Search Results

1. The Heritability of Macular Response to Supplemental Lutein and Zeaxanthin: A Classic Twin Study

Investigative Ophthalmology & Visual Science 2012;53(8):4963-4968.

Purpose.

Antioxidant supplements may reduce age-related macular degeneration (AMD) progression. The macular carotenoids are of particular interest because of their biochemical, optical, and anatomic properties. This classic twin study was designed to determine the heritability of macular pigment (MP) augmentation in response to supplemental lutein (L) and zeaxanthin (Z).

Methods.

A total of 322 healthy female twin volunteers, aged 16–50 years (mean 40 ± 8.7) was enrolled in a prospective, nonrandomized supplement study. Macular pigment optical density (MPOD) measurements using two techniques (2-wavelength fundus autofluorescence [AF] and heterochromatic flicker photometry [HFP]), and serum concentrations of L and Z, were recorded at baseline, and at 3 and 6 months following daily supplementation with 18 mg L and 2.4 mg Z for a study period of 6 months.

Results.

At baseline, mean MPOD was 0.44 density units (SD 0.21, range 0.04–1.25) using HFP, and 0.41 density units (SD 0.15) using AF. Serum L and Z levels were raised significantly from baseline following 3 months' supplementation (mean increase 223% and 633%, respectively, P < 0.0001 for both), with no MPOD increase. After 6 months' supplementation, a small increase in MPOD was seen (mean increase 0.025 ± 0.16, P = 0.02, using HFP). Subdivision of baseline MPOD into quartiles revealed that baseline levels made no difference to the treatment effect. Genetic factors explained 27% (95% confidence interval [CI] 7–45) of the variation in MPOD response. Distribution profiles of macular pigment did not change in response to supplementation.

Conclusions.

MPOD response to supplemental L and Z for a period of 6 months was small (an increase over baseline of 5.7% and 3.7%, measured using HFP and AF, respectively), and was moderately heritable. Further study is indicated to investigate the functional and clinical impact of supplementation with the macular carotenoids.

A classical twin study of 322 twins determined the heritability of macular pigment augmentation in response to 6 months' supplemental lutein and zeaxanthin. There was a small increase in macular pigment optical density, which was moderately heritable; genetic factors explained 27% of variance.

doi:10.1167/iovs.12-9618

PMCID: PMC3410678 PMID: 22700713

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2. The role of heredity in determining central retinal thickness

Liew, S H Melissa | Gilbert, Clare E | Spector, Tim D | Marshall, John | Hammond, Christopher J

The British Journal of Ophthalmology 2007;91(9):1143-1147.

Aims

To examine the relative roles of genetic and environmental factors in central retinal thickness, by performing a classical twin study.

Methods

310 subjects were recruited from the TwinsUK adult registry at St Thomas' Hospital. Optical coherence tomography (Zeiss, stratus OCT3) was used to measure the average retinal thickness in the central 1 mm diameter area. The covariance of central retinal thickness (CRT), within MZ and DZ twin pairs, was compared and genetic modelling techniques were used to determine the relative contributions of genes and environment to the variation in CRT observed in this population.

Main outcome measure

CRT (average retinal thickness in the central 1 mm diameter area, centred on the fovea).

Results

The mean CRT of all subjects was 212.1 μm (range 165–277). CRT was statistically related to refractive error, with increasing myopia associated with a thinner CRT. CRT was more highly correlated within MZ twin pairs (r = 0.88) than with DZ twin pairs (r = 0.58), suggesting a genetic role. A model combining additive genetic and unique environmental factors provided the best fitting model and gave a heritability estimate of 0.90.

Conclusion

Genetic factors appear to play an important role in CRT, with a heritability estimate of 0.90.

doi:10.1136/bjo.2007.114215

PMCID: PMC1954930 PMID: 17360735

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3. The key informant method: a novel means of ascertaining blind children in Bangladesh

Muhit, Mohammad A | Shah, | Gilbert, Clare E | Hartley, Sally D | Foster, Allen

The British Journal of Ophthalmology 2007;91(8):995-999.

Background

Most information on the causes of blindness has come from examining children in special education. To obtain a more representative population‐based sample of children, a novel method was developed for ascertaining severe visually impaired (SVI) or blind (BL) children by training local volunteers to act as key informants (KIs).

Objective

To compare the demography and cause of blindness in children recruited by KIs with other ascertainment methods.

Method

Children with SVI/BL were recruited in all 64 districts of Bangladesh. Three sources for case ascertainment were utilised: schools for the blind (SpEdu), community‐based rehabilitation (CBR) programmes and KIs. All data were recorded using the standard WHO/PBL Eye Examination Record.

