Cataract complications during a pandemic
Ophthalmologists should be wary of the impact of COVID-19
The newly described viral pathogen SARS-CoV-2 has changed the world as we know it. Belonging to the group of coronaviruses that are known to easily hop between species, SARS-CoV-2 is believed to have hopped from bats to humans.
Presenting with constitutional symptoms such as fever (88%), fatigue (38%), headache, nasal congestion, sore throat, dry (68%) or productive cough (33%) in many cases, SARS-CoV-2 can in some patients go on to a severe pulmonary phase (Stage 2) and sometimes onwards to a hyperinflammatory phase (Stage 3). Systemic factors such as inflammation, homeostatic changes, endothelial dysfunction and coagulopathy can cause a progressive thrombotic cascade leading on to microvascular and large vessel thrombosis and multi-organ involvement that can be fatal.
EFFECT OF COVID-19 ON BURDEN OF OCULAR DISEASE AND CATARACT
The SARS-CoV-2 pandemic brought a change to the way we practise. At the beginning of the pandemic, all elective eye surgeries as well as routine non-emergent visits to the ophthalmologist were suspended for fear of transmission of infection as well as to conserve personal protective equipment (PPE) for those who needed it more. However, currently in many countries, patients are coming for routine evaluations and elective surgeries. Unfortunately, in many patients, new disease has presented or existing disease has progressed, sometimes irreversibly. Lack of access to care and/or medications as well as fear of going to the hospital despite having serious disease has taken its toll on many patients.
There is a huge backlog of cataract that has built up. Cataract progression has caused a decrease in uncorrected and best-corrected visual acuity (BCVA). More patients are presenting with mature cataracts and severely limited vision. Patients with progressive nuclear sclerosis where a change in spectacles might have improved BCVA continue to wear old glasses, which no longer adequately correct.
Cataract-related complications are seen in higher numbers such as phacomorphic or phacolytic glaucoma, leaking Morgagnian cataract, progressive zonulopathy with subluxation etc. Bilateral cataracts as well as loss of depth perception from unilateral cataracts can be problematic and may even be the cause for increased risk of falls or road traffic accidents, thereby increasing systemic morbidity and demands on an already strained health system.
In many patients, even if the cataract is mild it may interfere with the patient’s ability to work and in such cases, cataract surgery is indicated without delay.
NON-CATARACT RELATED COMPLICATIONS
Other ocular co-morbidities may affect patients with cataract such as progression of glaucoma, relapse of uveitis or even rejection of a previously well-functioning corneal graft. Patients with advanced cataract may not notice worsening of underlying disease such as diabetic retinopathy, age-related macular degeneration etc, resulting in continuing damage.
COVID-positive patients may present to the ophthalmologist in many ways including non-specific symptoms such as watering, conjunctivitis, pink eye, chemosis, dry eye etc, symptoms that were noticed in one-third of patients with COVID-19. Some of these symptoms were reported to be more common in those with more severe disease.
Retinitis, vasculitis, uveitis and optic neuritis from coronaviruses are reported in animals; however, ocular manifestations in humans were initially considered rare and not very severe.
Recently though, more severe ocular disease has been associated with COVID-19. This includes non-specific retinopathy due to microangiopathy, retinal vascular occlusions including central retinal artery occlusion, vein occlusions, non-arteritic ischaemic optic neuropathy, maculopathy, Miller Fisher syndrome, oculomotor nerve palsies, panuveitis, optic neuritis etc. There are also reports of severe orbital mucormycosis, which may become life threatening.
If found to be positive for SARS-CoV-2, surgery may need to be postponed until about two weeks after symptom onset, though there are various other criteria proposed by professional bodies.
PLANNING CATARACT SURGERY
Performing cataract surgery safely needs certain changes in protocols. Patient questionnaires about possible exposure to COVID-19, hand hygiene, masking and social distancing should be strictly employed. Telephonic and online consultations should be used where possible to cut down actual visit time to the minimum.
Teleophthalmology may be used where photo documentation together with measurement of physical parameters by allied health personnel are evaluated by the surgeon to further investigate or order a direct examination or treatment. Electronic records make streamlining easier and e-consenting to surgery may also be done.
Though the virus has been detected in tear samples by RT-PCR, the risk of viral transmission through ocular secretions is possibly low. This has however not been proven conclusively. Precautions such as using cotton-tipped applicators to lift eyelids/ apply eyedrops and proper disinfection techniques for contact surfaces, tonometers, trial frames, B-scan probes, applanation heads and contact lenses should be employed. Use of appropriate PPE such as N95 masks, gloves, eye protection and/ or a face shield are important. Direct ophthalmoscopy should be avoided. Two teams and staggered schedules may be considered for health care workers.
Preference for surgery may be given to those with advanced cataract, bilateral disease, one-eyed patients, those with ocular co-morbidities that affect decision-making and situations such as the second eye in bilateral high myopes with one eye operated to avoid postoperative aniseikonia. Surgeries should be scheduled according to complexity, with more demanding surgeries allotted to senior surgeons so that theatre time can be kept to a minimum.
Immediate sequential bilateral cataract surgery may be considered in some cases to decrease risks associated with presenting for surgery twice. Patients requiring general anaesthesia need special care and protocols to be followed with surgeons and staff not entering the room for 15 minutes after intubation or extubation.
Pre-surgical COVID testing may be decided on a case-to-case basis as well as depending on individual country/ hospital guidelines.
PRECAUTIONS IN SURGERY
Surgery is ideally done wearing an N-95 mask or a filtering facepiece respirator. Topical anaesthesia is preferred. The patient may be given a mask that is taped along the upper edge to the nose to avoid air leak. Unnecessary talking should be discouraged during surgery.
Infectivity and aerosolisation can be decreased by proper draping, avoiding leak of exhaled air from under the drape, instillation of 5% povidone iodine drops into the conjunctival sac, replacing aqueous with viscoelastic before initiating ultrasound, switching on irrigation only after entering the anterior chamber and applying viscoelastic (HPMC) over the incision while emulsifying.
Post-surgical counselling time should be kept to a minimum and may be done telephonically.
Dr Soosan Jacob is Director and Chief of Dr Agarwal’s Refractive and Cornea Foundation at Dr Agarwal’s Eye Hospital, Chennai, India and can be reached at email@example.com