CET// PHYSIOLOGY 1 CET POINT A number of physiological changes to the eye can occur during pregnancy. This CET article provides further detail on the effects of pregnancy on pre-existing ocular disease and the eye diseases that can arise during this time. Ocular complications during pregnancy Mark Petrarca BSc (Hons), MCOptom ABOUT THE AUTHOR 46 Mark Petrarca is an optometrist currently undertaking medical and surgical training at St Bartholomew’s Hospital and the London School of Medicine and Dentistry. INTRODUCTION Pregnancy is both an exciting and anxious time for expectant parents. During pregnancy, widespread physiological changes take place in the female body due to the hormones released from the placenta and maternal endocrine glands; these hormones have effects on most organ systems, including the eyes. In addition to the physiological changes, pregnancy can have an impact on pre-existing ocular disease as well as the development of new ocular disease.1 This article will discuss the most commonly reported ocular complications during pregnancy. PHYSIOLOGICAL CHANGES TO THE EYE During pregnancy there can be significant physiological changes to the structure and functioning of the eye. Changes can occur in the ocular adnexa and the cornea, with potential effects on tear production and intraocular pressure. These Course code: C-39551 Deadline: March 7, 2015 LEARNING OBJECTIVES To be able to explain to patients about the ocular changes that can arise during pregnancy (Group 1.2.4) To be able to recognise the ocular changes that can arise during pregnancy by interpreting existing records (Group 2.2.5) To understand the impact of pregnancy upon contact lens wear (Group 5.2.1) To understand the impact pregnancy may have on pre-existing ocular pathology arising from systemic disease (Group 6.1.13) LEARNING OBJECTIVES To be able to explain to patients about the ocular changes that can arise during pregnancy (Group 1.2.4) To understand the impact of pregnancy upon contact lens wear (Group 5.2.2) To be aware of the ocular diseases that can arise during pregnancy (Group 8.1.5) LEARNING OBJECTIVES To be able to explain to patients about the ocular changes that can arise during pregnancy (Group 1.2.4) To be able to recognise the ocular changes that can arise during pregnancy by interpreting existing records (Group 2.2.5) To understand the impact of pregnancy upon contact lens wear (Group 5.4.1) LEARNING OBJECTIVES To understand the impact pregnancy may have on pre-existing ocular pathology arising from systemic disease (Group 1.1.1) February 7, 2015 For the latest CET visit www.optometry.co.uk/cet CET Sponsored by changes are typically benign, temporary in nature, and will resolve postpartum. Ocular adnexal changes The ocular adnexa can be affected by a condition known as chloasma, also called the ‘mask of pregnancy’ (see Figure 1). Chloasma refers to the blotchy, brown discolouration of the skin on the face around the eyes. It is thought that elevated levels of the hormones oestrogen and progesterone stimulate increased activity of melanocytes in the skin. Spider angiomas, a type of telangiectasia, can also develop on the face and upper body.2 Both of these skins conditions are very common and will slowly fade postpartum. Another frequently reported change seen during and after pregnancy is the onset of a unilateral ptosis, and is the result of increased fluid retention and hormonal changes.3,4 Effect on tear production Many women experience dry eyes during pregnancy. Indeed, one study reported reduced tear production in 80% of pregnant women during the third trimester.5 Disruption of the lacrimal acinar cells is thought to be the cause.6 Women reporting symptoms of dry eyes during pregnancy may, therefore, benefit from use of lubricating eye drops and other dry eye treatment strategies. Corneal changes and effect on refraction During pregnancy the cornea can increase in curvature and thickness.7,8 There may also be a optometrytoday decrease in corneal sensitivity.9 These corneal changes are the result of increased water retention by the ocular tissues and usually occur later in pregnancy. As a result, patients may present with temporary alterations in refraction and contact lens wearers are more likely to report reduced lens tolerance.10 It may, therefore, be advisable to delay prescribing new spectacle or contact lens prescriptions until several weeks postpartum. Refractive eye surgery is also contraindicated until six months after birth and following the cessation of breast-feeding. Effect on intraocular pressure Studies that measured intraocular pressures in pregnant women, found that during the second half of pregnancy, intraocular pressure (IOP) tends to decrease in healthy eyes. In patients with ocular hypertension, this decrease can be even greater.11,12 Possible