE

The relationships of retinal drusen, retinal pigmentary abnormalities, and macular degeneration to age and sex were studied in 4926 people between the ages of 43 and 86 years who participated in the Beaver Dam Eye Study.

METHODS

The presence and severity of various characteristics of drusen and other lesions typical of age-related maculopathy were determined by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.

RESULTS

One or more drusen were present in the macular area of at least 1 eye in 95.5% of the population. People 75 years of age or older had significantly higher frequencies (P less than 0.01) of the following characteristics than people 43 to 54 years of age: larger sized drusen (greater than or equal to 125 microns, 24.0% versus 1.9%), soft indistinct drusen (23.0% versus 2.1%), retinal pigment abnormalities (26.6% versus 7.3%), exudative macular degeneration (5.2% versus 0.1%), and geographic atrophy (2.0% versus 0%).

CONCLUSION

These data indicate signs of age-related maculopathy are common in people 75 years of age or older and may pose a substantial public health problem.

Undertreatment of glaucoma among black Americans

BACKGROUND

Cross-sectional studies and those using national data sets estimate that glaucoma-related blindness is between six and eight times more common among black Americans than among whites. Community-based studies have found that glaucoma is four to six times more prevalent among blacks. It is not known why blacks with glaucoma are more likely to become blind than whites with glaucoma.

METHODS

To investigate the possibility that undertreatment of glaucoma is an important factor contributing to this higher rate of blindness, we studied the population-based rates of incisional and laser surgery for open-angle glaucoma among blacks and whites in a 5 percent random sample of Medicare claims for 1986 through 1988.

RESULTS

For all U.S. census divisions combined, the rate of surgery for glaucoma among black Medicare beneficiaries was 2.2 times higher than the rate among white beneficiaries (95 percent confidence interval, 2.1 to 2.3). We calculated an expected rate of treatment among blacks on the basis of the rate of treatment among whites and the assumption that glaucoma is four times more prevalent among blacks--a conservative estimate. The observed rate of glaucoma surgery among blacks was 45 percent lower than the expected rate we calculated, which may in part account for the excess rate of blindness among blacks. The magnitude of this difference in treatment rates varied from 29 percent in the Middle Atlantic states to 50 percent in the South Atlantic states.

CONCLUSIONS

Older black Americans are not receiving potentially sight-saving care for open-angle glaucoma at the same rate as older white Americans.

Calculating the predictive power of the Henson field screener in a population at risk of glaucomatous field loss

Suprathreshold field screeners are in common use for the detection of glaucomatous field loss. The predictive power of a positive result (PP+) depends on the sensitivity and specificity of the screener in the population in which it is to be used. Using data from 755 normal individuals (1510 eyes), we calculated the PP+ of the Henson CFS2000 screening programme for a population aged 50 and over. 4.3% of normal eyes failed the screening programme. Ignoring one or two misses on the screening programme immediately adjacent to the disc reduced this figure to 1.3% and significantly improved the PP+ of the programme. Calculations of the PP+ at increasing glaucoma prevalence levels indicates this to be particularly relevant at low levels such as those encountered when screening middle aged and elderly populations. Optometrists should perform routine field analysis when screening for glaucoma provided they adhere to strict protocols.