NEI-supported research has contributed important knowledge about the cause, progression, and treatment of many eye diseases. Some notable examples are described below.
Age-related macular degeneration AMD typically happens when aging damages the
macula. It is a leading cause of vision loss for older adults. It can blur the sharp central vision needed to read, see faces, and do close-up work. NEI has supported several studies investigating treatments for AMD, including: •
Age-Related Eye Disease Study (AREDS): This
randomized controlled trial showed that a
dietary supplement formula with high doses of
antioxidants,
zinc, and
copper reduced the risk of advanced AMD and related vision loss. •
Age-Related Eye Disease Study 2 (AREDS2): This study investigated the roles of zinc and
beta-carotene in the original AREDS formulation. It also examined whether adding
omega-3 fatty acids and the antioxidants
lutein and
zeaxanthin would improve the effectiveness of the AREDS formulation. Although AREDS2 found no overall additional benefits, it did show that two groups of participants had improved results: participants who took the AREDS formulation with no beta-carotene and participants with very low initial levels of lutein and zeaxanthin in their diets. •
Complications of Age-Related Macular Degeneration Prevention Trial: This study assessed the safety and effectiveness of laser treatment in preventing vision loss caused by AMD in people with large
drusen. It showed that laser treatment was not effective at preventing vision loss. •
Submacular Surgery Trials: These trials investigated the risks and benefits of surgery to remove a type of
lesion—known as
choroidal neovascularization—that is associated with AMD. The results showed that surgery to remove these lesions did not help preserve or improve vision in patients with AMD.
Diabetic retinopathy Diabetic retinopathy is an eye condition that can cause vision loss and blindness in people with diabetes. NEI has supported several studies on the treatment of diabetic retinopathy, including: •
Diabetic Retinopathy Study: This study evaluated whether treatment with either an
argon laser or
xenon arc lamp could prevent severe vision loss caused by diabetic retinopathy. It showed that this type of treatment effectively reduced the risk of severe vision loss, especially in patients at higher risk. •
Diabetic Retinopathy Vitrectomy Study: This study assessed whether patients with diabetic retinopathy would benefit from early
vitrectomy (within one to six months). The results showed that patients receiving early vitrectomy had better
visual acuity than those receiving delayed vitrectomy (after 12 months). •
Early Treatment Diabetic Retinopathy Study: This multicenter, randomized clinical trial investigated using laser treatment and
aspirin to treat and delay the progression of
clinically significant macular edema. This study showed that focal
argon laser photocoagulation reduced the risk of additional vision loss but that aspirin had no effect on the risk, onset, progression, or severity of
retinopathy. •
Anti-VEGF therapy for diabetic retinopathy: This two-year, NEI-supported study, by the DRCR Retina Network found that the drug
Lucentis can be an effective treatment for people with advanced
diabetic retinopathy or proliferative diabetic retinopathy. Lucentis is a
vascular endothelial growth factor (VEGF) inhibitor that can block the growth of abnormal blood vessels—a feature of proliferative diabetic retinopathy. The results suggested that VEGF inhibitors like Lucentis may help prevent
macular edema.
Glaucoma Glaucoma refers to a group of eye diseases that damage the
optic nerve and cause vision loss and blindness. Open-angle glaucoma is the most common form of glaucoma in the United States. Most clinical trials focus on managing open-angle glaucoma by reducing intraocular pressure (IOP), the only known modifiable risk factor for glaucoma. NEI has supported several studies, including: •
Advanced Glaucoma Intervention Study: This
prospective, multicenter randomized trial aimed to assess the long-range outcomes of two intervention sequences to manage advanced glaucoma. After seven years, the study found different results for Black/African American patients and white patients. As a result, a treatment program that begins with
laser surgery is recommended for Black/African American patients with advanced glaucoma, while a treatment program that begins with
trabeculectomy is recommended for white patients with advanced glaucoma and no life-threatening health problems. •
Collaborative Initial Glaucoma Treatment Study: This study compared the effects of medical treatment to early filtration surgery in newly diagnosed open-angle glaucoma. It found that increased eye pressure was significantly decreased in both the medically and surgically treated groups, with the surgery group having a larger decrease. However, in the surgery group, the need for subsequent cataract surgery was significantly higher, and patients were more likely to lose visual acuity and visual field within the first few years. After four years, patients in both groups were similar in visual acuity and visual field. Few patients developed serious vision loss from glaucoma after either treatment. •
Early Manifest Glaucoma Trial: This study evaluated the effects of reducing
eye pressure versus no treatment or late treatment for early open-angle glaucoma. It showed that reducing eye pressure can be valuable as early glaucoma treatment—but when to offer this treatment should be decided on a case-by-case basis. •
Fluorouracil Filtering Surgery Study: This study investigated the safety and effectiveness of
5-fluorouracil after
trabeculectomy. It showed that using 5-fluorouracil after glaucoma surgery improved patients' results and reduced the need for additional surgeries and medications. •
Glaucoma Laser Trial and Glaucoma Laser Trial Follow-up Study: The initial study examined the safety and effectiveness of argon
laser trabeculoplasty for treating primary open-angle glaucoma. The results showed that argon laser trabeculoplasty was as safe and effective as using
timolol maleate eye drops (the standard treatment). The follow-up study confirmed the results and showed that the
side effects of argon laser trabeculoplasty were temporary. •
Ocular Hypertension Treatment Study: This study measured the effectiveness of medicated
eye drops to treat
high eye pressure to see whether this treatment could help prevent primary open-angle glaucoma. It showed that treating high eye pressure with medicated eye drops can safely and effectively delay or prevent primary open-angle glaucoma.
