Copyright to identify the author of this work is claimed in accordance with the UK Copyright, Designs and Patents Act 1988. It covers basic and understandable anatomy and physiology (which are the basics of understanding how the eye functions, and why and how problems occur), and relates this to patient care and needs.
Preface
Acknowledgements
The Ophthalmic Patient
Introduction
Post-trauma survivors will be in varying degrees of shock depending on the nature and type of accident, and they and their loved ones can be very distressed. This visual loss can be untreatable and permanent, it can be progressive, or vision can be restored.
Registration for the sight-impaired or severely sight-impaired
This means that they have very little time to adapt to the hospital environment and little time to ask the questions that may initially be forgotten in the midst of all the activity. In many conditions there is no or only mild visual impairment and this may be temporary.
Assistance and rehabilitation
The statutory definition for the purpose of registration as a blind person under the National Assistance Act 1948 is that the person is 'so blind as to be unable to perform any work for which sight is essential'. There is no statutory definition of partially sighted, although a person who does not qualify to be registered as blind but is nevertheless significantly visually impaired may be registered as partially sighted.
Voluntary organisations
The registry is a good guide to whether a person is coming to terms with vision loss. Some social services departments have delegated this task to their local voluntary organization dealing with blind and partially sighted people within their area.
The Ophthalmic Nurse
The nurse must be aware of her position and work on the patient's right side when dealing with the right eye and vice versa with the left. The nurse must always remember that there is an individual person behind the eyes being treated, and must care for each patient as a completely unique person.
Assessment of patients
Therefore, the nurse must be manual dexterous and must also have the best possible vision when performing nursing procedures. Since ophthalmic patients can be of any age group, the nurse must be familiar with the special requirements of all ages—especially those of the young and the elderly.
Patient information and teaching
It is also helpful to integrate counseling skills such as using active listening, silence and attention, and paraphrasing to gain additional understanding of the patient's needs. The patient or caregiver will need time to practice these skills following the nurse's guidance.
Professional issues
Nurses have continued to expand their roles in response to the changing demands of the service, increasingly taking on tasks previously performed by physicians. Ophthalmic nurses have a primary responsibility for the quality of care they provide, regardless of the setting.
The nurse in the outpatient department
The visual acuity of all patients visiting the outpatient clinic is recorded, usually under the responsibility of the nurse. She can tell the patient how long the approximate waiting time for the operation is, what it entails and how long the hospital stay will be.
The nurse in the accident and emergency department
The ophthalmic trained nurse will be able to give information to the patient that needs to be discussed in order to come into the hospital for surgery. She must also be able to competently and expertly perform a variety of ophthalmic procedures.
The day case and ward nurse
Postoperative eye care includes dressings, cleaning the eye or skin wound, eye inspection, instillation of drops, and eye protection. Advise patients to avoid using dry cotton wool near the eye, as the fibers may get into the eye.
The nurse in the theatre
Ophthalmic instruments tend to be small, delicate and expensive, so great care must be taken when handling them. A record of which individual instruments and sets of instruments were used for a particular procedure should be maintained in the case notes.
Ophthalmic Nursing Procedures
General principles
Regardless of which type of hemianopia is present, it is important to approach and communicate from the patient's intact side or from the front. Explanations should take into account the patient's learning style and intellectual ability, their physical and emotional state, and any sensory deficits.
Recording visual acuity
Common Charts Used to Measure Distance Visual Acuity The most common chart for measuring distance visual acuity in an adult who can read and write is the Snellen chart (Figure 3.1). It is important to remember to identify in the patient's notes which charting system was used to test the patient's visual acuity; if, for example, the Kay picture card is used, this must be stated in the notes.
PROCEDURE GUIDELINE
Measuring a patient's visual acuity should never be considered a mundane task and time should be set aside for this important skill. Depending on the child's age, different methods of measuring visual acuity should be adapted to suit the child's age, abilities, knowledge, understanding and experience.
Ophthalmic procedures utilising ANTT principles
Principles and protocol for ophthalmic medication instillation/application
If required by the ophthalmic surgeon, the wound or scar should be massaged using the ointment. The district nurse should be involved where it is felt necessary to ensure that eye treatment is carried out.
Clinical practice guidelines
The patient's height and weight are needed to calculate the dosage of Visudyne (Verteporfin). The corrective lens should be in place and the patient taken to the perimeter.
Emergency Ophthalmic Procedures
Slit-lamp examination
Further adjustment of the slit lamp can be achieved with the lever located on the bottom of the table of the slit lamp. Shorter patients or children can be examined right in front of the slit lamp.
Goldmann applanation tonometry
Once the eye is perfectly aligned, look through the eyepieces and fine-tune the focus by using the joystick and moving the exposure lever. 1 The prism comes into contact with the center of the cornea by moving the slit lamp.
Examining the eye
The upper lid is everted to inspect the palpebral conjunctiva over the subtarsal area. 6 Grasp the lashes on the top lid with one hand and gently pull forward and down.
Removing a conjunctival or corneal foreign body
This is to accurately assess the patient prior to examination and removal of foreign bodies. This is to reassure the patient and to obtain the patient's consent and cooperation regarding the procedure.
Applying pad and bandage
You should hold the bandage sleeve upwards with the tail pointing to the right or left depending on the eye to be covered. 2 Apply it under the ear on the affected side and over the center of the eye pad.
Removing a corneal rust ring
Testing for tear film break-up time: assessing the quality of tears
Using the blue slit-lamp filter, the tear film is scanned and the operator begins counting from one until the first dry spot appears. The time that elapses before the appearance of the first dry point is the tear film separation time.
