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C-56708

An eye on pregnancy

This article will present the most common physiological and pathological ocular conditions induced or affected by pregnancy, as well as the effect of ocular treatments.

Introduction

Pregnancy represents a physiological state associated with a large variety of changes throughout the mother’s body, including metabolic, hormonal, circulatory, immunologic, pulmonary and renal, which allow a healthy gestation and delivery. All organs are affected during this process, including the eye. The changes can be either physiological or pathological and most of the time they revert back to the normal state after delivery or cessation of breastfeeding. In addition, the course of diseases present before the pregnancy can also be altered. Moreover, treatments that were tolerated by the body before gestation could have a detrimental effect on the foetus and, therefore, need to either be stopped or replaced by alternatives.

Physiological ocular changes associated with pregnancy

Structural changes (see Table 1)
Skin and eyelids 

One of the most common changes associated with pregnancy (in up to 90% of cases) is represented by an increase in pigmentation on the face and lids, a reversible condition commonly known as melisma, chloasma or the ‘mask of pregnancy’.1 The amount of pigmentation occurring in each individual woman depends on factors such as genetics, skin pigmentation before pregnancy and sun exposure.Sometimes, spider-like dilated capillaries can also occur on the face and upper body. All of these changes will slowly disappear after delivery but sometimes patches of pigmentation will persist.

CET 1 Table 1

Conjunctiva and cornea

Hormonal changes also affect the tear film physiology and result in dry eye. Pigmentary enhancements, vascular changes and small conjunctival haemorrhages after capillary ruptures (hyposphagma) can also occur, the latter especially during labour, and are harmless.

General water retention in pregnancy also affects corneal thickness, corneal curvature and contributes to a decreased corneal sensitivity. These changes might adversely affect contact lens wear during pregnancy and postpartum lactation. Pigmentary corneal deposits (Krukenberg spindles) can also occur.3

Lens

Fluctuations in refraction observed during pregnancy can also be the result of increased lens hydration and thickness; this can occur in up to 14% of pregnancies.4

Functional changes (see Table 2)
Accommodation

Transient changes in refraction also arise due to temporary reduction in accommodative function during pregnancy and breastfeeding.6

CET 1 Table 2

Intraocular pressure (IOP)

One of the most common ocular findings during pregnancy is decreased IOP. The normal values reduce by 2–3mmHg due to the influence of progesterone on the episcleral veins and, therefore, aqueous humour efflux.7 In addition, pregnancy-induced acidosis also contributes to the observed decrease in IOP values; this change is accentuated as the pregnancy progresses.8

Visual field (VF)

Some studies have revealed that the mean threshold sensitivity increases significantly in the third trimester of pregnancy; these changes are unnoticed by the patients and completely reversible after delivery.9

Pathological ocular changes associated with pregnancy 

Pre-existing conditions 
Glaucoma 

With the exception of women suffering from the juvenile or a secondary form of the disease, it is rare to have a pregnant woman that is suffering from primary glaucoma. However, with more and more women having children later in life, it is possible that this situation will change. 

Many anti-glaucoma medications have a harmful effect on the foetus and, therefore, the treatment plan needs to be changed in most of the cases (see Table 3).10 Sometimes even discontinuation of therapy may be acceptable, as IOP tends to reduce during pregnancy.11 Alternative treatments such as laser trabeculoplasty may be considered on a case-by-case basis. In all cases, working closely with the patient’s obstetrician is highly advisable. 

It is worth noting here that although the IOP can be monitored with non-contact tonometry (NCT), applanation tonometry with a combination of topical anaesthetic and fluorescein can be performed during pregnancy without restriction.7 The use of occasional dilating drops during pregnancy, for the purposes of ocular examination, is safe. 

