Comparison of 20% SF6 and 6% C3F8 Gas for Anterior Chamber Tamponade in Endothelial Keratoplasty.

PURPOSE: The aim of this study was to compare the rates of rebubbling after Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping endothelial keratoplasty (DSEK) between patients who had anterior chamber (AC) graft tamponade with 20% sulfur hexafluoride gas (SF6) and 6% perfluoropropane gas (C3F8). METHODS: The charts of 431 patients undergoing EK from June 8, 2010, to April 16, 2023, were reviewed. Patients undergoing EK alone as well as combined procedures with cataract extraction and intraocular lens implantation were included. Eyes with tube shunts, anterior chamber intraocular lenses, and large peripheral iridotomy with posterior loss of bubble, and patients undergoing cyclophotocoagulation or synechialysis were excluded. All rebubble procedures were performed within 1 month after initial surgery. RESULTS: A total of 346 eyes using SF6 and 167 eyes using C3F8 were analyzed. Overall, 46 eyes (9%) required rebubbling; 33 eyes (10%) in the SF6 group and 13 eyes (8%) in the C3F8 group. For those patients undergoing DMEK, the odds of requiring rebubbling in the C3F8 group were about 22% lower than that of patients in the SF6 group (operating room [OR]: 0.782; P < 0.001). For patients undergoing DSEK, however, the gas type did not significantly affect rebubbling rates (P = 0.99). CONCLUSIONS: For DMEK, utilization of 6% C3F8 as an AC tamponade was associated with a significantly lower odds of graft rebubbling compared with 20% SF6. Gas type did not result in a significant difference for DSEK. Utilization of 6% C3F8 for graft tamponade could be considered to reduce graft detachment rates in DMEK.

Results of the United States Food and Drug Administration Clinical Trial of the CustomFlex Artificial Iris.

PURPOSE: To evaluate safety and efficacy of a custom-manufactured artificial iris device (CustomFlex Artificial Iris; HumanOptics AG) for the treatment of congenital and acquired iris defects. DESIGN: Multicenter, prospective, unmasked, nonrandomized, interventional clinical trial. PARTICIPANTS: Patients with photophobia, sensitivity secondary to partial or complete congenital or acquired iris defects, or both. METHODS: Eyes were implanted from November 26, 2013, to December 1, 2017, with a custom, foldable artificial iris by 1 of 4 different surgical techniques. Patients were evaluated 1 day, 1 week, and 1, 3, 6, and 12 months after surgery. At each examination, slit-lamp findings, intraocular pressure, implant position, subjective visual symptoms, and complications were recorded. Corrected distance visual acuity (CDVA) and endothelial cell density (ECD) were measured at 3, 6, or 12 months as additional safety evaluations. The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was used to assess health-related quality of life affected by vision. The Global Aesthetic Improvement Scale was used to assess cosmetic results. MAIN OUTCOME MEASURES: Photosensitivity, glare, visual symptoms, NEI VFQ-25 score, Global Aesthetic Improvement Scale rating, prosthesis-related adverse events, intraocular lens (IOL)-related adverse events, and surgery-related adverse events 12 months after surgery. RESULTS: At the 12-month postoperative examination, a 59.7% reduction in marked to severe daytime light sensitivity (P < 0.0001), a 41.5% reduction in marked to severe nighttime light sensitivity (P < 0.0001), a 53.1% reduction in marked to severe daytime glare (P < 0.0001), and a 48.5% reduction in severe nighttime glare (P < 0.0001) were found. A 15.4-point improvement (P < 0.0001) in the NEI VFQ-25 total score was found, and 93.8% of patients reported an improvement in cosmesis as measured by the Global Aesthetic Improvement Scale 12 months after surgery. No loss of CDVA of > 2 lines related to the device was found. Median ECD loss was 5.3% at 6 months after surgery and 7.2% at 12 months after surgery. CONCLUSIONS: The artificial iris surpassed all key safety end points for adverse events related to the device, IOL, or implant surgery and met all key efficacy end points, including decreased light and glare sensitivity, improved health-related quality of life, and satisfaction with cosmesis. The device is safe and effective for the treatment of symptoms and an unacceptable cosmetic appearance created by congenital or acquired iris defects.