Results

1935 children were recruited. Approximately 800 KIs were trained. The majority of the children were recruited by the KIs (64.3%). Children recruited by KIs were more likely to be female (odds ratio (OR) 1.6, p<0.001), of pre‐school age (OR 14.1, p<0.001), from rural areas (OR 5.9, p<0.001), be multiply impaired (OR 3.1, p = 0.005) and be suffering from treatable eye diseases (OR 1.3, p = 0.005) when compared with those in SpEdu. Overall a child with an avoidable causes of SVI/BL had 40% (adjusted CI 1.1 to 1.7, p = 0.015) and 30% (CI 1.0 to 1.7, p = 0.033) higher odds of being ascertained using the KIs compared with SpEdu and CBR methods, respectively.

Conclusion

Using this innovative approach has resulted in one of the largest studies of SVI/BL children to date. The findings indicate that KIs can recruit large numbers of children quickly, and that the children they recruit are more likely to be representative of all blind children in the community.

doi:10.1136/bjo.2006.108027

PMCID: PMC1954788 PMID: 17431019

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4. Why Do People Not Attend for Treatment for Trachomatous Trichiasis in Ethiopia? A Study of Barriers to Surgery

PLoS Neglected Tropical Diseases 2012;6(8):e1766.

Background

Trachomatous trichiasis (TT) surgery is provided free or subsidised in most trachoma endemic settings. However, only 18–66% of TT patients attend for surgery. This study analyses barriers to attendance among TT patients in Ethiopia, the country with the highest prevalence of TT in the world.

Methodology/Principal Findings

Participants with previously un-operated TT were recruited at 17 surgical outreach campaigns in Amhara Region, Ethiopia. An interview was conducted to ascertain why they had not attended for surgery previously. A trachoma eye examination was performed by an ophthalmologist. 2591 consecutive individuals were interviewed. The most frequently cited barriers to previous attendance for surgery were lack of time (45.3%), financial constraints (42.9%) and lack of an escort (35.5% in females, 19.6% in males). Women were more likely to report a fear of surgery (7.7% vs 3.2%, p<0.001) or be unaware of how to access services (4.5% vs 1.0% p<0.001); men were more frequently asymptomatic (19.6% vs 10.1%, p<0.001). Women were also less likely to have been previously offered TT surgery than men (OR = 0.70, 95%CI 0.53–0.94).

Conclusions/Significance

The major barriers to accessing surgery from the patients' perspective are the direct and indirect costs of surgery. These can to a large extent be reduced or overcome through the provision of free or low cost surgery at the community level.

Trial Registration

ClinicalTrials.gov NCT00522860 and NCT00522912

Author Summary

Trachoma is the commonest infectious cause of blindness worldwide. It causes trichiasis (inturning of the eyelashes to touch the eye), which can cause visual loss. Trachomatous trichiasis (TT) affects over eight million people, of whom 1.2 million live in Ethiopia – the most affected country worldwide. Surgery is the mainstay of treatment for TT. Despite the provision of free surgery in many areas, attendance rates are frequently low. An understanding of these barriers is fundamental for instituting measures to increase surgical uptake. In this study we interviewed 2591 people with TT in Ethiopia about their reasons for not having previously attended for surgery. The major barriers to attendance were lack of time, financial constraints and lack of an escort. TT is more prevalent in women and the elderly. Some barriers were particularly frequent in these high risk groups: lack of escort, fear of surgery and not knowing the surgical location impeded women more frequently than men, while financial constraints, transport difficulties and lack of escort affected more of those aged over fifty years than younger participants. It is likely that providing surgery closer to the patients would lessen many of these barriers.

doi:10.1371/journal.pntd.0001766

PMCID: PMC3429389 PMID: 22953007

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5. Capacity building of nurses providing neonatal care in Rio de Janeiro, Brazil: methods for the POINTS of care project to enhance nursing education and reduce adverse neonatal outcomes

Darlow, Brian A | Zin, Andrea A | Beecroft, Gina | Moreira, Maria EL | Gilbert, Clare E

BMC Nursing 2012;11:3.

Background

Increased survival of preterm infants in developing countries has often been accompanied by increased morbidity. A previous study found rates of severe retinopathy of prematurity varied widely between different neonatal units in Rio de Janeiro. Nurses have a key role in the care of high-risk infants but often do not have access to ongoing education programmes. We set out to design a quality improvement project that would provide nurses with the training and tools to decrease neonatal mortality and morbidity. The purpose of this report is to describe the methods and make the teaching package (POINTS of care--six modules addressing Pain control; optimal Oxygenation; Infection control; Nutrition interventions; Temperature control; Supportive care) available to others.

