Evaluation of a new transpalpebral tonometer for self-measuring intraocular pressure

PURPOSE

We developed a novel transpalpebral self-tonometer called the TapEye tonometer (TET) based on palpation of the upper eyelid. Our goal was to evaluate a method for improving the accuracy of measuring intraocular pressure (IOP) through the eyelid.

METHODS

Participants underwent standardized training by technicians and were required to be able to use the TET for study inclusion. Subsequently, a noncontact tonometer and Goldmann applanation tonometer (GAT) were used. All participants were instructed to measure their IOPs using the three tonometers at baseline (visit 1) and at 1 month (visit 2). At visit 2, the corrected IOP value measured by the TET (c-TET) was calculated using the difference between the TET and GAT measurements obtained at visit 1.

RESULTS

No significant correlations were found between the TET and GAT measurements at any visit, but the correlation between the c-TET and GAT measurements at visit 2 was significant. The mean difference between the c-TET and GAT measurements was 0.4 ± 3.7 mmHg in the right eye and 0.5 ± 3.4 mmHg in the left eye.

CONCLUSIONS

After correcting the IOP based on the difference between the TET and GAT measurements at the initial visit, the corrected IOP value of the TET was correlated with that of the GAT at the second visit. The TET has the potential to address an unmet need by providing a tool for minimally invasive IOP measurements.

TRIAL REGISTRATION

Clinical trial registration number: jRCTs032220268.

Evaluation of a new portable corneal topography system for self-measurement using smartphones: a pilot study

PURPOSE

Herein, we propose the use of the "KeraVio Ring", which is a portable, selfie-based, smartphone-attached corneal topography system that is based on the Placido ring videokeratoscope. The goal of this study was to evaluate and compare corneal parameters between KeraVio Ring and conventional corneal tomography images.

METHODS

We designed the KeraVio Ring as a device comprising 3D-printed LED rings for generating Placido rings that can be attached to a smartphone. Two LED rings are attached to a cone-shaped device, and both corneas are illuminated. Selfies were taken using the KeraVio Ring attached to the smartphone without assistance from any of the examiners. Captured Placido rings on the cornea were analysed by intelligent software to calculate corneal parameters. Patients with normal, keratoconus, or LASIK-treated eyes were included. Anterior segment optical coherence tomography (AS-OCT) was also performed for each subject.

RESULTS

We found highly significant correlations between the steepest and flattest keratometry, corneal astigmatism, and vector components obtained with the KeraVio Ring and AS-OCT. In subjects with normal, keratoconus, and LASIK-treated eyes, the mean difference in corneal astigmatism between the two devices was -0.8 ± 1.4 diopters (D) (95% limits of agreement (LoA), -3.6 to 2.0), -1.8 ± 3.7 D (95% LoA, -9.1 to 5.5), and -1.5 ± 1.3 D (95% LoA, -4.0 to 1.1), respectively.

CONCLUSIONS

The experimental results showed that the corneal parameters obtained by the KeraVio Ring were correlated with those obtained with AS-OCT. The KeraVio Ring has the potential to address an unmet need by providing a tool for portable selfie-based corneal topography.

Combination of violet light irradiation and collagenase treatments in a rabbit model of keratoconus

Purpose

We evaluated the use of collagenase treatment to generate a rabbit model of keratoconus and the impact of violet light (VL) irradiation on the disease model in six Japanese White rabbits.

Methods

After epithelial debridement, the collagenase group was treated with a collagenase type II solution for 30 min; the control group was treated with a solution without collagenase. Three rabbits also underwent VL irradiation (375 nm, irradiance 310 μW/cm²) for 3 h daily for 7 days after topical collagenase application. Slit-lamp microscopy results, steep keratometry (Ks), corneal astigmatism, central corneal thickness, and axial length were examined before and after the procedure. The corneas were obtained on day 7 for biomechanical evaluation.

Results

A significant increase in Ks and corneal astigmatism was observed in the collagenase and VL irradiation groups compared with the control group on day 7. No significant difference was found in the change in corneal thickness between the groups. The elastic modulus at 3, 5, and 10% strain was significantly lower in the collagenase group than in the control group. There was no significant difference in the elastic modulus at any level of strain between the collagenase and VL irradiation groups. The average axial length at day 7 was significantly longer in the collagenase and VL irradiation groups than in the control group. Collagenase treatment induced a model of keratoconus by steepening the keratometric and astigmatic values. There was no significant difference in the observed elastic behavior of normal and ectatic corneas under physiologically relevant stress levels.

Conclusion

VL irradiation did not cause regression of corneal steepening in a collagenase-induced model during short-term observation.

3D-printed eye model: Simulation of intraocular pressure

PURPOSE

To develop artificial eye models using 3D printing and to evaluate the correlation between different corneal thicknesses and intraocular pressures (IOPs).

METHODS

We designed 7 artificial eye models using a computer-aided design system and fabricated them using 3D printing. Corneal curvature and axial length were based on the Gullstrand eye model. Hydrogels were injected into the vitreous cavity, and seven different corneal thicknesses (200 to 800 μm) were prepared. In this proposed design, we also produced different corneal stiffnesses. A Tono-Pen AVIA tonometer was used by the same examiner to perform five consecutive IOP measurements in each eye model.

RESULTS

Different eye models were ideally created using 3D printing. IOP measurements were successfully performed in each eye model. The corneal thickness was significantly correlated with IOP (R2 = 0.927; 𝑃<0.001).

CONCLUSION

The 3D-printed eye model is useful for evaluating IOP measurements. This technique might be a promising alternative to the conventional porcine eye model.

Infectious keratitis after corneal crosslinking for keratoconus caused by levofloxacin-resistant microorganisms

Introduction

We present seven cases of infectious keratitis after corneal crosslinking (CXL) to attenuate keratoconus progression.

Methods

Of 524 consecutive patients who underwent CXL, 7 cases (4 males and 3 females; 21.5 ± 7.1 years) developed postoperative infectious keratitis were retrospectively reviewed. CXL was performed using the Dresden protocol or an accelerated protocol involving epithelial removal.

Results

All cases appeared normal on the day after surgery, but subsequently developed eye pain, blurred vision, corneal infiltration, inflammation of the anterior chamber, and ciliary injection on day 2 or 3. Methicillin-resistant Staphylococcus aureus was cultured from two eyes, methicillin-sensitive Staphylococcus aureus from two eyes, and Streptococcus pneumoniae from one eye. All detected bacteria were resistant to levofloxacin (LVFX). Five of the seven cases, especially four of the five severe cases with hypopyon, had a history of atopic dermatitis. All cases were observed after 2015.

Conclusions

Infectious keratitis after CXL caused by microbes resistant to LVFX is increasing. In addition to careful postoperative observation of the cornea, preoperative evaluation of bacteria within the conjunctival sac evident on nasal swab cultures may be useful to identify potentially problematic microbes and inform the selection of appropriate antibiotics.