Accuracy of intraocular lens calculation formulas for flanged intrascleral intraocular lens fixation with double-needle technique.

PURPOSE: To evaluate the refractive prediction error (RPE) of intraocular lens (IOL) calculation formulas in eyes that have undergone the Yamane technique for scleral fixation of IOLs. SETTING: Alkek Eye Center, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas. DESIGN: Retrospective case series from electronic chart review. METHODS: Patients who had undergone scleral fixation of secondary IOLs were selected. The IOL RPEs for 4 IOL prediction formulas-Barrett Universal II, Holladay 1, Hoffer Q, and SRK/T formulas-were obtained by subtracting the predicted spherical equivalent from the postoperative spherical equivalent. The arithmetic mean RPE, mean absolute error (MAE), and percentages of eyes with prediction error of 0.50 diopter (D) or lesser and 1.00 D or lesser were calculated and compared. RESULTS: Forty eyes of 40 patients met inclusion criteria. All formulas produced hyperopic mean arithmetic RPE. MAE values were 0.73 D for Holladay 1, 0.76 D for Barrett Universal II, 0.80 D for SRK/T, and 0.86 D for Hoffer Q formulas. The percentage of eyes with prediction error of 0.50 D or lesser and 1.00 D or lesser with these formulas were 45% (18 eyes) and 75% (30 eyes) for Holladay 1, 38.5% (15 eyes) and 77% (30 eyes) for Barrett Universal II, 32.5% (13 eyes) and 67.5% (27 eyes) for SRK/T, and 27.5% (11 eyes) and 62.5% (25 eyes) for Hoffer Q formulas. There were no statistically significant differences in prediction errors between the 4 formulas. CONCLUSIONS: Refractive outcomes of the Yamane technique were less predictable than those of standard cataract surgery. Arithmetic RPE ranged from hyperopic to predicted values for all formulas tested.

Catastrophic globe disruption as a result of a TASER injury.

BACKGROUND: Injuries caused by the TASER(®) (TASER International, Inc., Scottsdale, AZ) have been well documented, and both direct and indirect ocular injuries have been reported. We present a case of severe perforating injury to the globe from a TASER dart with central cornea penetration. OBJECTIVES: To describe the presentation and management of a penetrating ocular injury from a TASER dart. CASE REPORT: A 47-year-old woman presented with a TASER dart injury penetrating through the central cornea. The injury resulted in a stellate corneal laceration, which was repaired with a final visual acuity of light perception without projection. CONCLUSION: This is a case of a severe TASER-related ocular injury resulting in significant vision loss. Although mechanical trauma seemed to be the main etiology for vision loss, electrical shock injury may also be contributory. Direct injury to the eye from a TASER dart is similar to other perforating projectile injuries and can have a devastating visual outcome.

Synthesis of calcium-silica composites: a route toward an in vitro model system for calcific band keratopathy precipitates.

Calcific band keratopathy (CBK) is a degenerative condition resulting in the deposition of calcium salts in the superficial layers of the cornea and causing significant visual disturbance and pain of the affected eye. Unfortunately, the amount of CBK precipitates recovered from the affected eye is very small therefore; it would be beneficial to prepare a synthetic material mimicking CBK material to further the development of therapeutics. Analyses of biological samples recovered from patients show the presence of silicon in addition to calcium, as well as a distinctive fused spherical morphology. This prompted us to study the reaction of various sources of silicon (fumed silica, silicic acid, and silicone oil) with CaCO(3) under a range of reaction conditions to gain an understanding of the formation of CBK. A silicon source alone was not found to be responsible for the fused spherical morphology, and a third component, a polar surfactant-like molecule such as sodium dodecyl sulfate or tetradecylphosphonic acid, was also required. The effects of silicon:calcium ratio and reaction time have been studied. The reaction of fumed silica with CaCO(3) in presence of sodium dodecyl sulfate results in the formation of spherical shapes resembling the structures and chemical composition observed in the eye samples, while no such structures were observed in the absence of silicon. Samples closely resembling human samples were also formed from the reaction of silicone oil with CaCO(3) in the presence of tetradecylphosphonic acid. Samples were characterized by SEM, XRD, and XPS and Raman spectroscopy.