Methods/Design

Six neonatal units, caring for 40% of preterm infants in Rio de Janeiro were invited to participate. In Phase 1 of the study multidisciplinary workshops were held in each neonatal unit to identify the neonatal morbidities of interest and to plan for data collection. In Phase 2 the teaching package was developed and tested. Phase 3 consisted of 12 months data collection utilizing a simple tick-sheet for recording. In Phase 4 (the Intervention) all nurses were asked to complete all six modules of the POINTS of care package, which was supplemented by practical demonstrations. Phase 5 consisted of a further 12 months data collection. In Phase 1 it was agreed to include inborn infants with birthweight ≤ 1500 g or gestational age of ≤ 34 weeks. The primary outcome was death before discharge and secondary outcomes included retinopathy of prematurity and bronchopulmonary dysplasia. Assuming 400-450 infants in both pre- and post-intervention periods the study had 80% power at p = < 0.05 to detect an increase in survival from 68% to 80%; a reduction in need for supplementary oxygen at 36 weeks post menstrual age from 11% to 5.5% and a reduction in retinopathy of prematurity requiring treatment from 7% to 2.5%.

Discussion

The results of the POINTS of Care intervention will be presented in a separate publication.

Trial registration

Current Controlled Trials: ISRCTN83110114

doi:10.1186/1472-6955-11-3

PMCID: PMC3395837 PMID: 22409747

Brazil; Neonatal care; Neonatal nursing; Quality improvement; Neonatal mortality; Premature infant; Retinopathy of prematurity; Education; Continual professional development

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6. Absorbable Versus Silk Sutures for Surgical Treatment of Trachomatous Trichiasis in Ethiopia: A Randomised Controlled Trial

PLoS Medicine 2011;8(12):e1001137.

In this randomized trial, Saul Rajak et al. compare silk sutures (removed at 7–10 days) or absorbable sutures (left in place) during surgery for the management of trachomatous trichiasis.

Background

Trachoma causes blindness through an anatomical abnormality called trichiasis (lashes touching the eye). Trichiasis can recur after corrective surgery. We tested the hypothesis that using absorbable sutures instead of silk sutures might reduce the risk of recurrent disease among patients with major trichiasis in a randomised trial.

Methods and Findings

1,300 individuals with major trichiasis from rural villages in the Amhara Region of Ethiopia were recruited and assigned (1∶1) by computer-generated randomisation sequence to receive trichiasis surgery using either an absorbable suture (polyglactin-910) or silk sutures (removed at 7–10 days) in an otherwise identical surgical technique. Participants were examined every 6 months for 2 years by clinicians masked to allocation. The primary outcome measure was recurrent trichiasis (≥one lash touching the eye) at 1 year. There was no difference in prevalence of recurrent trichiasis at 1 year (114 [18.2%] in the absorbable suture group versus 120 [19.7%] in the silk suture group; odds ratio = 0.90, 95% CI 0.68–1.20). The two groups also did not differ in terms of corneal opacification, visual acuity, conjunctival inflammation, and surgical complications.

Conclusions

There was no evidence that use of absorbable polyglactin-910 sutures was associated with a lower prevalence of trichiasis recurrence at 1 year postsurgery than silk sutures. However, from a programmatic perspective, polyglactin-910 offers the major advantage that patients do not have to be seen soon after surgery for suture removal. The postoperative review after surgery using absorbable polyglactin-910 sutures can be delayed for 3–6 months, which might allow us to better determine whether a patient needs additional surgery.

Trial registration

ClinicalTrials.gov NCT00522860

Please see later in the article for the Editors' Summary

Editors' Summary

Background

Globally, around 40 million people—mostly people living in rural areas in developing countries where there are water shortages, poor personal hygiene, and crowded living conditions—have active trachoma, an infectious eye disease that is caused by Chlamydia trachomatis. This bacterium is spread through contact with infected eye secretions or with contaminated towels or clothes, and by flies. Recurrent infections with C. trachomatis during early childhood cause inflammation of the tissue lining the eye lid (chronic conjunctival inflammation), which can lead to conjunctival scarring. If this scarring is severe, the eyelids turn inwards (entropion) and the lashes rub across the eye's surface (the cornea). This condition—trachomatous trichiasis—is extremely painful and, if not treated with surgery, can lead to irreversible corneal opacities and visual impairment by middle age. It is estimated that 8 million people have trichiasis and that an additional 8 million people are blind or visually impaired as a result of the condition.

