Clinical utility of femtosecond laser-assisted astigmatic keratotomy after cataract surgery

Purpose

To examine the clinical utility of femtosecond laser-assisted astigmatic keratotomy (FSL-AK) for eyes after cataract surgery.

Methods

Eight eyes of 6 patients with an intraocular lens and corneal astigmatism of 2.0 diopters (D) or more underwent FSL-AK. The mean preoperative manifest cylindrical refraction was 2.88 ± 0.64 D and the mean corneal astigmatism was 2.84 ± 0.83 D. Paired symmetrical arcuate incisions were created with the same settings, except for the incision depth. Uncorrected distance visual acuity (UDVA), manifest cylindrical power, and surgically induced astigmatism (SIA) were measured at 1 day, 1 week, and 1 month postoperatively. Fourier analysis of corneal topography and incision depths measured with anterior-segment optical coherence tomography were evaluated 1 month postoperatively.

Results

In all eyes, the UDVA improved at 1 week and 1 month postoperatively, and the manifest cylinder also decreased postoperatively, while the SIA showed overcorrections in 6 eyes. Fourier analysis showed decreases in spherical and regular astigmatic components and increases in higher-order irregularity. The mean incision depth was measured as 60 µm deeper than the intended depth.

Conclusion

The FSL-AK effectively reduced corneal astigmatism and improved the UDVA, although it was demonstrated that the deeper incisions led to overcorrection.

     

The PALM Technique: histological findings of masked phototherapeutic keratectomy on rabbit corneas

Background

To compare the corneal healing response between conventional and phototherapeutic keratectomy through a masking agent, in rabbit corneas.

Methods

24 adult rabbits underwent phototherapeutic keratectomy. Animals were divided in two groups: 12 received photoablation through a masking agent (PALM gel) and the remaining 12 received conventional phototherapeutic keratectomy of equal depth and served as control. Light and transmission electron microscopy was performed in specimens of both groups obtained: immediately after, four hours, one week, one, three and six months after treatment.

Results

Reepitheliazation was complete within five days in all eyes. Light and transmission electron microscopy did not reveal any differences of the healing process in the experimental eyes compared to the controls.

Conclusion

Photoablation through the PALM technique did not result any evident alterations of the reepithelisation and stromal healing process.

     

Limbal stem cell and oral mucosal epithelial transplantation from ex vivo cultivation in LSCD-induced rabbits: histology and immunologic study of the transplant epithelial sheet

Purpose

To evaluate the results of cultivated limbal epithelial and oral mucosal epithelial transplantation (CLET and COMET) in limbal stem cell deficiency (LSCD)-induced rabbit model.

Materials and methods

Six New Zealand white rabbits were divided into two groups of three rabbits each. Limbal tissue was harvested from the first group, and oral mucosal biopsy was obtained from the second group. The tissues were cultured using an explant technique with amniotic membrane as a substrate and co-culture with the 3T3 fibroblast and air-lifting method. The right eye of each rabbit was induced to have LSCD using alkali burns. After three weeks, the LSCD-induced rabbit eyes were transplanted with the cultivated limbal and oral mucosal epithelial sheet in the first and second group, respectively. The transplanted eye was evaluated weekly post-operation. After 2 months, all transplanted eyes were enucleated and the epithelial morphology and phenotype of ocular surfaces were studied and compared with normal corneal and oral mucosal tissue.

Results

At 2-month post-transplantation, the eyes of four animals recovered with corneal transparency, one partially recovered, and one failed. The histology of the majority of transplanted eyes was stratified layers of corneal epithelia similar to normal rabbit cornea with some different findings such as goblet cells in the limbal region. Corneal epithelial thickening and stromal vascularization in two animals were observed. Phenotypic characterization of transplanted eyes showed a similar pattern of marker expression with the absence of p63 expression in the limbal or corneal epithelium in the COMET group.

Conclusions

The histology and phenotype of transplanted eyes after CLET and COMET were most likely to have similar characteristics as a normal healthy rabbit eye even though the COMET eyes have some inferior characteristics to the CLET eyes.