Iris-sutured intraocular lenses for ectopia lentis in children.

PURPOSE: To compare outcomes and complications of pars plana lensectomy-vitrectomy (PPL-PPV) for the management of ectopia lentis in children with and without a foldable iris-sutured intraocular lens (IOL). SETTING: Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA. METHODS: This study comprised 22 eyes of 12 consecutive pediatric patients with ectopia lentis who had PPL-PPV by the same vitreoretinal surgeon with (12 eyes; Group L) or without (10 eyes; Group A) insertion of a foldable iris-sutured IOL between June 1998 and October 2006. Outcome measures included the proportion of eyes achieving visual acuity of 20/40 or better, mean logMAR visual acuity, and complications. RESULTS: There was no statistically significant difference between the 2 groups in the proportion of eyes achieving a visual acuity of 20/40 or better (Group A: 5/10; Group L: 10/12) (P = .17) or the mean postoperative best corrected logMAR visual acuity (Group A: 0.41 [20/52]; Group L: 0.24 [20/35]) (P = .18). Complications included IOL dislocation in 4 (33%) of 12 eyes in Group L (95% confidence interval, 11%-65%). Eyes with dislocated IOLs had retrieval with resuturing of the IOL to the iris and had a mean visual acuity of 20/27 at the last follow-up. No retinal detachment was observed. CONCLUSION: Pars plana lensectomy-vitrectomy with iris-fixation of a foldable IOL for the management of ectopia lentis yielded visual outcomes as least as good as those of optically corrected aphakia with a significant risk for dislocation.

Bilateral acanthamoeba keratitis.

PURPOSE: To determine the prevalence and characteristics of binocular involvement among patients with Acanthamoeba keratitis. DESIGN: Retrospective case series. METHODS: Risk factors and outcomes of bilateral infection were explored among consecutive cases of Acanthamoeba keratitis diagnosed at a single institution from 1997 through mid 2007. RESULTS: Fifty eyes were confirmed to have Acanthamoeba keratitis by microbiologic or histopathologic testing; two-thirds occurred during a regional outbreak beginning in 2004. Five (11%) of 45 patients had infection of both eyes, including three with concurrent involvement and two with successive disease of the contralateral cornea. Three binocularly infected patients used soft contact lenses, and two wore rigid gas-permeable lenses. Nine of 10 eyes achieved visual acuity of 20/30 or better after antiamebic therapy. CONCLUSIONS: Bilateral Acanthamoeba keratitis is an infectious complication of contact lens wear. With laboratory confirmation, vision often can be restored with medical therapy.

Descemet's stripping endothelial keratoplasty under topical anesthesia.

We describe a technique for performing Descemet's stripping endothelial keratoplasty under topical anesthesia and report the results in 7 patients. No patient reported intraoperative discomfort, and no operative complications were noted. Using a topical anesthetic approach in appropriate patients eliminates the risks associated with retrobulbar and peribulbar blocks.

The incidence and risk factors for developing dry eye after myopic LASIK.