Why Was This Study Done?

Surgery for trichiasis, antibiotics for infection, and facial cleanliness and environmental improvements to reduce transmission together constitute the SAFE strategy for the control of blinding trachoma. Unfortunately, trichiasis recurs in nearly two-thirds of patients within 3 years of surgery, often within the first year. How the surgery is performed, its quality, and the severity of entropion and conjunctival scarring at the time of surgery all contribute to trichiasis recurrence. In this randomized trial (a study in which randomly chosen groups of patients receive different treatments for a disease and are followed to compare the outcomes of these interventions), the researchers investigate whether using absorbable sutures instead of silk sutures reduces the risk of recurrent disease among patients with major trichiasis (more than five lashes touching the cornea). Sutures are used to sew up surgical incisions. Silk sutures, which are used routinely during trichiasis surgery, have to be removed 7–10 days after surgery when the incision may not have stably healed. Absorbable sutures might provide more stable fixation of the eye tissue while healing is taking place and might, therefore, reduce the recurrence of trichiasis after surgery.

What Did the Researchers Do and Find?

The researchers randomly assigned 1,300 people living in Ethiopia (the country with the highest rates of trachoma and trichiasis) to receive trichiasis surgery using silk sutures (removed at 7–10 days) or absorbable sutures (left in place); the other details of the surgery were identical for all the patients. The trial's primary outcome was recurrent trichiasis (one or more lash touching the eye) at 1 year. Secondary outcomes included the rate of recurrence, visual acuity, corneal opacity, and conjunctival inflammation at 2 years, and surgical complications. At 1 year, 18.2% of the patients in the absorbable suture group and 19.7% in the silk suture group had developed recurrent trichiasis. That is, the prevalence of recurrence in the two groups was similar. There was also no difference in the rate of trichiasis recurrence between the groups 2 years after surgery. Moreover, the two groups did not differ in terms of corneal opacity and visual acuity, conjunctival inflammation, or surgical complications.

What Do These Findings Mean?

These findings provide no evidence to suggest that the use of absorbable sutures during trichiasis surgery is clinically better than the use of silk sutures. However, the researchers note that the use of absorbable sutures would eliminate the need for patients to return to the clinic soon after their operation to have their sutures removed. In remote rural settings, it can be difficult for patients, who are often elderly and poor, to attend clinics. Thus, it might be better for trachoma services to concentrate on encouraging patients to return 3–6 months after surgery when the need for additional surgery can be determined rather than trying to encourage them to come back after 7–10 days for suture removal. The use of absorbable sutures would also avoid any complications arising from patients failing to come back to have their stitches removed. The researchers suggest, therefore, that trachoma control programs should now consider the potential logistical advantages of using absorbable sutures rather than silk sutures during trichiasis surgery despite the lack of any apparent clinical difference between the two suture types.

Additional Information

Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001137.

An accompanying PLoS Medicine Research Article by Saul Rajak et al. describes another randomized trial undertaken by these researchers that compares surgery and epilation (eyelash removal) for the treatment of trichiasis in Ethiopia

The World Health Organization has information on trachoma (in several languages), including details of the Alliance for Global Elimination of Trachoma by the year 2020 (GET 2020) and a personal story about blinding trachoma

The UK National Health Service Choices website also provide information on trachoma

Orbis, an international nonprofit organization devoted to blindness prevention and treatment in developing countries, provides information about trachoma

The International Trachoma Initiative provides detailed information about trachoma and a personal story about trichiasis surgery in Ethiopia

The Global Atlas of Trachoma is an open-access resource on the geographical distribution of trachoma

Light for the World is a nonprofit organization dedicated to ensuring the rights of persons with disabilities in developing countries, including people in Ethiopia with trachoma

doi:10.1371/journal.pmed.1001137

PMCID: PMC3236737 PMID: 22180732

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7. Surgery Versus Epilation for the Treatment of Minor Trichiasis in Ethiopia: A Randomised Controlled Noninferiority Trial

PLoS Medicine 2011;8(12):e1001136.

In this randomized, non-inferiority trial, Saul Rajak et al compare epilation and surgery for the management of minor trichiasis in Ethiopia, the country with the most cases of trachomatous trichiasis.

