Mark D. Mifflin

Corneal profile analysis after Descemet stripping endothelial keratoplasty and its relationship to postoperative hyperopic shift

PURPOSE: To evaluate changes in the corneal profile after Descemet stripping endothelial keratoplasty (DSEK) using anterior segment optical coherence tomography (AS‐OCT) analysis and to describe its relationship to a dynamic postoperative hyperopic shift. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, USA. METHODS: In this retrospective observational study, 9 eyes had DSEK and were followed with manifest refractions and AS‐OCT analysis. To assess changes in the thickness of the cornea, measurements for each AS‐OCT image were taken at the vertex of the cornea, at 1.5 mm on each side of the vertex, and at the distal edges of the graft. RESULTS: Patients were followed for a mean of 134 days (range 46 to 228 days). Monthly Graft thinning rates were 5.2 μm per month at the vertex, 7.9 μm per month 1.5 mm from the vertex, and 26 μm per month at the edges, with the edges thinning significantly faster than the cornea vertex (P = .0024) and the points on either side of the 3.0 mm visual axis (P = .0018). The mean spherical equivalent (SE) showed an initial hyperopic shift that decreased over the ensuing 100 to 200 days postoperatively. The mean monthly postoperative SE change was −0.25 diopter (D) with a mean preoperative to postoperative SE change of +1.26 D. CONCLUSIONS: The donor graft underwent changes after DSEK, which may account for the induced hyperopia and its diminishment over time via changes in the posterior corneal curvature. Results suggest that intraocular lenses be targeted to −1.00 to −1.25 D of myopia for combined DSEK and cataract procedures.

Laser in situ keratomileusis flap complications using mechanical microkeratome versus femtosecond laser: Retrospective comparison

PURPOSE: To compare the incidence of flap complications after creation of laser in situ keratomileusis (LASIK) flaps using a zero‐compression microkeratome or a femtosecond laser. SETTING: John A. Moran Eye Center, Department of Ophthalmology, University of Utah, Salt Lake City, Utah, USA. DESIGN: Evidence‐based manuscript. METHODS: The flap complication rate was evaluated during the initial 18 months of experience using a zero‐compression microkeratome (Hansatome) or a femtosecond laser (IntraLase FS60) for flap creation. RESULTS: The flap complication rate was 14.2% in the microkeratome group and 15.2% in the femtosecond laser group (P = .5437). The intraoperative flap complication rate was 5.3% and 2.9%, respectively (P = .0111), and the postoperative flap complication rate, 8.9% and 12.3%, respectively (P = .0201). The most common intraoperative complication in the microkeratome group was major epithelial defect/sloughing; the rate (2.6%) was statistically significantly higher than in the femtosecond laser group (P = .0006). The most common postoperative complication in both groups was diffuse lamellar keratitis (DLK) (6.0%, microkeratome; 10.6%, femtosecond laser) (P = .0002). CONCLUSION: Although the total complication rates between the 2 groups were similar, the microkeratome group had significantly more epithelial defects intraoperatively and the femtosecond laser group had significantly more DLK cases postoperatively. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Visual outcomes after wavefront-guided photorefractive keratectomy and wavefront-guided laser in situ keratomileusis: Prospective comparison

PURPOSE: To compare visual outcomes between wavefront‐guided photorefractive keratectomy (PRK) and wavefront‐guided laser in situ keratomileusis (LASIK). SETTING: Academic center, Salt Lake City, Utah, USA. METHODS: In this randomized prospective study, myopic eyes were treated with wavefront‐guided PRK and or wavefront‐guided LASIK using a Visx Star S4 CustomVue platform with iris registration. Primary outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities and manifest refraction. Secondary outcome measures were higher‐order aberrations (HOAs) and contrast sensitivity. RESULTS: The PRK group comprised 101 eyes and the LASIK group, 102 eyes. At 6 months, the mean UDVA was −0.03 logMAR ± 0.10 [SD] (20/19) and 0.07 ± 0.09 logMAR (20/24), respectively (P = .544). In both groups, 75% eyes achieved a UDVA of 20/20 or better (P = .923); 77% of eyes in the PRK group and 88% in the LASIK group were within ±0.50 diopter of emmetropia (P = .760). There was no statistically significant difference between groups in contrast sensitivity at 3, 6, 12, or 18 cycles per degree. The mean postoperative HOA root mean square was 0.45 ± 0.13 μm in the PRK group and 0.59 ± 0.22 μm in the LASIK group (P = .012), representing an increase factor of 1.22 and 1.74, respectively. CONCLUSIONS: Wavefront‐guided PRK and wavefront‐guided LASIK had similar efficacy, predictability, safety, and contrast sensitivity; however, wavefront‐guided PRK induced statistically fewer HOAs than wavefront‐guided LASIK at 6 months. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