Irrigating the eye
9 First, pour a stream of fluid up the cheek toward the eye to prepare the patient for fluid entering the eye. Allow approximately five minutes between watering and pH testing; testing faster than this means you are testing the irrigating fluid still in the eye and not the tear film.
The Globe: A Brief Overview
The posterior chamber is the area between the posterior surface of the iris and the anterior surface of the crystalline lens. The vitreous humor is a clear gelatinous substance that fills the posterior segment of the eye between the crystalline lens and the retina.
The nerve supply to the eye
The blood supply to the eye
The Protective Structures, Including Removal of an Eye
The orbit
The pen capsule is a thin membrane that surrounds the globe from the edge of the cornea to the optic nerve and adheres closely to the sclera below.
The eyelids
Conditions of the orbit
CONDITION GUIDELINE
The infection does not spread beyond the orbital septum of the upper eyelid into the orbit. 4 Treatment of eyelid droop – the nurse will prepare the patient for eyelid surgery after the M¨uller muscle is divided.
Removal of an eye
A pin can be used to connect the prosthesis to the hydroxyapatite implant to allow for greater movement of the prosthesis when it is in place. 4 Turn the lower cover and slide the lower border of the prosthesis into the lower part of the fornix.
Conditions of the eyelids
Blepharitis can be an acute or chronic inflammatory condition of the eyelid margins and is usually bilateral (Figure 6.8). The patient should remove the offending eyelash(es) that are causing irritation to the eye.
REFLECTIVE ACTIVITY
Skin grafting or flaps may be necessary, depending on the size and position of the tumor. Surgery on the eyelids must be performed with great care to avoid either an ectropion, entropion or trichiasis.
The Lacrimal System and Tear Film
The lacrimal gland
The nerve supply of the lacrimal gland is via the lacrimal nerve, the first branch of the ophthalmic division of the trigeminal nerve. The function of the lacrimal gland is to produce tears in response to stimulation of the trigeminal nerve through, for example, emotions; foreign body in the cornea or conjunctiva; or noxious fumes, such as smoke or peeled onions.
The lacrimal drainage system
The nasolacrimal duct is a downward continuation of the sac for 12-24 mm before it opens into the inferior meatus of the nose under the inferior turbinate bone. The infratrochlear nerve, a branch of the nasociliary nerve, the third branch of the ophthalmic division of the trigeminal nerve, provides the nerve supply to the nasolacrimal duct.
The tear film
1 Oil: the outer layer produced by the meibomian glands of the tarsal plates and also the glands of Moll and Zeis. 3 Mucin: the inner layer produced by the goblet cells of the conjunctiva is a moisturizing substance for easy spreading across the cornea.
Conditions of the lacrimal system
CONDITION GUIDELINES
Sometimes the tube is left in situ (DCR and tubing) for 3-6 months to maintain the patency of the new drainage channels. 1 It is necessary to carefully collect the history of the existing disease, to systematically examine the eyelids, conjunctiva and cornea.
The Conjunctiva and Sclera
The conjunctiva
Conditions of the conjunctiva
A pterygium is a triangular lump in the conjunctiva (Figure 8.3), which usually occurs on the nasal side, but can also be temporary. A pinguecula is a yellow, triangular lump found in the conjunctiva of the elderly and in people who work in exposed conditions.
The sclera
3 Four middle openings: located at the 'equator' where the four vortex veins emerge through the sclera. 4 Anterior opening: lies 4 mm posterior to the limbus where the anterior ciliary vessels pierce the sclera.
Conditions affecting the sclera
2 Posterior aperture: lies around the optic nerve and is the area where the long and short ciliary vessels and nerves enter the sclera to travel forward in the eye to supply the choroid and ciliary body. It has a rich blood supply from the long posterior ciliary arteries to nourish the underlying sclera.
The Cornea
The function of the cornea is to protect the eye and allow refraction of light. The cornea is very sensitive and receives its nerve supply via the long ciliary nerve from the nasociliary nerve.
Physiology of corneal symptoms
The cornea is somewhat nourished by the aqueous humor and capillaries at the edge of the cornea and by the tear film, which contains oxygen from the air.
Conditions of the cornea
A review of the ophthalmic literature on the use of non-steroidal anti-inflammatory drugs in the control of corneal pain is well documented. None of the studies showed any significant adverse effects from the use of topical non-steroidal anti-inflammatory drugs.
The Uveal Tract
The choroid
Blood supply and drainage from the choroid is via the short posterior ciliary artery; and choroidal and vortex veins.
The ciliary body
The nerve supply to the ciliary body is via the short ciliary nerve from the oculomotor nerve.
The iris
The capillaries from these arteries anastomose with the anterior ciliary arteries to form the arterial circle of the iris. The main function of the iris is to control the amount of light entering the eye through the dilation and constriction of the pupil.
Conditions of the uveal tract
Keratic precipitates may be present on the posterior surface of the cornea if the inflammation is severe. Intermediate uveitis is inflammation of the uveal tract which is located in the vitreous humor and peripheral retina.
Glaucoma
Because of cross-infection concerns, disposable prism heads or prism caps should be used. In addition, non-disposable prisms should be inspected regularly to ensure that they are not damaged, as this may result in corneal irritation or damage to the epithelium.
Anatomy and physiology
The posterior chamber is the area between the posterior surface of the iris and the anterior surface of the lens and suspensory ligaments. The blood supply and outflow of blood from the angle of the anterior ventricle takes place through:.
Related disorders – glaucoma
A rapid closure of parts of the angle (see Gonioscopy below) causes the pressure to rise. As more of the angle is blocked with subsequent attacks, chronic closed-angle glaucoma develops.