Diabetic retinopathy (DR) 

There are no differences between the grading of DR between the pregnant and non-pregnant patient, but pregnancy has a detrimental effect on pre-existing DR. Risk factors for progression include coexisting hypertension, severity of DR before conception, duration of diabetes before conception, poor glycaemic control, rapid anti-diabetic treatment and changes in retinal blood flow.12 Patients without DR before becoming pregnant will develop this change in 8-10% of cases, while patients that already have DR will further progress at a rate of 25–29%.13 In addition, vitreous haemorrhages, retinal detachment and blindness as a result of DR are more commonly seen in pregnant patients. DR monitoring in pregnant patients is, therefore, very important. A guideline is presented in Table 4.12,13 

Even before the patient becomes pregnant, an interdisciplinary collaboration, involving the obstetrician, general practitioner, endocrinologist and the ophthalmologist should be arranged. Nevertheless, decisions about laser treatment or vitrectomy for retinopathic changes should be made by the ophthalmologist soon after DR is diagnosed on the basis of the ocular changes alone, regardless of whether the patient is pregnant or not.14

CET 1 Table 3

Thyroid disease (Grave’s hyperthyroidism)

Grave’s disease is the most common cause of hyperthyroidism and can affect women, many of whom are of child-bearing age.15 The disease manifests with tremor, weight loss, cardiovascular changes (tachycardia, fibrillation), intolerance to heat, diarrhoea, irritability, insomnia, and menstrual irregularities. Ocular changes such as exophthalmia, eyelid retraction, conjunctival oedema, ocular irritation, abnormal ocular motility, diplopia, and sometimes visual abnormalities and loss, occur in a large number of patients. 

Pregnancy has a negative impact on Grave’s disease in the first trimester but the condition improves afterwards. The ocular complications should be managed according to normal practice and the ophthalmologist or optometrist that is responsible for the care of the patient should work in collaboration with the patient’s obstetrician and endocrinologist.

Multiple sclerosis (MS)

Another disease that may occur in women of child-bearing age is MS, an acquired demyelinating disorder of the central nervous system that commonly manifests for the first time as an episode of optic neuritis. It has been demonstrated that although pregnancy seems to have a beneficial effect on MS, with symptoms decreasing in severity during gestation, post-delivery, the attacks increase before coming back to the pre-pregnancy levels.16 

Uveitis

Reports show systemic inflammatory conditions, such as rheumatoid arthritis, are positively influenced by pregnancy, possibly due to an increase in the internal corticosteroid levels. However, there are also reports showing that the risk of uveitis is increased in the first trimester of pregnancy.7 Nevertheless, topical anti-inflammatory treatment is considered safe during pregnancy, especially when administered in consultation with the patient’s obstetrician. The cycloplegics used for pain in these cases are also relatively safe but the studies published so far offer limited information so caution is recommended. Posterior uveitis (such as toxoplasmosis) can also be reactivated during pregnancy.

Pituitary adenoma

During pregnancy, there is an enlargement of the pituitary gland; this process could unveil previously asymptomatic small adenomas and result in various symptoms from headache, to visual field defects and vision loss. Pituitary apoplexy represents infarction or haemorrhage of the pituitary gland that can occur in pregnancy. This complication beside the above symptoms, can also produce ophthalmoplegia. After delivery, the adenoma may reduce again in size and all symptoms might disappear. 

Ocular allergies

Ocular allergies can be perennial (due to allergens such as dust or cosmetics) or seasonal (hay fever). The symptoms or occurrence in pregnancy is not different to what happens in non-pregnant women. However, some of the drugs used to treat allergies need to be used with caution during gestation.

CET 1 Table 4

Pregnancy-induced pathologies

Pregnancy-induced hypertension (PIH)

A pregnant woman dies every minute across the world, and a large percentage of these deaths are due to PIH, a disorder that occurs in up to 15% of pregnancies and accounts for about a quarter of all antenatal admissions in the UK.17 This fact is frightening considering that most women go undiagnosed until very late in the course of the disease.

PIH can be classified in two forms: pre-eclampsia and eclampsia. Pre-eclampsia includes a triad of hypertension, oedema and proteinuria. Eclampsia includes the same triad with added seizures.