Amblyopia (lazy eye) Amblyopia is a type of visual impairment that occurs when the brain does not recognize visual signals from one eye and favors the other eye. NEI has supported research into effective treatment for amblyopia, including: •
Amblyopia treatment in older children: This study aimed to evaluate whether children older than 7 years with amblyopia could benefit from the treatments used in younger children (
prescription eyeglasses,
patching, and
atropine eye drops). The results showed that older children whose amblyopia was not corrected with eyeglasses alone can benefit from patching or atropine eye drops—especially if they did not get treatment for amblyopia earlier in childhood. •
Amblyopia Treatment Studies: These studies examined several methods of treating amblyopia, including prescription eyeglasses, patching, and atropine eye drops. The results showed that: • Wearing prescription eyeglasses is effective for some children with amblyopia, though others also need occlusion treatment, like patching. • Increasing the daily duration of patching can increase the effectiveness of correction with eyeglasses. • Using atropine eye drops daily is as effective as patching for at least six hours per day. • Wearing a Bangerter filter (a sticker attached to an eyeglass lens to make it opaque) full time is as effective as patching for two hours per day. •
Patching regimens to treat severe amblyopia: An NEI-funded study showed that six hours of daily patching was as effective as full-time patching in treating severe amblyopia in children. •
Pediatric vision scanner for amblyopia screening: NEI funded the development of blinq, a handheld device that easily and accurately screens children for amblyopia.
Corneal stromal keratitis Corneal stromal keratitis or herpetic simplex keratitis is inflammation of the
cornea caused by
herpes infection of the eye. NEI-funded research led to a breakthrough in treatment for this condition: •
Acyclovir Prevention Trial: This multicenter, randomized clinical trial was part of a larger study called the Herpetic Eye Disease Study (HEDS). It investigated whether the oral
antiviral drug acyclovir would prevent herpes infection of the eye from recurring. The study showed that acyclovir reduced the recurrence of both herpes infection of the eye and corneal stromal keratitis, a severe form of the disease.
Optic nerve diseases Optic nerve diseases, like
optic neuropathy and
optic neuritis, can damage the connection between the eye and the visual processing centers of the brain and cause vision loss. NEI has supported studies on the treatment of optic nerve disease, including: •
Ischemic Optic Neuropathy Decompression Trial: This study aimed to evaluate the safety and efficacy of optic nerve
decompression surgery to treat nonarteritic
ischemic optic neuropathy. It found that compared with careful follow-up, this surgery was not beneficial in treating this condition. •
Optic Neuritis Treatment Trial: This study assessed the efficacy of
oral prednisone alone or
intravenous methylprednisolone followed by oral prednisone for treating optic neuritis, which is frequently associated with
multiple sclerosis. The results showed that patients who received intravenous methylprednisolone recovered their vision faster than those who received oral prednisone and had a much lower risk of experiencing optic neuritis again.
