Scleral lens influence on corneal curvature and pachymetry in keratoconus patients.

OBJECTIVES: To investigate the influence of full scleral lenses on corneal curvature and pachymetry in keratoconus patients. METHODS: In this intervention study, 20 eyes of 14 patients were measured by Scheimpflug imaging (Pentacam HR, Oculus) at two time points: directly and ≥1 week after scleral lens removal. Steep, flat and maximal keratometry (K(steep), K(flat) and K(max)) and optical pachymetry were analyzed. A generalized estimating equation analysis was performed to correct for paired eyes. RESULTS: Directly after scleral lens removal, all three curvature parameters were significantly flatter compared to ≥1 week after scleral lens removal. Average K(steep) was 0.7 diopter (D) lower (P<0.001), average K(flat) was 0.5D lower (P=0.037) and average K(max) was 1.1D lower (P<0.001). Directly after scleral lens removal, average optical pachymetry was ±2.5% higher (P<0.001) compared to ≥1 week after scleral lens removal. CONCLUSIONS: Although scleral lenses do not mechanically touch the cornea, curvature and pachymetry seem to be influenced by scleral lens wear in keratoconus patients. The duration of these changes remain unclear.

Transepithelial versus epithelium-off corneal cross-linking for the treatment of progressive keratoconus: a randomized controlled trial.

PURPOSE: To compare the clinical effects and safety of transepithelial corneal cross-linking (CXL) to epithelium-off (epi-off) CXL in progressive keratoconus. DESIGN: Randomized clinical trial (noninferiority). METHODS: Patients received either transepithelial CXL with Ricrolin TE (n = 35) or epi-off CXL with isotonic riboflavin (n = 26) in 1 academic treatment center, using a simple unrestricted randomization procedure. The main outcome measure was clinical stabilization of keratoconus after 1 year, defined as a maximal keratometry (Kmax) increase <1 diopter (D). RESULTS: Average Kmax was stable at all visits in the transepithelial group, while after epi-off CXL a significant flattening of 1.2-1.5 D was demonstrated from the 3-month follow-up onwards. The trend over time in Kmax flattening was significantly different between the groups (P = .022). Eight eyes (23%) in the transepithelial group showed a Kmax increase of >1 D after 1 year (range 1.3-5.4 D) vs none in the epi-off group (P = .017). There was significant different trend in corrected distance visual acuity (CDVA), with a more favorable outcome in the transepithelial group (P = .023). In the transepithelial group, no complications occurred and in the epi-off group, 4 eyes (15%) developed complications owing to healing problems (sterile infiltrate, herpes keratitis, central haze, and stromal scar). CONCLUSION: This study showed that although transepithelial CXL was a safe procedure without epithelial healing problems, 23% of cases showed a continued keratoconus progression after 1 year. Therefore, at this time, we do not recommend replacing epi-off CXL by transepithelial CXL for treatment of progressive keratoconus.

Scleral lens tolerance after corneal cross-linking for keratoconus.

PURPOSE: Subjective and objective evaluation of scleral lens tolerance and fitting before and after corneal cross-linking (CXL) for progressive keratoconus. METHODS: In this prospective cohort, evaluations were made of 18 unilateral eyes in patients who underwent CXL and had been wearing scleral lenses before the procedure. All the patients gave informed consent; they were able to cooperate with the study, were eligible for CXL, had been wearing well-fitting scleral lenses for at least 3 months, and had no other active ocular disease. Data were collected before and 1 year after CXL. Outcome measures were changes in clinical and subjective scleral lens performance. The following components were studied: scleral lens corrected distance visual acuity, scleral lens specifications, scleral lens fit, wearing time, and subjective measures on visual analogue scale questionnaires (1 to 100 mm). RESULTS: There was no significant change in scleral lens corrected distance visual acuity (p = 0.632). Sixty-one percent of eyes needed a scleral lens fit and/or power change. Wearing time (median, 16 hours per day) and subjective tolerance were found to be stable. CONCLUSIONS: Scleral lens tolerance after CXL appeared to be stable.

Standard and hypoosmolar corneal cross-linking in various pachymetry groups.