Corneal Cross-Linking for Paediatric Keratoconus: A Systematic Review and Meta-Analysis

All corneal cross-linking techniques attenuated disease progression in patients with pediatric keratoconus for at least one year based on a meta-analysis. A standard and accelerated technique led to marked improvement in visual acuity. We determined the efficacy and safety of corneal cross-linking (CXL) in pediatric keratoconus by conducting a systematic review and meta-analysis. The PubMed and Cochrane databases were searched for relevant studies on the effects of standard, transepithelial, and/or accelerated CXL protocols in patients aged 18 years or younger. Standardized mean differences with 95% confidence intervals were calculated to compare the data collected at baseline and 12 months. The primary outcomes were maximum keratometry (Kmax) and uncorrected visual acuity (UCVA), and the secondary outcomes were the thinnest corneal thickness (TCT), best-corrected visual acuity (BCVA), and manifest refraction spherical equivalent or cylindrical refraction. Our search yielded 7913 publications, of which 26 were included in our systematic review and 21 were included in the meta-analysis. Standard CXL significantly improved the Kmax, UCVA, and BCVA, and significantly decreased the TCT. Accelerated CXL significantly improved UCVA and BCVA. In the transepithelial and accelerated-transepithelial CXL methods, each measurable parameter did not change after treatments. All CXL techniques attenuated disease progression in patients with pediatric keratoconus for at least one year. Standard and accelerated CXL led to marked improvement in visual acuity.

Evaluation of the Physiological Corneal Intrastromal Riboflavin Concentration and the Corneal Elastic Modulus After Violet Light Irradiation

Purpose

KeraVio is a corneal crosslinking treatment modality that utilizes violet light (VL)-emitting glasses and topical epithelium-on riboflavin administration. We focus on the new KeraVio protocol without riboflavin. This study aims to quantify the physiological intrastromal concentrations of riboflavin in corneas without riboflavin decreases and evaluate the biomechanics of corneas after VL irradiation.

Methods

Twelve human donor corneas were included in this study and randomly categorized into four groups. The corneas underwent four imbibition techniques (physiological riboflavin without drops, epithelial [epi]-on with 0.05% flavin adenine dinucleotide [FAD], epi-off with FAD, and 0.1% riboflavin epi-off). Corneas in the FAD epi-on, FAD epi-off, and riboflavin epi-off groups were instilled with the respective solution every 2 minutes for 30 minutes. An ex vivo experiment was conducted with 24 porcine corneas arranged into three treatment groups and one control group. Corneas in the KeraVio with FAD epi-on group were treated with VL irradiation at 0.31 mW/cm² for 4.8 hours (5.4 J/cm²) and simultaneously received FAD drops every 30 minutes during the VL irradiation. Corneas in the group with KeraVio without FAD epi-on were only treated with VL irradiation (5.4 J/cm²).

Results

We identified the original physiological riboflavin of human corneal stroma at a concentration of 0.31 ± 0.03 µg/g, but its value was approximately 39-fold smaller than that in the 0.1% riboflavin epi-off group. The group with KeraVio without FAD and the standard corneal crosslinking group showed a significant increase in biomechanical stability compared with the controls, whereas the elastic modulus in the treated groups was equivalent.

Conclusions

We preliminarily identified physiological riboflavin in human corneas without adding riboflavin drops. The VL exposure may strengthen the corneal biomechanics without requiring the use of additional riboflavin drops.

Translational Relevance

We preliminarily identified physiological riboflavin in the human cornea without adding riboflavin drops. VL irradiation without riboflavin drops may increase the corneal stiffness using physiological riboflavin.

Steroid-eluting contact lenses for corneal and intraocular inflammation

Ocular inflammation is one of the leading causes of blindness worldwide, and steroids in topical ophthalmic solutions (e.g. dexamethasone eye drops) are the mainstay of therapy for ocular inflammation. For many non-infectious ocular inflammatory diseases, such as uveitis, eye drops are administered as often as once every hour. The high frequency of administration coupled with the side effects of eye drops leads to poor adherence for patients. Drug-eluting contact lenses have long been sought as a potentially superior alternative for sustained ocular drug delivery; but loading sufficient drug into contact lenses and control the release of the drug is still a challenge. A dexamethasone releasing contact lens (Dex-Lens) was previously developed by encapsulating a dexamethasone-polymer film within the periphery of a hydrogel-based contact lens. Here, we demonstrate safety and efficacy of the Dex-Lens in rabbit models in the treatment of anterior ocular inflammation. The Dex-Lens delivered drug for 7 days in vivo (rabbit model). In an ocular irritation study (Draize test) with Dex-Lens extracts, no adverse events were observed in normal rabbit eyes. Dex-Lenses effectively inhibited suture-induced corneal neovascularization and inflammation for 7 days and lipopolysaccharide-induced anterior uveitis for 5 days. The efficacy of Dex-Lenses was similar to that of hourly-administered dexamethasone eye drops. In the corneal neovascularization study, substantial corneal edema was observed in rabbit eyes that received no treatment and those that wore a vehicle lens as compared to rabbit eyes that wore the Dex-Lens. Throughout these studies, Dex-Lenses were well tolerated and did not exhibit signs of toxicity. Dexamethasone-eluting contact lenses may be an option for the treatment of ocular inflammation and a platform for ocular drug delivery. STATEMENT OF SIGNIFICANCE: Inflammation of the eye can happen either on the ocular surface (i.e. the cornea) or inside the eye, both of which can result in loss of vision or even blindness. Ocular inflammation is normally treated by steroid eye drops. Depending on the type and severity of inflammation, patients may have to take drops every hour for days at a time. Such severe dosing regimen can lead to patients missing doses. Also, more than 95% drug in an eye drop never goes inside the eye. Here we present a contact lens that release a steroid (dexamethasone) for seven days at a time. It is much more efficient than eye drops and a significant improvement since once worn, the patient will avoid missing doses.

Clinical outcomes of KeraVio using violet light: emitting glasses and riboflavin drops for corneal ectasia: a pilot study

BACKGROUND/AIMS

We developed a novel technology consisting of violet light (VL)-emitting glasses and defined the combination of VL irradiation and riboflavin treatment as KeraVio. Our goal was to evaluate the clinical results of KeraVio in patients with progressive corneal ectasia.

METHODS

Eyes were exposed to VL (375 nm, irradiance 310 μW/cm²)-emitting glasses for 3 hours daily for 6 months, and a riboflavin solution was administered onto the corneal epithelium six times during each 3-hour VL irradiation. The primary end point was a change in the maximum keratometry (Kmax) value over 6 months compared with that over the 1 year before baseline.

RESULTS

The efficacy of KeraVio was evaluated in 20 eyes with severe progression, and its safety was evaluated in all 40 eyes. The mean changes in Kmax over the 1 year before baseline and during the 6-month observation period were 6.03±3.41 dioptres (D) and -0.81±3.34 D, respectively (p=0.002). At 6 months, the Kmax value decreased by more than 2 D in 4 eyes (20%), remained within 2 D in 13 eyes (65%), and increased by 2 D or more in 3 eyes (15%). The corneal stromal demarcation line was identified in 16 eyes (80%), and its depth was 206.3±54.9 μm at 1 month. No significant decrease in endothelial cell density, lenticular opacity or transient corneal haze was noted.