Practitioners should be aware of the ocular symptoms associated with PIH; these include blurring/loss of vision, diplopia, scotomas and photopsia. A fundus examination can reveal hypertensive retinopathy (in 40–100% of cases), exudative retinal detachments, white-centered retinal hemorrhages, papillophlebitis, Elschnig spots, macular oedema, retinal pigment epithelial (RPE) defects, vascular occlusion, optic neuritis, optic atrophy, ischaemic optic neuropathy and cortical blindness.18 Patients presenting with these signs and symptoms should be referred as an emergency for proper evaluation and prompt treatment. Sometimes, the only measure that can be taken in these cases in order to save the life of the mother and the child is an emergency delivery of the baby. This decision is often taken based on the systemic symptoms and also the fundus appearance. For example, a severe and rapidly progressive retinopathy shows that the maternal circulation is failing generally and the foetus is in grave danger, therefore, action needs to be taken immediately.

Retinal artery and vein occlusion

In pregnancy, there is an increase in the coagulation status. Both branch and central retinal artery occlusions have been reported to occur in pregnancy, with retinal vein occlusions less common than arterial occlusions.However, due to their acute presentation, they require emergency diagnosis, referral and treatment.

Central serous retinopathy (CSR)

CSR represents a serous detachment of the neurosensory retina that occurs over an area of leakage from the choriocapillaris through the RPE. CSR typically resolves spontaneously in most patients. However, even if the central visual acuity returns to normal, many of these patients still notice dyschromatopsia, loss of contrast sensitivity, metamorphopsia, or, in rare cases, nyctalopia.20

Although CSR is predominantly seen in men, it can also occur in pregnant women especially in the third trimester. The disease is reversible after a few months post-delivery but can recur in the same eye if the patient becomes pregnant again.21 In pregnancy, CSR occurs due to the hormonal and circulatory changes but also because of hypercoagulability, increased vascular permeability, decreased colloidal osmotic pressure, and changes in prostaglandin levels that all occur during gestation.22 CSR needs to be monitored and any changes documented. The patient needs to be reassured and informed about the self-limiting nature of the condition.

CET 1 Table 5

Other

Ischaemic optic neuropathy can occur in pregnancy resulting from circulatory changes and an increase in coagulation. The symptoms and treatment are similar to those in a non-pregnant patient.

Purtscher-like retinopathy may also be seen in pregnant women in labour. It presents with sudden decrease in vision (less that 6/60) and white patches on the retina, cotton-wool spots and haemorrhages.

Disseminated intravascular coagulation (DIC) can occur in pregnancy with acute circulatory complications and at the ocular level can present with occlusions of the capillaries leading to RPE atrophy and serous retinal detachments.

Medication and pregnancy

A large number of diagnostic and therapeutic drugs can be used safely during pregnancy. However, there is a lack of complete knowledge about safety of ophthalmic drugs in pregnancy. This article has already outlined the safety of ocular drugs for the treatment of glaucoma, uveitis and ocular allergies. The implications of using common ocular diagnostic drugs during pregnancy is outlined in Table 5.

Chloramphenicol is an over-the-counter drug used to treat mild anterior eye infections. Its administration was previously linked to aplastic anaemia; however, more recent reviews have concluded that the risk is relatively low if the treatment regime is respected. Nevertheless, there are still recommendations to avoid this drug during the last weeks of pregnancy and breastfeeding because it might cause cyanosis and hypothermia in the baby, a condition known as ‘grey baby syndrome.’23 Other studies recommend that the use of chloramphenicol during pregnancy should be avoided altogether.24

Other antibiotics that need to be avoided during pregnancy are neomycin and tetracycline. Safe antibiotics are erythromycin, ophthalmic tobramycin, ophthalmic gentamicin, polymyxin B, acyclovir and the quinolones. Antivirals should be used with caution.22

Conclusion

When the patient is a pregnant woman, the role of the optometrist is complex, from education about the importance of ocular screening, reassurance if benign changes are observed, to appropriate referral when the situation requires it. An important aspect of the optometric care in pregnancy is represented by the management of unstable refractions and contact lens or spectacle prescriptions. Careful assessment of the retinal health and monitoring of pre-existing diseases should be the standard practice to ensure that pregnant patients receive appropriate care that will contribute to a normal gestation and safe delivery of a healthy baby. 