PURPOSE: To investigate the influence of corneal thickness on the outcome of corneal cross-linking (CXL) for progressive keratoconus. METHODS: In this cohort study, 72 unilateral eyes were treated by CXL and divided into three groups according to central corneal thickness (CCT) measured by ultrasound pachymetry after 30-minute riboflavin. Group 1 (CCT <400 µm) underwent hypoosmolar CXL; group 2 (CCT 400 to 460 µm) and group 3 (CCT >460 µm) underwent standard CXL. Visual acuity, refraction, topography, ultrasound and optical pachymetry, intraocular pressure, endothelial cell count, and complications were evaluated 1 year post-CXL. RESULTS: Ultrasound CCT after riboflavin instillation decreased significantly in groups 1 and 2 (-57 ± 44 µm and -39 ± 23 µm, respectively) and increased in group 3 (+15 ± 37 µm). One year post-CXL, maximal keratometry decreased significantly in group 2. Keratoconus progression was halted in 92% (group 1), 97% (group 2), and 86% (group 3). Optical pachymetry decreased significantly in all groups. Corrected distance visual acuity improved significantly in groups 1 and 3. No significant difference was found in visual acuity, keratometry, optical pachymetry, or endothelial cell density change between groups. Complication rates were comparable between the groups; there was no significant difference in CXL failure (p = 0.687) or corrected distance visual acuity loss (p = 0.617). CONCLUSIONS: During CXL, corneas with CCT less than or equal to 460 µm seem to dehydrate faster than corneas with CCT greater than 460 µm. Both standard and hypoosmolar CXL are safe and effective treatments, with comparable amounts of stabilization after 1 year.

Corneal cross-linking for treatment of progressive keratoconus in various age groups.

PURPOSE: To compare the effect of corneal cross-linking (CXL) for keratoconus in various age groups and to investigate the influence of the topographic cone location on the outcome of CXL. METHODS: This cohort study included 95 patients (119 eyes) diagnosed as having progressive keratoconus who underwent epithelium-off standard protocol CXL from January 2010 through May 2012. For statistical analysis, patients were divided into three age groups: pediatric patients (< 18 years), adolescent patients (18 to 26 years), and adults (> 26 years). Visual acuity and refraction, topography, intraocular pressure, and endothelial cell counts were recorded preoperatively and postoperatively. RESULTS: Topographic cones were located more centrally in pediatric corneas (0.85 ± 0.66 mm) compared to adolescent corneas (1.49 ± 0.76 mm, P = .002) and adult corneas (1.86 ± 0.99 mm, P < .001). Pediatric corneas flattened 1 year after CXL by a mean of 1.8 diopters (D), compared to 1.1 D in the other age groups. Central cones (0 to 1 mm) were steeper (62.3 ± 8.3 D) before treatment than peripheral cones (3 to 4 mm) (55.9 ± 8.9 D). One year after CXL, corrected distance visual acuity improved in all age groups, with the highest improvement in pediatric eyes (-0.23 ± 0.40 logMAR, P = .044). CONCLUSIONS: Before CXL, cones of pediatric keratoconic corneas were located more centrally than in the two older age groups. After CXL, pediatric corneas showed more corneal flattening and more corrected distance visual acuity improvement. Pediatric CXL was equally safe compared to adolescent and adult CXL.

Effect of the eyelid speculum on pachymetry during corneal collagen crosslinking in keratoconus patients.

PURPOSE: To compare central corneal thickness (CCT) with and without using an eyelid speculum during corneal collagen crosslinking (CXL). SETTING: University Medical Center Utrecht, Utrecht, the Netherlands. DESIGN: Prospective nonrandomized comparative study. METHODS: Eyes with progressive keratoconus were treated by CXL and consecutively divided into 2 groups. In Group A, an eyelid speculum remained in place throughout the entire CXL procedure. In Group B, the eyelids remained closed during the 30-minute riboflavin instillation. Intraoperative ultrasound pachymetry measurements were performed at different timepoints. The visual acuity, refraction, keratometry, pachymetry, and endothelium were evaluated 6 months after CXL. The main outcome measures were intraoperative CCT measurements and the clinical CXL effect after 6 months. RESULTS: Fifty-two eyes (50 patients) were treated. After riboflavin instillation, a statistically significant difference in CCT reduction was found between the 2 groups (P<.001), with a mean CCT decrease of 62 µm±53 (SD) (13%±11%) in Group A and 11±35 µm (2%±8%) in Group B. No statistically significant between-group differences were found after epithelial removal or ultraviolet-A (UVA) irradiation. Six months after CXL, no statistically significant between-group difference was found in the visual acuity, refraction, keratometry, pachymetry, or endothelium. CONCLUSIONS: Avoidance of an eyelid speculum during riboflavin instillation resulted in less CCT reduction during CXL. This finding could increase the chance of attaining the required pachymetry safety margin for applying UVA and thus decrease the chance of premature CXL treatment termination. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Effective corneal collagen crosslinking in advanced cases of progressive keratoconus.

