Preoperative Considerations

 

Patient selection

 

Successful management of cataracts relies on developing a clear understanding of the patient’s health, visual disability, and nature of any pre-existing comorbidities at the preoperative visit. Need for cataract surgery is guided by the patient’s current visual acuity as well as the ramifications of reduced vision on the individual’s quality of life.

 

Determining the need for cataract surgery in a patient with disability is not always clear. The caregiver’s account can serve as a proxy for assessing visual disability for the patient. However, this must also be supplemented by the cataract surgeon’s own evaluation of the patient’s potential benefit from cataract surgery. For instance, it is not uncommon for a change in behaviour such as increasing frustration, anger, withdrawal, or self-harm to be a sign of visual loss.9 However, these symptoms of physical ill health are often mistakenly attributed to behavioural problems or sometimes seen as being inherent to the patient’s disability.9

 

In view of a limited history and physical examination, the decision to operate is based on achieving functional vision for day-to-day activities for the patient balanced against the postoperative risks. Anecdotally, concerns regarding eye rubbing, adherence to postoperative drop regimens, and postoperative infection are common grounds for declining cataract surgery to patients with cognitive impairment.9 In this group of patients, caregivers often assume the main responsibility of ensuring adherence to postoperative instructions. Surgical outcomes depend on the caregivers’ preparedness and their ability to follow through with the care plan.10 With that knowledge and shared understanding of the postsurgical course, an informed decision can be undertaken to select an optimal candidate for cataract extraction and intraocular lens (IOL) implantation.

 

Surgical planning

 

The primary goal of the initial preoperative clinic assessment is to establish an understanding of patient factors that may influence optimal surgical performance and outcome of cataract surgery.11 These considerations may include the ability of the patient to lie flat for the duration of the surgery and have the mental focus to understand and cooperate during the procedure. For instance, surgical positioning may pose an extreme challenge in patients with cervical spine immobility due to ankylosing spondylitis, severe arthritis, or kyphosis. Evaluating these patients in the office examination chair provides the surgeon an opportunity to anticipate necessary accommodations for carrying out surgery safely and comfortably. In general, reviewing the mechanics of the surgical procedure is beneficial for all patients preoperatively and especially for patients with hearing loss, extreme anxiety, or cognitive impairment.11

 

The surgical technique may need to be modified depending on collateral history and examination from the initial consult. Patients known to rub eyes, for instance, will benefit from a modified surgical approach, including elements such as a scleral tunnel for the main incision with buried sutures under overhanging conjunctiva or by ensuring the integrity of a corneolimbal incision with a 10-0 nylon suture. Commonly, patients with mental disability or dementia present with a dense white or brunescent cataract owing to delay in seeking medical attention or longstanding neglect of visual health. Therefore, the surgeon should prepare additional tools on standby, including trypan blue dye, iris hooks, capsular tension rings, or pupil dilating rings. Alternatively, one may consider an extracapsular cataract extraction of a dense lens and/or be prepared to implant an anterior chamber IOL if needed.

 

A pre-emptive management of posterior capsular opacification with intraoperative posterior continuous curvilinear capsulorhexis (PCCC) may also be helpful in the uncooperative patient. The surgeon may consider this option for patients who may not be a good candidate for a postoperative neodymium-doped yttrium aluminum garnet (Nd:YAG) capsulotomy due to technical difficulties with seating at the slit lamp, or lack of cooperation.

 

Moreover, special anesthetic accommodations may be warranted for patients with cognitive ­impairments, such as dementia, cerebral palsy, or Down syndrome. While conscious intravenous ­sedation is an option, an uncooperative patient may require general anesthesia to avoid the risk of ­complication from inability to follow instructions or excessive movement during surgery. Therefore, in such situations, it is often helpful to initiate an anesthesia consult as part of the presurgical planning. Given the additional logistical challenges with organizing surgery under general anesthesia, the surgeon might consider immediately sequential bilateral cataract surgery if cataract is present in both eyes.

