Results of corneal collagen cross-linking in patients with corneal ectasia after laser refractive surgery-A prospective study.

PURPOSE: To evaluate the safety and efficacy of epithelium-off (epi­off) corneal cross-linking (CXL) in patients with post-LASIK corneal ectasia (PLE) SETTING: Private clinical practice DESIGN: Prospective clinical trial METHODS: 82 eyes of adult patients post-LASIK, ages 21-67, with a topography pattern consistent with corneal ectasia, corrected distance visual acuity (CDVA) worse than 20/20, and minimum corneal pachymetry > 400 µm underwent epi­off CXL. Exclusion criteria were patients with corneas that were thinner than 400 µm or demonstrated central corneal scarring, history of herpetic eye disease, pregnancy or nursing. Follow up examinations of spherical equivalent, uncorrected distance visual acuity (UDVA), CDVA, steep keratometry (KSteep) and minimum pachymetry occurred on different but highly overlapping subsets of the operated eyes yearly until 5 years post-CXL. RESULTS: Over the 5 years of follow up, spherical equivalent did not significantly change while UCVA and CDVA stabilized or improved to a non-significant degree. KSteep and minimum pachymetry continued to be decreased to a statistically significant degree (p < 0.05 at 5 years). CONCLUSIONS: CXL in PLE patients is safe and efficacious: it halts progression of PLE and may improve visual function. KSteep and minimum pachymetry decrease post-CXL. Patients with PLE should be encouraged to stop progression of the disease by undergoing epi­off CXL once progression is established.

Results of corneal crosslinking in adolescents with progressive keratoconus: prospective study.

PURPOSE: To evaluate the safety and efficacy of epithelium-off (epi-off) corneal crosslinking (CXL) in adolescents with progressive keratoconus (KC). SETTING: Private clinical practice. DESIGN: Nonrandomized prospective clinical trial. METHODS: 230 adolescent patients aged 10 to 19 years with progressive KC (increasing maximum keratometry [Kmax] or astigmatism of 1.00 diopter or greater associated with decreased corrected distance visual acuity [CDVA]) underwent CXL. Exclusion criteria were age at time of CXL younger than 10 years or older than 19 years, corneas that were thinner than 400 µm or demonstrated central corneal scarring, history of herpetic eye disease, or pregnancy or nursing. Follow-up examinations of uncorrected distance visual acuity (UDVA), CDVA, Kmax, and minimum pachymetry occurred on 130 eyes at 1 year, 77 eyes at 2 years, and 55 eyes at 3 years post-CXL. RESULTS: In this study, 230 eyes of adolescent patients were evaluated. UDVA significantly improved from preoperatively to 1 year, 2 years, and 3 years post-CXL. CDVA values significantly improved from preoperatively to 1 year, 2 years, and 3 years post-CXL. Kmax values significantly reduced (improved) from preoperatively to 1 year and 3 years post-CXL and reduced (improved) (P = .22) from preoperatively to 2 years post-CXL. Minimum pachymetry decreased significantly from preoperatively to 1 year, 2 years, and 3 years post-CXL. CONCLUSIONS: CXL in patients aged 10 to 19 years was safe and efficacious, halted progression of KC and could improve UCVA, CDVA, and Kmax. Minimum pachymetry decreased and stabilized post-CXL. Ophthalmologists should encourage adolescent patients with KC to obtain prompt evaluation and possible CXL to halt progression of the disease.

Management of cap striae following challenging small incision lenticule extraction surgery - A case report.

A 24-year-old female underwent small incision lenticule extraction (SMILE) for myopic astigmatism OU. In the left eye, cap-lenticular adhesion along with tearing of the cap occurred, resulting in a gaped incision and transverse striae involving the visual axis on the first post op day. Uncorrected distance visual acuity (UDVA) was 20/32. The case was managed with interface wash and stretching of the cap, in order to iron out the striae. Post intervention, the UDVA improved to 20/20, striae resolved, and interface remained clear through a follow-up of nine months, suggesting that cap striae in SMILE may be similarly managed as the flap striae in laser-assisted in situ keratomileusis (LASIK), resulting in satisfactory visual outcomes.