PURPOSE: To evaluate the 1-year results of corneal collagen crosslinking (CXL) in mild to moderate cases and advanced cases of progressive keratoconus. SETTING: Department of Ophthalmology, University Medical Center Utrecht, the Netherlands. DESIGN: Retrospective cohort study. METHODS: Eyes with progressive keratoconus had CXL between January 2010 and April 2011. Patients were divided into 2 subgroups as follows: Group 1, mild to moderate keratoconus with a preoperative maximum keratometry (K) of less than 58.0 diopters (D), and Group 2, advanced keratoconus with a maximum K of 58.0 D or more. Visual acuity, refraction, and elevation-based topography were evaluated at baseline and 12 months after CXL. RESULTS: The study comprised 53 eyes of 42 patients. In the overall group, progression was halted in 48 eyes (91%). The CXL-induced corneal flattening occurred in 11 (42%) of 26 eyes in Group 1 and 20 (74%) of 27 eyes in Group 2. Five of 7 keratoconus indices improved 12 months after CXL. The failure rate was comparable in the subgroups (3 eyes in Group 1, 2 eyes in Group 2). No major complications occurred in either subgroup. CONCLUSIONS: Stabilization after CXL was achieved in mild to moderate cases and advanced cases of progressive keratoconus. The amount of failure was comparable in the 2 subgroups. The CXL-induced flattening was more pronounced in the advanced subgroup.

Two cases of keratoconus diagnosed after pregnancy.

PURPOSE: This case report aims to demonstrate that pregnancy-induced biomechanical corneal changes in combination with risk factors for ectasia can develop into (the exacerbation of) keratoconus. CASE REPORT: We describe two women who were clinically diagnosed with keratoconus after their second pregnancy. Both women were myopic and had a history of allergies and contact lens wear. It is unclear whether these two women had a newly diagnosed keratoconus that developed during pregnancy or had experienced an exacerbation of an unrecognized, subclinical keratoconus. CONCLUSIONS: Nowadays, documented progression of keratoconus can be treated by corneal crosslinking to stabilize the weakened cornea. Therefore, it is important to understand the effects of hormonal changes in (keratoconic) eyes during pregnancy and to include topographic imaging in unexplained visual deterioration in young individuals, especially during or after a pregnancy.

[Corneal crosslinking as treatment for progressive keratoconus]. / 'Corneal crosslinking' als behandeling van progressieve keratoconus.

Corneal crosslinking (CXL) is a relatively new medical treatment for progressive cases of keratoconus. This disease is characterized by corneal deformation and thinning, leading to corneal surface distortion and visual disability, mainly occurring in young patients. CXL was first applied in humans in 1999 and is internationally considered the standard treatment for cases of rapidly progressing keratoconus. The treatment protocol consists of corneal epithelial removal, the administration of riboflavin eye drops and irradiation with ultraviolet-A light. The primary goal of CXL is to mechanically stabilize and strengthen the cornea. CXL plays an important role in the treatment of keratoconus and may in the future delay or eliminate the need for a corneal transplantation.

Corneal crosslinking for progressive keratoconus in four children.

The authors describe four children with progressive keratoconus treated by corneal crosslinking (CXL). The current CXL guidelines recommend treatment of patients 18 years and older. Nevertheless, keratoconus can rapidly progress in young teenagers. CXL could be a safe procedure to prevent a keratoplasty at a young age.

Anterior chamber depth is significantly decreased after scleral buckling surgery.