     

Correlative factors’ analysis of postural-related ocular cyclotorsion with image-guided system

Purpose

To explore the correlation between ocular cyclotorsion induced by sitting and supine positions as well as other selected factors, validated by an image-guided system.

Study design

A cross-sectional study conducted in 73 inpatients (85 eyes) who received intraocular operations in China Medical University.

Methods

The ocular cyclotorsion degree was recorded using an image-guided system (Verion Reference Unit, Alcon) by comparing images captured in sitting position, as well as pre- and post-different anesthesia methods in the supine position. Possible correlative factors including age, gender, eye axial length, best corrected visual acuity (BCVA), astigmatism degree, astigmatism axis, anesthesia, and comparison in laterality of eyes on ocular cyclotorsion were analyzed.

Results

The total cyclotorsion rate was 88.24% and the cyclotorsion degree ranged from ? 14.0° to + 12.0° with an average of 4.6° ± 3.4°. Excyclotorsion was predominant OD whereas incyclotorsion was predominant OS (p < 0.05). The effect of eye axial length, BCVA, astigmatism degree, astigmatism axis, anesthesia method, age and gender on cyclotorsion orientation was not statistically significant, neither did these factors show any significant differences in the ocular cyclotorsion degree (p > 0.05). Pre- and post-anesthesia, and different anesthetic methods, did not show any significant influence on the ocular cyclotorsion degree (p > 0.05).

Conclusions

Cyclotorsion orientation seems to be correlated only with eye laterality. None of the other investigated factors, including age, gender, eye axial length, BCVA, astigmatism degree, astigmatism axis and anesthesia seems to affect cyclotorsion orientation or degree.

     

Allogenic cultivated limbal stem cell transplantation versus cadaveric keratolimbal allograft in ocular surface disorder: 1-year outcome

Purpose

To compare the outcome of allogenic ex vivo cultivated limbal stem cell transplantation (LSCT) versus cadaveric keratolimbal allograft in patients with limbal stem cell deficiency (LSCD).

Methods

In this prospective interventional study from Army Hospital Research and Referral in New Delhi, 50 eyes of 40 patients with ocular surface disorder having LSCD underwent either cultivated LSCT (group 1: 25 eyes of 20 patients) or keratolimbal allograft transplantation (group 2: 25 eyes of 20 patients). The outcome measures were gain of two or more lines of best-corrected visual acuity (BCVA), absence of conjunctival vascularization over cornea, corneal neovascularization regression, regression of visually significant corneal opacity (iris details poorly visible), Schirmer’s 1 ≥10 s, tear break-up time (TBUT) ≥10 s, and absence of fluorescein staining.

Results

At 1 year of follow-up, both groups experienced significant improvement in all outcome measures, but there was no significant difference between both groups in improvement of two or more lines of BCVA (P = 0.841), absence of conjunctival vascularization over cornea (P = 0.812), corneal neovascularization (P = 0.074), visually significant corneal opacity (P = 0.075), Schirmer’s 1 ≥10 s (P = 0.814), TBUT ≥10 s (P = 0.382), or absence of fluorescein stain (P = 1.00).

Conclusion

Both allogenic ex vivo cultivated LSCT and cadaveric keratolimbal allograft transplantation are comparable in terms of visual gain and ocular surface restoration.

     

Wound stability and surgically induced corneal astigmatism after transconjunctival single-plane sclerocorneal incision cataract surgery

Purpose

To compare intraocular pressure (IOP) immediately after cataract surgery, and surgically induced corneal astigmatism (SIA) and corneal shape changes between eyes with transconjunctival single-plane sclerocorneal incisions (TSSIs) and eyes with clear corneal incisions (CCIs).

Methods

Bilateral eyes of 64 patients undergoing phacoemulsification were randomized to undergo 2.4-mm temporal TSSI or CCI. IOP was measured preoperatively, and in the immediate postoperative periods. SIA was determined using vector analysis, and corneal shape changes and irregular astigmatism were evaluated using a videokeratography preoperatively, and in the early postoperative periods.