Corneal Perforation After Corneal Cross-Linking in Keratoconus Associated With Potentially Pathogenic ZNF469 Mutations.

PURPOSE: To report a case of bilateral and repetitive corneal perforations after corneal cross-linking (CXL) for keratoconus in a woman harboring potentially pathogenic variants in the ZNF469 gene and to characterize the keratoconus phenotype in this woman and her daughter who shared the same ZNF469 mutations. METHODS: Clinical characterization of the proband and her daughter followed by sequencing of the genes associated with brittle cornea syndrome, ZNF469 and PRDM5, in both individuals. RESULTS: An Ashkenazi Jewish woman in her sixth decade presented with diffuse corneal thinning and progressive steepening consistent with keratoconus. After CXL, epithelium-off in the first eye and epithelium-on in the second, she developed spontaneous corneal perforations in each eye. Her daughter in her fourth decade demonstrated a similar pattern of diffuse corneal thinning and progressive corneal steepening but did not undergo CXL and did not develop corneal perforation. Screening of the ZNF469 and PRDM5 genes revealed 3 missense ZNF469 variants (c.2035G>A, c.10244G>C, and c.11119A>G) in cis arrangement on 1 allele of ZNF469 in both proband and her daughter. Although the 3 variants share low (<0.01) global minor allele frequencies, each has significantly higher minor allele frequencies (0.01-0.03) in the Ashkenazi Jewish population, leading to uncertainty regarding a pathogenic role for the identified variants. CONCLUSIONS: CXL may be associated with the development of corneal perforation in particular at-risk individuals with keratoconus. Identifying clinical and genetic risk factors, including screening of ZNF469 and PRDM5, may be useful in the prevention of significant complications after CXL.

Corneal Cross-Linking for Pediatric Keratcoconus Review.

PURPOSE: To comprehensively review the available published literature for cross-linking in the pediatric population. METHODS: Review of the literature published in English in PubMed. RESULTS: Two hundred ten publications were considered. One hundred fifteen were considered relevant to this review. CONCLUSIONS: Studies of cross-linking in pediatric patients are sparse, with relatively short follow-up times, and mostly on small groups of patients. Treatment with cross-linking halts progression of keratoconus in the pediatric population, and early treatment seems to be cost-effective compared with later penetrating keratoplasty. Long-term effects and regression rates remain unclear, and further studies are needed in this population.

Prospective evaluation of intense pulsed light and meibomian gland expression efficacy on relieving signs and symptoms of dry eye disease due to meibomian gland dysfunction.

PURPOSE: The aim of this study was to estimate the efficacy of intense pulsed light (IPL), followed by meibomian gland expression (MGX), for reducing the number and severity of signs and symptoms of dry eye disease (DED) secondary to meibomian gland dysfunction (MGD). PATIENTS AND METHODS: In a prospective study conducted in two sites, 40 subjects (80 eyes) with moderate to severe MGD were enrolled. Major inclusion criteria consisted of at least two of the following measures being compatible with DED in both eyes: tear breakup time (TBUT), meibomian gland score (MGS), corneal fluorescein staining (CFS), Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire, and tear film osmolarity (TFO). Enrolled patients underwent four treatment sessions, 3 weeks apart. Each treatment included the administration of 10-15 pulses of IPL on the cheeks and nose, followed by MGX of the upper and lower eyelids. TBUT, MGS, CFS, SPEED, TFO, and lipid layer thickness (LLT) were measured at baseline (BL) and at 9, 12, and 15 weeks after BL. RESULTS: Due to different staining methods used for TBUT measurements, TBUT and CFS were analyzed separately for each site. From BL to the final follow-up, the number of signs compatible with DED decreased from 3.3±0.1 to 1.4±0.1. TBUT improved by +93% (n=38; P<0.0001) and +425% (n=42; P<0.0001) for sites 1 and 2, respectively. SPEED, MGS, and CFS improved by -55% (n=80; P<0.0001), -36% (n=80; P<0.0001), and -58% (n=38; P<0.0001), respectively. In 20 eyes with abnormally elevated TFO at BL, TFO improved by -7% (n=20; P<0.005). LLT did not change (n=38; P=0.88). CONCLUSION: In subjects with moderate to severe MGD, IPL combined with MGX reduced the number and severity of symptoms and signs of DED. Except for LLT, all examined outcome measures significantly improved after 15 weeks. These results support the efficacy of IPL + MGX in relieving both signs and symptoms of DED secondary to MGD.