Background

Trachomatous trichiasis can cause corneal damage and visual impairment. WHO recommends surgery for all cases. However, in many regions surgical provision is inadequate and patients frequently decline. Self-epilation is common and was associated with comparable outcomes to surgery in nonrandomised studies for minor trichiasis (

Methods and Findings

1,300 individuals with minor trichiasis from Amhara Regional State, Ethiopia were recruited and randomly assigned (1∶1) to receive trichiasis surgery or epilation. The epilation group were given new forceps and epilation training. The surgical group received trichiasis surgery. Participants were examined every 6 months for 2 years by clinicians masked to allocation, with 93.5% follow-up at 24 months. The primary outcome measure (“failure”) was ≥five lashes touching the eye or receiving trichiasis surgery during 24 months of follow-up, and was assessed for noninferiority with a 10% prespecified noninferiority margin. Secondary outcomes included number of lashes touching, time to failure, and changes in visual acuity and corneal opacity.

Cumulative risk of failure over 24 months was 13.2% in the epilation group and 2.2% in the surgical group (risk difference = 11%). The 95% confidence interval (8.1%–13.9%) includes the 10% noninferiority margin. Mean number of lashes touching the eye was greater in the epilation group than the surgery group (at 24 months 0.95 versus 0.09, respectively; p<0.001); there was no difference in change in visual acuity or corneal opacity between the two groups.

Conclusions

This trial was inconclusive regarding inferiority of epilation to surgery for the treatment of minor trichiasis, relative to the prespecified margin. Epilation had a comparable effect to surgery on visual acuity and corneal outcomes. We suggest that surgery be performed whenever possible but epilation be used for treatment of minor trichiasis patients without access to or declining surgery.

Trial registration

ClinicalTrials.gov NCT00522912

Please see later in the article for the Editors' Summary

Editors' Summary

Background

About 40 million people are affected at any one time by active trachoma, an infectious eye disease caused by the bacterium Chlamydia trachomatis. Trachoma, which is responsible for more than 3% of the world's blindness, mostly affects people living in rural areas in developing countries where there are water shortages, poor personal hygiene, and crowded living conditions. C. trachomatis is spread through contact with infected eye secretions or with contaminated towels or clothes, and by flies. Recurrent infections with C. trachomatis during childhood cause inflammation of the lining of the eye lid (chronic conjunctival inflammation), which can lead to conjunctival scarring. If this scarring is severe, the eyelids turn inwards and the eye lashes rub across the eye's surface (the cornea). This condition—trachomatous trichiasis—is extremely painful. Patients describe the pain like having thorns scraping their eyes when they blink. If left untreated, trichiasis can lead to irreversible corneal opacities and visual impairment.

Why Was This Study Done?

The SAFE strategy—surgery for trichiasis, antibiotics for infection, and facial cleanliness and environmental improvements to reduce transmission—aims to control trachoma in countries where it is common. Unfortunately, current surgical activity is only keeping up with new cases of trichiasis; it is not clearing the backlog. The reasons for this treatment gap are complex but in many regions surgical provision is inadequate. Moreover, although the World Health Organization recommends surgery for all cases of trachomatous trichiasis, people with minor trichiasis (only a few eyelashes touching the cornea) often decline surgery, preferring to pull out their eyelashes (epilation), an intervention that has to be repeated when the eyelashes regrow. In this randomized, noninferiority trial, the researchers compare epilation and surgery for the management of minor trichiasis in Ethiopia, the country with the most cases of trachomatous trichiasis. In a randomized trial, randomly chosen groups of patients are given different treatments for a disease and then followed to compare the outcomes of these interventions. A noninferiority trial investigates whether one treatment is not worse than another treatment.

What Did the Researchers Do and Find?

The researchers randomly assigned 1,300 Ethiopians with minor trichiasis to receive surgery or to be given epilation training and good quality epilation forceps. The primary trial outcome was “failure”—five or more lashes touching the eye or receiving trichiasis surgery during the 24-month follow-up period. The researchers decided in advance that epilation would be deemed noninferior to surgery if its failure rate was less than 10% greater than that of surgery (a noninferiority margin of 10%). Secondary outcomes included the number of lashes touching the eye and changes in visual acuity and corneal opacity. The cumulative risk of failure over 24 months was 13.2% in the epilation group and 2.2% in the surgical group, a difference of 11%. The 95% confidence interval for this difference was 8.1%–13.9%. That is, there was a 95% probability that the true failure rate lay within this range. The mean number of lashes touching the eye at 24 months was 0.95 and 0.09 in the epilation and surgery groups, respectively, a significant difference (that is, a difference unlikely to have occurred by chance). Finally, the changes in visual acuity or corneal opacity during the trial were similar in the two groups.

What Do These Findings Mean?

