Patient Expectations and Patient Education
Patients with severe visual loss despite successful surgery can be depressed and despondent because of their postoperative recovery period. In addition, these patients may have to change their activities of daily living and rearrange their work schedules to accommodate their visual rehabilitation schedule.1 During this time, it is important to address the patients’ short-term and long-term expectations. At this time, if the clinician senses that the patient feels morose or pensive about his long-term prognosis of visual recovery, the clinician can suggest a consultation with a social worker, psychologist, or psychiatrist. It is important that postoperative patients have support systems or else their sense of despair can turn into anger. The anger then turns into litigious behavior.2
Health Literacy
Functional literacy or the ability to understand the complex maneuvers in traction retinal detachment and vitrectomy surgery is important. In a study with 402 patients with diabetes and hypertension, 92% of the patients understood that blood pressure of 160/100 mm Hg is “high” compared to 55% of patients with poor literacy skills. Functional illiteracy is a problem in educating patients about chronic diseases and their health outcomes.3
In another study involving 408 patients with Type 2 diabetes, the authors found that those patients who have poor health literacy will have poor glycemic control and higher rates of retinopathy. Thus, inadequate health education may account for diabetes-related problems in disadvantaged populations.4 Thus, in patients who are poorly educated or who have marginal understanding of the complexity of the surgery and surgical expectations, the retinal surgeon and staff must be constantly vigilant in educating and reeducating the patient and family members in order to manage postoperative expectations.
To improve management of patient expectations for surgery and postoperative visual loss, referral to behavioral therapists may be helpful. In a study with 51 patients with Type 2 diabetes and major depression, the researchers found that after cognitive behavioral therapy, the mean hemoglobin A1c levels were lower than those of the control group.5
Poor Visual Outcome but Great Anatomical Results
In diabetic patients, there is a risk of poor postoperative visual acuity despite excellent anatomic surgical results. The most important point to stress to the diabetic patient is that the recovery period is slow and is to be expected. Emphasize that it is “normal” to have a prolonged visual recuperation. The rods and cones must be anatomically aligned without edema for the visual recovery to occur. We have instances where the patient sees 20/25 after detachment surgery but the optical coherence tomography (OCT) scan shows edematous fluid. Or conversely, there is a small amount of macular edema or central subfield thickness on the OCT, yet the vision is 20/100.
In cases of prolonged, poor postoperative visual outcome, persisting 6 months or more, one would consider ERG testing to evaluate the health of the rods and cones. Interestingly, the ERG will improve by 6 to 8 weeks postoperatively mirroring the improvement in visual acuity.
Vitrectomy
Vitrectomies for vitreous hemorrhage may seem uncomplicated to the patient however, there are complications associated with unexpected findings intraoperatively. A dense vitreous hemorrhage may reveal a combined traction and rhegmatogenous retinal detachment in a proliferative diabetic retinopathy (PDR) eye. Combined traction and rhegmatogenous retinal detachment are serious adverse side effects of the disease and may have a poor visual prognosis. Favorable preoperative prognostic factors include a visual acuity of 5/200 or better, absence of rubeosis, and absence of macula retinal detachment.6,7 Thus, it is important to communicate the favorable and unfavorable prognostic factors to the patient and family prior to surgery. As a consequence, the patient can manage his or her expectations of the surgery.
Laser Burns and Consequent Laser-Induced Atrophy of the Retina
Laser complications can occur with diode laser and panretinal photocoagulation. The deeper tissue penetration that occurs with diode laser may then damage the short ciliary nerves. When the eye is anesthetized, the laser surgeon may not be aware of the damage to the nerves. After the procedure tonic pupils can be noted in the patients.8
Panretinal photocoagulation can cause macular edema if a heavy treatment of more than 1,000 to 1,200 burns is performed in one setting. This can occur because the retina is already ischemic and releases vascular endothelial growth factors (VEGFs) as well as inflammatory cells.9
Postoperatively after panretinal laser photocoagulation, there can be macular gliosis as well. This is most likely due to the contracting of the posterior hyaloid membrane as it stretches over the arcades in the equatorial aspect of the vitreous interface with the internal limiting membrane Thus, macular edema can occur as the blood supply is distorted after laser. Postoperatively, the physician can use nonsteroidal anti-inflammatory drug (NSAID) eyedrops or steroid eyedrops. There is also a role for anti-VEGF injections such as bevacizumab to treat residual macular edema.9
Treatment of Complications after Panretinal Photocoagulation for Proliferative Diabetic Retinopathy
In refractory cases of poor visual acuity after panretinal photocoagulation in the presence of macular edema, one can initiate a trial of NSAIDs and/or carbonic anhydrase inhibitors. They may aid in the resolution of residual postoperative macular edema after panretinal photocoagulation. These agents are sometimes used as long as 3 months after surgery for postoperative macular edema after vitrectomy and membrane peeling.
Vascular Endothelial Growth Factor
VEGF has been shown to be an angiogenic inducer in various in vivo and in vitro models.9,10 VEGF has been known to increase retinal vascular permeability by increasing the phosphorylation of tight junction proteins.10 Hypoxia has been shown to induce VEGF gene transcription.10 It has been shown that there are elevated levels of VEGF in ocular fluids in patients with PDR.10,11 Thus, with that type of background, anti-VEGF drugs such as bevacizumab have been used for PDR and persistent proliferative diabetic rertinopathy despite laser treatment.10–15 In some surgical cases with severe PDR and associated traction retinal detachment, bevacizumab may be injected preoperatively. Postoperative injections of bevacizumab may be used as well.
MRI Imaging and Unexplained Visual Loss after Treatment
In some instances when a patient presents for a second opinion after having had previous retinal detachment and diabetic vitreous hemorrhage surgery with poor visual acuity results, one might consider optic nerve imaging of the retina and the visual pathways in the brain.
PDR or quiescent PDR can have associated loss of vision from anterior ischemic optic neuropathy (AION). It can present with disc edema in the setting of quiescent PDR and eventually, the disc edema becomes AION or it can spontaneously resolve without any visual symptoms. In patients with diabetes and asymptomatic optic disc edema, 31% of these patients will go onto AION.8
Macular Laser Complications
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