Wavefront-Guided Versus Wavefront-Optimized Photorefractive Keratectomy: Visual and Military Task Performance.

PURPOSE: To compare visual performance, marksmanship performance, and threshold target identification following wavefront-guided (WFG) versus wavefront-optimized (WFO) photorefractive keratectomy (PRK). METHODS: In this prospective, randomized clinical trial, active duty U.S. military Soldiers, age 21 or over, electing to undergo PRK were randomized to undergo WFG (n = 27) or WFO (n = 27) PRK for myopia or myopic astigmatism. Binocular visual performance was assessed preoperatively and 1, 3, and 6 months postoperatively: Super Vision Test high contrast, Super Vision Test contrast sensitivity (CS), and 25% contrast acuity with night vision goggle filter. CS function was generated testing at five spatial frequencies. Marksmanship performance in low light conditions was evaluated in a firing tunnel. Target detection and identification performance was tested for probability of identification of varying target sets and probability of detection of humans in cluttered environments. RESULTS: Visual performance, CS function, marksmanship, and threshold target identification demonstrated no statistically significant differences over time between the two treatments. Exploratory regression analysis of firing range tasks at 6 months showed no significant differences or correlations between procedures. Regression analysis of vehicle and handheld probability of identification showed a significant association with pretreatment performance. CONCLUSIONS: Both WFG and WFO PRK results translate to excellent and comparable visual and military performance.

Wavefront-optimized surface retreatments of refractive error following previous laser refractive surgery: a retrospective study.

BACKGROUND: Retreatments are sometimes necessary to correct residual or induced refractive errors following refractive surgery. Many different combinations of primary treatment methods and retreatment techniques have been studied, however, few studies have investigated wavefront-optimized (WFO) technology for retreatment following primary refractive surgery. This study aimed to report the outcomes of WFO photorefractive keratectomy (PRK) retreatments of refractive error following previous laser refractive surgery with PRK, laser in situ keratomileusis (LASIK), or laser-assisted subepithelial keratectomy (LASEK). METHODS: We reviewed records of patients who underwent WFO PRK retreatments using the Allegretto Wave Eye-Q 400 Hz Excimer Laser System (Alcon Surgical) between January 2008 and April 2011 at Walter Reed Army Medical Center and Madigan Army Medical Center. Outcomes were recorded in terms of uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), corrected distance visual acuity (CDVA), and complications at 1 month (M), 3 M, and 6 M post-op. RESULTS: Seventy-eight patients (120 eyes) underwent WFO PRK retreatment during the study period. Primary surgery was surface ablation in 87 eyes (78 PRK, 9 LASEK) and LASIK in 33 eyes. The mean spherical equivalent before retreatment was -0.79 ± 0.94 D (-3.00 to 1.88 D). UDVA was ≥ 20/20 in 69 eyes (60.0 %) at 1 M, 54 eyes (71.1 %) at 3 M, and 27 eyes (73.0 %) at 6 M follow-up. MRSE was within ±0.50 D of emmetropia in 78 eyes (67.8 %) at 1 M, 59 eyes (77.6 %) at 3 M, and 25 eyes (67.6 %) at 6 M follow-up. CDVA was maintained within ±1 line of pre-op in 113 of 115 eyes (98.3 %) at 1 M, 74 of 76 eyes (97.4 %) at 3 M, and 37 eyes (100 %) at 6 M follow-up. CONCLUSION: Although follow-up was limited beyond 3 M, WFO PRK retreatments in patients with residual refractive error may be a safe and effective procedure. Further studies are necessary to determine the long-term safety and stability of outcomes.

Wavefront-guided versus wavefront-optimized photorefractive keratectomy: Clinical outcomes and patient satisfaction.