Because the 95% confidence interval for the difference in failure rate of the two interventions included the preset inferiority margin, these findings provide no evidence that epilation is noninferior to surgery for the management of minor trichiasis. That is, statistically speaking, this trial is inconclusive. Thus, if one were to consider only the primary clinical outcome when deciding whether to include epilation in the management of mild trichiasis, one would reject it because this trial indicates that surgery is better than epilation at preventing lashes touching the eye. However, epilation had a comparable effect to surgery on visual acuity and corneal opacity changes and, importantly, in real life, surgical services are likely to remain unacceptable, unavailable, inaccessible, or prohibitively expensive for many people with trachomatous trichiasis in the medium term. The researchers suggest, therefore, that surgery should be performed for minor trachomatous trichiasis whenever possible but that epilation should be considered when surgery is not available or is declined by the patient.

Additional Information

Please access these Web sites via the online version of this summary at http://dx.doi.org/ 10.1371/journal.pmed.1001136.

An accompanying PLoS Medicine Research Article by Saul Rajak et al. describes another randomized trial undertaken by these researchers that compares the use of absorbable and silk sutures for the surgical treatment of trachomatous trichiasis in Ethiopia

The World Health Organization has information on trachoma (in several languages), including details of the Alliance for Global Elimination of Trachoma by the year 2020 (GET 2020) and a personal story about blinding trachoma

The UK National Health Service Choices web site also provides information on trachoma

Orbis, an international nonprofit organization devoted to blindness prevention and treatment in developing countries, provides information about trachoma

The International Trachoma Initiative provides detailed personal story about trichiasis surgery in Ethiopia information about trachoma and a personal story about trichiasis surgery in Ethiopia

The Global Atlas of Trachoma is an open-access resource on the geographical distribution of trachoma

Light for the World is a nonprofit organization dedicated to ensuring the rights of persons with disabilities in developing countries, including people in Ethiopia with trachoma

doi:10.1371/journal.pmed.1001136

PMCID: PMC3236738 PMID: 22180731

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8. The Clinical Phenotype of Trachomatous Trichiasis in Ethiopia: Not All Trichiasis Is Due to Entropion

Investigative Ophthalmology & Visual Science 2011;52(11):7974-7980.

This study found that many patients with trachomatous trichiasis have minimal or no entropion, but rather the trichiasis is frequently due to metaplastic or misdirected eyelashes. The World Health Organization recommends entropion surgery for all. The results of tarsal rotation surgery in patients without manifest entropion should be investigated and alternative treatment strategies evaluated.

Purpose.

Trachomatous trichiasis (TT) is usually described as a cicatricial entropion of the upper lid; however, other forms of trichiasis have been reported. This variation in clinical phenotype is potentially important for treatment guidelines. Therefore, this study was conducted to investigate the range of disease type and severity encompassed by TT.

Methods.

Individuals presenting with TT to surgical treatment campaigns were examined by a single ophthalmologist using the Detailed WHO Trachoma Grading System. Additional features were graded, including type of trichiatic lashes (metaplastic, misdirected, and entropic), lower lid trichiasis, entropion severity, and lid margin mucocutaneous junction (MCJ) position.

Results.

Recruited were 2556 individuals with previously unoperated TT in at least one eye (4310 eyes). The median number of lashes touching the eye was 2 (range, 0 [epilating]–133). Entropion was absent or mild in 2328 (54.0%) eyes, moderate in 1259 (29.2%) eyes, and severe in 723 (16.8%) eyes. Trichiatic lashes were predominantly metaplastic or misdirected (80.2%), rather than secondary to entropion; 4204 (97.7%) had anteroplacement of the MCJ; and lower lid trichiasis was present in 494 (11.5%). Entropion was more severe among those with a low BMI, those who were female, those aged less than 50 years, and those with moderate to severe conjunctival inflammation, central corneal opacity, and severe conjunctival scarring.

Conclusions.

Many patients with TT have minimal or no entropion. The trichiasis is frequently attributable to metaplastic or misdirected eyelashes. The results of tarsal rotation surgery in TT patients without manifest entropion should be investigated and potentially alternative treatment strategies evaluated.

doi:10.1167/iovs.11-7880

PMCID: PMC3219424 PMID: 21896855

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9. The Nigerian national blindness and visual impairment survey: Rationale, objectives and detailed methodology

BMC Ophthalmology 2008;8:17.

Background

Despite having the largest population in Africa, Nigeria has no accurate population based data to plan and evaluate eye care services. A national survey was undertaken to estimate the prevalence and determine the major causes of blindness and low vision. This paper presents the detailed methodology used during the survey.