OBJECTIVE: Myopic patients have an increased risk for the development of a rhegmatogenous retinal detachment (RRD). Currently, myopic patients have the choice to undergo correction of their refractive error by the implantation of a phakic intraocular lens (pIOL). After pIOL implantation, progressive endothelial cell loss may result if the anterior chamber is too shallow. Because scleral buckling (SB) surgery for treatment of an RRD may in itself result in a decreased anterior chamber depth (ACD), this may become an important issue not only for the retinal surgeon who is faced with a patient who has both an RRD and a pIOL, but also for the refractive surgeon who should consider the potential problems of the implantation of pIOL in an eye that has previously undergone SB surgery. The goal of this study was to evaluate how long changes in ACD persist after SB procedures in patients with RRD. DESIGN: Prospective case series. PARTICIPANTS: Thirty-eight eyes with a primary RRD treated by SB using an encircling element and a radial or segmental buckle; 31 fellow eyes served as controls. METHODS: Anterior chamber depth (in the horizontal meridian) and axial length were measured preoperatively and at 1 week and 1, 3, 6, 9, and 12 months postoperatively with an anterior optical coherence tomography method and an IOLMaster (Carl Zeiss Meditec, Jena, Germany), respectively. MAIN OUTCOME MEASURES: In all 38 eyes, ACD was significantly reduced compared with preoperative levels up to 9 months after SB surgery. RESULTS: Anterior chamber depth returned to normal at 1 year after surgery. Axial length was significantly enlarged during the whole follow-up period. No significant differences were found between the use of radial or segmental buckles. CONCLUSIONS: Anterior chamber depth may remain decreased after SB for a longer time period than previously reported. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Efficacy and safety of femtosecond laser-assisted corneal endothelial keratoplasty: a randomized multicenter clinical trial.

BACKGROUND: To evaluate the efficacy and safety of femtosecond laser-assisted endothelial keratoplasty (FLEK) versus penetrating keratoplasty (PK) in patients with corneal endothelial disease. METHODS: A randomized multicenter clinical trial of 80 eyes of 80 patients with corneal endothelial disease were randomized to FLEK or PK. Clinical outcomes (astigmatism and visual acuity) and incidence of postoperative complications were compared between the two groups. RESULTS: At 12 months, the percentage of eyes with a refractive astigmatism less than or equal to 3 diopters was higher in the FLEK group in comparison with the PK group (86.2% vs. 51.3%, P=0.004). The mean postoperative best corrected visual acuity was 20/70+/-2 lines in the FLEK group and 20/44+/-2 lines in the PK group (P<0.001), but the gain in the best corrected visual acuity between the two groups was not significantly different. The endothelial cell loss in the FLEK and PK group was 65+/-12% and 23+/-15% (P<0.001). The most common postoperative complication in the FLEK group was graft dislocation (27.8%). Wound healing related problems occurred in six eyes (15%) in the PK group and in none of the FLEK eyes. CONCLUSIONS: FLEK effectively reduces postoperative astigmatism and results in an absence of wound healing related problems in patients with endothelial disease. However, visual acuity is lower as compared with conventional PK, and the high level of endothelial cell loss warrants a modification of the insertion technique of the endothelial graft.

Use of anterior segment optical coherence tomography to study corneal changes after collagen cross-linking.

PURPOSE: To investigate the stromal demarcation line after corneal cross-linking using anterior segment optical coherence tomography (AS-OCT) and its influence on the short-term results of cross-linking in patients with progressive keratoconus. DESIGN: Prospective, nonrandomized study. METHODS: Twenty-nine eyes of 29 patients with progressive keratoconus (n = 28) or after laser in situ keratomileusis ectasia (n = 1) were included and treated with corneal cross-linking at our institution. Measurements at 1, 3, 6, and 12 months after corneal cross-linking were: refraction, best-corrected visual acuity (BCVA), tonometry, corneal topography, AS-OCT, specular microscopy, and aberrometry. Demarcation line depth was measured centrally, 2 mm temporally, and 2 mm nasally by two independent observers using AS-OCT and was correlated with clinical parameters. RESULTS: The stromal demarcation line was visible with AS-OCT at 1 month after surgery in 28 of 29 eyes. Pairwise comparisons between the two observers of the AS-OCT measurements did not show a statistically significant difference. After an initial steepening of maximal keratometry values and a decrease in BCVA at 1 month after surgery (both with P < .012), no significant changes were found at 3, 6, and 12 months after surgery compared with before surgery. Refractive cylinder, topographic astigmatism, aberration values, endothelial cell density, and intraocular pressure remained stable during all postoperative visits. A deeper demarcation line depth was associated with a larger decrease in corneal thickness (r = -0.506; P = .012). CONCLUSIONS: AS-OCT is a useful device to detect the stromal demarcation line after corneal cross-linking. At 3 to 12 months follow-up, all clinical parameters remained stable, indicating stabilization of the keratoconic disease.

