LASIK studies and visual symptoms

  [caption id="attachment_6151" align="alignnone" width="350"] Elizabeth M Hofmeister MD[/caption] Two large studies of patients receiving LASIK found lower rates of all categories of visual symptoms,including glare and halos, as well as fewer dry eye symptoms after surgery than before surgery, US Navy Captain Elizabeth M Hofmeister MD told the 2016 ASCRS•ASOA Symposium & Congress in New Orleans, USA. The anonymous online studies are among the first to compare preoperative with postoperative symptoms, and challenge widespread notions that LASIK causes dysphotopsias and dry eye. Patient satisfaction with vision was also very high, reported Dr Hofmeister, of the Naval Medical Center San Diego, USA. Just 16 of 496 patients, or 3%, in the two PROWL studies were not satisfied at three or six months after surgery. And while the numbers were too small to support a statistically valid analysis, these dissatisfied patients trended toward poorer visual outcomes and worse dry eye. The two studies used an anonymous online questionnaire to collect data on visual and dry eye symptoms and satisfaction with vision and surgical results from active duty sailors at one, three and six months following femtosecond LASIK surgery. Six-month data were available from PROWL 1, and limited three-month data from PROWL 2. SUBSTANTIAL IMPROVEMENTS In terms of efficacy for PROWL 1, six months after surgery 13% achieved 20/10 uncorrected binocular vision, with 76% 20/12.5, 99% 20/20, and 100% 20/40 or better. These figures were substantial improvements over pre-op best corrected values, when only 1% had 20/10, with 34% 20/12.5, 96% 20/16, and 100% 
20/25 or better. Similarly, baseline visual symptoms decreased significantly in every category after surgery, with ghost images, glare and starbursts declining at one month and halos below pre-op rates at three months, with continuing improvement in all categories at six months. Dry eye symptoms, as measured by the Ocular Surface Disease Index, also declined substantially after surgery, from 19% with moderate to severe symptoms pre-op to 10% six months post-op. In terms of satisfaction, six months after surgery 98% of patients in PROWL 1 were satisfied with the result of LASIK surgery, and 2%, or four patients, were not. GRADING SATISFACTION Some 97% were satisfied with their current vision and 3%, or six patients, were not. In PROWL 2, 96% were satisfied with their vision at three months while 4%, or 10 patients, were not. The 16 unsatisfied patients from the two studies were more likely to have uncorrected vision of 20/40 or worse in either eye, residual myopia of 0.50D or more, at least one visual symptom, and moderate to severe dry eye symptoms, Dr Hofmeister reported. Grading satisfaction with present vision on a 100-point scale, mean satisfaction among seven patients in PROWL 2 with uncorrected vision of 20/40 or worse in either eye was 57.1 compared with 88.2 for 243 patients with better than 20/40 uncorrected. To prevent dissatisfied LASIK patients, Dr Hofmeister recommended striving for “super vision” of better than 20/20 using accurate cylinder axis treatment and carefully developing correction nomograms based on achieved results. She also recommended screening for dry eye and treating Meibomian dysfunction, and counselling patients on surgical risks and realistic outcome expectations. While satisfaction will be high if patient expectations are met, there will be a few patients who are not satisfied despite your best efforts, Dr Hofmeister concluded. Elizabeth M Hofmeister: elizabeth.m.hofmeister.mil@mail.mil