Buddy Russell

Risk factors and prognosis for corneal ectasia after LASIK

PURPOSE To review cases of corneal ectasia after laser in situ keratomileusis (LASIK), identify preoperative risk factors, and evaluate methods and success rates of visual rehabilitation for these cases. DESIGN Retrospective nonrandomized comparative trial. PARTICIPANTS Ten eyes from seven patients identified as developing corneal ectasia after LASIK, 33 previously reported ectasia cases, and two control groups with uneventful LASIK and normal postoperative courses: 100 consecutive cases (first control group), and 100 consecutive cases with high myopia (> 8 diopters [D]) preoperatively (second control group). METHODS Retrospective review of preoperative and postoperative data for each case compared with that of previously reported cases and cases with uneventful postoperative courses. MAIN OUTCOME MEASURES Preoperative refraction, topographic features, residual stromal bed thickness (RSB), time to the development of ectasia, number of enhancements, final best-corrected visual acuity (BCVA), and method of final correction. RESULTS Length of follow-up averaged 23.4 months (range, 6-48 months) after LASIK. Mean time to the development of ectasia averaged 16.3 months (range, 1-45 months). Preoperative refraction averaged -8.69 D compared with -5.37 D for the first control group (P = 0.005). Preoperatively, 88% of ectasia cases met criteria for forme fruste keratoconus, compared with 2% of the first control group (P < 0.0000001) and 4% of the second control group (P = 0.0000001). Seven eyes (70%) had RSB <250 microm, as did 16% of eyes in the first control group and 46% of the second control group. The mean RSB for ectasia cases (222.8 microm) was significantly less than that for the first control group (293.6 micro m, P = 0.0004) and the second control group (256.5 microm; P = 0.04). Seven eyes (70%) had enhancements. Only 10% of eyes lost more than one line of BCVA, and all patients eventually achieved corrected vision of 20/30 or better. One case required penetrating keratoplasty (10%), while all others required rigid gas-permeable contact lenses for correction. CONCLUSIONS Significant risk factors for the development of ectasia after LASIK include high myopia, forme fruste keratoconus, and low RSB. All patients had at least one risk factor other than high myopia, and significant differences remained even when controlling for myopia. Multiple enhancements were common among affected cases, but their causative role remains unknown. We did not identify any patients who developed ectasia without recognizable preoperative risk factors.

The Infant Aphakia Treatment Study: Design and Clinical Measures at Enrollment

OBJECTIVE To compare the use of contact lenses and intraocular lenses (IOLs) for the optical correction of unilateral aphakia during infancy. METHODS In a randomized, multicenter (12 sites) clinical trial, 114 infants with unilateral congenital cataracts were assigned to undergo cataract surgery with or without IOL implantation. Children randomized to IOL treatment had their residual refractive error corrected with spectacles. Children randomized to no IOL treatment had their aphakia treated with a contact lens. MAIN OUTCOME MEASURES Grating acuity at 12 months of age and HOTV visual acuity at 4 1/2 years of age. APPLICATION TO CLINICAL PRACTICE This study should determine whether either treatment for an infant with a visually significant unilateral congenital cataract results in a better visual outcome. RESULTS Enrollment began December 23, 2004, and was completed January 16, 2009. The median age at the time of cataract surgery was 1.8 months. Fifty patients were 4 to 6 weeks of age at the time of enrollment; 32, 7 weeks to 3 months of age; and the remaining 32, more than 3 to less than 7 months of age. Fifty-seven children were randomized to each treatment group. Eyes with cataracts had shorter axial lengths and steeper corneas on average than the fellow eyes. CONCLUSIONS The optimal optical treatment of aphakia in infants is unknown. However, the Infant Aphakia Treatment Study was designed to provide empirical evidence of whether optical treatment with an IOL or a contact lens after unilateral cataract surgery during infancy is associated with a better visual outcome.