Methods

A nationally representative sample of persons aged 40 years and above was selected. Children aged 10–15 years and individuals aged <10 or 16–39 years with visual impairment were also included if they lived in households with an eligible adult. All participants had their height, weight, and blood pressure measured followed by assessment of presenting visual acuity, refractokeratomery, A-scan ultrasonography, visual fields and best corrected visual acuity. Anterior and posterior segments of each eye were examined with a torch and direct ophthalmoscope. Participants with visual acuity of < = 6/12 in one or both eyes underwent detailed examination including applanation tonometry, dilated slit lamp biomicroscopy, lens grading and fundus photography. All those who had undergone cataract surgery were refracted and best corrected vision recorded. Causes of visual impairment by eye and for the individual were determined using a clinical algorithm recommended by the World Health Organization. In addition, 1 in 7 adults also underwent a complete work up as described for those with vision < = 6/12 for constructing a normative data base for Nigerians.

Discussion

The field work for the study was completed in 30 months over the period 2005–2007 and covered 305 clusters across the entire country. Concurrently persons 40+ years were examined to form a normative data base. Analysis of the data is currently underway.

Conclusion

The methodology used was robust and adequate to provide estimates on the prevalence and causes of blindness in Nigeria. The survey would also provide information on barriers to accessing services, quality of life of visually impaired individuals and also provide normative data for Nigerian eyes.

doi:10.1186/1471-2415-8-17

PMCID: PMC2572038 PMID: 18808712

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10. Poverty and blindness in Pakistan: results from the Pakistan national blindness and visual impairment survey

BMJ : British Medical Journal 2007;336(7634):29-32.

Objective To explore the association between blindness and deprivation in a nationally representative sample of adults in Pakistan.

Design Cross sectional population based survey.

Setting 221 rural and urban clusters selected randomly throughout Pakistan.

Participants Nationally representative sample of 16 507 adults aged 30 or above (95.3% response rate).

Main outcome measures Associations between visual impairment and poverty assessed by a cluster level deprivation index and a household level poverty indicator; prevalence and causes of blindness; measures of the rate of uptake and quality of eye care services.

Results 561 blind participants (<3/60 in the better eye) were identified during the survey. Clusters in urban Sindh province were the most affluent, whereas rural areas in Balochistan were the poorest. The prevalence of blindness in adults living in affluent clusters was 2.2%, compared with 3.7% in medium clusters and 3.9% in poor clusters (P<0.001 for affluent v poor). The highest prevalence of blindness was found in rural Balochistan (5.2%). The prevalence of total blindness (bilateral no light perception) was more than three times higher in poor clusters than in affluent clusters (0.24% v 0.07%, P<0.001). The prevalences of blindness caused by cataract, glaucoma, and corneal opacity were lower in affluent clusters and households. Reflecting access to eye care services, cataract surgical coverage was higher in affluent clusters (80.6%) than in medium (76.8%) and poor areas (75.1%). Intraocular lens implantation rates were significantly lower in participants from poorer households. 10.2% of adults living in affluent clusters presented to the examination station wearing spectacles, compared with 6.7% in medium clusters and 4.4% in poor cluster areas. Spectacle coverage in affluent areas was more than double that in poor clusters (23.5% v 11.1%, P<0.001).

Conclusion Blindness is associated with poverty in Pakistan; lower access to eye care services was one contributory factor. To reduce blindness, strategies targeting poor people will be needed. These interventions may have an impact on deprivation in Pakistan.

doi:10.1136/bmj.39395.500046.AE

PMCID: PMC2174750 PMID: 18087076

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11. Corneal Endothelial Cells Provide Evidence of Accelerated Cellular Senescence Associated with HIV Infection: A Case-Control Study

PLoS ONE 2013;8(2):e57422.

Background

Cellular senescence may be a key factor in HIV-related premature biological aging. We assessed features of the corneal endothelium that are known to be associated with biological aging, and cellular senescence markers in HIV-infected adults.

Methods

Case-control study of 242 HIV-infected adults and 249 matched controls. Using specular microscopy, the corneal endothelium was assessed for features of aging (low endothelial cell density [ECD], high variation in cell size, and low hexagonality index). Data were analysed by multivariable regression. CDKN2A expression (a cell senescence mediator) was measured in peripheral blood leukocytes and 8-hydroxy-2′-deoxyguanosine (8-OHDG; an oxidative DNA damage marker) levels were measured in plasma.

Results

The median age of both groups was 40 years. Among HIV-infected adults, 88% were receiving antiretroviral therapy (ART); their median CD4 count was 468 cells/µL. HIV infection was associated with increased odds of variation in cell size (OR = 1.67; 95% CI: 1.00–2.78, p = 0.04). Among HIV-infected participants, low ECD was independently associated with current CD4 count <200 cells/µL (OR = 2.77; 95%CI: 1.12–6.81, p = 0.03). In participants on ART with undetectable viral load, CDKN2A expression and 8-OHDG levels were higher in those with accelerated aging, as reflected by lower ECD.