PURPOSE: To compare visual outcomes following Visx Star S4 Customvue wavefront-guided and Allegretto Wave Eye-Q 400 Hz wavefront-optimized photorefractive keratectomy (PRK). SETTING: Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir, Virginia, and Walter Reed National Military Medical Center, Bethesda, Maryland, USA. DESIGN: Prospective randomized clinical trial. METHODS: Active-duty United States military soldiers were randomized to have wavefront-guided (Visx Star S4 Customvue) or wavefront-optimized PRK. Participants were followed up to 12 months postoperatively. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest spherical equivalent (SE). Secondary outcome measures included refractive astigmatism, higher-order aberrations (HOAs), contrast sensitivity, subjective visual complaints, and patient satisfaction. RESULTS: The study evaluated 108 soldiers (mean age 30.3 years ± 6.3 [SD]; mean manifest SE -3.51 ± 1.63 D). At 12 months postoperatively, achieved UDVA, CDVA, manifest SE, and refractive astigmatism were comparable between wavefront-guided and wavefront-optimized groups (P > .213). Spherical aberration and total HOAs significantly increased from baseline in both groups (P < .006). The change in coma, trefoil, spherical aberration, and total HOAs (P > .254) were comparable between groups. There were fewer losses of photopic low-contrast visual acuity (LCVA) at 5% contrast after wavefront-guided compared to wavefront-optimized treatment (P = .003). There was no significant difference between treatment groups in visual symptoms, overall vision expectation, and satisfaction (P > .075). CONCLUSION: Wavefront-guided treatment offered a small advantage in photopic LCVA. Refractive outcomes, HOAs, self-reported visual difficulties, overall vision expectation, and satisfaction were otherwise comparable between wavefront-guided and wavefront-optimized treatments. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Refractive surgery policy and its effect on visual acuity qualification rates for the 2004 and 2011 Army ROTC flight applicant pools.

OBJECTIVES: The goal of this study was to ascertain the effect of recent U.S. Army Aviation corneal refractive surgery (CRS) policy changes on the size of flight school applicant pools by comparing statistics from the 2004 and 2011 Warrior Forge Army Reserve Officers' Training Corps training camps. METHODS: A retrospective chart review was performed using the United States Army Aeromedical Activity's Aeromedical Electronic Resource Online database. RESULTS: Of the 607 applicants from 2004, 100 (16%) were disqualified for decreased visual acuity and had refractive errors correctable by CRS. Thirty-four cadets (6%) had prior CRS, and 21 qualified for flight school in 2004. Of the 625 applicants from 2011, 105 (17%) were disqualified for decreased visual acuity and had correctable refractive errors. Sixty-four applicants (10%) had prior CRS, and 54 subsequently qualified in 2011. CONCLUSIONS: Changes to Army Aviation CRS policy over the last decade have been associated with an increased number of initial flight applicants who now meet visual acuity standards. However, only a small percentage is using this resource. Army Aviation has the potential to significantly widen its applicant pool if more candidates are made aware of accepted CRS techniques that can help them to meet rigorous vision standards.

Pediatric PRK (PhotoRefractive Keratectomy) with Mitomycin C (MCC) for Persistent Anisometropic Amblyopia. A Case Report.