Results of cataract surgery after implantation of an iris-fixated phakic intraocular lens.

PURPOSE: To report the results of cataract surgery after previous implantation of an Artisan iris-fixated phakic intraocular lens (pIOL) for the correction of myopia. SETTING: University center and private practice. METHODS: This study comprised eyes with previous implantation of an iris-fixated pIOL to correct myopia and subsequent pIOL explantation combined with cataract surgery and in-the-bag implantation of a posterior chamber IOL. Predictability of refractive results, changes in endothelial cell density (ECD), and postoperative best corrected visual acuity (BCVA) were analyzed. RESULTS: The mean follow-up after cataract surgery in the 36 eyes of 27 consecutive patients was 5.7 months +/- 7.5 (SD). The mean time between pIOL implantation and cataract surgery was 5.0 +/- 3.4 years. After explantation of the pIOL and subsequent cataract surgery, the mean spherical equivalent (SE) was -0.28 +/- 1.11 diopters (D); the SE was within +/-1.00 D of the intended correction in 72.2% of patients and within +/-2.00 D in 86.1% of patients. The mean endothelial cell loss after the combined procedure was 3.5% +/- 13.2% and the mean postoperative BCVA, 0.17 +/- 0.18 logMAR. CONCLUSIONS: In patients with a history of implantation of an iris-claw pIOL for the correction of myopia, cataract surgery combined with explantation of the pIOL yielded acceptable predictability of the postoperative SE and minimal loss of ECD, resulting in a gain in BCVA.

Higher-order aberrations after implantation of iris-fixated rigid or foldable phakic intraocular lenses.

PURPOSE: To evaluate higher-order aberrations (HOAs) after implantation of Artiflex phakic intraocular lenses (pIOLs). SETTING: Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, The Netherlands. METHODS: This retrospective comparative case series comprised 27 eyes (14 patients) that had Artiflex pIOL implantation and 22 eyes (13 patients) that had Artisan pIOL implantation. Refractive data, pupil size, IOL decentration, and HOA values were recorded and compared. Laboratory analysis was performed. Follow-up was 1 year. RESULTS: In the Artiflex group, the mean spherical equivalent (SE) changed from -9.95 diopters (D) +/- 1.43 (SD) (range -6.75 to -12.13 D) to -0.30 +/- 0.53 D (range -1.94 to 0.56 D). Postoperatively, trefoil-y increased (increase factor 1.73) and spherical aberration decreased (increase factor 0.55). The mean pIOL decentration was 0.24 +/- 0.12 mm; 96.3% were decentered 0.5 mm or less. There was a significant correlation between pIOL decentration and postoperative spherical aberration and coma-y. In the Artisan group, the mean SE changed from -9.90 +/- 2.74 D (range -4.00 to -14.50 D) to -0.20 +/- 0.42 D (range -0.75 to 0.50 D). Postoperatively, trefoil-y and spherical aberration increased (increase factors 3.32 and 6.84, respectively). Laboratory analysis confirmed the negative and positive spherical aberration profile of the Artiflex pIOL and Artisan pIOL, respectively. CONCLUSIONS: Artiflex pIOL implantation decreased spherical aberration, while Artisan pIOL implantation increased spherical aberration. Trefoil-y increased in both groups. These changes might be explained by incision size differences in relation to trefoil and differences in optic design in relation to spherical aberration.

Irregular astigmatism after cataract surgery resulting from inadequate clear corneal incision formation.

