Long-term Retinal Effects of Pre-eclampsia
New research suggests clinicians should be wary of traction retinal detachment in patients with this common gestational diagnosis.
By Rebecca Hepp, Managing Editor
Add retinal disorders to the long list of possible long-term effects of pregnancy, according to a new study. Researchers looked at more than a million women who delivered a baby in Quebec from 1989 to 2013 and tracked later hospitalizations until March 2014. Of the women studied, the 5.8% diagnosed with pre-eclampsia were more prone to retinal disorders and metabolic disease compared with the study participants without pre-eclampsia.
“We have always known women with pre-eclampsia are at risk for retinal vascular disorders during and immediately after their pregnancies,” says Jill Autry, OD, RPh, a partner at the Eye Center of Texas ophthalmology center. “Interestingly, this article suggests long-term concerns not only for an increased risk of vascular retinopathies but for other retinal conditions such as traction retinal detachment.”
Without adjustments, the study found women with pre-eclampsia had 5.3 times the risk of traction detachments and 3.7 times the risk of retinal breaks. While adjusting for age, parity, period and socioeconomic status had little influence, adjusting for metabolic disorders significantly weakened the associations—for traction detachments and diabetic retinopathy (DR) in particular. Nonetheless, the risks associated with pre-eclampsia continued to be elevated for traction detachments, retinal breaks and DR, the study authors said.
“The study hypothesizes the retinal vascular system may be permanently weakened by pre-eclampsia, as well as the RPE,” Dr. Autry says. “This could put the patient at risk for increased vascular disease, retinal ischemia, serous detachments and traction detachments due to subsequent neovascularization. Important to note is that there was not a significant difference found in rhegmatogenous RD, which further supports a vascular association, not a vitreous link.”
The researchers also broke down the data by gestational onset of pre-eclampsia and found, compared with patients without pre-eclampsia, women with early-onset pre-eclampsia had 8.4 times the risk of DR and 4.6 times the risk of nondiabetic retinopathy. Women with late-onset pre-eclampsia had only 3.6 times the risk of diabetic retinopathy and 1.9 times the risk of nondiabetic retinopathy compared with no pre-eclampsia.
The study had several limitations, including a lack of information on smoking, ethnicity and drug use, as well as the visual acuity associated with the retinal disorders. Finally, the study only addressed patients hospitalized, as the administrative hospital data did not include information on outpatient clinics.
“Many patients with pre-eclampsia have risk factors for the development of vascular disease in their lifetime,” Dr. Autry says. “Patients older than 40, those with underlying DM and HTN, who are overweight or have kidney disease, a history of blood clots, or autoimmune diseases are all at increased risk for pre-eclampsia and, therefore, at higher risk for the long-term associated chronic illnesses also seen in retinal disorders,” she notes. “Certainly, all patients with these risk factors should have regular dilated eye exams over their lifetimes, and maybe we should use a history of pre-eclampsia as a confounding risk factor as well.”
Despite these limitations, the researchers admit metabolic diseases explained only part of the issue, suggesting pre-eclampsia could be an independent risk factor for retinal disorders. Further research will help determine whether a history of pre-eclampsia would also be an indication for screening.
|Auger N, Fraser WD, Paradis G, et al. Pre-eclampsia and long-term risk of maternal retinal disorders. Obstetrics and Gynecology. December 02, 2016. [Epub ahead of print].|
Research Links Zika Virus to Glaucoma
When medical history lists the important issues of 2016, the Zika outbreak will certainly be near the top. The first case of Zika-induced microcephaly reached the United States in January 2016.1 Only a few weeks later, the World Health Organization declared it an international public health emergency, and President Obama sought to infuse $1.8 billion into the fight against Zika.2,3 By November, researchers had identified several systemic issues caused by the virus—including an association with glaucoma in infants, according to a new case study.
Investigators from Yale University, in partnership with a team in Brazil, published a case report linking exposure to the virus during gestation to the development of glaucoma after birth. The report, published in the November issue of Ophthalmology, looked at 13 infants in Brazil who were exposed to Zika in utero. The infants were born with normal head sizes, but later experienced slow head growth. Eleven of them were later diagnosed with microcephaly, and one—a three-month-old male—developed glaucoma.4 This is the first reported link between glaucoma and the Zika virus, the researchers say.
However, this is not the first instance of Zika’s potential impact on ocular disease. In May, a JAMA Ophthalmology report linked congenital Zika infection with several vision-threatening conditions, such as optic nerve abnormalities, bilateral macular lesions and perimacular lesions.5
1. McNeil D. Hawaii reports baby born with brain damage linked to Zika virus. 16 Jan 2016. The New York Times.
2. Sikka V, Chattu V, Popli R, et al. The emergence of Zika virus as a global health security threat: A review and a consensus statement of the INDUSEM joint working group. JGID. 2016 Feb;8(1):3-15.
3. The White House. Office of the Press Secretary. Fact sheet: Preparing for and responding to the Zika virus at home and abroad. 8 Feb 2016. Available at www.whitehouse.gov/the-press-office/2016/02/08/fact-sheet-preparing-and-responding-zika-virus-home-and-abroad. Accessed December 13, 2016.
