glaucoma in Africa – Page 2 – Tropical Ophthalmology

Amsler Grid Test for Advanced Glaucoma!

Colleagues from Ethiopia have done a wonderful Study on applicability of simple Amsler grid to test for visual fieldndefects of central 10 degree field. And they actually found that this works! A usual bkack-on-white Amsler grid was sensitive and specific (80% and 90% accordingly) in comparison with threshold 10 degree Humphrey visual field test. So the defects at the Amsler grid correlated good with the real field losses. A useful additional test for the scarce people/equipment resources!

PLoS One. 2020 Mar 10;15(3):e0230017.
Amsler Grid Test for Detection of Advanced Glaucoma in Ethiopia
Girum W Gessesse 1, Lemlem Tamrat 1, Karim F Damji 2
Affiliations
1Department of Ophthalmology, St Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia.
2Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Canada.

Abstract
Objective: This study was done to determine the validity of amsler grid test black on white (BOW), as well as white on black (WOB) for identifying central visual field (VF) defects in patients with advanced glaucoma.

Design: Prospective study.

Participants: We prospectively included 100 consecutive eyes of 88 adult patients with advanced glaucoma and 100 eyes of 100 normal individuals. We used a lottery method to choose the side of the eye for the control groups.

Methods: All participants had reliable Humphrey 10-2 Swedish Interactive Threshold Algorithm (SITA) standard VF. Both the BOW and WOB amsler grid tests were done for each group. Sensitivity, specificity, and positive and negative predictive values of the amsler grid scotoma area were calculated with the 10-2 VF as the reference standard.

Results: The mean ± standard deviation (SD) of age and the 10-2 VF mean deviation (MD) of advanced glaucoma eyes were 59.8 ± 11.8 (range 34-84) years and -19.94 ± 9.8(range -34.98–0.52) respectively. Among 108 eyes with normal 10-2 VF test, 103 had a normal BOW amsler grid test and 5 had an abnormal BOW test. Among 92 eyes with an abnormal 10-2 VF test, 74 had an abnormal and 18 had normal BOW amsler grid test. Sensitivity, specificity, and positive and negative predictive values of the BOW amsler grid test were 80.4%, 95.4%, 93% and 85.1% respectively whereas that of the WOB amsler grid test were 71.7%, 95.4%, 93% and 72.8% respectively.

Conclusion: The sensitivity and specificity of both BOW and WOB amsler grid tests were high in detecting VF defects in advanced glaucoma.

11.05.2020 Add Comment

Glaucoma in Sub-Saharan Africa: Epidemiology

A brilliant study from Kenya. J Glaucoma. Author manuscript; available in PMC 2019 May 1.
Published in final edited form as:
J Glaucoma. 2018 May; 27(5): 455–463.
doi: 10.1097/IJG.0000000000000941
PMCID: PMC5933523
EMSID: EMS76546
PMID: 29557831
Glaucoma features in an East African population: a six-year cohort study of older adults in Nakuru, Kenya.

Prevalence of Glaucoma: slightly more than 4,0%.

Challenges in Africa good outlined:

Management of glaucoma remains a major challenge in SSA with limited availability and poor adherence to medical treatment when available. A primary surgical approach has problems also, in that patients presenting due to visual loss in one eye need to be persuaded to undergo surgery, most frequently with direct financial costs to them, in the other eye which they do not as yet consider to have a problem. The operation of choice, trabeculectomy augmented by antimetabolites, does not improve the vision in most cases, but in fact can lead to visual acuity reduction. Identification of new treatment options in Africa therefore remains a priority.

03.11.2019 Add Comment

Juvenile Glaucoma in Africa

It is sad to see a very young person going needlessly blind. This is a case of bilateral advanced stage juvenile glaucoma in young 16 y.o. lady. She had bilateral deepest cupping of 1,0 and 6/60 vision in one eye and finger counts at 3 m in the other. Her intraocular pressures were, as it is common here and especially in young persons, – slightly below 50 mm Hg in one eye and 55 mm Hg in the other eye.

The problem of glaucoma in Africa is described nicely and in details elsewhere: https://www.iapb.org/blog/my-challenges-managing-glaucoma-sub-saharan-africa, https://www.ncbi.nlm.nih.gov/pubmed/19225348. My few cents will be like this (in order of relevance):

Lack of early recognition among the patients
Lack of IOP and disks screening among even trained mid-level ophthalmic staff
Poverty, leading to huge delays to a hospital visit
Poverty, leading to inability to buy medications for chronic disease
Unavailability of fency eye drops (only timolol is available in most of rural places, and it’s value in IOP 50 mm Hg is from limited to none)
Lack of follow-ups, leading to unnecessary failure of trabeculectomies

Each of those makes majority of patients with glaucoma present in advanced stages (rarely amenable to medications).

I opted bilateral trabeculectomy with 5-fluorouracil in this case (however, in ideal circumstances I would preferr mitomycin – it is stated to be more effective in studies). She underwent uneventful surgeries for both eyes (one week apart). Right eye (the worse eye), however, showed persistent leakage from fornix-based bleb, and had to be sutured additionally after a week postop. Both eyes dropped the IOPs to mid teens, and the girl’s parents were counselled properly on very important follow-ups during next few months. Failure of trabeculectomy is common first 6 months after the surgery.

Right eye: Bleb additionally sutured to close leakage. I acknowledge, that this is not the ideal way to close leaking bleb, and will release this sutures upon ten days.

Left eye: fornix based diffuse bleb

P.S. I am still not sure on what is the best practice in trabeculectomy in african population regarding the tenon’s capsule. It can be either excised a little, or just undermined, or even sutured to the limbus below the conjunctiva. There were no RCTs on that, and that’s quite important: I feel the chances are higher for the bleb to become cystic if tenon’s was excessively excised.

16.07.2017 Add Comment