Results

Wound hydration was performed in 23 eyes (35.9 %) of the TSSI group and in 60 (93.8 %) of the CCI group (P < 0.0001). Mean IOP was significantly higher in the TSSI group than in the CCI group at 30, 60, and 120 min postoperatively (P ≤ 0.0179). SIA tended to be smaller in the TSSI group than the CCI group, but the difference was not significant. The higher order irregular astigmatism was smaller in the TSSI group than in the CCI group at 2 days (P = 0.0312). The videokeratography revealed a wound-related flattening postoperatively in both groups; this change disappeared within 4 weeks in the TSSI group, whereas it persisted until 12 weeks in the CCI group.

Conclusion

IOP was significantly higher immediately after TSSI than after CCI and required less wound hydration, suggesting better stability with TSSI. Higher order irregular astigmatism and wound-related corneal flattening were smaller after TSSI than after CCI in the early periods, suggesting that fewer corneal shape changes with TSSI.

     

Comparative analysis of the visual and refractive outcomes of a refractive segmented multifocal intraocular lens with and without toricity: 1-year results

Purpose

To compare the visual and refractive outcomes up to 1 year postoperatively following implantation of a refractive segmented or a refractive segmented toric multifocal intraocular lens (IOL).

Methods

This retrospective study included 108 eyes of 64 patients who underwent cataract surgery with implantation of a refractive segmented multifocal IOL (Lentis Mplus LS-313 MF30 IOL) (LM group) and 81 eyes of 49 patients with implantation of a refractive segmented toric multifocal IOL (Lentis Mplus LU-313 MF30T IOL) (LMT group). The visual and refractive postoperative outcomes and the rate of additional refractive procedures were evaluated up to 1 year postoperatively.

Results

The uncorrected distance visual acuity (VA) and uncorrected near VA exceeded 1.0 and 0.60 in decimal VA, respectively, and both were stable postoperative groups. The postoperative subjective refractive astigmatism was also stable and the postoperative refraction was near emmetropia in both groups. No significant differences were found in the need for additional surgical refractive procedures.

Conclusion

The outcomes with a refractive segmented toric multifocal IOL were comparable to those with a non-toric model despite higher preoperative corneal astigmatism.

     

Safety and reliability of femtosecond laser-assisted cataract surgery for Japanese eyes

Purpose

To assess the safety and efficacy of femtosecond laser-assisted cataract surgery (FLACS) in Japanese eyes.

Study design

Retrospective case series.

Methods

The clinical records of 529 consecutive eyes of 312 Japanese patients who underwent FLACS from 2013 to 2016 were reviewed. The completion rates of anterior capsulotomy and corneal incisions using the femtosecond laser (LenSx, Alcon) and the number of attempts to achieve secure docking between the cornea and laser system were recorded. The uncorrected and corrected distance visual acuities (VAs) and uncorrected and distance-corrected near VAs 1 week postoperatively were evaluated.

Results

Anterior capsulotomies were completed in 98.7% of eyes. The corneal incisions were incomplete in 8.3%, which included eyes with arcus senilis and neovascularization. The mean corneal endothelial cell reduction rate was 5.5%. Multiple docking attempts were required in 22.9% of eyes, while canthotomy was performed in two eyes. The postoperative VAs were favorable.

Conclusion

FLACS was safe and reliable in Japanese eyes. Further improvements in docking are required to accommodate small corneas and narrow palpebral spaces.

     

Prognostic factors after aflibercept therapy for typical age-related macular degeneration and polypoidal choroidal vasculopathy

Purpose

To determine factors predictive of visual outcomes in eyes treated with intravitreal aflibercept injections (IAIs) for typical neovascular age-related macular degeneration (AMD) or polypoidal choroidal vasculopathy (PCV).

Study design

Retrospective, multicenter, institutional, consecutive, interventional case series.