CONCLUSION

Based on our 6-month results, daily treatment of progressive corneal ectasia with KeraVio can halt disease progression without any safety concerns.

CLINICAL TRIAL REGISTRATION NUMBER

jRCTs032180217.

Factors influencing subjective symptoms in dry eye disease

AIM

To retrospectively investigate the association between dry eye symptoms and clinical or in vivo confocal microscopy parameters in patients with dry eye disease (DED), and to compare these parameters between eyes with DED and normal subjects.

METHODS

This retrospective, cross-sectional, controlled study comprised 25 consecutive patients with non-Sjögren dry eye disease and age- and sex-matched 25 healthy subjects. Each patient underwent a complete examination of the ocular surface in the following order: tear osmolarity measurements, InflammaDry test, tear break-up time, corneal fluorescein staining, Schirmer I test, subjective symptoms questionnaire using the dry eye-related quality-of-life score (DEQS), and in vivo confocal microscopy analysis of the central cornea. Beck depression inventory (BDI) as depressive scale and history of medications and smoking were also evaluated. Stepwise multiple regression analysis was used to assess the factors affecting the DEQS.

RESULTS

In univariate analysis, DEQS was associated with tear break-up time (ρ=-0.48, P=0.01), oral medications, such as hypotensive drug (ρ=0.56, P=0.004) and anti-depressant (ρ=0.57, P=0.003), and BDI (ρ=0.61, P=0.001) in patients with DED. In multiple regression analysis, explanatory variables relevant to the DEQS were the anti-depressant medications (P=0.04, partial regression coefficient B=21.04) and BDI (P=0.02, B=0.76, adjusted R ²=0.54) in these patients.

CONCLUSION

Our study shows a significant association between depression and dry eye symptoms. It suggests that dry eye symptoms associate with higher depressive symptoms and its medications, although our patients were not followed longitudinally.

Resolution of fluoroquinolone-resistant Escherichia coli keratitis with a PROSE device for enhanced targeted antibiotic delivery

Purpose

To report the resolution of a fluoroquinolone-resistant Escherichia coli keratitis with use of a prosthetic replacement of the ocular surface ecosystem (PROSE) device for enhanced targeted delivery of moxifloxiacin.

Observations

A 62-year-old female presented with a 3-day history of pain, photophobia, and declining vision in left eye. The patient had a 2-year history of binocular PROSE treatment for ocular chronic graft-vs-host disease (cGVHD). A corneal ulcer was diagnosed and treated with topical 0.5% moxifloxacin solution 6 times per day, with continued wear of the PROSE device. After 4 days, worsening symptoms led to an increase in application of moxifloxicin to every 2 hours while awake. The drug was administered by removal of the device, cleaning and replenishing the reservoir with sterile saline, and adding one drop of the drug to the reservoir prior to reinsertion. Four days later, the corneal surface was epithelialized with only small subepithelial infiltrate remaining. The corneal culture grew an E. coli isolate carrying multiple mutations in the topoisomerase genes. These mutations were correlated with varying levels of resistance to ciprofloxacin (256 μg/mL), levofloxacin (8 μg/mL), and moxifloxacin (16 μg/mL).

Conclusions and Importance

Although the infecting E. coli strain exhibited resistance to fluoroquinolones, the infection resolved when moxifloxacin was combined with PROSE therapy. Frequent dosing to the PROSE reservoir is likely to increase fluoroquinolone bioavailability and may represent a valuable approach to overcome antibiotic resistance.

Two-years results of small-incision lenticule extraction and wavefront-guided laser in situ keratomileusis for Myopia

PURPOSE

To compare the 2-years visual and refractive outcomes between small-incision lenticule extraction (SMILE) and wavefront-guided laser in situ keratomileusis (LASIK) in eyes with myopia and myopic astigmatism.

METHODS

Our retrospective case-control study examined 30 eyes of 30 patients with the manifest refraction spherical equivalent (MRSE) of -3.71 ± 1.83 dioptres (D) who underwent SMILE and 30 eyes of 30 patients with MRSE of -3.81 ± 1.40 D who underwent wavefront-guided LASIK. We assessed the 2-years clinical outcomes.

RESULTS

Logarithm of the minimal angle of resolution (LogMAR)-corrected distance visual acuity (CDVA) was -0.23 ± 0.07 in the SMILE group and -0.24 ± 0.07 in the wavefront-guided LASIK group 2 years postoperatively (p = 0.82). Logarithm of the minimal angle of resolution-uncorrected distance visual acuity (UDVA) was -0.18 ± 0.09 and -0.15 ± 0.11 (p = 0.30, respectively). In the SMILE and wavefront-guided LASIK groups 2 years postoperatively, 100% and 73% of eyes, respectively, were within 0.5 D of the prompted MRSE correction (p = 0.005). Changes in the MRSE of -0.10 ± 0.30 D and -0.23 ± 0.51 D occurred from 3 months to 2 years (p = 0.40, respectively). We found a significant correlation between myopic regression and the changes in the keratometric readings from 3 months to 2 years after wavefront-guided LASIK (r = -0.48, p = 0.002), but not after SMILE (r = -0.004, p = 0.90).

CONCLUSION

Small-incision lenticule extraction offers better refractive outcomes than wavefront-guided LASIK during a 2-years follow-up for the correction of myopia and myopic astigmatism.

Impact of Forward and Backward Scattering and Corneal Higher-Order Aberrations on Visual Acuity after Penetrating Keratoplasty

PURPOSE

To assess the relationship of forward and backward scattering and corneal higher-order aberrations (HOAs) with corrected distance visual acuity (CDVA) after penetrating keratoplasty (PK).

METHODS

This retrospective study comprised 25 eyes of 25 consecutive patients who underwent PK using the VisuMax femtosecond laser system and age-matched 25 eyes of 25 healthy subjects. We quantitatively assessed objective scattering index (OSI) using the double-pass instrument (OQAS II, Visiometrics), corneal densitometry (CD) and corneal HOAs with the Scheimpflug rotating camera (Pentacam HR, Oculus) 1 year postoperatively.

RESULTS

The OSI, CD, and corneal HOAs were significantly larger in the PK group than those in the control group (p ≤ 0.011). We found significant correlations of logMAR CDVA with the OSI (r = 0.477, p = 0.016), and with the anterior, posterior, and total corneal HOAs of the central 4-mm zone (anterior: r = 0.573, p = 0.003, posterior: r = 0.596, p = 0.002, total: r = 0.472, p = 0.017), but no significant association with the CD of the 0-2 mm zone at any layers (anterior: r = 0.236, p = 0.257, center: r = 0.139, p = 0.506, posterior: r = 0.073, p = 0.728, total: r = 0.212, p = 0.308). Similar results were obtained when the analysis was repeated with corneal HOAs of the central 6-mm zone and CDs in 2-6 mm zone.

CONCLUSIONS

Our pilot study demonstrated that the postoperative CDVA was significantly correlated with OSI and corneal HOAs, but not with backward scattering in post-PK eyes, suggesting that OSI as well as corneal HOAs plays an essential role in postoperative visual performance after PK.