mechanisms for these changes include increased aqueous outflow, decreased episcleral venous pressure, and decreased scleral rigidity. IOP changes typically return to pre-pregnancy levels within two months postpartum.13 THE EFFECTS OF PREGNANCY ON PREEXISTING OCULAR DISEASE Pregnancy can have a significant impact on pre-existing eye diseases. In some cases it can cause further deterioration, whereas in others it can be beneficial. Eye diseases which can be affected by pregnancy include: CET IN ONE PLACE live bookshop CET Points for Optoms, DOs, CLOs and IPs www.optometry.co.uk/cet online enewsletter tv Figure 1 Chloasma seen as brown blotches on the face around the eyes diabetic retinopathy, glaucoma, uveitis, ocular toxoplasmosis, optic neuropathies, pituitary adenomas, meningiomas, and migraines. Diabetic retinopathy This is the most common ocular condition to be affected by pregnancy. Studies have demonstrated the link between pregnancy and the progression of diabetic retinopathy (DR).14 The ophthalmic status should be carefully evaluated in these patients with some suggesting a review should be performed every trimester and within three months postpartum.15 Patients that are diagnosed with gestational diabetes pose a very low risk for the development of retinopathy and, therefore, do not require regular retinopathy screening.16 Patients with severe nonproliferative and proliferative retinopathy have the greatest tendency for progression, while SE VEN CE T PO IN AVAILA TS BL ONLINE E NOW VRICS For the latest CET visit www.optometry.co.uk/cet February 7, 2015 47 CET// PHYSIOLOGY Ocular toxoplasmosis Figure 2 Proliferative diabetic retinopathy 48 those with mild to no retinopathy remain fairly stable during pregnancy. In the Diabetes in Early Pregnancy (DIEP) study, 55% of women with moderate to severe non-proliferative retinopathy demonstrated disease progression whereas 19% of women with mild retinopathy and 10% with no retinopathy showed progression.17 The progression of retinopathy in pregnancy can depend on a variety of factors including: the severity of retinopathy at conception, level of glycaemic control, duration of diabetes, and the presence of any other coexisting vascular diseases.18 Laser photocoagulation is the mainstay of treatment for DR. If retinopathy progresses during pregnancy and severe nonproliferative changes develop it should be treated promptly. Treatment should not be delayed as proliferative changes frequently progress despite intervention with laser photocoagulation (see Figure 2).18,19 7, 8, 7 9 -February 2015 SAT MON 9 FEBRUARY 2015 Excel London EXCEL LONDON February 7, 2015 For the latest CET visit www.optometry.co.uk/cet Glaucoma Glaucoma is primarily a disease of the older population, however, it can affect women of childbearing age. Studies have shown that pregnancy affects the IOP of women with preexisting glaucoma. Both elevations and reductions of IOP have been reported during pregnancy. Visual field test results may also fluctuate during pregnancy.20 During labour, there are reports of increased instances of acute closed-angle glaucoma.21 Uveitis Chronic uveitis may improve during pregnancy; this is possibly due to immunosuppressive effects and high steroid levels present in pregnant women. When flare-ups do occur, they tend to arise during the first trimester; there is also a rebound in activity within the first six months postpartum. This has been seen in patients with ankylosing spondylitis, sarcoidosis and Vogt Koyanagi-Harada syndrome.22-24 Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. It can be acquired by ingestion of infected meat or congenitally if the mother becomes infected during pregnancy and passes it on to the developing foetus via transplacental transmission. Following infection, localised pigmented chorioretinal scars are left behind which may contain the organism in its inactive, encysted form. Occasionally these encysted Toxoplasma organisms reactivate during pregnancy leading to new episodes of toxoplasmosis. Mild cases, which do not threaten the macula, may resolve without treatment. In more severe cases, the duration of the inflammatory episode can be reduced with a regime of antimicrobials such as spiramycin, pyrimethamine and sulfadiazine. Corticosteroids may be given in combination with antimicrobials as an adjuvant therapy, however, indications for their usage is currently debated.25 Pregnant women presenting with reactivated toxoplasmic retinochoroiditis are often concerned about the possibility of transmitting congenital toxoplasmosis to the foetus. However, the risk of transmission in these cases is very low. It is thought that the foetus is protected from congenital toxoplasmosis by maternal antibodies that developed after the mother’s initial infection.26,27 Optic neuropathies There