PURPOSE: To determine the incidence of dry eye and its risk factors after myopic laser-assisted in situ keratomileusis (LASIK). DESIGN: Single-center, prospective randomized clinical trial of 35 adult patients, aged 24 to 54 years, with myopia undergoing LASIK. METHODS: setting and study population: Participants were randomized to undergo LASIK with a superior or a nasal hinge flap. They were evaluated at 1 week and 1, 3, and 6 months after surgery. intervention: Bilateral LASIK with either a superior-hinge Hansatome microkeratome (n = 17) or a nasal-hinge Amadeus microkeratome (n = 18). main outcome measures: The criterion for dry eye was a total corneal fluorescein staining score > or =3. Visual acuity, ocular surface parameters, and corneal sensitivity were also analyzed. Cox proportional-hazard regression was used to assess rate ratios (RRs) with 95% confidence intervals. RESULTS: The incidence of dry eye in the nasal- and superior-hinge group was eight (47.06%) of 17 and nine (52.94%) of 17 at 1 week, seven (38.89%) of 18 and seven (41.18%) of 17 at 1 month, four (25%) of 16 and three (17.65%) of 17 at 3 months, and two (12.50%) of 16 and six (35.29%) of 17 at 6 months, respectively. Dry eye was associated with level of preoperative myopia (RR 0.88/each diopter, P = .04), laser-calculated ablation depth (RR 1.01/microm, P = 0.01), and combined ablation depth and flap thickness (RR 1.01/microm, P = 0.01). CONCLUSIONS: Dry eye occurs commonly after LASIK surgery in patients with no history of dry eye. The risk of developing dry eye is correlated with the degree of preoperative myopia and the depth of laser treatment.

Long-term outcomes of photorefractive keratectomy for anisometropic amblyopia in children.

PURPOSE: To evaluate the long-term visual acuity (VA) and refractive error responses to excimer laser photorefractive keratectomy (PRK) for treatment of anisometropic amblyopia in children. DESIGN: Prospective interventional case-control study. PARTICIPANTS: Eleven children, 2 to 11 years old, with anisometropic amblyopia who were noncompliant with conventional therapy with glasses or contact lenses and occlusion therapy were treated with PRK. A cohort derived retrospectively of 13 compliant and 10 noncompliant children with refractive errors similar to those of the PRK group who were treated with traditional anisometropic amblyopia therapy served as control groups. INTERVENTION: Photorefractive keratectomy for the eye with the higher refractive error. MAIN OUTCOME MEASURES: (1) Refractive error reduction and stability in the treated eye, (2) cycloplegic refraction, (3) VA, (4) stereoacuity, and (5) corneal haze up to 3 years after PRK. Compliant and noncompliant children with anisometropia amblyopia were analyzed as controls for refractive error and VA. RESULTS: Preoperative refractive errors were -13.70 diopters (D) (+/-3.77) for the myopic group and +4.75 D (+/-0.50) for the hyperopic group. Mean postoperative refractive errors at last follow-up (mean, 31 months) were -3.55 D (+/-2.2.5) and +1.41 D (+/-1.07) for the myopic and hyperopic groups, respectively. At last follow-up, cycloplegic refractions in 4 (50%) of 8 myopes and all hyperopes (100%) were within 3 D of that of the fellow eye. Five (63%) of 8 myopic children achieved a refraction within 2 D of the target refraction. Two (67%) of 3 hyperopic patients maintained their refractions within 2 D of the target. Refractive regressions (from 1 year after surgery to last follow-up) were 0.50+/-1.41 D (myopes) and 0.60+/-0.57 D (hyperopes). Seven children (77%) were able to perform psychophysical VA testing preoperatively and postoperatively. Five (71%) of the 7 children had uncorrected VA improvement of at least 2 lines, and 4 (57%) of 7 had best spectacle-corrected VA improvement of at least 2 lines, with 1 improving 7 lines. Five (55%) of 9 children had improvement of their stereoacuity at last follow-up. Subepithelial corneal haze remained negligible. The mean final VA of the PRK group was significantly better than that of the noncompliant control group (P = 0.003). The mean final refractive error for both myopic and hyperopic groups was also significantly better that that of the control groups (P = 0.007 and P<0.0001, respectively). CONCLUSIONS: Photorefractive keratectomy for severe anisometropic amblyopia in children resulted in long-term stable reduction in refractive error and improvement in VA and stereopsis, with negligible persistent corneal haze.