Comparison of the Effect of Epithelial Removal by Transepithelial Phototherapeutic Keratectomy or Manual Debridement on Cross-linking Procedures for Progressive Keratoconus.

PURPOSE: To compare the visual, refractive, keratometric, topographic, and pachymetric outcomes of corneal collagen cross-linking (CXL) for progressive keratoconus following epithelial removal by transepithelial phototherapeutic keratectomy (PTK) or manual debridement. METHODS: In this analysis, 339 eyes (78% male, 22% female) that had undergone CXL following manual epithelial debridement (n = 180) or ablation via PTK (n = 159) were evaluated preoperatively and at 6, 12, and 24 months postoperatively for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), maximum corneal keratometry, pachymetry, and spherical equivalent. The data were analyzed in a t test to evaluate the relative efficacy of each epithelial removal procedure. RESULTS: Manual epithelial debridement and ablation via PTK produce equivalent changes for all variables at each time interval with the exception of maximum corneal keratometry at 6 months postoperatively, for which PTK exhibited a significantly improved (flatter) result. This difference was present but not statistically significant at 12 and 24 months postoperatively. CONCLUSIONS: Prior to CXL, both manual epithelial debridement and ablation via PTK result in equivalent visual, refractive, and keratometric outcomes up to 24 months postoperatively. [J Refract Surg. 2016;32(10):699-704.].

Results of toric intraocular lenses for post-penetrating keratoplasty astigmatism.

PURPOSE: Evaluate the usefulness of toric intraocular lens (IOL) implantation during cataract surgery in patients after penetrating keratoplasty (PKP). DESIGN: Retrospective case review. PARTICIPANTS: A total of 21 eyes of 16 patients with prior PKP and moderate to high regular astigmatism after full suture removal underwent phacoemulsification and implantation of a single-piece acrylic toric IOL (SN6AT series; Alcon, Fort Worth, TX). METHODS: Patients underwent comprehensive examinations at standard intervals, including visual acuity, manifest refraction, and corneal topography. MAIN OUTCOME MEASURES: Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) expressed as the logarithm of the minimum angle of resolution (logMAR) and manifest refraction astigmatism. RESULTS: From preoperatively to the last visit (mean, 14.7 ± standard deviation 12.8 months), the 21 eyes had significant improvement in UDVA (logMAR, 0.90 ± 0.48 to 0.23 ± 0.25; P = 0.0001) and CDVA (logMAR, 0.31 ± 0.14 to 0.08 ± 0.13; P = 0.0001). A total of 14 of 21 eyes (67%) and 17 of 21 eyes (81%) had UDVA and CDVA of ≥ 20/30, respectively. Preoperative topographic astigmatism was 4.57 ± 2.05 diopters (D). Postoperative manifest refraction astigmatism was 1.58 ± 1.25 D overall, but lower (0.75 ± 0.54 D) in the T7-T9 subgroup (excluding 1 outlier whose corneal astigmatism doubled after surgery) than in the T4-T6 subgroup (1.88 ± 1.28 D; P = 0.013). A total of 16 of all 21 eyes (76.2%) and 8 of 9 eyes (89%) in the T7-T9 subgroup were within 1 D of postoperative manifest astigmatism as predicted or better. CONCLUSIONS: Toric IOLs placed during cataract surgery after PKP and full suture removal can reduce manifest refraction cylinder to predictably low levels with corresponding improvement in UDVA and CDVA in patients with moderate to high regular preoperative topographic astigmatism.

Penetrating keratoplasty using femtosecond laser-enabled keratoplasty with zig-zag incisions versus a mechanical trephine in patients with keratoconus.