appears to be a reduced incidence of optic neuritis during pregnancy. This is probably due to the immunosuppressive effects associated with pregnancy. Optic neuritis is often associated with multiple sclerosis (MS). In patients REGISTER NOW AT 100percentoptical.com CET //REFLECTIVE LEARNING Having completed this CET exam, consider whether you feel more confident in your clinical skills – how will you change the way you practice? How will you use this information to improve your work for patient benefit? with MS the relapse rate may decrease in the third trimester and then increase during the early postpartum period.28 Optic neuropathy has also been reported in patients with hyperemesis gravidarum – a complication of pregnancy characterised by intractable nausea, vomiting, and dehydration and is estimated to affect 0.5–2.0% of pregnant women. Optic neuropathy occurs in these cases due to excessive loss or insufficient intake of vitamin B. 29 Pituitary adenomas and meningiomas In pregnancy, both pituitary adenomas and meningiomas tend to grow rapidly, and are most likely to manifest during the second half of pregnancy. Intracranial disorders can present with persistent headaches, nausea and vomiting, decrease in visual acuity, visual field loss, and oculomotor palsies. Diagnosis of intracranial disorders can be delayed as some of the symptoms associated with pregnancy, such as nausea, vomiting and headaches may be incorrectly attributed to the pregnancy itself and not as presentations of intracranial disorders.30-32 Migraines Migraine headaches are a common occurrence, affecting 15% of the general population.33 There is a greater prevalence of migraine headaches among women, suggesting that hormone levels, especially oestrogen, can influence the occurrence, frequency, and severity of migraine attacks. Oestrogen levels fluctuate during pregnancy and this can potentially lead to changes in the characteristics of migraine attacks. Both increased and decreased frequencies have been reported.34 EYE DISEASE ASSOCIATED WITH PREGNANCY Pregnancies that are abnormal can lead to the development of eye disease. Examples of pregnancy-associated diseases with ocular manifestations include: pre-eclampsia/eclampsia and vascular clotting disorders such as disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), and haemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome. Pre-eclampsia and eclampsia Pre-eclampsia is a condition characterised by hypertension and proteinuria during pregnancy. It affects about 5% of women and occurs in the second half of pregnancy.35 If a pregnant woman with pre-eclampsia develops seizures, then the disorder is classified as eclampsia.36 Visual disturbances, including scotoma, reduced vision and photopsia, are reported in 25% of women with severe pre-eclampsia and in 50% of women with eclampsia.37 On examination the three most common ocular findings are hypertensive retinopathy, serous retinal detachment, and cortical blindness. In pregnancy-induced hypertensive retinopathy, 60% of women will develop retinal arteriolar spasm and narrowing. Other findings may include haemorrhages, hard exudates, cotton wool spots, and papilloedema.38 The degree of retinopathy usually correlates with the severity of pre-eclampsia.39 The incidence of serous retinal detachments is approximately 1% for severe pre-eclampsia and 10% for eclamptic patients.40 It is thought to be caused by choroidal ischaemia.41 Cortical blindness has also been reported as a cause of visual loss in women with pre-eclampsia and eclampsia. Cortical blindness affects approximately 1–15% of patients with severe pre-eclampsia and eclampsia. It can cause sudden bilateral visual loss in the presence of normal fundi and normal pupillary responses.42 Cerebral oedema in the occipital cortex is believed to be the cause of vision loss. One proposed theory suggests that vasospasms associated with pre-eclampsia cause transient ischaemia, which in turn produces cytotoxic oedema. Vision usually returns within four hours to eight days.43,44 HELLP syndrome Approximately 4–12% of women with severe pre-eclampsia or eclampsia develop haemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome. HELLP can be fatal to both mother and unborn baby. It usually occurs in the last trimester of pregnancy. However, approximately one-third of HELLP cases occur after the baby is born in the first week after delivery.45 Ocular findings associated with HELLP syndrome include bilateral serous retinal detachment with yellow/ white sub-retinal opacities and sometimes vitreous haemorrhage.46 ‘‘’’ Pregnancy-associated diseases with ocular manifestations include pre-eclampsia/eclampsia and vascular clotting disorders Central serous retinopathy In central serous retinopathy (CSR) there is an accumulation of sub-retinal fluid