Iris repair after a catastrophic laser in situ keratomileusis complication.

This report illustrates the surgical approach to and results of a complex iris reconstruction. The presentation and long-term visual and architectural results (follow-up of 4 years) of the repair of a severe anterior segment injury after entry into the anterior chamber by a microkeratome during laser in situ keratomileusis is described. The techniques used in the repair are described in detail, and a historical review of iris repair techniques is presented.

Photorefractive keratectomy for pediatric anisometropia: safety and impact on refractive error, visual acuity, and stereopsis.

PURPOSE: To establish the safety and possible efficacy of excimer laser photorefractive keratectomy (PRK) for treatment of pediatric anisometropia. DESIGN: Interventional case series METHODS: This is a prospective, noncomparative interventional case series at an individual university practice of photorefractive keratectomy in 11 children aged 2 and 11 years with anisometropic amblyopia who were unable or unwilling to use contact lens, glasses, and occlusion therapy to treat the amblyopia. The eye with the higher refractive error was treated with PRK using a standard adult nomogram. The refractive treatment goal was to decrease the anisometropia to 3 diopters or less. Main outcome measures were cycloplegic refraction, refractive correction, degree of corneal haze, uncorrected and best spectacle-corrected visual acuity, and stereopsis over 12 months. RESULTS: All patients tolerated the procedure well. The mean refractive target reduction was -10.10 +/- 1.39 diopters for myopia and +4.75 +/- 0.50 diopters for hyperopia. The mean achieved refractive error reduction at 12 months for myopia was -10.56 +/- 3.00 diopters and for hyperopia was +4.08 +/- 0.8 diopters. Corneal haze at 12 months was minimal. Uncorrected visual acuity improved by 2 or more lines in 6 (75%) of the eight children able to perform psychophysical acuity tests. Best spectacle-corrected visual acuity improved by 2 lines in 3 (38%) of patients. Stereopsis improved in 3 (33%) of nine patients. CONCLUSIONS: Pediatric PRK can be safely performed for anisometropia. The refractive error response in children appears to be similar to that of adults with comparable refractive errors. Visual acuity and stereopsis improved despite several children being outside the standard age of visual plasticity. Photorefractive keratectomy may play a role in the management of anisometropia in selected pediatric patients.

Successful implementation of a protocol for photorefractive keratectomy in children requiring anesthesia.

PURPOSE: To describe a protocol for treating children with photorefractive keratectomy (PRK) under general anesthesia and to review intraoperative and postoperative complications. SETTING: Institutional academic practice. METHODS: Nine patients between 3 years and 9 years of age were treated with PRK under general anesthesia for anisometropia with unilateral high myopia or high hyperopia and amblyopia of the affected eye. Induction of anesthesia and the surgical procedure were carried out in separate rooms. The laser beam was centered on the entrance pupil, and eye position was monitored throughout the procedure. Specific precautions were taken before and during the procedure to prevent unwanted effects of inhalational anesthetic agents on laser performance. RESULTS: All children did well, with no anesthesia-related or treatment-related complications. CONCLUSIONS: Our protocol for PRK under general anesthesia was effective and efficient in children who were unable to cooperate for the procedure using local anesthesia. It can be adapted for laser in situ keratomileusis and other refractive surgical procedures in children and uncooperative adults.

Laser in situ keratomileusis flap suturing to treat recalcitrant flap striae.

PURPOSE: To describe the management of resistant laser in situ keratomileusis (LASIK) flap striae using interrupted sutures. SETTING: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. METHODS: Interrupted sutures were used to treat striae in the LASIK flaps in 7 eyes of 7 patients. The mean interval from LASIK to the time of suturing was 11.8 months (range 3.0 to 29.0 months). The preoperative best spectacle-corrected visual acuity (BSCVA) was 20/20(-2) to 20/100. All patients had subjective visual complaints with spectacle correction, and all corneas had obvious macrostriae on slitlamp biomicroscopic examination. RESULTS: The mean patient follow-up was 7.0 months (range 1.5 to 14.0 months). Six patients regained a BSCVA of 20/20 or better with resolution of preoperative irregular astigmatism and subjective visual disturbance. In 1 patient, mild central striae recurred. CONCLUSION: Flap suturing was an effective means of treating visually significant flap striae.

