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Corneal Disorders
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Darren S. J. Ting, Rashmi Deshmukh, Daniel S. W. Ting, Marcus Ang
The cornea is a vital transparent structure that forms “the front window of the eye,” playing a key role in vision and ocular surface defense. Corneal damage from insults such as infection, inflammation, and trauma can lead to corneal opacity and resultant visual impairment. According to a recent World Health Organization (WHO) report, corneal opacity represents the fifth leading cause of blindness globally.1 It is estimated that around 4.2 million people were suffering from moderate to severe visual impairment secondary to corneal diseases in 2019.1 More importantly, avoidable corneal blindness has been shown to be significantly more prevalent (up to 90% of all blindness) in developing countries such as Africa (for example, Ethiopia), Myanmar, and many others, primarily attributed to poor sanitation, malnutrition, lower educational level, and limited access to healthcare facilities.2–4
On-Scene Body Assessment
Published in Kevin L. Erskine, Erica J. Armstrong, Water-Related Death Investigation, 2021
Kevin l. Erskine, Erica J. Armstrong
Another ocular change is called corneal opacity. This change is not specifically related to or caused by exposure to air but is enhanced or accelerated by such exposure. On an individual who has died with the eyes open, a thin, whitish film will form over the surface of the cornea within minutes of death, and within two to three hours of death, corneal opacity will develop, giving the cornea a frosted glass appearance (Figure 3.4). If the individual dies with the eyes closed, the appearance of the corneal film will be delayed by several hours, and the appearance of the corneal opacity may be delayed over 24 hours.
Global data on vision loss
Published in John Ravenscroft, The Routledge Handbook of Visual Impairment, 2019
While the prevalence has reduced and the number of people with vision impairment has increased there are only quite small changes in the proportions of the main causes of vision loss (Table 2.2). One important change has been in the proportion of people with cataracts globally, which has reduced particularly in the MSVI category from 26.6% to 18.4%. There are now only very small proportions of the global population with trachoma, as programmes to eliminate trachoma have been successful with the global proportions reducing from 2.8% of vision loss to 1% in 2015. Corneal opacity has also seen a reduction. Age-related macular degeneration has seen a small decline but the proportions of vision loss due to glaucoma and diabetic retinopathy have changed very little.
Peters Anomaly: Novel Non-Invasive Alternatives to Penetrating Keratoplasty
Published in Seminars in Ophthalmology, 2023
Raksheeth Nathan Rajagopal, Merle Fernandes
Postoperative complications, including intense and prolonged anterior segment inflammation, cataract, retinal detachment, graft-related issues, and phthisis, are more common in the pediatric population.37–39 Thus, careful observation appears to be an acceptable strategy, especially in unilateral, less severe cases of PA in which at least some part of the visual axis is clear. Aggressive and early amblyopia management is mandatory in these cases. Spontaneous reduction and even partial clearing of the corneal opacity have been reported by a few authors.40,41 It is prudent to also regularly screen these patients for glaucoma, observe corneal transparency, and estimate visual acuity. Observation can be combined with pharmacological dilation, follow-up if the opacity occupies only the central cornea.42 Enlarging the pupil in this manner facilitates the transmission of visual stimulus through the paracentral clear cornea, possibly preventing stimulus deprivation and consequent amblyopia.
Disparities in Access to Corneal Tissue in the Developing World
Published in Seminars in Ophthalmology, 2023
Catherine Liu, Hajirah N. Saeed
The epidemiology of corneal blindness and disease is complex. Significant variation in etiology and prevalence exists between countries and even populations within those countries. Broadly speaking, corneal opacity is a major cause of corneal blindness and may be a result of many pathologies including corneal injury, infectious keratitis, dystrophy, keratoconus, iridocorneal endothelial syndrome, onchocerciasis, trachoma, and iatrogenic causes.7,8 In developing countries, corneal blindness is most often attributable to anterior cornea pathologies whereas in developed countries, endothelial disease is most often reported.9 However, in the developing world the causes of corneal opacity are often unknown and data collection remains difficult. Nevertheless, rates of corneal blindness are enormously higher in the developing world compared to industrialized nations, so much so that corneal blindness often ranks second only to cataract as the most common cause of blindness.3 The three areas with the greatest burden of corneal blindness are western sub-Saharan Africa, eastern sub-Saharan Africa, and South Asia.10(Figure 1)
Fungal Keratitis in the Egyptian Delta: Epidemiology, Risk Factors, and Microbiological Diagnosis
Published in Ophthalmic Epidemiology, 2022
Nashwa Sadik, Sara Mohamed Elzeiny, Yasmine Emad Ali, Doaa Sobeih
Fungal keratitis often has worse outcomes compared to bacterial keratitis and is more likely to require surgical intervention with subsequent impact on vision.44 In this study, 77% of our patients responded to medical treatment and healed with corneal opacity without surgical intervention despite poor visual acuity. Similarly, our results were consistent with the results of prior studies that were done at the same locality. The outcome, however, varies despite using the same treatment protocol of topical amphotericin B and natamycin. For instance, some research studies showed favorable outcomes in response to medical treatment of approximately 90% and 63% of their patients, while other studies showed poor outcomes.15,32,36,39 Despite the prevalence of the less virulent yeast infection in such studies, the older age of patients and the OCD among their subjects could explain the low success.