[Two Cases of Severe Infectious Keratitis Treated with Corneal Collagen Crosslinking]

Purpose: Corneal collagen crosslinking (CXL) is effective not only in halting the progression of keratoconus but also in management of infectious keratitis. However, as far as we can ascertain, there are no reports of CXL for the treatment of severe infectious keratitis in Japan. Thus, we report 2 cases in which CXL was effective for infectious corneal ulcer. Cases: A 82-year old man and 76-year-old woman. Both of which were treated with local antibiotic therapy; however, the therapy was not empirically effective. Thus, we performed CXL following the standard Dresden protocol after obtaining informed consent from each case. Two weeks after CXL, slit-lamp examinations revealed improvements of corneal transparency and keratitis in each case. No serious complications such as corneal perforations and infectious recurrences occurred after the treatments. Conclusion: Two cases of infectious keratitis improved in corneal opacity and had showed inhibitory effect on infected cornea. CXL seems to be an effective therapeutic alternative in resistant cases of infectious keratitis, although the exact etiology of this effective treatment remains unclear.

Assessment of subjective intraocular forward scattering and quality of vision after posterior chamber phakic intraocular lens with a central hole (Hole ICL) implantation

PURPOSE

To evaluate the subjective intraocular forward scattering and quality of vision after posterior chamber phakic intraocular lens with a central hole (Hole ICL, STAAR Surgical) implantation.

METHODS

We prospectively examined 29 eyes of 29 consecutive patients (15 men and 14 women; ages, 37.2 ± 8.8 years) undergoing Hole ICL implantation. We assessed the values of the logarithmic straylight value [log (s)] using a straylight meter (C-Quant^™ , Oculus) preoperatively and 3 months postoperatively. The patients completed a questionnaire detailing symptoms on a quantitative grading scale (National Eye Institute Refractive Error Quality of Life Instrument-42; NEI RQL-42) 3 months postoperatively. We compared the preoperative and postoperative values of the log(s) and evaluated the correlation of these values with patient subjective symptoms.

RESULTS

The mean log(s) was not significantly changed, from 1.07 ± 0.20 preoperatively, to 1.06 ± 0.17 postoperatively (Wilcoxon signed-rank test, p = 0.641). There was a significant correlation between the preoperative and postoperative log(s) (Spearman's correlation coefficient r = 0.695, p < 0.001). The postoperative log(s) was significantly associated with the scores of glare in the questionnaire (Spearman's correlation coefficient r = -0.575, p = 0.017).

CONCLUSIONS

According to our experience, Hole ICL implantation does not induce a significant additional change in the subjective intraocular forward scattering. The symptom of glare after Hole ICL implantation was significantly correlated with the postoperative intraocular forward scattering in relation to the preoperative one.

Effect of Light Scattering and Higher-order Aberrations on Visual Performance in Eyes with Granular Corneal Dystrophy

This study was aimed to assess the relationship of intraocular forward scattering, corneal backward scattering, and corneal higher-order aberrations (HOAs) with corrected distance visual acuity (CDVA) in eyes with granular corneal dystrophy (GCD). We retrospectively examined forty two eyes of 42 consecutive patients who diagnosed GCD, and age-matched 20 eyes of 20 healthy subjects. We assessed objective scattering index (OSI) using the double-pass instrument (OQAS II, Visiometrics), corneal densitometry (CD) using the Scheimpflug rotating camera (Pentacam HR, Oculus), and corneal HOAs using the Hartmann-Shack aberrometry (KR-9000, Topcon). The OSI, CD, and corneal HOAs were significantly larger in the GCD group than those in the control group (Mann-Whitney U test, p < 0.001). We found significant correlations of logMAR CDVA with the OSI (Spearman correlation coefficient r = 0.577, p < 0.001), and with the CD (r = 0.340, p = 0.028), but no significant association with corneal HOAs (r = 0.061, p = 0.701). Intraocular forward scattering, corneal backward scattering, and corneal HOAs in eyes with GCD were higher than that in normal eyes. The CDVA was significantly correlated with intraocular forward scattering, but not with corneal HOAs in eyes with GCD, suggesting that light scattering, especially forward scattering, plays a more vital role in visual performance than corneal aberrations in eyes with GCD.

Long-Term Comparison of Posterior Chamber Phakic Intraocular Lens With and Without a Central Hole (Hole ICL and Conventional ICL) Implantation for Moderate to High Myopia and Myopic Astigmatism: Consort-Compliant Article

The study shows a promising next-generation surgical option for the correction of moderate to high ametropia. Hole implantable collamer lens (ICL), STAAR Surgical, is a posterior chamber phakic intraocular lens with a central artificial hole. As yet, however, no long-term comparison of the clinical results of the implantation of ICLs with and without such a hole has hitherto been conducted. A prospective, randomized, controlled trial was carried out in order to compare the long-term clinical outcomes of the implantation, in such eyes, of ICLs with and without a central artificial hole.Examinations were conducted of the 64 eyes of 32 consecutive patients with spherical equivalents of -7.53 ± 2.39 diopters (D) (mean ± standard deviation) in whom implantation of a Hole ICL was performed in 1 eye, and that of a conventional ICL was carried out in the other, by randomized assignment. Before 1, 3, and 6 months, and 1, 3, and 5 years after surgery, the safety, efficacy, predictability, stability, intraocular pressure, endothelial cell density, and adverse events of the 2 surgical techniques were assessed and compared over time.The measurements of LogMAR uncorrected and corrected distance visual acuity 5 years postoperatively were -0.17 ± 0.14 and -0.24 ± 0.08 in the Hole ICL group, and -0.16 ± 0.10 and -0.25 ± 0.08 in the conventional ICL group. In these 2 groups, 96% and 100% of eyes, respectively, were within 1.0 D of the targeted correction 5 years postoperatively. Manifest refraction changed by -0.17 ± 0.41 D and -0.10 ± 0.26 D occurred in from 1 month to 5 years in the Hole and conventional ICL groups, respectively. Only 1 eye (3.1%), which was in the conventional ICL group, developed an asymptomatic anterior subcapsular cataract.Both Hole and conventional ICLs corrected of ametropia successfully throughout the 5-year observation period. It appears likely that the presence of the central hole does not significantly affect these visual and refractive outcomes.

TRIAL REGISTRATION

UMIN000018771.

Predictability of Intraocular Lens Power Calculation After Simultaneous Pterygium Excision and Cataract Surgery

This study was aimed to assess the predictability of intraocular lens (IOL) power calculation after simultaneous pterygium excision and phacoemulsification with IOL implantation. We retrospectively reviewed the clinical charts of 60 eyes of 60 consecutive patients (mean age ± standard deviation, 73.5 ± 7.0 years) who developed pterygium and cataract. We determined visual acuity (logMAR), manifest spherical equivalent, manifest astigmatism, corneal astigmatism, and mean keratometry, preoperatively and 3 months postoperatively. Corrected visual acuity was significantly improved from 0.19 ± 0.20 preoperatively to -0.06 ± 0.07 postoperatively (P < 0.001, Wilcoxon signed-rank test). Uncorrected visual acuity was also significantly improved from 0.62 ± 0.33 preoperatively to 0.31 ± 0.32 postoperatively (P < 0.001). At 3 months, 48% and 82% of the eyes were within ± 0.5 and ± 1.0 D, respectively, of the targeted correction. We found significant correlations of the prediction errors with the changes in the mean keratometry (Spearman signed-rank test, r = -0.535, P < 0.001) and with the pterygium size (r = -0.378, P = 0.033). Simultaneous pterygium and cataract surgery was safe and effective, and the accuracy was moderately predictable. However, it should be noted that a significant myopic shift occurred postoperatively, possibly resulting from the steepening of the cornea after pterygium removal, especially when the size of pterygium was large.