Methods

One hundred nine eyes (107 patients) with treatment-naïve neovascular AMD at 3 university hospitals were studied. After a loading phase of 3 monthly 2.0-mg IAIs, injections were administered every 2 months. The baseline clinical characteristics were investigated in relation to the 12-month visual outcomes. Changes in the mean best-corrected visual acuity (BCVA) were measured at 12 months after initiation of aflibercept therapy.

Results

Forty-five eyes (41.3%) had typical neovascular AMD, and 64 eyes (58.7%) had PCV. The changes in the mean BCVA at 12 months compared with baseline did not differ significantly (P = .737) between the 2 groups. Stepwise analysis showed that larger gains in the BCVA at 12 months were associated with poor BCVA (P < .001), no pigment epithelial detachment (P = .004), and subretinal fluid (P = .039) at baseline in eyes with typical neovascular AMD; larger gains in the BCVA were associated with poorer BCVA (P < .001), presence of choroidal vascular hyperpermeability (CVH) (P = .013), and subretinal fluid (P = .044) at baseline in eyes with PCV.

Conclusions

Although poorer BCVA and the presence of subretinal fluid predicted larger gains in BCVA in both subtypes treated with aflibercept, eyes with typical neovascular AMD had greater improvement if no pigment epithelial detachment was present, while eyes with PCV had greater improvement if CVH was present.

     

Alterations in contact lens fitting parameters following cross-linking in keratoconus patients of Indian ethnicity

Background

Most studies have either excluded patients using contact lens or not taken their effect while analyzing post-collagen cross-linkage (CXL) changes. This study aims to study impact of CXL on lens fit in both quantitative and qualitative manner.

Objective

To evaluate changes in CL fit post-CXL and to correlate these changes with alterations in corneal topographic parameters.

Study design

Prospective intervention study on 20 keratoconic eyes of 14 patients (age > 18 years), with mean follow-up of 6 months.

Methods

Preoperative evaluation included UCVA, BCVA, corneal topography, AS-OCT and contact lens fit. Patients were evaluated at 2 weeks, 1, 3, 4 and 6 months post-CXL; contact lens trial with standard rigid gas permeable (RGP) lens performed at 3 and 6 months.

Main outcome measure

Changes in objective and subjective parameters of lens fit.

Results

Over 6-month follow-up post-CXL, improvement in visual acuity by one Snellen line, both UCVA and BCVA, and decrease in flat/mean/apical K by 0.8 D, 0.8 D and 1.3 D, respectively, resulted in significant improvement in RGPCL fit. Almost 20% increase in near-ideal fit, 100% acceptable fit, 65% improved subjective comfort with 8 h/day increase in duration of comfortable CL wear were observed.

Conclusion

Despite no statistically significant change in objective parameters of lens fit, a tendency for flatter lens fit along with contact lens induced further flattening of the ectatic cornea which resulted in marked improvement in both objective and subjective contact lens fit.

     

Performing corneal crosslinking under local anaesthesia in patients with Down syndrome

Purpose

To report on the ability to perform corneal crosslinking (CXL) under local anaesthesia for the treatment of keratoconus in patients with Down syndrome.

Methods

Nine eyes of seven patients with both keratoconus and Down syndrome were scheduled for an epithelium-off CXL procedure under local anaesthesia. Exclusion criteria were a corneal thickness under 400 µm and the presence of corneal scars. A standardized clinical decision tool was used to estimate patient cooperation and the likelihood for a successful procedure under local rather than general anaesthesia.

Results

In seven eyes, the CXL was completed successfully. The treatment was aborted in two eyes due to insufficient corneal thickness (<400 µm) prior to ultraviolet-A irradiation, even after employing hypoosmolar riboflavin. No adverse events occurred post-operatively, except for one case of delayed epithelial healing (23 days).

Conclusions

With a proper patient selection, CXL under local anaesthesia can be achieved in patients with Down syndrome.

     

Distribution of the anterior,posterior, and total corneal astigmatism in healthy eyes

Purpose

To evaluate the magnitude and axis orientation of the anterior, posterior, and total corneal astigmatism in normal healthy eyes of an Iranian population.