and detachment of the neurosensory retina (see Figure 3, page 50). CSR is a disease that is usually associated with men between 20–50 years of age. However, in pregnancy the incidence of CSR in women increases significantly. Patients typically present with unilateral metamorphopsia, reduced visual acuity, a positive scotoma and micropsia. The onset of visual symptoms usually occurs during the third trimester but it can also develop during the first and second trimesters.47 Elevated levels of endogenous cortisol are thought to lead to increased permeability in the blood-retinal barrier, choriocapillaris, and retinal pigment epithelium (RPE). White fibrous For the latest CET visit www.optometry.co.uk/cet February 7, 2015 49 CET// PHYSIOLOGY eye for DIC to manifest. Patients often complain of visual loss from choroidal infarction or haemorrhage, or serous retinal detachments.51 TTP is a rare systemic coagulopathy that is similar to DIC, characterised by thrombus formation in small vessels and platelet deficiencies. Clinical findings are generally related to retinal arteriole narrowing, serous retinal detachments and optic disc oedema.51,52 USAGE OF OPHTHALMIC DRUGS IN PREGNANCY 50 Figure 3 OCT showing central serous retinopathy. Image courtesy of BBR Optometry Ltd, Hereford subretinal exudates are seen in 90% of pregnancy-associated cases of CSR, compared with 20% of general cases.48 Diagnosis is typically made clinically, but optical coherence tomography has shown to be useful in both identifying and monitoring patients with CSR.49 Observation is the treatment of choice as the condition usually resolves within a few months of postpartum. However, changes to the central visual field, metamorphopsia, and RPE alterations may persist. Occlusive vascular disorders Pregnancy is associated with changes in the coagulation and fibrinolytic systems. As a result, the ease at which blood coagulates and forms clots is increased. Pregnancy is, therefore, a hypercoagulative state; this phenomenon is believed to be a physiological adaptive mechanism to prevent excessive haemorrhaging during pregnancy and child birth.50 Unfortunately, this hypercoagulative state is associated with an increased risk of developing vessel occlusions and clotting disorders such as disseminated intravascular coagulation (DIC) and thrombotic thrombocytopenic purpura (TTP). Both branch and central retinal artery occlusions can occur in pregnancy. Retinal vein occlusions can also occur but are rare. DIC is an acute pathological process associated with widespread activation of the clotting system resulting in thrombus formation in small vessels throughout the body. This leads to compromised tissue blood flow and ultimately leads to multiple organ damage. Additionally, the coagulation process consumes large quantities of clotting factors and platelets, and as a result, normal clotting is disrupted and severe bleeding occurs. It is associated with obstetric complications such as abruptio placentae, pre-eclampsia/ eclampsia, amniotic fluid embolism, retained intrauterine fetal demise, and septic abortion. The choroid is the most common location in the Exam questions Under the enhanced CET rules of the GOC, MCQs for this exam appear online at www.optometry.co.uk/cet/exams. Please complete online by midnight on March 7, 2015. You will be unable to submit exams after this date. Answers will be published on www.optometry.co.uk/cet/exam-archive and CET points will be uploaded to the GOC every two weeks. You will then need to log into your CET portfolio by clicking on ‘MyGOC’ on the GOC website (www.optical.org) to confirm your points. February 7, 2015 For the latest CET visit www.optometry.co.uk/cet The usage of ophthalmic medications during pregnancy can pose a potential risk to both the mother and foetus. In the majority of cases the risk is usually low, due to the dosages used and the topical mode of administration.53 The risk of systemic absorption can be further reduced by punctal occlusion, eyelid closure, and blotting the excess drops away during administration.54 Pregnant women that require regular use of ophthalmic medications for chronic eye diseases, such as glaucoma for example, may need to have their medications changed or consider alternative treatments for the duration of their pregnancy. CONCLUSION Practitioners will examine the eyes of many pregnant women in routine practice. In the vast majority of cases the ocular changes seen in pregnancy are either physiological or transient in nature. Occasionally, pregnancy can be associated with pathology that can cause sight loss. It is, therefore, important that clinicians have a firm understanding of the various ocular changes associated with pregnancy and the implications they may have for management. 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