Visual rehabilitation and outcomes for ectasia after corneal refractive surgery

PURPOSE: To analyze the visual outcomes and method of final visual correction in eyes with corneal ectasia after laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK). SETTING: Emory University Department of Ophthalmology and Emory Vision, Atlanta, Georgia, USA. METHODS: This retrospective review comprised 74 eyes of 45 patients with corneal ectasia after LASIK (72 eyes) or PRK (2 eyes). Outcomes included postoperative uncorrected visual acuity (UCVA), best spectacle‐corrected visual acuity (BSCVA), best corrected visual acuity (BCVA), and refraction; method of final visual correction; and time to rigid gas‐permeable (RGP) contact lens failure. RESULTS: Corneal ectasia developed a mean of 19.2 months after surgery. Postoperatively, the mean UCVA was 20/400 and the mean BSCVA before ectasia management was 20/108. After ectasia management, the mean BCVA was 20/37 and the final BCVA was 20/40 or better in 78% of eyes. Final visual correction was achieved with RGP lenses in 77% of eyes, spectacles in 9%, collagen crosslinking in 3%, intracorneal ring segments in 1%, and penetrating keratoplasty (PKP) in 8%. Two eyes with intracorneal ring segments required segment explantation and subsequent PKP. One eye that had PKP had a graft‐rejection episode; there were no graft failures. Two eyes (3%) did not require a visual device to improve visual acuity. The mean time for successful RGP lens wear was 24.8 months; 80% of cases initially managed with RGP lenses were successful with this form of treatment. CONCLUSIONS: The majority of eyes developing postoperative corneal ectasia achieved functional visual acuity with RGP lens wear and did not require further intervention. Penetrating keratoplasty can usually be postponed or avoided by alternative methods of visual rehabilitation; however, PKP, when necessary, can provide good visual outcomes.

Contact Lenses in the Treatment of Patients with Overcorrected Radial Keratotomy

Thirty-two eyes of 28 patients who underwent radial keratotomy had a hyperopic overcorrection after the surgical procedure. Anisometropia, with associated aniseikonia and depth perception problems were present in many of these patients. The patients were subsequently fit with contact lenses. Conventional methods of fitting contact lenses in these patients were unsuccessful. A trial lens technique is used with the initial lens having a base curve equal to the preoperative keratometry measurements and the power equal to the preoperative spherical equivalent. Superficial neovascularization developed within the radial incisions in 33% of the eyes fitted with soft contact lenses. Gas permeable contact lenses offered patients the best-corrected visual acuity as well as minimal complications. In addition, the anisometropia was minimized, and fluctuating vision was eliminated in cases in which it was a problem.

Keratolysis following excimer laser phototherapeutic keratectomy in a patient with keratoconus.

PURPOSE We report a case of keratolysis following phototherapeutic keratectomy (PTK) for a subepithelial nodule in a patient with keratoconus. METHODS A 29-year-old male with keratoconus who became contact lens intolerant because of a raised subepithelial nodule was treated with excimer laser phototherapeutic keratectomy (PTK). RESULTS The epithelium failed to heal postoperatively, and progressive keratolysis led to a central descemetocele by the eighth postoperative day. The patient was managed with a penetrating keratoplasty. CONCLUSIONS Excimer laser phototherapeutic keratectomy has been shown to be an effective treatment for subepithelial nodules in patients with keratoconus. Rapidly progressive keratolysis is a potential complication of this procedure.