Retinopathy of prematurity Retinopathy of prematurity happens when abnormal
blood vessels grow in the retina and cause vision loss and blindness in babies who are
premature or who weigh less than 3 pounds at birth. NEI has supported studies investigating the treatment and progression of retinopathy of prematurity, including: •
Cryotherapy for Retinopathy of Prematurity Trial: This study measured the effectiveness of
cryotherapy in preventing vision loss in babies with retinopathy of prematurity. It showed that cryotherapy could prevent vision loss without risking babies' future ability to see. •
Early Treatment of Retinopathy of Prematurity Study: This study aimed to help doctors use certain eye characteristics to predict which babies would benefit from early treatment with cryotherapy to prevent severe vision loss later in life. The results showed that weekly examinations made it possible to identify infants who would benefit from early treatment. •
Effects of Light Reduction on Retinopathy of Prematurity Trial: This study measured the effect of reduced light exposure in babies with retinopathy of prematurity. It showed that light exposure does not significantly affect premature babies' risk for developing retinopathy of prematurity. •
Supplemental Therapeutic Oxygen for Prethreshold Retinopathy of Prematurity) Trial: This study aimed to determine what effect, if any,
supplemental oxygen therapy has on how retinopathy of prematurity progresses in premature babies. It showed that supplemental oxygen does not cause moderate illness to become severe, so there is no need to restrict the use of oxygen therapy in babies with moderate retinopathy of prematurity. •
Telemedicine Approaches to Evaluating Acute-phase Retinopathy of Prematurity Trial: This study measured whether trained medical staff at a remote image reading center could use retinal photos to identify babies with retinopathy of prematurity as accurately as ophthalmologists examining babies in person. The results showed that the trained medical staff were almost as accurate as ophthalmologists at identifying retinopathy of prematurity in premature babies. They also found nearly half of advanced cases 15 days earlier, on average, than ophthalmologists.
Retinitis pigmentosa Retinitis pigmentosa refers to a group of genetic eye diseases that cause cells in the retina to degenerate, leading to impaired
night vision and loss of
peripheral vision. NEI has supported research into therapies that slow disease progression, including: •
Gene therapy: In a canine model, NEI-funded research showed that gene therapy prevented vision loss in late-stage retinitis pigmentosa by stopping the thinning of the retinal layer (where
photoreceptors are located) and preserving the surviving photoreceptors.
Uveitis Uveitis is inflammation of the
uvea, the middle layer of the eye between the
sclera and the
retina. NEI has supported several studies to examine the causes of uveitis, including: •
First-line Antimetabolites as Steroid-sparing Treatment Trial: This study compared two
steroid-sparing immunosuppressant treatments for uveitis:
methotrexate and
mycophenolate mofetil. It showed that methotrexate is at least as effective as mycophenolate at treating uveitis. •
Multicenter Uveitis Steroid Treatment Trial: This study compared two treatments for uveitis:
steroid and
immunosuppressant pills and a steroid eye
implant (
fluocinolone acetonide implant). This study showed that for most people with uveitis, treatment with steroid and immunosuppressant pills is safer and more effective than steroid implants. •
PeriOcular vs. INTravitreal Corticosteroids for Uveitic Macular Edema Trial: This study compared three treatments for uveitic
macular edema, a common
complication of uveitis:
periocular (near the eye)
triamcinolone acetonide shots,
intravitreal (inside the eye) triamcinolone acetonide shots, and intravitreal shots to place implants that slowly release
dexamethasone inside the eye. This study showed that intravitreal delivery of either
steroid was more effective than periocular delivery at controlling uveitic macular edema and preserving vision. •
Uveitis and T cells: NEI researchers studied
gut bacteria and how it protects the body's natural flora to learn more about how
immune cells attack the eye in
autoimmune eye diseases like uveitis. The study showed that the activation of immune cells, also known as
T cells, to attack the eye is affected by gut bacteria. These results shed light on the causes of uveitis and other autoimmune diseases.
Leber congenital amaurosis Leber congenital amaurosis is a rare inherited eye disease that impairs vision starting in infancy. NEI supported work leading to a
gene therapy for one type of this disease: •
RPE65 gene therapy: NEI-funded research led to the discovery of the RPE65 gene and a
gene therapy for Leber congenital amaurosis associated with an
RPE65 gene mutation. This gene makes a
protein in the
retinal pigment epithelium. In a clinical trial testing the gene therapy, patients with the gene mutation received healthy RPE65 genes by injection. Participants reported an improved ability to see in dim light within days of the treatment, and researchers found evidence of improved eyesight and retinal sensitivity. In December 2017, Luxturna became the first directly administered gene therapy approved in the United States that targets a disease caused by mutations in a specific gene. It was approved for the treatment of patients with confirmed biallelic RPE65 mutation-associated retinal dystrophy that leads to vision loss and may cause complete blindness in certain patients.
Technology development NEI has invested in the development of technologies to support
diagnosis and management. A few examples of this investment include: •
Laser therapies: NEI has contributed to the development and evaluation of medical laser treatments to treat
AMD,
glaucoma, and
myopia (nearsightedness), and other
refractive errors. •
Noninvasive imaging: NEI-funded researchers supported the development of
optical coherence tomography, a technology that allows doctors to see the tissues inside the eye in real time without surgery. With optical coherence tomography, doctors can look for early signs of eye diseases and monitor how a patient's disease progresses or responds to treatment. == Education and outreach activities ==