PURPOSE: To evaluate the safety and efficacy of photorefractive keratectomy (PRK) with Mitomycin C (MMC) for the treatment of severe pediatric anisometropia and amblyopia resistant to more conservative treatment modalities. METHODS: A 3 year-old-child, who at 18 months old underwent unilateral diode laser treatment for threshold ROP, developed 11 diopters of anisometropic myopia and secondary dense amblyopia of the Right Eye. Only after all conservative treatment options failed was he treated with PRK and MMC. Principal outcome measures included cycloplegic refraction, the amount of refractive correction, degree of corneal haze and change in visual acuity. RESULTS: On presentation: BCVA: 20/CF OD; 20/30 OS. CRNS: -11.50 diopters sphere OD; -0.50 diopters sphere OS. Unilateral PRK followed by application of MMC (0.2 mg/ml) for 1 min was performed under general anesthesia. Three-month postoperative findings include: VA: 20/30 OD; 20/25 OS. CRNS: +0.25 diopters sphere OD. At one year, the BCVA remained equal at the 20/30 level despite mild myopic regression OD. CRNS OD at one year was -1.25 +050 x 116. No corneal haze was appreciated. CONCLUSION: In this child, treatment with PRK and MMC safely reduced the anisometropia thus facilitating his visual rehabilitation. While encouraging, further study is required to verify the longer term results of this single case. PURPOSE: To evaluate the safety and efficacy of photorefractive keratectomy (PRK) with Mitomycin C (MMC) for the treatment of severe pediatric anisometropia and amblyopia resistant to more conservative treatment modalities. METHODS: A 3 year-old-child, who at 18 months old underwent unilateral diode laser treatment for threshold ROP, developed 11 diopters of anisometropic myopia and secondary dense amblyopia of the Right Eye. Only after all conservative treatment options failed was he treated with PRK and MMC. Principal outcome measures included cycloplegic refraction, the amount of refractive correction, degree of corneal haze and change in visual acuity. RESULTS: On presentation: BCVA: 20/CF OD; 20/30 OS. CRNS: -11.50 diopters sphere OD; -0.50 diopters sphere OS. Unilateral PRK followed by application of MMC (0.2 mg/ml) for 1 min was performed under general anesthesia. Three-month postoperative findings include: VA: 20/30 OD; 20/25 OS. CRNS: +0.25 diopters sphere OD. At one year, the BCVA remained equal at the 20/30 level despite mild myopic regression OD. CRNS OD at one year was -1.25 +050 x 116. No corneal haze was appreciated. CONCLUSION: In this child, treatment with PRK and MMC safely reduced the anisometropia thus facilitating his visual rehabilitation. While encouraging, further study is required to verify the longer term results of this single case.

Virtual reality simulation in acquiring and differentiating basic ophthalmic microsurgical skills.

OBJECTIVE: A virtual reality (VR) surgical simulator (EyeSi ophthalmosurgical simulator: VRMagic, Mannheim, Germany) was evaluated as a part-task training platform for differentiating and developing basic ophthalmic microsurgical skills. METHODS: Surgical novice performance (residents, interns, and nonmicrosurgical ophthalmic staff) was compared with surgical expert performance (practicing ophthalmic microsurgeons) on a basic navigational microdexterity module provided with the EyeSi simulator. RESULTS: Expert surgeons showed a greater initial facility with all microsurgical tasks. With repeated practice, novice surgeons showed sequential improvement in all performance scores, approaching but not equaling expert performance. CONCLUSION: VR simulator performance can be used as a gated, quantifiable performance goal to expert-level benchmarks. The EyeSi is a valid part-task training platform that may help develop novice surgeon dexterity to expert surgeon levels.

Effect of lidocaine gel on povidone-iodine antisepsis and microbial survival.

PURPOSE: To determine whether the use of lidocaine gel prior to povidone-iodine antisepsis is associated with increased microbial survival. SETTING: Ophthalmology Department, Madigan Army Medical Center, Fort Lewis, Washington, USA. METHODS: A standardized suspension of Staphylococcus epidermidis was used to inoculate 5 blood agar plates that served as a control. A second group of 5 blood agar plates was inoculated, and then lidocaine gel was applied to the plates. A third group of 5 blood agar plates was inoculated, lidocaine gel was applied, and then povidone-iodine 5% was applied and allowed to cover the plates. A fourth group of 5 blood agar plates was inoculated, and then povidone-iodine 5% was allowed to cover the plates. Cultures of Staphylococcus aureus, Pseudomonas aeruginosa, and Haemophilus influenza were tested in a similar fashion. Microbial growth was evaluated after 24 hours. RESULTS: The number of colony forming units (CFUs) was similar in the control group and the S epidermidis, S aureus, and P aeruginosa lidocaine only and lidocaine with povidone-iodine groups. In these groups, each plate grew between 200 CFUs and 300 CFUs. In the Haemophilus influenza series, the lidocaine with povidone-iodine group had fewer CFUs than the control group. In all 4 series, the povidone-iodine only group had the least amount of CFUs, ranging from 0 to 6. CONCLUSIONS: The use of lidocaine gel before application of povidone-iodine 5% resulted in decreased effectiveness of antisepsis and increased microbial survivability. The increase in microbial survivability may increase the risk for postoperative infection in ocular surgery performed under topical anesthesia.

Long-term graft survival in patients with Down syndrome after penetrating keratoplasty.