Stereopsis Results at 4.5 Years of Age in the Infant Aphakia Treatment Study

PURPOSE To determine whether stereopsis of infants treated for monocular cataracts varies with the type of optical correction used. DESIGN Randomized prospective clinical trial. METHODS The Infant Aphakia Treatment Study randomized 114 patients with unilateral cataracts at age 1-7 months to either primary intraocular lens (IOL) or contact lens correction. At 4.5 years of age a masked examiner assessed stereopsis on these patients using 3 different tests: (1) Frisby; (2) Randot Preschool; and (3) Titmus Fly. RESULTS Twenty-eight patients (25%) had a positive response to at least 1 of the stereopsis tests. There was no statistically significant difference in stereopsis between the 2 treatment groups: Frisby (contact lens, 6 [11%]; IOL, 7 [13%]; P = .99), Randot (contact lens, 3 [6%]; IOL, 1 [2%]; P = .62), or Titmus (contact lens, 8 [15%]; IOL, 13 [23%]; P = .34). The median age at surgery for patients with stereopsis was younger than for those without stereopsis (1.2 vs 2.4 months; P = .002). The median visual acuity for patients with stereopsis was better than for those without stereopsis (20/40 vs 20/252; P = .0003). CONCLUSION The type of optical correction did not influence stereopsis outcomes. However, 2 other factors did: age at surgery and visual acuity in the treated eye at age 4.5 years. Early surgery for unilateral congenital cataract and the presence of visual acuity better than or equal to 20/40 appear to be more important than the type of initial optical correction used for the development of stereopsis.

The Infant Aphakia Treatment Study Contact Lens Experience: One-Year Outcomes

Purpose: We describe our experience correcting a cohort of infants with contact lenses in the Infant Aphakia Treatment Study. Materials and Methods: Fifty-seven infants 1–6 months of age were randomized to contact lens wear. An examination under anesthesia was performed at the time of enrollment and at approximately 1 year of age. A traveling examiner assessed visual acuity at approximately 1 year of age. Results: Forty-two treated eyes (74 %) were fitted with silicone elastomer (SE) contact lenses; 12 eyes (21 %) with rigid gas permeable (RGP) contact lenses, and 3 eyes (5%) wore both lens types. Median visual acuity was +0.80 logMAR in both lens type–wearing groups. The mean (± SD) keratometric power of the treated eyes was 46.3±2.8 D at baseline and 44.6±2.3 D at 1 year of age for a mean decrease of 0.2±0.2 D/mo. Keratometric astigmatism of treated eyes was 1.98±1.37 D at baseline and 1.62±0.98 D at 1 year of age for a mean decrease of 0.05±0.2 D/mo. The mean RGP lens base curve at baseline was 47.62 D±2.62 D versus 47.00 D±3.50 D at 12 months after surgery. Children wearing SE lenses required a mean of 10.9 replacements (range 2–24) compared to 16.8 replacements (range 8–32) for children wearing RGP lenses. Three adverse events occurred. Conclusions: Contact lenses were worn successfully with relatively few adverse events by a cohort of infants with unilateral aphakia. The visual acuity results were identical independent of the contact lens material or modality. RGP lenses needed replacement more often than SE lenses.

The Infant Aphakia Treatment Study Contact Lens Experience to Age of 5 Years.

Purpose: To describe our experience treating a cohort of unilateral aphakic infants with contact lenses in the Infant Aphakia Treatment Study (IATS). Materials and methods: Fifty-seven of the 114 infants in the IATS were randomized to contact lens wear; all were followed until age 5 years, although a few had lapses in care. An examination under anesthesia, including keratometry, was performed at the time of enrollment and at approximately 1 year of age; keratometry was performed again at 5 years of age. A traveling examiner assessed visual acuity at approximately 1 year of age and again at 4.5 years of age. Results: Twenty-four treated eyes (46%) wore silicone elastomer (SE) contact lenses, 11 eyes (19%) rigid gas permeable (GP) contact lenses and 17 eyes (29%) wore both lens types at various points of time. Median logMAR visual acuity was +0.70 (interquartile range (IQR), +0.30 to 1.20) in the SE group and 2.03 (IQR, +0.20 to 2.28) in the GP group at age 4.5 years. The mean (±SD) keratometric power of the treated eyes was 46.3±2.8 diopter (D) at baseline, 44.6±2.3 D at 1 year of age, and 44.3±1.7 D at 5 years of age. Keratometric astigmatism of treated eyes was 1.98±1.37 D at baseline, 1.62±0.98 D at 1 year of age, and 2.00±1.00 D at 5 years of age. Thirteen contact lens-related adverse events occurred among 7 patients after age 1 year. Conclusions: A cohort of infants with unilateral aphakia successfully wore contact lenses with relatively few adverse events.

