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Importance: Determining factors associated with endothelial cell loss after Descemet stripping automated endothelial keratoplasty (DSAEK) could improve long-term graft survival., Objective: To evaluate the associations of donor, recipient, and operative factors with endothelial cell density (ECD) 3 years after DSAEK in the Cornea Preservation Time Study., Design, Setting, and Participants: This cohort study was a secondary analysis of data collected in a multicenter, double-masked, randomized clinical trial. Forty US clinical sites with 70 surgeons participated, with donor corneas provided by 23 US eye banks. Individuals undergoing DSAEK for Fuchs dystrophy or pseudophakic/aphakic corneal edema were included., Interventions: The DSAEK procedure, with random assignment of a donor cornea with a preservation time of 0 to 7 days or 8 to 14 days., Main Outcomes and Measures: Endothelial cell density at 3 years as determined by a reading center from eye bank and clinical specular or confocal central endothelial images., Results: The study included 1090 participants (median age, 70 years) with 1330 affected eyes (240 bilateral cases [22.0%]), who underwent DSAEK for Fuchs dystrophy (1255 eyes [94.4%]) or pseudophakic/aphakic corneal edema (PACE) (75 eyes [5.6%]). Of these, 801 eyes (60.2%) belonged to women and 1207 (90.8%) to white individuals. A total of 749 participants (913 eyes; 164 [21.9%] bilateral cases) had functioning grafts with acceptable endothelial images preoperatively and at 3 years postoperatively and were included in this analysis. Factors associated with a lower ECD at 3 years (estimated effect with 99% CI) in the final multivariable model included donors with diabetes (-103 [-196 to -9] cells/mm2), lower screening ECD (-234 [-331 to -137] per 500 cells/mm2), recipient diagnosis of PACE (-257 [-483 to -31] in cells/mm2), and operative complications (-324 [-516 to -133] in cells/mm2). Endothelial cell loss (ECL) from a preoperative measurement to a 3-year postoperative measurement was 47% (99% CI, 42%-52%) for participants receiving tissue from donors with diabetes vs 43% (99% CI, 39%-48%) without diabetes; it was 53% (99% CI, 44%-62%) for participants diagnosed with PACE vs 44% (99% CI, 39%-49%) for those diagnosed with Fuchs dystrophy, and 55% (99% CI, 48%-63%) in participants who experienced operative complications vs 44% (99% CI, 39%-48%) in those who did not. No other donor, recipient, or operative factors were significantly associated with 3-year ECD., Conclusions and Relevance: Donor diabetes, lower screening ECD, a PACE diagnosis in the recipient, and operative complications were associated with lower ECD at 3 years after DSAEK surgery and may be associated with long-term graft success. While causation cannot be inferred, further studies on the association of donor diabetes and PACE in recipients with lower 3-year ECD warrant further study.

Purpose: To report 2 cases of ocular chemical burns associated with the use of a swim goggle antifog agent and to review the literature for this and similar antifog products., Methods: Case reports and systematic review of the medical literature, material safety data, product safety reports, and consumer reviews., Results: Two males, one 46 years and the other 41 years, were referred to our clinic with chemical burns of the ocular surface after using the same goggle antifog agent while swimming in a triathlon. Both sustained significant epithelial defects. Fortunately, with prompt treatment, both of our patients returned to their baseline vision within a few weeks without suffering sight-threatening complications., Conclusions: These are the first cases of ocular chemical burn secondary to use of an eyewear antifog agent to be reported in the medical literature. Similar reports found in consumer forums suggest that our cases are not isolated and these products may have the potential to cause vision-threatening chemical burns.