A multicenter study to map genes for Fuchs endothelial corneal dystrophy: Baseline characteristics and heritability

Purpose: To describe the methods for family and case–control recruitment for a multicenter genetic and associated heritability analyses of Fuchs endothelial corneal dystrophy (FECD). Methods: Twenty-nine enrolling sites with 62 trained investigators and coordinators gathered individual and family information, graded the phenotype, and collected blood and/or saliva for genetic analysis on all individuals with and without FECD. The degree of FECD was assessed in a 0 to 6 semiquantitative scale using standardized clinical methods with pathological verification of FECD on at least 1 member of each family. Central corneal thickness was measured by ultrasonic pachymetry. Results: Three hundred twenty-two families with 330 affected sibling pairs with FECD were enrolled and included a total of 650 sibling pairs of all disease grades. Using the entire 7-step FECD grading scale or a dichotomous definition of severe disease, heritability was assessed in families via sib–sib correlations. Both binary indicators of severe disease and semiquantitative measures of disease severity were significantly heritable, with heritability estimates of 30% for severe disease, 37% to 39% for FECD score, and 47% for central corneal thickness. Conclusions: Genetic risk factors have a strong role in the severity of the FECD phenotype and corneal thickness. Genotyping this cohort with high-density genetic markers followed by appropriate statistical analyses should lead to novel loci for disease susceptibility.

A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function

Purpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. Results: At 6 months, mean values for UDVA (logMAR) were −0.043 ± 0.668 and −0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK): analysis of visual outcomes and higher order aberrations

Purpose To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs), contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK) using wavefront (WF) guided VISX CustomVue and WF optimized WaveLight Allegretto platforms. Methods In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients), with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, root-mean-square (RMS) value of total and grouped HOAs, contrast sensitivity, and Schirmers testing. Results Mean values for UDVA (logMAR) were −0.067 ± 0.087 and −0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909). UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000). In the WF optimized group, total HOA increased 4% (P = 0.012), coma increased 11% (P = 0.065), and spherical aberration increased 19% (P = 0.214), while trefoil decreased 5% (P = 0.490). In the WF guided group, total HOA RMS decreased 9% (P = 0.126), coma decreased 18% (P = 0.144), spherical aberration decreased 27% (P = 0.713) and trefoil decreased 19% (P = 0.660). One patient lost one line of CDVA secondary to residual irregular astigmatism. Conclusion Both the WaveLight Allegretto and the VISX CustomVue platforms had equal visual and safety outcomes. Most wavefront optimized HOA values trended upward, with a statistically significant increase in total HOA RMS. Eyes treated with the WF guided platform showed a decreasing trend in HOA values.

Chronic migraine is associated with reduced corneal nerve fiber density and symptoms of dry eye

We used in vivo corneal confocal microscopy to investigate structural differences in the sub‐basal corneal nerve plexus in chronic migraine patients and a normal population. We used a validated questionnaire and tests of lacrimal function to determine the prevalence of dry eye in the same group of chronic migraine patients. Activation of the trigeminal system is involved in migraine. Corneal nociceptive sensation is mediated by trigeminal axons that synapse in the gasserian ganglion and the brainstem, and serve nociceptive, protective, and trophic functions. Noninvasive imaging of the corneal sub‐basal nerve plexus is possible with in vivo corneal confocal microscopy.