Methods

In a prospective cross-sectional study, ophthalmic and anterior segment parameters of 153 healthy eyes of 153 subjects were evaluated by Galilei dual Scheimpflug analyzer. The magnitude and axis orientation [with-the-rule (WTR), against-the-rule (ATR), and oblique] of the anterior, posterior, and total corneal astigmatism measurements (ACA, PCA, and TCA) were compared according to the age, sex, and other ophthalmic parameters.

Results

The mean ± SD age of the study population was 30 ± 5.9 years. The mean magnitude was 1.09 ± 0.76 diopters (D) for ACA, 0.30 ± 0.13 D for PCA, and 1.08 ± 0.77 D for TCA. Males had a significantly higher magnitude of PCA than females (p = 0.041). Most eyes had a WTR anterior astigmatism and an ATR posterior astigmatism. The WTR astigmatism had a higher mean magnitude compared to the ATR and oblique astigmatism in all the astigmatism groups, with a significant difference in the ACA and TCA groups (p < 0.05). PCA magnitude exceeded 0.50 D in only 7.8% of the subjects. ACA, PCA, and TCA were significantly correlated with each other and also had a significant correlation with the anterior and posterior maximum corneal elevation measurements (p < 0.001).

Conclusion

The results of this study although are limited due to the small number of participants and confined to our demographics, provided information regarding a population that was not described before and may be helpful in obtaining optimum results in astigmatism correction in refractive surgery or designing new intraocular lenses.

     

Twenty five-gauge endoscopic vitrectomy for proliferative vitreoretinopathy with severe corneal opacity

Purpose

To report 4 cases undergoing 25-gauge endoscopic vitrectomy for the treatment of proliferative vitreoretinopathy with severe corneal opacity in which a transpupillary view of the fundus was not possible.

Study Design

A retrospective interventional case series.

Methods

The main outcomes measured were postoperative anatomic status of the retina and subjective improvement of vision. Results: Postoperative reattachment of the retina and subjective improvement of vision were achieved in all 4 eyes.

Conclusion

Twenty five-gauge endoscopic vitrectomy provides a clear view making it possible conduct pars plana vitrectomy in order to reattach the retina in cases of proliferative vitreoretinopathy with severe corneal opacity.

     

Intravitreal anti-VEGF treatment for choroidal neovascularization secondary to punctate inner choroidopathy

Purpose

To assess the outcome of patients with choroidal neovascularization (CNV) secondary to punctate inner choroidopathy (PIC) receiving intravitreal anti-VEGF (vascular endothelial growth factor) injections.

Methods

Sixteen eyes of 16 patients diagnosed with CNV secondary to PIC were retrospectively assessed.

Results

Eleven women and five men with a mean age of 35 years (SD 11, range 16–56 years) received intravitreal anti-VEGF for PIC-related CNV. On average, 3.5 injections (SD 2.7, range 1–9) were given per eye. Thirteen eyes were treated with bevacizumab, two eyes with ranibizumab and one eye received both substances. The mean follow-up was 15 months (SD 11, range 6–40 months). BCVA improved in eight eyes (mean Δ +2.8 lines), remained stable in four eyes and decreased in four eyes (mean Δ ?4.3 lines).

Conclusions

CNV development is a frequent complication of PIC. Intravitreal anti-VEGF therapy seems to be safe and effective for PIC-related CNV.

     

Hornhautspende

Background

One of the most important requirements for successful corneal transplantation is the availability of donor tissue and thus the approval for postmortem corneal tissue donation. The aim of this study was to investigate donor willingness compared to the continuously increasing demand in recent years.

Material and methods

Archives of the local eye bank at the Department of Ophthalmology, University of Cologne, Germany in the time period between 1 July 2011 and 31 December 2015 were examined regarding the willingness for corneal donations in deceased patients from the University Hospital of Cologne. Absolute numbers of deceased, exclusion criteria for donation as well as the rate of negative and affirmative decisions were evaluated.