Purpose: To assess the repeatability and reliability of IOLMaster (Carl Zeiss Meditec, Inc., Dublin, CA) axial length and keratometry measurements (K readings) with a soft contact lens on normal eyes. The method is designed for eyes with corneal irregularities or after endothelial keratoplasty., Methods: Biometry was performed on 20 healthy right eyes of volunteer subjects with mean age, 27.3 +/- 4.9 years; axial length, 24.77 +/- 1.04 mm; and K reading, 43.48 +/- 1.69 D. Axial length and keratometry were measured and repeated with -0.5 D SofLens38 (Bausch & Lomb, Rochester, NY) and Acuvue2 (Johnson & Johnson, New Brunswick, NJ) soft contact lenses. Repeatability and reliability were evaluated. Contact lens thickness was measured directly by corneal optical coherence tomography (OCT)., Results: Axial lengths increased 59 +/- 10 microm with SofLens38 and 134 +/- 13 microm with Acuvue2, and these changes correlated with the OCT contact lens thicknesses (P = 0.995). The axial length variability remained constant (P = 0.18), measuring 24 +/- 10 microm for SofLens38 and 23 +/- 8 microm for Acuvue2 compared with 20 +/- 7 microm with no lens. K readings of 43.08 +/- 1.66 D with SofLens38, 42.79 +/- 1.57 D with Acuvue2, and 43.48 +/- 1.69 D with no lens corresponded to differences of -0.40 +/- 0.12 D with SofLens38 and -0.69 +/- 0.19 D with Acuvue2. The K-reading variability increased slightly from 0.04 to 0.09 D with either lens., Conclusions: Low-power soft contact lenses enable reliable and repeatable IOLMaster axial length and K-reading measurements. Correcting for the measurable lens thickness and lens effects, a <0.5-D error in the Sanders-Retzlaff-Kraff (SRK) II power formula is predicted.

The rate of corneal epithelial healing was determined as a function of the oxygen level present at the tear-cornea interface. Oxygen levels of 1.77, 2.3, 5.3, 8.55, 10.12, and 16.45% were created over the rabbit cornea with tarsorrhaphy and various contact lenses. Full depth epithelial defects of 4.5 mm diameter were created in 6 animals for each test condition with the fellow eye serving as a control and healing in air (21.09% oxygen). The defect (radius) was measured at 24-h intervals until healing occurred. Statistically significant (p less than 0.05, paired Student t-test) delays in healing were found with oxygen levels of 8.55% and below. These delays were most profound over the initial 24 h. The healing rate with tarsorrhaphy, at the 1.77% oxygen level, over the first 24 h was 5.2 microns/h radius, only 15.2% of the paired control, 34.0 microns/h radius, healing in air (21.09% oxygen). Healing rates over the initial 24 h under contact lenses allowing 2.3, 5.3, 8.55, 10.12, and 16.45% oxygen were 6.1, 23.5, 26.5, 43.0, and 45.0 microns/h in radius, respectively.

A quantitative comparison is made of the effects of two of the most completely dissociating representatives from the pH spectrum, sodium hydroxide and hydrochloric acid, on oxygen uptake by the corneal epithelium. Based on initial observations, a 6 to 1 time ratio in the exposure period (acid, 60 seconds; base, 10 seconds) was found necessary to localize and define similar aerobic effects by the 2 agents on their concentration scales. A further dosage adjustment factor was required, a 5/1 concentration ratio of acid to base, to achieve near parity of the major depressive thresholds of those 2 agents, as well as to illustrate in the resulting graphical model several unique features of each in their aerobic effects on corneal tissue at lower concentrations.

With the use of a micropolarographic system, the effects of a series of unbuffered sodium hydroxide concentrations on oxygen uptake by the corneal epithelium of rabbit were measured in vivo. Based on an exposure model of 10 sec. followed by a saline rinse, concentrations of greater than 0.10 N were found to cause an abrupt and severe decline in oxygen uptake, with oxygen flux responses associated with 0.13 N and greater being indistinguishable 10 min later from those of a cornea completely denuded of epithelium. Initial flux variations, characteristic of exposure responses to concentrations of 0.10 N or less, gradually diminished, however, stabilizing within 1 hr to levels not significantly different (P less than 0.01) from pre-exposure fluxes or those of saline controls.