Association of Contact Lens Adherence With Visual Outcome in the Infant Aphakia Treatment Study: A Secondary Analysis of a Randomized Clinical Trial

Importance Although contact lenses have been used for decades to optically correct eyes in children after cataract surgery, there has never been a prospective study looking at contact lens adherence in children with aphakia, to our knowledge. Objective To evaluate contact lens adherence and its association with visual outcome in a cohort of children treated for unilateral cataract surgery. Design, Setting, and Participants Secondary analysis of a multicenter randomized clinical trial of 57 infants born from August 22, 2004, to April 25, 2008, who were randomized to 1 of 2 treatments and followed up to age 5 years. Data analysis was performed from August 9, 2016, to December 7, 2017. Interventions Unilateral cataract extraction and randomization to implantation of an intraocular lens vs contact lens to correct aphakia. Main Outcomes and Measures Contact lens adherence was assessed by a 48-hour recall telephone interview that was administered every 3 months starting 3 months after surgery to age 5 years. A traveling examiner assessed visual acuity in patients at aged 4.5 years. Adherence to prescribed contact lens use was estimated as the mean percentage of waking hours as reported in 2 or more interviews for each year of life. Results Of 57 infants who were randomized to contact lens treatment, 32 (56%) were girls, and 49 (86%) were white. A total of 872 telephone interviews were completed. In year 1, a median of 95% participants wore their contacts lenses nearly all waking hours (interquartile range [IQR], 84%-100%); year 2, 93% (IQR, 85%-99%); year 3, 93% (IQR, 85%-99%); year 4, 93% (IQR, 75%-99%); and year 5, 89% (IQR, 71%-97%). There was a tendency for poorer reported adherence at older ages (F = 3.86, P < .001). No differences were identified when the results were analyzed by sex, insurance coverage, or age at cataract surgery. Using linear regression, children who wore the contact lens for a greater proportion of waking hours during the entire study period tended to have better visual acuity at age 4.5 years, even after accounting for adherence to patching (partial correlation = –0.026; P = .08). Conclusions and Relevance These results confirm that it is possible to achieve a high level of aphakic contact lens adherence over a 5-year period in children. Trial Registration clinicaltrials.gov Identifier: NCT00212134

Improved Vision and Contact Lens Wear Time With Piggy-back Contact Lens Systems in Children After Penetrating Corneal Trauma.

Objective: Consecutive case series of children treated successfully with “piggy-back” (PB) contact lens systems after corneal trauma. Methods: We reviewed the medical record of all children ages 4 to 14 years treated at the Emory Eye Center between January 11, 2003 and January 11, 2013 with PB contact lens systems. Results: Four children with a history of corneal penetrating trauma were treated with a PB lens system, with a mean age of 7±0.08 (range: 6–8) years. Best-corrected spectacle vision was count fingers in two children and logMAR +0.70 (Snellen equivalent 20/100) and logMAR +0.6 (Snellen equivalent 20/80) in the remaining two. The PB lens system was introduced with a mean of 15.7±6.5 (range: 9–22) months after the injury. All patients were initially fitted with gas-permeable (GP) lenses. Each child achieved 11 or more hours of daily contact lens wear time in PB systems. The mean best-corrected logMAR visual acuity using the PB system was 0.26±0.21 (Snellen equivalent 20/36). The mean improvement in best-corrected logMAR between GP and PB lens systems was +0.21±0.11, which corresponds to an improvement of greater than two lines on the Snellen chart. Conclusion: Piggy-back contact lens systems can be helpful to improve vision and contact lens wearing time in children with irregular astigmatism after corneal trauma, who are intolerant of GP contact lenses.