About the author

Dr Doina Gherghel MD, PhD, FHEA, Dipl. OB (ABS) is an academic ophthalmologist with 16 years of experience in teaching undergraduate and postgraduate optometrists. She is a glaucoma specialist and her research is mainly into using the eye as a window to the health of the human body. She has many publications in this field and is a world leader in glaucoma and blood flow research.

References

  1. Jadotte YT, Schwartz RA (2010) Melasma: Insights and perspectives. Acta Dermatovenerol Croat 18:124–9.
  2. Stolp W, Kamin W, Liedtke M (1989) [Eye diseases and control of labor. Studies of changes in the eye in labor exemplified by subconjunctival hemorrhage (hyposphagmas)] Geburtshilfe Frauenheilkd. 49:357–362
  3. Weinreb RN, Lu A, Key T (1987) Maternal ocular adaptations during pregnancy. Obstetrical and Gynecological Survey 42:471–483.
  4. Sharma S RW, Sharma T, Downey G (2006) Refractive issues in pregnancy. Aust N Z J Obstet Gynaecol 46:186–188
  5. Park SB (1992) The effect of pregnancy on corneal curvature. CLAOJ Oct;18(4):256-9.
  6. Garg P and Aggarwal P (2012) Ocular changes in pregnancy. Nep J Oph 4(1):150-161
  7. Mackensen F, Paulus WE, Max R et al (2014) Ocular Changes During Pregnancy. Deutsches Ärzteblatt International 111(33-34):567-576. 
  8. Akar Y, Yucel I, Akar ME et al (2005) Effect of pregnancy on intraobserver and intertechnique agreement in intraocular pressure measurements. Ophthalmologica Jan-Feb; 219(1):36-42.
  9. Akar Y, Yucel I, Akar ME, Uner M, Trak B (2005) Long-term fluctuation of retinal sensitivity during pregnancy. Can J Ophthalmol 40:487–91
  10. Sowka JW (2006) The pregnant glaucoma patient. Review of Optometry Vol. No: 143:09Issue: 9/15
  11. Green K, Phillips CI, Cheeks L et al (1988) Aqueous humor flow rate and intraocular pressure during and after pregnancy. Ophthalmic Res 20:353-7
  12. Bona M, Wong A (2007) The eyes in pregnancy. Ophthalmology Rounds. May/June, Vol. 5, Issue 3
  13. Taub MB. Pregnancy and retina (2008) Review of Optometry, Vol. No: 145:06 Issue: 6/1
  14. Errera MH, Kohly RP, da Cruz L (2013) Pregnancy-associated retinal diseases and their management. Surv Ophthalmol 58:127–142
  15. Lazarus JH (2011) Thyroid function in pregnancy. Br Med Bull 97:137–48
  16. Confavreux C, Hutchinson M, Hours MM, et al (1998) Rate of pregnancy-related relapse in multiple sclerosis. Pregnancy in Multiple Sclerosis Group. N Eng J Med Jul 30;339(5): 285-91
  17. James RP and Nelson-Piercy C (2004) Management of hypertension before, during, and after pregnancy. Heart 90(12):1499-1504
  18. Cheung A, Scott IU (2017) Ocular changes during pregnancy. EyeNet Magazine, March 
  19. Cheung A and Scott IU (2012) Ocular Changes During Pregnancy. Last accessed 3 July 2017
  20. Theng K, Dahi AA (2017) Central serous retinopathy. eMedicine, January
  21. Sunness JS, Haller JA, Fine SL (1993) Central serous chorioretinopathy and pregnancy. Arch Ophthalmol 111(3): 360-364
  22. Chawla S, Chaudhary T, Aggarwal S et al (2013) Ophthalmic considerations in pregnancy. Med J Armed Forces India. Jul; 69(3): 278–284.
  23. Bathia J, Sadiq MN, Chaudhary TA et al (2007). Eye changes and risk of ocular medications during pregnancy and their management. Pak J Ophthalmol 23.1
  24. Chawla S, Chaudhary T, Aggarwal S et al (2013) Ophthalmic considerations in pregnancy. Medical Journal, Armed Forces India, 69(3) 278–284.