BACKGROUND/AIMS: This paper will compare the visual outcomes of two different penetrating keratoplasty (PKP) techniques in patients with keratoconus. It is a retrospective comparative surgical case series of 116 keratoconus patients (137 eyes) who had PKP at the Cornea Eye Institute, Beverly Hills, California, USA. METHODS: 56 keratoconus patients (66 eyes) underwent femtosecond laser-enabled keratoplasty (FLEK) with a zig-zag incision configuration. Their visual parameters were compared with those of 60 patients (71 eyes) who had traditional blade mechanical trephination PKP. The range of follow-up was between 3 and 6 months. The main outcome measures included uncorrected visual acuity and best spectacle-corrected visual acuity (BSCVA), manifest refractive spherical equivalent and topographically determined astigmatism. RESULTS: BSCVA was significantly better as early as 3 months postoperatively (p=0.001) in the FLEK group. Visual recovery to 20/40 after 3 months was significantly better in the FLEK group (p<0.001). Topographic astigmatism was lower in the FLEK group, but the difference between the two groups reached significance only at 3 months of follow-up (p=0.001). Postoperative complications noted were not different between the two groups. CONCLUSIONS: Faster visual recovery and better long-term outcomes were observed in keratoconus patients who had FLEK compared with those who had the mechanical PKP procedure with 6 months of postoperative follow-up.

Comparison of corneal surface higher-order aberrations after endothelial keratoplasty, femtosecond laser-assisted keratoplasty, and conventional penetrating keratoplasty.

PURPOSE: To evaluate and compare corneal higher-order aberrations (HOAs) after Descemet stripping automated endothelial keratoplasty (DSAEK), femtosecond laser-assisted penetrating keratoplasty (FLAK), and conventional penetrating keratoplasty (PKP). METHODS: A retrospective comparison of consecutive surgical series of 67 eyes of 59 patients between 1.5 and 19 months after corneal transplant surgery (22, 34, and 11 corneas underwent DSAEK, FLAK, and PKP, respectively, by a single surgeon). The main outcome measures were anterior and posterior corneal surface HOAs (Zernike polynomials, third to eighth order) determined with Scheimpflug photography at 4.0- and 6.0-mm optical zones and best spectacle-corrected visual acuity (BSCVA) (logarithm of the minimum angle of resolution equivalents). RESULTS: DSAEK had fewer total anterior HOAs compared with FLAK [P = 5.27 × 10(-5) (4.0 mm) and P = 1.02 × 10(-5) (6.0 mm)] and PKP [P = 1.82 × 10(-4) (4.0 mm) and P = 1.56 × 10(-4) (6.0 mm)] but greater total posterior HOAs than FLAK [P = 0.001 (4.0 mm) and P = 0.007 (6.0 mm)] and PKP [at 4.0-mm optical zone (P = 0.047)]. FLAK had fewer total anterior and posterior HOAs than PKP, but differences were not statistically significant. DSAEK grafts exhibited statistically significantly greater posterior HOAs than either type of PKP. The magnitude of anterior and posterior HOAs weakly correlated with BSCVA. CONCLUSIONS: DSAEK induces fewer anterior surface HOAs but greater posterior surface HOAs than FLAK or PKP. Differences between FLAK and PKP are not statistically significant. Anterior and posterior HOAs correlate weakly with poorer visual outcome and likely contribute to decreased BSCVA after keratoplasty.

Quantitative assessment of UVA-riboflavin corneal cross-linking using nonlinear optical microscopy.

PURPOSE: Corneal collagen cross-linking (CXL) by the use of riboflavin and ultraviolet-A light (UVA) is a promising and novel treatment for keratoconus and other ectatic disorders. Since CXL results in enhanced corneal stiffness, this study tested the hypothesis that CXL-induced stiffening would be proportional to the collagen autofluorescence intensity measured with nonlinear optical (NLO) microscopy. METHODS: Rabbit eyes (n = 50) were separated into five groups including: (1) epithelium intact; (2) epithelium removed; (3) epithelium removed and soaked in riboflavin, (4) epithelium removed and soaked in riboflavin, with 15 minutes of UVA exposure; and (5) epithelium removed and soaked in riboflavin, with 30 minutes of UVA exposure. Corneal stiffness was quantified by measuring the force required to displace the cornea 500 µm. Corneas were then fixed in paraformaldehyde and sectioned, and the collagen autofluorescence over the 400- to 450-nm spectrum was recorded. RESULTS: There was no significant difference in corneal stiffness among the three control groups. Corneal stiffness was significantly and dose dependently increased after UVA (P < 0.0005). Autofluorescence was detected only within the anterior stroma of the UVA-treated groups, with no significant difference in the depth of autofluorescence between different UVA exposure levels. The signal intensity was also significantly increased with longer UVA exposure (P < 0.001). Comparing corneal stiffness with autofluorescence intensity revealed a significant correlation between these values (R(2) = 0.654; P < 0.0001). CONCLUSIONS: The results of this study indicate a significant correlation between corneal stiffening and the intensity of collagen autofluorescence after CXL. This finding suggests that the efficacy of CXL in patients could be monitored by assessing collagen autofluorescence.