Epithelial healing and ocular discomfort after photorefractive keratectomy in children.

OBJECTIVE: To document the rate of healing of the corneal epithelial defect created by photorefractive keratectomy (PRK) and the degree of discomfort experienced by children treated with PRK. SETTING: Baylor College of Medicine, Texas Children's Hospital, Houston, Texas, USA. METHODS: Ten patients between 3 and 10 years of age were treated with PRK for severe anisometropia. All had anisometropic amblyopia refractory to conventional therapy with glasses or contact lenses and occlusion therapy. The size of the corneal epithelial defect was documented daily until the defect healed completely. Postoperative discomfort was documented daily using a pain-assessment scale until the epithelial defect healed completely. RESULTS: Two children were treated with PRK for hyperopic anisometropia; the rest were treated for myopic anisometropia. Cumulatively, the corneal epithelium had healed completely by day 3 in 6 patients (60%), by day 4 in 9 patients (90%), and by day 5 in all patients. The mean healing time was 3.5 days. Patients experienced mild discomfort on the day of surgery and on the first postoperative day. They had minimal pain on day 2. After day 2, no patient reported pain or other discomfort. CONCLUSIONS: The corneal epithelial defect created by PRK healed promptly and was associated with minimal postoperative discomfort in children treated with the protocol described.

Corneal and scleral trauma.

Corneal and scleral wounds commonly occur in the context of serious eye trauma, and their management requires careful evaluation and planning prior to closure. The globe must be closed so that it is watertight with the original anatomy restored and the original function can be as closely approximated as possible. Closure of the cornea and sclera is different from the typical skin technique of "halving" the wound. Long corneal wounds are closed utilizing the Rowsey-Hays technique whereas scleral wounds extending posteriorly are closed in a stepwise fashion, proceeding posteriorly only after the anterior portion has been sutured. Suture removal from the cornea is dependent on a variety of factors including length of the laceration, age of the patient, and Keratorefractive anomalies caused by the sutures themselves.

Scanning electron microscopic evaluation of the surface characteristics of 4 microkeratome systems in human corneas.

PURPOSE: To evaluate the surface characteristics of keratectomy specimens created with 4 microkeratomes by scanning electron microscopy (SEM). SETTING: Two university institutions. METHODS: Keratectomies were performed in 10 fresh, unfrozen human eyes with 1 of 4 microkeratomes: the Draeger rotary microkeratome (Storz Instruments), the Universalkeratome (Phoenix), the Automated Corneal Shaper (Bausch & Lomb), or the Hansatome (Bausch & Lomb). The beds and edges of the keratectomy specimens were then examined by SEM. Standardized photographs were taken, and the surface and cut-edge characteristics of the keratectomies were compared. RESULTS: Irregularities were noted in the cut edges of Bowman's membrane and the surface of the keratectomy beds with all instruments. The irregularities were most prominent in corneas cut with the Draeger instrument and least prominent in those cut with the Universalkeratome. The serrations in Bowman's membrane and the irregularities in the keratectomy bed appeared to be related to the blade movement in oscillating blade instruments. CONCLUSIONS: All 4 microkeratomes caused some degree of surface irregularity. The Draeger microkeratome, which uses a continuously rotating blade, resulted in the greatest number of Bowman's membrane serrations and irregularities in the keratectomy bed. The tissue irregularities may be related to the development of pressure ridges ahead of the blade. In instruments that use an oscillating blade, chatter marks appear to be related to the reciprocating movement of the blade as it travels across the corneal stroma.