 

Biometry

 

Accurate preoperative measurements of the eye are essential to achieving the desired post­operative refractive result. As a general principle, it is helpful to obtain biometric data for both eyes even if surgery is planned for only one. An accurate reading that is obtained opportunistically can not only be useful in planning future surgery but also serve as a secondary check for determining the accuracy of measurements between the eyes.11

 

Selection of an IOL implant can be guided by several techniques. A-scan ultrasonography can measure axial length by using either an immersion technique or a contact applanation method. Alternatively, noncontact optical biometers that use optical coherence reflectometry can be used to measure multiple parameters, such as axial length, corneal curvature, anterior chamber depth, lens thickness and corneal diameter. In particularly challenging cases, an intraoperative measurement can be obtained using a handheld keratometer and ­A-scan. If these portable keratometers are unavailable, the surgeon may need to substitute average keratometry values based on population studies, or the patient’s refraction obtained via streak retinoscopy and/or autorefractor reading. Because the level of patient cooperation and technological limitations impact the accuracy of each method, the technician or physician performing biometry should be adept at customizing his/her approach to obtain the most accurate measurements for the particular patient. With evolving technology, intraoperative aberrometry systems that conduct an aphakic refraction to calculate IOL power may be very beneficial in providing these patients with the best postoperative refractive outcome.

 

It is imperative that ophthalmologists have a detailed discussion with patients and caregivers about the limitations of their measurements, and the possibility of a postoperative refractive error. The postoperative refractive goal should be based around knowledge of the individual’s hobbies, lifestyle, and occupation. Selecting intermediate viewing distance as the target, for instance, may be suitable in the patient with dementia or Down syndrome whose primary field of working distance is within that range. For instance, mild myopia (-0.75D to -1.00D) would provide approximately 20/40 uncorrected distance Snellen visual acuity, which is sufficient for watching television and useful intermediate vision for computer work or viewing on handheld electronic reading devices such as iPads or Kindles.

 

Intraoperative Considerations

 

Surgical or preoperative holding area environment

 

Patient cooperation and adherence to nil per os guidelines can be ensured by booking those with special needs as the first case of the day, if possible. The surgical experience of patients with disabilities can be made less daunting by ensuring a smooth transfer of pertinent patient information among the surgical team members. Clearly indicating the mental disability and/or physical impairment on the patient’s medical chart can be helpful in orienting all team members to accommodate any special care needs on the day of surgery. Furthermore, attempts to minimize or streamline the flow of information can help with easing patient and caregiver anxiety on the day of the surgery. Explaining each step of the surgery clearly can aid better patient cooperation during the operation.

 

Anesthesia

 

Patients’ surgical experience can be optimized by reassessing cooperation and re-evaluating safety of operation on the day of surgery. Decision on the type of anesthesia is determined after considering all options with the goal to maximize patient cooperation and minimize risk. The team may choose a number of anesthetic options, including local analgesia (topical drops, infiltrative agents, intracameral injection), regional nerve block (retrobulbar, peribulbar, or subtenon block), intravenous sedation, or general anesthesia. A pre-anesthesia consult is often helpful in planning for patient-specific considerations.

 

Positioning

 

Surgical positioning may pose an extreme challenge in patients with cervical spine immobility due to ankylosing spondylitis, severe arthritis, or kyphosis. Physical disabilities such as scoliosis or kyphosis may prevent a patient from lying flat on the operating table. The surgeon must first position the patient’s head in a surgically acceptable position. In order to support the patient’s neck and achieve a planar position for the eye, up to 10 pillows may be required, and in more extreme cases the surgeon may need to perform standing phacoemulsification. The cataract surgeon should anticipate possible changes on the day of the surgery and be prepared to modify surgical technique as needed.

 

Postoperative Considerations

 

Patients with disabilities are at greater risk for developing postoperative complications.9 There are several possible explanations for this result. First, many of the cataracts are late-stage at presentation, which makes the surgery complex and prolongs the postoperative recovery time. Moreover, in the disabled population, postoperative recovery relies heavily on the caregiver as well as patient cooperation. Streamlined interventions can reduce the rate of complications in these patients. A simplified postoperative care plan summarized on a take-home instruction sheet and a calendar demonstrating drop regimen for each day following surgery can clarify the instructions on drop start and end dates. Choosing combination steroid-antibiotic drops can simplify their regimen and make drop administration less cumbersome for caregivers and patients.