Visual and refractive outcomes of small incision lenticule extraction for the correction of myopia: 1-year follow-up

OBJECTIVE

To assess the 1 year clinical outcomes of small incision lenticule extraction (SMILE) for the correction of myopia and myopic astigmatism using a 500 kHz femtosecond laser system.

METHODS

This prospective study evaluated 52 eyes of 39 consecutive patients (31.8±6.9 years, mean age±SD) with spherical equivalents of -4.11±1.73 D (range, -1.25 to -8.25 D) who underwent SMILE for myopia and myopic astigmatism. Preoperatively, 1 week, and 1, 3, 6 and 12 months postoperatively, we assessed the safety, efficacy, predictability, stability, corneal endothelial cell loss and the adverse events of the surgery.

RESULTS

The logarithm of the minimal angle of resolution (logMAR) uncorrected distance visual acuity and LogMAR corrected distance visual acuity were -0.16±0.11 and -0.22±0.07, respectively, 1 year postoperatively. At 1 year, all eyes were within±0.5 D of the targeted correction. Manifest refraction changes of -0.05±0.32 D occurred from 1 week to 1 year postoperatively (p=0.20, Wilcoxon signed-rank test). The endothelial cell density was not significantly changed from 2804±267 cells/mm(2) preoperatively to 2743±308 cells/mm(2) 1 year postoperatively (p=0.12). No vision-threatening complications occurred during the observation period.

CONCLUSIONS

SMILE performed well in the correction of myopia and myopic astigmatism, and no significant change in endothelial cell density or any other serious complications occurred throughout the 1-year follow-up period, suggesting its viability as a surgical option for the treatment of such eyes.

Comparison of Subjective Refraction under Binocular and Monocular Conditions in Myopic Subjects

To compare subjective refraction under binocular and monocular conditions, and to investigate the clinical factors affecting the difference in spherical refraction between the two conditions. We examined thirty eyes of 30 healthy subjects. Binocular and monocular refraction without cycloplegia was measured through circular polarizing lenses in both eyes, using the Landolt-C chart of the 3D visual function trainer-ORTe. Stepwise multiple regression analysis was used to assess the relations among several pairs of variables and the difference in spherical refraction in binocular and monocular conditions. Subjective spherical refraction in the monocular condition was significantly more myopic than that in the binocular condition (p < 0.001), whereas no significant differences were seen in subjective cylindrical refraction (p = 0.99). The explanatory variable relevant to the difference in spherical refraction between binocular and monocular conditions was the binocular spherical refraction (p = 0.032, partial regression coefficient B = 0.029) (adjusted R² = 0.230). No significant correlation was seen with other clinical factors. Subjective spherical refraction in the monocular condition was significantly more myopic than that in the binocular condition. Eyes with higher degrees of myopia are more predisposed to show the large difference in spherical refraction between these two conditions.

Effect of Intraocular Forward Scattering and Corneal Higher-Order Aberrations on Visual Acuity after Descemet's Stripping Automated Endothelial Keratoplasty

Purpose

To assess the relationship of intraocular forward scattering and corneal higher-order aberrations (HOAs) with best spectacle corrected visual acuity (BSCVA) after Descemet’s stripping automated endothelial keratoplasty (DSAEK), and to compare these parameters between DSAEK and non-Descemet’s stripping automated endothelial keratoplasty (n-DSAEK) groups.

Methods

This retrospective study enrolled thirty eyes of 30 consecutive patients who underwent standard DSAEK, and who underwent successful phacoemulsification with intraocular lens implantation before DSAEK. The mean age at the time of surgery was 71.7 ± 10.4 years. We quantitatively evaluated the objective scattering index (OSI) using the double-pass instrument (OQAS II, Visiometrics) and corneal HOAs using Hartmann-Shack aberrometry (KR-9000PW, Topcon) 3 months postoperatively.

Results

The mean OSI, corneal HOAs, and logMAR BSCVA 3 months after DSAEK were 7.91 ± 3.58, 0.43 ± 0.27 μm, and 0.32 ± 0.25, respectively. We found a significant correlation between the OSI and logMAR BSCVA (Spearman correlation coefficient r=0.714, p<0.001), but no significant association between corneal HOAs and logMAR BSCVA 3 months postoperatively (r=0.209, p=0.267). We found no significant differences in any postoperative parameters between the DSAEK and n-DSAEK groups (p>0.05).

Conclusions

Our pilot study demonstrated that the postoperative corrected visual acuity was significantly correlated with intraocular forward scattering, but not with corneal HOAs in post-DSAEK eyes, suggesting that intraocular forward scattering plays a more essential role in postoperative visual performance than corneal aberrations after DSAEK. The detailed visual performance, such as HOAs and intraocular scattering, after n-DSAEK appears to be essentially equivalent to that after DSAEK.

Effect of femtosecond laser setting on visual performance after small-incision lenticule extraction for myopia

AIM

To compare the effect of the two femtosecond laser settings on visual performance after small-incision lenticule extraction (SMILE) for myopia and myopic astigmatism.

METHODS

Forty-four eyes of 22 consecutive patients who underwent SMILE with an energy level of 140 nJ (spot distance 3.0 µm) in one eye, and with an energy level of 170 nJ (spot distance 4.5 µm) in the other eye, the eyes being randomly assigned. Preoperatively, 1 week, and 1 and 3 months postoperatively, the values of the modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI) and Optical Quality Analysis System (OQAS) values (OVs) for these eyes were quantitatively assessed using an Optical Quality Analysis System (Visiometrics).

RESULTS

No significant differences were detected between the two groups in the visual and refractive outcomes, or in the MTF cutoff frequency, the Strehl ratio, the OSI, the OV 100%, the OV 20% or the OV 9% at any time point before or after surgery.

CONCLUSIONS

SMILE with energy settings of 140 and 170 nJ was effective for the correction of myopia and myopic astigmatism. It is indicated that the differences in laser setting (140 nJ, spot distance 3.0 µm vs 170 nJ, spot distance 4.5 µm) did not significantly affect the optical quality including the intraocular scattering of eyes undergoing SMILE.

CLINICAL TRIAL NUMBER

The protocol was registered with University Hospital Medical Information Network Clinical Trial Registry (UMIN000016241).

Comparison of astigmatic correction after femtosecond lenticule extraction and wavefront-guided LASIK for myopic astigmatism

PURPOSE

To compare postoperative astigmatic correction between femtosecond lenticule extraction (FLEx) and wavefront-guided LASIK in eyes with myopic astigmatism.