Penetrating keratoplasty in active Acanthamoeba keratitis.

PURPOSE: To report the results of penetrating keratoplasty (PK) in active Acanthamoeba keratitis (AK). METHODS: Nine patients with deep stromal infiltrates because of AK were treated with intensive antiamoebic medical therapy followed by PK during the acute infectious phase because of poor clinical response or poor compliance. Antiamoebic therapy was tapered after PK. RESULTS: Visual acuity ranged from 20/15 to 20/50 after an average of 17 months after PK with no signs of recurrences. Patients had rapid resolution of symptoms. CONCLUSION: PK is a viable option for active AK not responding to maximum medical treatment.

Donor risk factors for graft failure in the cornea donor study.

PURPOSE: The purpose of this study was to assess the relationship between donor factors and 5-year corneal graft survival in the Cornea Donor Study. METHODS: Donor corneas met criteria established by the Eye Bank Association of America, had an endothelial cell density of 2300 to 3300/mm, and were determined to be of good to excellent quality by the eye banks. Donor corneas were assigned using a random approach and surgeons were masked to information about the donor cornea including donor age. Surgery and postoperative care were performed according to the surgeons' usual routines and subjects were followed for 5 years. Donor and donor cornea factors were evaluated for their association with graft failure, which was defined as a regraft or a cloudy cornea that was sufficiently opaque to compromise vision for a minimum of 3 consecutive months. RESULTS: Graft failure was not significantly associated with the type of tissue retrieval (enucleation versus in situ), processing factors, timing of use of the cornea, or characteristics of the donor or the donor cornea. Adjusting for donor age did not affect the results. CONCLUSION: Donor and donor cornea characteristics do not impact graft survival rates for corneas comparable in quality to those used in this study.

Comparison of penetrating keratoplasty performed with a femtosecond laser zig-zag incision versus conventional blade trephination.

PURPOSE: To evaluate visual outcomes and astigmatism in patients who underwent penetrating keratoplasty (PK) with 2 different incision techniques. DESIGN: Retrospective comparison of a consecutive surgical series. PARTICIPANTS: Fifty-seven consecutive patients who underwent PK at the University of California, Irvine, academic referral practice. METHODS: A comparison of 49 eyes of 43 patients that underwent femtosecond laser zig-zag incision pattern PK versus 17 eyes of 14 patients that underwent conventional Barron suction trephination PK performed contemporaneously. All PKs were closed with an identical, 24-bite running nylon suture technique. MAIN OUTCOME MEASURES: Topographically determined astigmatism, best spectacle-corrected visual acuity (BSCVA), and recovery of full visual potential. RESULTS: The postoperative follow-up ranged from 1 to 12 months. There was a significant difference in average astigmatism between the groups at postoperative month 1 (P = 0.013) and 3 (P = 0.018). By month 3, the average astigmatism was 3 diopters (D) in the zig-zag group and 4.46 D in the conventional group. Of the patients with normal macular and optic nerve function (n(ZZ) = 32; n(con) = 14), a significant difference in BSCVA was seen at month 1 (P = 0.0003) and month 3 (P = 0.006) with 81% of the zig-zag group versus 45% of the conventional group achieving BSCVA of > or =20/40 by month 3 (P = 0.03). CONCLUSIONS: The femtosecond laser generated zig-zag-shaped incision results in a more rapid recovery of BSCVA and induces less astigmatism compared with conventional blade trephination PK. FINANCIAL DISCLOSURE(S): Proprietary commercial disclosure may be found after the references.