4. de Paula Freitas B, Ko A, Khouri R, et al. Glaucoma and congenital Zika syndrome. Ophthalmology. 2016 Nov;123(11):S0161-6420.
5. de Paula Freitas B, de Oliveira Dias J, Prazeres J, et al. Ocular findings in infants with microcephaly associated with presumed Zika virus congenital infection in Salvador, Brazil. JAMA Ophthalmology. 2016 May;134(5):529-35.
The Root of Space-Flight Induced Visual Impairment
Until now, researchers were unsure of the underlying mechanism that causes visual impairment intracranial pressure (VIIP) in astronauts serving lengthy missions in space. But new research suggests it is related to volume changes in the cerebrospinal fluid (CSF). Concerns arose as the severe structural changes proved irreversible upon return to Earth.
The last decade has seen a pattern of visual impairment in astronauts who flew long-duration space missions, according to researchers. Blurry vision led to further testing that revealed globe flattening and increased optic nerve protrusion. The primary source of the problem was previously thought to be a shift of vascular fluid toward the upper body within the microgravity of space. This new study, however, suggests the microgravity confuses the CSF by the lack of posture-related pressure changes in space.
Researchers used quantitative imaging algorithms to assess any correlation between changes in CSF volume and structures of the visual system. Results showed that, in addition to increased post-flight globe flattening and inflammation at the head of the optic nerve, long-duration astronauts also had significantly greater post-flight increases in orbital CSF volume.
This research is the first to provide quantitative evidence from short- and long-duration astronauts and identify the role of CSF in globe deformations in astronauts with VIIP.
Video Games & Low Vision
In a study recently published in Scientific Reports, researchers from Vanderbilt University and the University of Rochester found action video games (AVGs)—a form of perception training—yield significant peripheral perception improvements in a pediatric low vision study group.1 These improvements manifested after only eight hours of training and, in a subset, improvements were measurable 12 months later.1
“Children who have profound visual deficits often expend a disproportionate amount of effort trying to see straight ahead, and as a consequence they neglect their peripheral vision,” said Duje Tadin, PhD, associate professor of Brain and Cognitive Sciences at the University of Rochester, in a press release.2
The scientists looked at 24 children and adolescents ages nine to 18 with low vision, and seven pediatric patients with normal vision as controls. The low vision cohort had best-corrected visual acuities between 20/60 and 20/300 and visual fields of at least 35 degrees in both hemifields. No history of cognitive impairment existed in any patient.1
The researchers divided the cohort into groups to study three training regimens: (1) a child-friendly, commercially available AVG; (2) a modified attentional tracking (MAT) task designed to mimic task-specific demands within AVGs; and (3) a control game similar to Tetris. The MAT was designed to have participants track multiple moving objects simultaneously while looking for another object that briefly appears and requires a response from the player; it also eliminated undesirable aspects of AVGs such as the need for a high level of hand-eye coordination and age-inappropriate material.1
By testing direction discrimination, perceptual crowding and a visual search task, researchers found the AVG group’s central and peripheral vision improved by as much as 50% after 10 training sessions.1
Paul Harris, OD, who focuses on vision therapy and rehabilitation at The Eye Center at Southern College of Optometry, says AVGs can be beneficial, but clinicians should be careful. “We know not all games will bring the same level of benefits, but AVGs played in moderation and mixed with movement activities in the real world can be incredibly beneficial in helping to increase the ability to search larger areas of the visual environment more quickly and with less effort.”
“Studies are continuing to show that, in the right amount and with the right kind of game, patients’ visual abilities actually improve in a lasting and positive way,” Dr. Harris adds. Vision therapists are incorporating more game play into therapy, he says, and “when supplemental at-home versions of the software can complement what is done in-office, these systems should help to achieve higher levels of cure in shorter periods of time with far more active involvement of our patients.”
1. Nyquist JB, Lappin JS, Zhang R, Tadin D. Perceptual training yields rapid improvements in visually impaired youth. Scientific Reports. 2016 Nov;6:37431.
2. University of Rochester. Brain training video games help low-vision kids see better. News release. November 28, 2016. Available at www.rochester.edu/newscenter/brain-training-video-games-help-low-vision-kids-see-better-201322. Accessed December 22, 2016.
In the News
The FDA recently granted an orphan drug designation to Impavido (miltefosine, Profounda) for the treatment of Acanthamoeba keratitis. “By creating miltefosine-induced alterations to the membrane architecture of the amoeba, miltefosine allows patients a therapeutic option that has potential advantages over conventional therapy approaches,” said CEO Todd MacLaughlan in a press release.
A federal appeals court recently rejected a request by major contact lens makers for a preliminary injunction, which would have blocked Utah’s anti-price fixing law. Utah passed a law stopping contact lens makers from setting minimum prices for their products, and this upholds a lower court’s ruling that allowed the law to go into effect.
A new study found 6.9% of 130 study participants developed cystoid macular edema (CME) following scleral buckling. The study also found the risk factors associated with CME after scleral buckle included older age, more extended retinal detachment, macular detachment and external drainage. Research suggests that clinicians should use caution when employing external drainage in older patients with extensive retinal detachment.
Lai TT, Huang JS, Yeh PT. Incidence and risk factors for cystoid macular edema following scleral buckling. Eye. December 9, 2016. [Epub].|