METHODS

Fifty-eight eyes of 41 patients undergoing FLEx and 49 eyes of 29 patients undergoing wavefront-guided LASIK to correct myopic astigmatism were examined. Visual acuity, cylindrical refraction, predictability of the astigmatic correction, and astigmatic vector components were compared between groups 6 months after surgery.

RESULTS

There was no statistically significant difference in manifest cylindrical refraction (P = .08) or percentage of eyes within ± 0.50 diopter (D) of its refraction (P = .11) between the surgical procedures. The index of success in FLEx was statistically significantly better than that of wavefront-guided LASIK (P = .02), although there was no significant difference between the groups in other indices (eg, surgically induced astigmatism, target-induced astigmatism, astigmatic correction index, angle of error, difference vector, and flattening index). Subgroup analysis showed that FLEx had a better index of success (P = .02) and difference vector (P = .04) than wavefront-guided LASIK in the low cylinder subgroup; the angle of error in FLEx was significantly smaller than that of wavefront-guided LASIK in the moderate cylinder subgroup (P = .03).

CONCLUSIONS

Both FLEx and wavefront-guided LASIK worked well for the correction of myopic astigmatism by the 6-month follow-up visit. Although FLEx had a better index of success than wavefront-guided LASIK when using vector analysis, it appears equivalent to wavefront-guided LASIK in terms of visual acuity and the correction of astigmatism.

Factors influencing contrast sensitivity function in myopic eyes

Purpose

To evaluate the factors affecting the area under the log contrast sensitivity function (AULCSF) in healthy myopic eyes.

Methods

We retrospectively examined 201 eyes of 201 consecutive subjects (age, 31.8±7.4 years (mean ± standard deviation)) with myopic refractive errors of −1.25 to −8.25 diopters (D). From the contrast sensitivity data, the area under the log contrast sensitivity function (AULCSF) was calculated. Stepwise multiple regression analysis was used to assess the factors affecting the AULCSF.

Results

The mean AULSCF was 1.09±0.09 (0.89 to 1.55). Explanatory variables relevant to the AULCSF were, in order of influence, the objective scattering index (OSI) (p = 0.018, partial regression coefficient B = –0.032) and logMAR CDVA (p = 0.022, B = –0.209) (adjusted R² = 0.231). No significant correlation was seen with other clinical factors such as gender, manifest refraction, pupil size, lens density, corneal HOAs, or ocular HOAs.

Conclusions

Although the great majority of the variance remains unexplained, eyes with lower OSI and better CDVA are more predisposed to show higher contrast sensitivity function. These results indicate that not only CDVA but also intraocular forward scattering may play some role in predicting the contrast sensitivity function in myopic subjects.

Three-year follow-up of posterior chamber toric phakic intraocular lens implantation for the correction of high myopic astigmatism in eyes with keratoconus

AIM

To assess the clinical outcomes following the use of toric implantable collamer lenses (toric ICL, STAAR Surgical) for the correction of high myopic astigmatism with keratoconus.

METHODS

This retrospective study evaluated 21 eyes of 11 patients with spherical equivalents of -9.70±2.33 D (mean±SD) and astigmatism of -3.21±1.56 D who underwent toric ICL implantation for keratoconus. Preoperatively, and at 1, 3 and 6 months and 1, 2 and 3 years postoperatively, we assessed the safety, efficacy, predictability, stability and adverse events of the surgery.

RESULTS

The logarithm of the minimum angle of resolution (logMAR) uncorrected distance visual acuity (UDVA) and the logMAR corrected distance visual acuity (CDVA) were -0.06±0.11 and -0.12±0.09, respectively, at 3 years postoperatively. At 3 years, 67% and 86% of the eyes were within ±0.5 and ±1.0 D, respectively, of the targeted correction. Manifest refraction changes of 0.04±0.33 D occurred from 1 month to 3 years postoperatively. No significant change in manifest refraction (analysis of variance, p=0.989) or keratometry (p=0.951), or vision-threatening complications occurred during the observation period.

CONCLUSIONS

Toric ICL implantation is beneficial according to measures of safety, efficacy, predictability and stability for the correction of refractive errors for keratoconus during a 3-year observation period. The disease did not progress even in the late-postoperative period, suggesting the viability of this procedure as a surgical option for the treatment of such eyes.

Clinical outcomes of penetrating keratoplasty performed with the VisuMax femtosecond laser system and comparison with conventional penetrating keratoplasty

PURPOSE

To assess the clinical outcomes of femtosecond laser-assisted keratoplasty (FLAK) using the VisuMax femtosecond laser system, and to compare them with those of conventional penetrating keratoplasty (PK).

METHODS

We retrospectively examined 20 eyes of 20 consecutive patients undergoing FLAK and 20 eyes of 20 age- and diagnosis-matched patients undergoing conventional PK. We quantitatively assessed corneal astigmatism, refractive astigmatism, and corrected visual acuity, 1, 3, and 6 months postoperatively, and endothelial cell density 6 months postoperatively.

RESULTS

Corneal and refractive astigmatism after FLAK were significantly lower after FLAK than that after conventional PK at 3 and 6 months postoperatively (p = 0.04 and p = 0.03, respectively, Mann-Whitney U test). FLAK provided significantly faster visual recovery than conventional PK at 1 month postoperatively (p = 0.02), but not at 3 and 6 months postoperatively (p = 0.52 and p = 0.80, respectively). We found no significant differences in the change in endothelial cell density between the two groups (p = 0.30).

CONCLUSIONS

FLAK using the VisuMax femtosecond laser system induces significantly less corneal and refractive astigmatism than conventional PK, and provides significantly faster visual recovery in the early postoperative period, possibly because the geometry of the donor-recipient matching is more physiological and requires less tight sutures. It is suggested that FLAK has advantages over conventional PK, in terms of astigmatism and fast visual recovery.

Wavefront-guided versus non-wavefront-guided photorefractive keratectomy for myopia: meta-analysis of randomized controlled trials

Purpose

To compare the efficacy, predictability, safety, and induced higher-order aberrations (HOAs) between wavefront-guided and non-wavefront-guided photorefractive keratectomy (PRK).

Methods

The Cochrane Central Register of Controlled Trials, PubMED, and EMBASE were searched for randomized controlled trials. Trials meeting the selection criteria were quality appraised, and data was extracted by 2 independent authors. Measures of association were pooled quantitatively using meta-analytical methods. Comparisons between wavefront-guided and non-wavefront-guided ablations were made as pooled odds ratios (ORs) or weighted mean differences. The pooled ORs and 95% confidence intervals (CIs) were computed for efficacy, safety, and predictability. The weighted mean differences and 95% CIs were used to compare induced HOAs.