Suction loss during femtosecond laser incision for penetrating keratoplasty.

We present a case of suction loss during a femtosecond laser incision for penetrating keratoplasty in the host cornea. This case illustrates a technique for completing the procedure with no further complications.

The long-term effect of vitreous presentation during extracapsular cataract surgery on postoperative visual acuity.

PURPOSE: To compare at two, three, and four years after surgery the effect on best-corrected visual acuity (BCVA) of anterior chamber (AC) intraocular lenses (IOLs) and posterior chamber (PC) IOLs implanted after vitreous presentation (VP) during extracapsular cataract extraction in patients having sufficient capsular support for a nonsutured PC IOL. DESIGN: The study was a randomized prospective, long-term, clinical trial. METHODS: Patients at 19 Department of Veterans Affairs Medical Centers having VP during cataract surgery with sufficient capsular support were randomized to receive either a PC IOL (230 patients) or an AC IOL (208 patients). Patients having insufficient capsular support (ICS; 143 patients) and a 5% random sample of nonvitreous presentation patients (NVP; 521 patients) were prospectively followed in the same fashion. RESULTS: There was no significant difference on the major outcome measure of BCVA of 20/40 or better between the PC IOL and AC IOL groups at two (88.7% vs 82.2%; P = .23), three (82.5% vs 91.8%; P = .18), and four (88.6% vs 92.6%; P = .69) years of follow-up. The ICS patients had significantly worse (P < .0083) or a trend to be worse (P < .05) BCVA of 20/40 or better than the other three groups at two and four years. CONCLUSIONS: The significant difference that the PC IOL was better than the AC IOL on the major outcome measure at one year reported previously was not maintained in later years. The poor results for ICS patients reported previously at one year continue at two and four years.

Pseudophakic corneal edema: A review of mechanisms and treatments.

PURPOSE: To review the pathological mechanisms and treatments for pseudophakic corneal edema (PCE), one of the most common indications for penetrating keratoplasty. METHODS: The literature was examined for the molecular biology associated with PCE and for the surgical and medical treatments for this disorder. RESULTS: The incidence of PCE has recently been decreasing because of improved surgical instrumentation, including improvements in intraocular lens designs that cause less trauma to the corneal endothelium. Extracellular matrix and growth factor abnormalities occur in PCE corneas and recently, the role of aquaporins, which are involved in the regulation of fluid movement across cells, has been investigated. CONCLUSIONS: Although newer treatment options have been suggested, penetrating keratoplasty still remains the most definitive treatment and has the highest success rate.

Outcomes in patients having vitreous presentation during cataract surgery who lack capsular support for a nonsutured PC IOL.

PURPOSE: The study's purpose was to determine the effect that lack of capsular support for a nonsutured posterior chamber (PC) intraocular lens IOL has on 1-year postoperative vision in patients suffering vitreous presentation (VP) during extracapsular cataract surgery. DESIGN: The study was a prospective, long-term clinical trial. METHODS: The study was conducted at 19 Department of Veterans Affairs medical centers. Patients having VP during cataract surgery with sufficient capsular support for a nonsutured PC IOL were randomized to receive either a PC IOL (230 patients) or an anterior chamber (AC) IOL (208 patients). Patients having insufficient capsular support (ICS) for a nonsutured PC IOL (143 patients) were prospectively followed in the same fashion. Best-corrected visual acuity (BCVA) at 1 year was obtained by a masked, certified examiner. RESULTS: The ICS group had considerably fewer patients with BCVA of 20/40 or better at 1 year (P < .0001) than the randomized PC IOL group (66.7% vs 91.1%) with a trend (P = .04) for having fewer patients than the randomized AC IOL group (66.7% vs 79.0%). The ICS group had significantly poorer rating of vision at 1 year by study raters, and the patients themselves than either of the randomized VP groups. CONCLUSIONS: The lack of capsular support for the placement of a nonsutured PC IOL after VP during extracapsular cataract surgery or the severity of the complication of VP associated with lack of capsular support would appear to cause visual problems beyond that related to the type of intraocular lens implanted.