Conclusions

The corneal endothelium shows features consistent with HIV-related accelerated senescence, especially among those with poor immune recovery.

doi:10.1371/journal.pone.0057422

PMCID: PMC3584030 PMID: 23460854

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12. Retinal Arterioles Narrow with Increasing Duration of Anti-Retroviral Therapy in HIV Infection: A Novel Estimator of Vascular Risk in HIV?

PLoS ONE 2012;7(12):e51405.

Objectives

HIV infection is associated with an increased risk of age-related morbidity mediated by immune dysfunction, atherosclerosis and inflammation. Changes in retinal vessel calibre may reflect cumulative structural damage arising from these mechanisms. The relationship of retinal vessel calibre with clinical and demographic characteristics was investigated in a population of HIV-infected individuals in South Africa.

Methods

Case-control study of 491 adults ≥30 years, composed of 242 HIV-infected adults and 249 age- and gender-matched HIV-negative controls. Retinal vessel calibre was measured using computer-assisted techniques to determine mean arteriolar and venular diameters of each eye.

Results

The median age was 40 years (IQR: 35–48 years). Among HIV-infected adults, 87.1% were receiving highly active antiretroviral therapy (HAART) (median duration, 58 months), their median CD4 count was 468 cells/µL, and 84.3% had undetectable plasma viral load. Unadjusted mean retinal arteriolar diameters were 163.67±17.69 µm in cases and 161.34±17.38 µm in controls (p = 0.15). Unadjusted mean venular diameters were 267.77±18.21 µm in cases and 270.81±18.98 µm in controls (p = 0.07). Age modified the effect of retinal arteriolar and venular diameters in relation to HIV status, with a tendency towards narrower retinal diameters in HIV cases but not in controls. Among cases, retinal arteriolar diameters narrowed with increasing duration of HAART, independently of age (167.83 µm <3 years of HAART vs. 158.89 µm >6 years, p-trend = 0.02), and with a HIV viral load >10,000 copies/mL while on HAART (p = 0.05). HIV-related venular changes were not detected.

Conclusions

Narrowing of retinal arteriolar diameters is associated with HAART duration and viral load, and may reflect heightened inflammatory and pro-atherogenic states of the systemic vasculature. Measurement of retinal vascular calibre could be an innovative non-invasive method of estimating vascular risk in HIV-infected individuals.

doi:10.1371/journal.pone.0051405

PMCID: PMC3519635 PMID: 23251521

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13. The Impact of Successful Cataract Surgery on Quality of Life, Household Income and Social Status in South India

PLoS ONE 2012;7(8):e44268.

Background

To explore the hypothesis that sight restoring cataract surgery provided to impoverished rural communities will improve not only visual acuity and vision-related quality of life (VRQoL) but also poverty and social status.

Methods

Participants were recruited at outreach camps in Tamil Nadu, South India, and underwent free routine manual small incision cataract surgery (SICS) with intra-ocular lens (IOL) implantation, and were followed up one year later. Poverty was measured as monthly household income, being engaged in income generating activities and number of working household members. Social status was measured as rates of re-marriage amongst widowed participants. VRQoL was measured using the IND-VFQ-33. Associations were explored using logistic regression (SPSS 19).

Results

Of the 294 participants, mean age ± standard deviation (SD) 60±8 years, 54% men, only 11% remained vision impaired at follow up (67% at baseline; p<0.001). At one year, more participants were engaged in income generating activities (44.7% to 77.7%; p<0.001) and the proportion of households with a monthly income <1000 Rps. decreased from 50.5% to 20.5% (p<0.05). Overall VRQoL improved (p<0.001). Participants who had successful cataract surgery were less likely to remain in the lower categories of monthly household income (OR 0.05–0.22; p<0.02) and more likely to be engaged in income earning activities one year after surgery (OR 3.28; p = 0.006). Participants widowed at baseline who had successful cataract surgery were less likely to remain widowed at one year (OR 0.02; p = 0.008).

Conclusion

These findings indicate the broad positive impact of sight restoring cataract surgery on the recipients’ as well as their families’ lives. Providing free high quality cataract surgery to marginalized rural communities will not only alleviate avoidable blindness but also - to some extent - poverty in the long run.

doi:10.1371/journal.pone.0044268

PMCID: PMC3432104 PMID: 22952945

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