Results

The study covered five trials involving 298 eyes. After wavefront-guided PRK, the pooled OR of achieving an uncorrected distance visual acuity of 20/20 (efficacy) was 1.18 (95% CI, 0.53–2.60; p = 0.69), the pooled OR of achieving a result within ±0.50 diopter of the intended target (predictability) was 0.86 (95% CI, 0.40–1.84; p = 0.70). No study reported a loss of 2 or more lines of Snellen acuity (safety) with either modality. In eyes with wavefront-guided PRK, the postoperative trefoil aberrations (mean difference −0.02; 95% CI, −0.03 to −0.00; p = 0.03) were significantly lower. There were no significant differences between the two groups in the postoperative total HOAs (mean difference −0.04; 95% CI, −0.23 to 0.14; p = 0.63), spherical (mean difference 0.00; 95% CI, −0.08 to 0.09; p = 0.93), and coma (mean difference −0.06; 95% CI, −0.14 to 0.03; p = 0.20) aberrations.

Conclusions

According to the meta-analysis, wavefront-guided PRK offered no advantage in efficacy, predictability, or safety measures over non-wavefront-guided PRK, although it may have induced fewer trefoil aberrations.

Factors influencing long-term regression after posterior chamber phakic intraocular lens implantation for moderate to high myopia

PURPOSE

To evaluate the factors affecting the long-term regression after posterior chamber phakic intraocular lens (Visian ICL; STAAR Surgical) implantation for myopia.

DESIGN

Retrospective observational case series.

METHODS

We retrospectively examined 60 eyes of 35 consecutive patients (age, 38.4 ± 9.3 years [mean ± standard deviation]) with myopic refractive errors of -4.00 to -15.25 diopters (D) undergoing ICL implantation. We assessed the amount of myopic regression from 1 month to 6 years after surgery. Stepwise multiple regression analysis was used to assess the factors affecting the amount of myopic regression.

RESULTS

The mean myopic regression from 1 month to 6 years after surgery was -0.33 ± 0.71 D (0.75 to -3.00 D). Explanatory variables relevant to the myopic regression were, in order of influence, patient age (partial regression coefficient B = -0.042, P < .0001) and preoperative axial length (B = -0.186, P = .013) (adjusted R(2) = 0.300). No significant correlation was seen with other clinical factors such as sex, preoperative refraction, intraocular pressure, white-to-white distance, anterior chamber depth, central corneal thickness, or mean keratometric readings.

CONCLUSIONS

Although the great majority of the variance remains unexplained, eyes of older patients and eyes with longer axial length are more predisposed to show greater myopic regression after ICL implantation. These results indicate that not only patient age but also axial length may play some role in predicting the long-term refractive outcomes of this surgical procedure.

Visual and refractive outcomes of femtosecond lenticule extraction and small-incision lenticule extraction for myopia

PURPOSE

To compare the visual and refractive outcomes of femtosecond lenticule extraction (FLEx) and small-incision lenticule extraction (SMILE) in eyes with myopia.

DESIGN

Prospective, randomized, masked clinical trial with intraindividual comparison.

METHODS

This study evaluated 52 eyes of 26 consecutive patients with spherical equivalents of -4.19 ± 1.65 diopters (D) (mean ± standard deviation) who underwent FLEx in 1 eye and SMILE in the other eye by randomized assignment. Before surgery, and 1 week and 1, 3, and 6 months after surgery, we assessed safety, efficacy, predictability, stability, and adverse events of the 2 surgical techniques.

RESULTS

LogMAR uncorrected and corrected distance visual acuity was, respectively, -0.17 ± 0.10, -0.20 ± 0.07 in the FLEx group and -0.15 ± 0.10, -0.19 ± 0.07 in the SMILE group 6 months postoperatively. In the FLEx and SMILE groups 6 months postoperatively, 96% and 100% of eyes, respectively, were within 0.5 D of the targeted spherical equivalent correction. Changes of -0.02 ± 0.39 D and 0.00 ± 0.30 D occurred in manifest refraction from 1 week to 6 months in the FLEx and SMILE groups, respectively. No clinically significant complications occurred in the FLEx or the SMILE group.

CONCLUSIONS

Both FLEx and SMILE performed well in the correction of myopia throughout the 6-month observation period. FLEx may be essentially equivalent to SMILE in terms of safety, efficacy, predictability, and stability, suggesting that the presence or absence of lifting the flap does not significantly affect these visual and refractive outcomes.

Longitudinal assessment of optical quality and intraocular scattering using the double-pass instrument in normal eyes and eyes with short tear breakup time

Purpose

To assess the longitudinal changes in optical quality including intraocular scattering in normal eyes and eyes with short tear breakup time (TBUT).

Methods

We prospectively examined twenty eyes of 20 healthy subjects, and age-matched twenty eyes of 20 short TBUT subjects. The modulation transfer function (MTF) cutoff frequency, the Strehl ratio, and the objective scattering index (OSI) were quantitatively assessed using an Optical Quality Analysis System. We investigated the changes in these variables measured consecutively at the initial examination, 5, and 10 seconds without blinking. We also compared these variables in eyes with short TBUT with those in normal eyes.

Results

No significant differences in the MTF cutoff frequency, Strehl ratio, or OSI were detected over a 10-second period in normal eyes. These variables also became significantly degraded even over a 5-second period in eyes with short TBUT (p<0.01). We found significant differences in these variables at 5 and 10 seconds (p<0.05), but none immediately after the blink between normal and short TBUT eyes.

Conclusions

Optical quality including intraocular scattering deteriorated significantly with time in eyes with short TBUT, whereas we found significant differences over a 10-second period in normal eyes. Eyes with short TBUT showed greater deterioration in optical quality after the blink than normal eyes. The longitudinal assessment of optical quality may be effective in distinguishing eyes with short TBUT from normal eyes.

Scleral buckling and pars plana vitrectomy for rhegmatogenous retinal detachment: an analysis of 542 eyes

PURPOSE

To investigate the anatomical success rates of scleral buckling (SB) and pars plana vitrectomy (PPV) performed for rhegmatogenous retinal detachment (RRD) in a large case series and to identify prognostic factors for the primary anatomical success rates of surgical techniques.

METHODS

We reviewed 542 consecutive eyes for primary RRD in this retrospective study. Follow-ups were performed for at least six months. In each of the two groups, 271 eyes were examined. The main outcome measure was the primary anatomical success rate. Multivariate analysis was also performed to determine whether independent risk factors of the preoperative parameters for redetachment exist.

RESULTS

The primary anatomical success rates were 93.7% and 96.3% in the SB and PPV groups; and the final anatomical success rates were 100% in both groups (each with 271 eyes). In the SB group, eyes with macula-off had significantly lower primary anatomical success rates than those with macula-on (p = 0.002). Preoperative break location or lens status had no significant effect on primary anatomical success rates in either group. Multivariate logistic regression analysis using four variables, namely, sex, posterior vitreous detachment, macular status and preoperative visual acuity, showed that the macular status was an independent risk factor for redetachment in the SB group (p = 0.039, odds ratio 3.7). The six-month follow-up visual acuity was significantly better than the preoperative visual acuity in both groups (p ≤ 0.001).

CONCLUSIONS

Both SB and PPV gave excellent primary and final anatomical success rates. The macula-off status was associated with a lower success rate in the SB group, although break location and lens status had no significant effect on success rates in either group.