Prospective, Contralateral Comparison of 120-μm and 90-μm LASIK Flaps Using the IntraLase FS60 Femtosecond Laser

PURPOSE To compare differences in visual acuity, contrast sensitivity, higher order ocular aberrations, quality of life, and patient-reported outcomes at 3 and 6 months postoperatively in eyes with stable myopia undergoing thin-flap (intended flap thicknesses of 120 or 90 μm) LASIK using the VISX Star S4 CustomVue excimer laser (VISX Inc), with flaps created by the IntraLase FS60 femtosecond laser (Abbott Medical Optics). METHODS In this prospective study, thin-flap LASIK was performed contralaterally on 94 eyes: 47 eyes with 120-μm intended flap thickness and 47 eyes with 90-μm intended flap thickness. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and higher order aberrations. RESULTS At 6 months, mean values for UDVA (logMAR) were -0.064±0.077 and -0.051±0.070 in the 120-μm and 90-μm groups, respectively (n=40, P=.431). Visual acuity of 20/20 was achieved in 98% of eyes with 120-μm flaps and 95% of eyes with 90-μm flaps, whereas 20/15 vision was achieved in 50% of eyes with 120-μm flaps and 45% of eyes with 90-μm flaps (P≥.454). Both groups had significant increases in total higher order aberrations (P≤.003). Significant differences were not found between groups in contrast sensitivity (P≥.258), CDVA (P≥.726), total higher order aberrations (P≥.477), or patient-reported outcomes (P≥.132). Patients in both groups reported increased quality of life postoperatively (P≤.002). CONCLUSIONS Under well-controlled surgical conditions, thin-flap LASIK achieved similar results in visual acuity, contrast sensitivity, and low induction of higher order aberrations in eyes with intended flap thicknesses of either 120 or 90 μm.

Aquarium Coral Keratoconjunctivitis

Zoanthids are an excellent, lowmaintenance, fast-growing coral beloved by the marine aquarist (Figure 1). Despite their ease and beauty, zoanthids have specialized stinging cells called nematocysts, which are modified cells that inject a toxin for capturing prey or are released in response to stress or irritation. Some zoanthids produce palytoxin (PTX), one of the most deadly marine toxins. The toxic effects of PTX have been reported with dermal and ocular contact as well as inhalation exposure during cleaning of an aquarium or handling zoanthid colonies. In this article we report 2 cases of PTX-induced keratoconjunctivitis after the handling of zoanthid coral.

Management and outcomes of descemet stripping automated endothelial keratoplasty with intraocular lens exchange, aphakia, and anterior chamber intraocular lens.

Purpose: To compare outcomes and complications of Descemet stripping automated endothelial keratoplasty (DSAEK) in complicated cases with intraocular lens (IOL) exchange, aphakia, or anterior chamber intraocular lens (ACIOL) implants with a group of noncomplicated DSAEK cases. Methods: Of the 30 complicated DSAEK cases, 14 eyes underwent concurrent IOL exchange, 5 ACIOLs were not removed, 5 eyes remained aphakic, and 5 eyes had IOL exchange done before or after DSAEK. One eye had an iris-supported phakic IOL removed, followed by cataract extraction with IOL implantation at the time of DSAEK. The comparison group included 109 consecutive DSAEK cases with a history of Fuchs dystrophy or pseudophakic bullous keratopathy. Results: In the complicated group with significant ocular comorbidities, 27.6% achieved best-corrected visual acuity (BCVA) ≥20/40 and 60% had a final BCVA ≥20/70. In the comparison group of patients without visually significant comorbidities, 94.4% of eyes achieved BCVA ≥20/40 with no complication of graft detachments. Of the 30 complicated eyes, 5 (16.7%) had graft detachments and 5 (16.7%) developed IOL dislocations. All grafts remained clear at the last follow-up visit, except 3 cases (10%) in the complicated group, 2 of which were because of primary graft failure and required penetrating keratoplasty. Conclusions: In comparison with uncomplicated DSAEK cases, higher graft and IOL dislocations were observed in cases involving IOL exchanges, ACIOLs, or aphakia.