 

Recently, perioperative antibiotic and steroid injections have gained popularity as an alternative in decreasing compliance concerns and reducing medical costs for the patient.12 In case of limited caregiver time and/or patient cooperation, alternative methods of medication delivery including subconjunctival, intracameral, or trans­zonular antibiotics at the end of the case may be a viable consideration. Notably, the European Society of Cataract & Refractive Surgeons (ESCRS) Endophthalmitis study group demonstrated the superiority of intracameral cefuroxime for postoperative infection control by showing a fivefold reduction in infectious endophthalmitis compared to topical therapy.13 A  transzonular intravitreal injection of ­Tri-Moxi-Vanc, a proprietary compounded mixture of triamcinolone, moxifloxacin, and vancomycin (Imprimis Pharmaceuticals, San Diego) at the end of cataract surgery has also been trialed and shown promising results towards a dropless postoperative course.13

 

With mentally impaired patients, a hockey helmet with a clear full-face visor in the post­operative period can help with avoiding eye rubbing. Patient or caregivers can be encouraged to bring the helmet to a preoperative visit or perform a three to four-week trial run with the helmet before booking surgery. This may foster a better understanding of the postoperative care required between patient and caregiver(s) as well as avert the need for any further equipment or restraints after surgery.

 

At the post-operative appointments, the caregiver’s impression of functional improvement may provide a better assessment of visual recovery compared to the patient’s performance on the Snellen visual acuity chart. When a detailed slit lamp examination is difficult, retinoscopic view of the red reflex can be used to assess for Descemet folds and the final post­operative refraction. Intraocular pressure measurement can be obtained using digital palpation or handheld tonometers if Goldmann applanation is not possible. In the setting of a combative patient, it is usually most effective and least invasive to note the absence of a hypopyon and correct lens placement on a quick look with the indirect ophthalmoscope.

 

Close postoperative follow-up is imperative to exclude the risk of cataract surgery-related complication. Scheduling those visits may be a challenge as it often relies on caregiver availability and patient’s current mental health. The surgeon may elect to coordinate the follow-up visits with patient’s other medical appointments. Additionally, the surgical team could use the day of the operation as an opportunity to perform a same day postoperative check. As discussed previously, given the limitations of biometry, these patients are at increased risk for a refractive surprise postoperatively. Refraction should be attempted at one-month postoperative visit to record the patient’s final refractive outcome and optimize the visual status further with glasses or contact lenses as necessary.

 

Summary

 

Ocular disorders are a common comorbidity in patients with physical and mental disabilities. The challenges prior to, during, and after procedures such as cataract surgery can usually be addressed through pre-emptive planning, teamwork, and reasonable adjustments while minimizing patient and caregiver distress throughout the surgical process.

 

Dr. Bedi is a Resident Physician, Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ontario. Dr. Rai is an Ophthalmologist, Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ontario. Dr. Sanghera is a Lecturer, Department of Ophthalmology & Vision Sciences, University of Toronto, and a Staff Member, Mount Sinai Hospital, Toronto, Ontario.

 

References:

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9. Rostron E, Pilling R. Cataract surgery in patients with learning disability. Focus – The Royal College of Ophthalmologists Quarterly Bulletin 2015. Available at: https://www.rcophth. ac.uk/wp-content/uploads/2015/05/Focus-Spring-2015.pdf. Accessed on January 16, 2018.

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11. Basic and Clinical Science Course: Section 11. San Francisco: American Academy of Ophthalmology, 2014.

12. Brennan K. Going dropless, being careful. Review of Ophthalmology. Available at: https://www.reviewofophthalmology.com/article/going-dropless-being-careful. Accessed on January 16, 2018.

13. ESCRS Endophthalmitis Study Group. Prophylaxis of postoperative endophthalmitis following cataract surgery: Results of the ESCRS multicenter study and identification of risk factors. Journal Cataract & Refract Surg. 2007;33(6): 978-988.

 

The authors stated that they have no disclosures to report in association with the contents of this issue.