Effect of fermented bilberry extracts on visual outcomes in eyes with myopia: a prospective, randomized, placebo-controlled study

PURPOSE

To investigate clinically the effects of yeast-fermented bilberry extract on visual outcomes in myopic eyes.

METHODS

In a prospective, randomized, placebo-controlled, cross-over study, we examined 30 eyes of 30 middle-aged healthy volunteers (mean age±standard deviation, 39.5±7.2 years) with myopia [manifest spherical equivalent, -2.40±1.88 diopters (D)], who were randomly assigned to 1 of 2 oral regimens: fermented bilberry extract (400 mg/day) or placebo. We quantitatively assessed visual acuity, refraction, pupil constriction rate, accommodation, and mesopic contrast sensitivity (CS), before and 1 month after treatment. Only the right eyes were tested. The amplitude of accommodation and CS were measured with an accommodometer (D'ACOMO; WOC) and a CS unit (VCTS-6500; Vistech), respectively. From the CS, the area under the log contrast sensitivity function (AULCSF) was calculated.

RESULTS

The mean amplitude of accommodation increased significantly, from 4.62±1.88 D before treatment, to 5.33±2.03 D after treatment in the study group (Wilcoxon signed-rank test, P=0.002). Moreover, the mesopic AULCSF was significantly increased, from 1.04±0.16 before, to 1.13±0.17 after, treatment (P=0.009). However, we found no significant changes in accommodation or AULCSF in the control group (P>0.05), or any significant changes in any other parameters in either group (P>0.05).

CONCLUSIONS

The present data show that fermented bilberry extract is effective in causing increases in subjective accommodation and in mesopic CS in myopic eyes.

Clinical evaluation of the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome: a prospective, randomized, multicenter study

PURPOSE

To assess the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome.

METHODS

This study evaluated 64 eyes of 32 patients (age: 62.6±12.8 years (mean±SD)) in whom treatment with 0.1% sodium hyaluronate was insufficiently responsive. The eyes were randomly assigned to one of the two regimens in each patient: topical administration of sodium hyaluronate and diquafosol tetrasodium in one eye, and that of sodium hyaluronate in the other. Before treatment, and 2 and 4 weeks after treatment, we determined tear volume, tear film break-up time (BUT), fluorescein and rose bengal vital staining scores, subjective symptoms, and adverse events.

RESULTS

We found a significant improvement in BUT (P=0.049, Dunnett test), fluorescein and rose bengal staining scores (P=0.02), and in subjective symptoms (P=0.004 for dry eye sensation, P=0.02 for pain, and P=0.02 for foreign body sensation) 4 weeks after treatment in the diquafosol eyes. On the other hand, we found no significant change in these parameters after treatment in the control eyes.

CONCLUSIONS

In dry eyes, where sodium hyaluronate monotherapy was insufficient, diquafosol tetrasodium was effective in improving objective and subjective symptoms, suggesting its viability as an option for the additive treatment of such eyes.

Clinical evaluation of the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome: a prospective, randomized, multicenter study

PURPOSE

To assess the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome.

METHODS

This study evaluated 64 eyes of 32 patients (age: 62.6±12.8 years (mean±SD)) in whom treatment with 0.1% sodium hyaluronate was insufficiently responsive. The eyes were randomly assigned to one of the two regimens in each patient: topical administration of sodium hyaluronate and diquafosol tetrasodium in one eye, and that of sodium hyaluronate in the other. Before treatment, and 2 and 4 weeks after treatment, we determined tear volume, tear film break-up time (BUT), fluorescein and rose bengal vital staining scores, subjective symptoms, and adverse events.

RESULTS

We found a significant improvement in BUT (P=0.049, Dunnett test), fluorescein and rose bengal staining scores (P=0.02), and in subjective symptoms (P=0.004 for dry eye sensation, P=0.02 for pain, and P=0.02 for foreign body sensation) 4 weeks after treatment in the diquafosol eyes. On the other hand, we found no significant change in these parameters after treatment in the control eyes.

CONCLUSIONS

In dry eyes, where sodium hyaluronate monotherapy was insufficient, diquafosol tetrasodium was effective in improving objective and subjective symptoms, suggesting its viability as an option for the additive treatment of such eyes.

Clinical evaluation of optical quality and intraocular scattering after posterior chamber phakic intraocular lens implantation

PURPOSE

We assessed the optical quality and intraocular scattering after posterior chamber phakic intraocular lens implantation.

METHODS

We examined prospectively 38 eyes of 19 consecutive patients undergoing implantable contact lens (ICL) implantation (mean age ± SD 36.3 ± 5.7 years), and 38 age-matched normal eyes of 19 healthy volunteers (mean age 36.4 ± 4.9 years). We assessed quantitatively the values of modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and the Optical Quality Analysis System (OQAS) values (OVs). We compared these variables in eyes undergoing ICL implantation to those in healthy eyes.

RESULTS

The mean MTF cutoff frequency, Strehl ratio, OSI, OV 100%, OV 20%, and OV 9% were 28.69 ± 8.59 cycles/degree, 0.17 ± 0.04, 1.06 ± 0.48, 0.96 ± 0.29, 0.83 ± 0.31, and 0.83 ± 0.32, respectively, 3 months after ICL implantation. We found no significant differences in the MTF cutoff frequency (Mann Whitney U test, P = 0.31), Strehl ratio (P = 0.46), OSI (P = 0.30), or OVs at contrasts of 100% (P = 0.51), 20% (P = 0.46), and 9% (P = 0.36), between the ICL and control groups.

CONCLUSIONS

The optical quality parameters, such as the MTF cutoff frequency, Strehl ratio, OSI, or OVs in the ICL group, were not significantly different from those in the control group, suggesting that the optical quality and intraocular scattering of eyes undergoing ICL implantation essentially was equivalent to those of healthy eyes.

Effect of aging on optical quality and intraocular scattering using the double-pass instrument

PURPOSE

To assess the effect of aging on optical quality in a normal population.

METHODS

We prospectively examined 100 normal eyes of 100 healthy volunteers (50 men, 50 women; ages, 20-69 years; mean age ± standard deviation, 44.6 ± 15.5 years). We quantitatively assessed the values of MTF cutoff frequency, Strehl ratio, and objective scattering index (OSI), using an Optical Quality Analysis System™ (Visiometrics, Terrassa, Spain). We took these measurements three times each, and the mean value obtained was used for statistical analysis. We investigated the relationships between subject age and these optical quality parameters.

RESULTS

The mean MTF cutoff frequency, Strehl ratio, and OSI, were 27.76 ± 8.41, 0.17 ± 0.05, and 1.29 ± 0.76 cycles/degree, respectively. We found a significant negative correlation between subject age and MTF cutoff frequency (Pearson's correlation coefficient r = -0.606, p < 0.001), and between age and Strehl ratio (r = -0.649, p < 0.001). We also found a significant positive correlation between subject age and OSI (r = 0.691, p < 0.001).

CONCLUSIONS

The MTF cutoff frequency and the Strehl ratio are significantly decreased, and the OSI is significantly increased, by aging, indicating that the optical quality of the eye is degraded in older subjects.