Results

In 235 (5.1?%) out of 4593 deceased at the University Hospital of Cologne, corneal donation was accomplished during the observation period. Of the patients 2923 (63.6?%) were excluded because of absolute contraindications for corneal donation and the rate of absolute contraindications increased from 46.6?% in 2011 to 68.9?% in 2015. Willingness for corneal donation in potentially suitable deceased patients diminished from 34.9?% in 2011, to 34.3?% in 2012, 35.5?% in 2013, 28.4?% in 2014 and to 24.1?% in 2015. In relation to the total number of deceased, the number of corneal tissue donations decreased from 11.5?% in 2011 to 3.5?% in 2015.

Conclusion

Despite a rising demand, data from Cologne seem to indicate that the number of corneal donations has declined to some extent. In order to increase the number of corneal donors in the future, further educational work as well as standardization and optimization of the tissue donation process seem to be urgently needed.

     

Efficacy of treat-and-extend regimen with aflibercept for pachychoroid neovasculopathy and Type 1 neovascular age-related macular degeneration

Purpose

To evaluate the efficacy of intravitreal aflibercept therapy using a treat-and-extend regimen on treatment-naïve pachychoroid neovasculopathy (PNV) and Type 1 neovascular age-related macular degeneration (AMD).

Methods

We retrospectively studied 42 eyes with PNV and 60 eyes with Type 1 neovascular AMD. We assessed best-corrected visual acuity (BCVA), central macular thickness (CMT), central choroidal thickness (CCT), and total number of injections over 2 years.

Results

The BCVA and CMT improvements during the 2-year treatment period did not differ significantly between PNV and AMD; however, CCT decreased significantly in PNV than in AMD (P<0.05). Management of PNV required significantly fewer injections than AMD during the 2-year period (P<0.05). There were no significant differences in BCVA, CMT and CCT changes between PNV with and without polypoidal lesions (28 vs. 14 eyes) during the 2 year period. Significantly fewer injections were needed for PNV with polypoidal lesions than for PNV without (P<0.01). There were no significant differences in BCVA, CMT and CCT changes, or in the number of injections during the 2-year treatment period, between AMD with and without polypoidal lesions (30 vs. 30 eyes).

Conclusion

Treat-and-extend regimen of intravitreal aflibercept injection may be equally effective in terms of improvement of BCVA and exudative changes both in eyes with PNV and those with Type 1 neovascular AMD requiring fewer injections for the former. Among eyes with PNV, those with polypoidal lesions needed fewer injections than those without polypoidal lesions.

     

Intraobserver and interobserver repeatability of ocular components measurement in cataract eyes using a new optical low coherence reflectometer

Background

The purpose of the study was to assess intraobserver and interobserver repeatability of eight ocular components measurement in cataract eyes using the optical low-coherence reflectometer Lenstar LS 900®.

Methods

Five consecutive measurements of ocular components were taken by two examiners using the Lenstar. Components analyzed were: central corneal thickness, lens thickness, anterior chamber depth, axial length, retinal thickness, keratometry, white-to-white distance, and pupillometry. Within-subject standard deviation and the coefficient of variation were calculated for evaluation of intraobserver repeatability. Bland–Altman analysis was used for assessment of interobserver repeatability.

Results

Thirty-two eyes of 22 patients were included. For both observers, the smallest intraobserver coefficient of variation was obtained for axial length, while the largest was found for corneal steepest meridian position. Interobserver repeatability demonstrated less repeatable results for white-to-white distance and corneal steepest meridian position. Considering axial length and anterior chamber depth values, predicted refractive error was 0?±?0.05 D and 0.02?±?0.19 D respectively in 95% of observations.

Conclusion

The Lenstar LS 900® evidenced excellent repeatability and observers´ independent results of all components analyzed except white-to-white distance and corneal steepest meridian position measurements. To the best of our knowledge, this is the first study on interobserver repeatability of optical low-coherence reflectometry in cataract eyes.

     

Thermal imaging of corneal transplant rejection

Purpose

Corneal transplant rejection is one of the most frequent complications, with a reported incidence of 16–30%. In our current research, we investigated the use of infrared thermography to detect ocular surface temperature. We also looked at a case of corneal transplant rejection and this case had an elevated ocular surface temperature when compared to the contralateral eye and other eyes without corneal transplant rejection.