A 66-year-old woman was referred to us due to visual complaints after cataract surgery. The patient's complaints were decreased visual acuity and a localized blur in her visual field. At slit lamp biomicroscopy, an unusually long and centrally located clear corneal incision was noted. Corneal topography revealed an irregular astigmatism in the optical axis, originating from the site of the incision. The patient's visual complaints were treated by fitting a rigid gas permeable contact lens, which increased her best corrected visual acuity to 20/16. This case report demonstrated that inadvertently long and centrally located corneal incisions should be avoided during cataract surgery to prevent high levels of irregular astigmatism. RGP contact lenses can lead to successful visual rehabilitation.

Long-term follow-up of a multifocal apodized diffractive intraocular lens after cataract surgery.

PURPOSE: To report the long-term performance of the AcrySof ReSTOR SA60D3 intraocular lens (IOL) after cataract surgery. SETTING: University Hospital Maastricht, Maastricht, The Netherlands. METHODS: This prospective clinical trial comprised 44 eyes (22 consecutive patients) having cataract surgery with implantation of the ReSTOR IOL. Monocular and binocular uncorrected distance visual acuity, best corrected distance visual acuity, uncorrected near visual acuity, best distance-corrected near visual acuity, spectacle dependence, undesired visual symptoms, patient satisfaction, and incidence of posterior capsule opacification were analyzed 6 months and 3 years postoperatively. RESULTS: The mean uncorrected distance acuity (logMAR) was 0.046 +/- 0.099 at 6 months and 0.115 +/- 0.173 at 3 years and the mean best corrected distance acuity, -0.040 +/- 0.075 and -0.018 +/- 0.093, respectively. Binocular uncorrected and best-corrected near acuities (logMAR) were 0.009 +/- 0.029 at 6 months and 0.014 +/- 0.035 at 3 years. All patients achieved a binocular uncorrected and best distance-corrected near acuity of 20/25 or better at 6 months and 3 years. On a quality-of-life questionnaire, patients reported good distance, intermediate, and near acuity without complaints of severe glare or halos. Complete spectacle independence for distance and near acuity was achieved by 83.7% and 81.9% of patients, respectively, at 6 months and 85.0% and 75.0% of patients, respectively, at 3 years. Four eyes (9.1%) required neodymium:YAG capsulotomy. CONCLUSIONS: Cataract surgery with the AcrySof ReSTOR SA60D3 IOL provided good, stable distance and near visual acuities over a 3-year follow-up, leading to low spectacle independence and high patient satisfaction.

Femtosecond laser-assisted inverted mushroom keratoplasty.

PURPOSE: To evaluate best-corrected visual acuity (BCVA), refractive outcome, corneal topography, optical coherence tomography, and endothelial cell density 12 months after femtosecond laser-assisted inverted mushroom keratoplasty. METHODS: We performed a prospective study of a surgical case series of 5 patients undergoing femtosecond laser-assisted inverted mushroom keratoplasty for pseudophakic bullous keratopathy or pre-Descemet X-linked ichthyosis. The femtosecond laser was used to create a top-hat configuration in the donor cornea and recipient cornea. Laser parameters were as follows: energy, 4.0 (anterior inner vertical side cut and horizontal lamellar cut) and 7.0 microJ (posterior outer vertical side cut); spiral pattern with a firing rate of 15 kHz. The size of the anterior inner diameter was 7.4 mm in the donor cornea and 7.0 mm in the recipient cornea. The posterior outer diameter was 9.0 mm in all eyes. RESULTS: At 6 and 12 months after surgery, all corneal grafts were clear and showed an excellent adaptation of the lamellar donor and recipient wound surfaces. At 12 months postoperatively, BCVA averaged 20/32 (range, 20/60-20/20), refractive cylinder averaged -3.20 +/- 2.0 D, topographical cylinder averaged 3.26 +/- 2.1 D, and the mean endothelial cell density was 1793 +/- 491 cells/mm2 (range, 954-2237 cells/mm2). The mean central corneal thickness and thickness of the posterior shelf was 517 +/- 3 and 175 +/- 8 microm, respectively. CONCLUSIONS: The femtosecond laser-assisted inverted mushroom keratoplasty shows good promise in surgical treatment of corneal diseases. The multiplanar fit between the donor and recipient cornea allows early suture removal and visual rehabilitation.