PURPOSE: To determine graft survival and long-term visual outcome after penetrating keratoplasty (PK) for keratoconus in patients with Down syndrome. METHODS: The records of all patients with Down syndrome who received PK by the same provider were reviewed. A retrospective analysis was performed to determine long-term graft survival, incidence of graft failure, and complication rate. RESULTS: Twenty-one PKs were performed on 18 eyes of 13 patients with Down syndrome with keratoconus. Three repeat PKs were performed for secondary graft failure. All 18 eyes had clear grafts at the most recent examination. Follow-up ranged from 4 to 88 months, with a mean of 34.9 months. The average age of patients was 42 years, with a range of 20 to 63 years. Preoperative visual acuity ranged from 20/160 to count fingers. Postoperatively, visual acuity was objectively measurable in 12 eyes of 8 patients and ranged from 20/30 to 20/200, with a mean of 20/60. Broken sutures and difficulties with unsedated suture removal complicated postoperative care in some patients. CONCLUSION: Clear grafts and improvements in visual acuity can be obtained after PK in patients with Down syndrome, but consideration must be given to careful postoperative care by health care providers and home support personnel.

Infectious keratitis after photorefractive keratectomy in the United States army and navy.

PURPOSE: To review the incidence, culture results, clinical course, management, and visual outcomes of infectious keratitis after photorefractive keratectomy (PRK) at 6 Army and Navy refractive surgery centers. DESIGN: Retrospective study. PARTICIPANTS: Twelve thousand six hundred sixty-eight Navy and Army sailors and service members. METHODS: Army and Navy refractive surgery data banks were searched for cases of infectious keratitis. A retrospective chart review and query of the surgeons involved in the care of those patients thus identified provided data regarding preoperative preparation, perioperative medications, treatment, culture results, clinical course, and final visual acuity. RESULTS: Between January 1995 and May 2004, we performed a total of 25337 PRK procedures at the 6 institutions. Culture proven or clinically suspected infectious keratitis developed in 5 eyes of 5 patients. All patients received topical antibiotics perioperatively. All cases presented 2 to 7 days postoperatively. Cultures from 4 cases grew Staphylococcus, including 2 methicillin-resistant S. aureus (MRSA). One case of presumed infectious keratitis was culture negative. There were no reported cases of mycobacterial or fungal keratitis. In addition, we identified 26 eyes with corneal infiltrates in the first postoperative week that were felt to be sterile, and which resolved upon removal of the bandage contact lens and increasing antibiotic coverage. CONCLUSIONS: Infectious keratitis is a rare but potentially vision-threatening complication after PRK. It is often caused by gram-positive organisms, including MRSA. Early diagnosis, appropriate laboratory testing, and aggressive antimicrobial therapy can result in good outcomes.

Topical tacrolimus treatment of atopic eyelid disease.

PURPOSE: To describe the effects of topical tacrolimus treatment of severe atopic eyelid disease. DESIGN: Interventional consecutive case series. METHODS: A description of clinical findings and therapeutic response for five consecutive adult patients (mean age, 56.2 years; range 44-62) treated with topical tacrolimus for severe atopic eyelid disease at one institution. RESULTS: Five patients with bilateral atopic eyelid disease that was refractory to treatment with topical corticosteroids were treated with tacrolimus 0.03% ointment, applied to the affected eyelid skin of both eyes twice daily. Eyelid induration, erythema, and eczematous changes were substantially improved within 1 to 3 weeks after initiation of topical tacrolimus treatment in all patients. There was an associated decrease in ocular surface irritation and inflammatory signs in each of four patients who also had atopic keratoconjunctivitis. No adverse effect associated with tacrolimus treatment was noted during continued treatment for 5 to 14 months. All patients were able to discontinue longstanding use of topical corticosteroid drugs. CONCLUSIONS: Application of topical tacrolimus on eyelid skin may be effective for treatment of severe atopic dermatitis of the eyelids, and may have secondary benefits for atopic keratoconjunctivitis. Topical tacrolimus may be used for at least 1 year without apparent adverse reaction in some patients, although the rate of adverse reaction cannot be determined from this small series.