Methods

Twenty-three eyes of twelve patients would serve as control to one eye with clinically evident corneal transplant graft rejection. A Flir T400 320 × 240 pixel, digital thermal camera was used to take a digital photograph and an infrared photograph of each eye. The images were analyzed with the Flir web viewer.

Results

We present here a case of corneal transplant rejection documented with both slit lamp photos as well as infrared and corneal surface photos. The studied patient’s unaffected eye, and the control group’s trends did indeed bring the expected results and proved thermal imagery in this particular field a viable examination method.

Conclusions

We feel that ocular thermography is a useful adjunctive diagnostic tool and that it may be useful to monitor routine corneal transplant patients. Further research into the temperature changes of corneal transplant patients is needed and may allow for earlier intervention for graft rejection.

     

Evaluation of corneal biomechanics in patients with keratectasia following LASIK using dynamic Scheimpflug analyzer

Purpose

To investigate the corneal biomechanics in eyes with keratectasia following LASIK using a dynamic Scheimpflug analyzer.

Design

Case–Control study.

Method

The subjects in the study included 12 eyes with keratectasia after LASIK (KE), 24 eyes with keratoconus (KC), 17 eyes without keratectasia after LASIK (LASIK), and 34 eyes with normal corneas (Normal). Corneal biomechanics of the four groups were evaluated using a dynamic Scheimpflug analyzer.

Results

Compared with Normal (7.06?±?0.54), the radius at the highest concavity (radius, mm) of LASIK (5.96?±?0.76), KE (4.93?±?0.61) and KC (5.39?±?1.02) were significantly small. The Deflection Amplitude (HCDLA, mm) of Normal (0.94?±?0.07) was significantly lower than those of KE (1.11?±?0.10) and KC (1.06?±?0.16), and was not significantly different from that of LASIK (0.98?±?0.07). There were significant differences between LASIK and KE in radius and HCDLA (P?<?0.05), whereas KE and KC had no differences in these parameters.

Conclusions

Corneal biomechanical features evaluated using the dynamic Scheimpflug analyzer suggest that biomechanical properties in eyes with keratectasia, keratoconus, and LASIK are different from those of normal eyes. Although the biomechanics in eyes with keratectasia differs from that in eyes with LASIK, it is similar to that in eyes with keratoconus.

     

Corneal crosslinking for keratoconus in Japanese populations: one year outcomes and a comparison between conventional and accelerated procedures

Purpose

We retrospectively investigated the efficacy of corneal crosslinking (CXL) on progressive keratoconus in a Japanese population and compared the outcomes of conventional and accelerated CXL.

Study design

A retrospective cohort study

Methods

A total of 108 consecutive eyes in 95 patients (75 men; 21.9 ± 6.2 years) with progressive keratoconus were enrolled. The epithelium was ablated in all eyes. After presoaking the corneal stroma in riboflavin, UV-A was irradiated at 3.0 mW/cm² (conventional CXL) for 30 min on 23 eyes and 18.0 mW/cm² for 5 min (accelerated CXL) on 85 eyes. Best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometric value, corneal thickness, corneal endothelial cell density (ECD), intraocular pressure, and complications were evaluated at 1, 3, 6, and 12 months after the procedure.

Results

BSCVA, manifest refraction, ECD, and corneal thickness did not change significantly after both procedures. The keratometric value was significantly decreased from the preoperative value at 12 months (p < 0.001). Progression to more than 1.0 D after CXL was observed in 10 eyes (9.3%). The ΔKmax was negatively associated with preoperative Kmax (p < 0.001) and positively associated with preoperative thinnest corneal thickness (p < 0.001). Both treatment modules showed no significant difference in all parameters.

Conclusion

CXL was as effective in treating keratoconus in Japanese patients as in individuals of other ethnicities. Overall, CXL could be performed using either the conventional or accelerated approach to halt the progression of keratoconus in Japanese populations.