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1.
《Contact lens & anterior eye》2019,42(3):289-294
ObjectivesTo evaluate the clinical performance and predictability using corneal topography in the fitting of a new large-diameter rigid gas permeable (RGP) contact lens design in eyes with keratoconus (KCN).MethodsThis study presents a review of eyes fitted with Alexa ES lenses for nonsurgical optimisation of visual correction. Anterior steep simulated keratometry (sim-K steep), corneal diameter (HVID), the Curvature at the apex in diopters (Cc), and distance from the corneal apex to the centre of the cornea (Lc) in millimetres derived from the Cone Location and Magnitude Index (CLMI) were recorded. Visual acuity, mean wearing time, final sagittal depth and adverse events were also recorded. Correlations between topographic indices and base curve were evaluated using the Pearson correlation coefficient.ResultsForty-six eyes from 26 patients (19 males/ 7 females) were included. Mean visual acuity improved from 0.49 ± 0.32 with glasses, to -0.02 ± 0.10 with the contact lens. The mean daily wear time was 12.19 ± 1.96 hours. No complications were detected in 95.65% of the eyes [95% CI (83.9%-99.2%)] but two episodes of non-infectious keratitis. The average sagittal depth of the lenses fitted was 0.425 ± 0.15 mm, and it was positively correlated with the Cc value (r² = 0.66, p< 0.0001, n=46) derived from the CLMI index of the pre-fitting topography.ConclusionsCorneoscleral RGP contact lenses are a safe, and effective alternative for managing KCN patients to corneal lenses. Also, clinical data derived from the corneal topography could be used to help to decide the first diagnostic lens to be assessed, easing the overall fitting process. 相似文献
2.
《Contact lens & anterior eye》2014,37(4):267-272
AimTo investigate whether cosmetic contact lenses (CCL) with surface pigments affect microbial adherence.MethodFifteen brands of CCL were purchased from optical, non-optical retail outlets, and via the Internet. A standardized rub-off test was performed on each CCL (five lenses per brand) to confirm the location of the pigments. The rub-off test comprised gentle rubbing on the surfaces of each CCL with wetted cotton buds for a maximum of 20 rubs per surface. A new set of CCL (five lenses per brand) were incubated in Pseudomonas aeruginosa overnight. Viable counts of adhered bacteria were determined by the number of colony-forming units (CFU) on agar media on each lens. The adherence of P. aeruginosa as well as Staphylococcus aureus and Serratia marcescens to three brands of CCL (A–C) (five lenses per brand) were also compared to their adherences on their clear counterparts.ResultsOnly two of the 15 brands of CCL tested (brands B and C) had pigments that did not detach with the rub-off test. The remaining 13 brands of CCL all failed the rub-off test and these lenses showed higher P. aeruginosa adherence (8.7 × 105–1.9 × 106 CFU/lens). Brands B and C lenses showed at least six times less bacterial adhesion than the other 13 brands. Compared to their clear counterparts, bacterial adherence to brands B and C lenses did not differ significantly, whereas brand A lenses showed significantly higher adherence.ConclusionSurface pigments on CCL resulted in significantly higher bacterial adherence. 相似文献
3.
《Contact lens & anterior eye》2019,42(5):540-545
Purpose: To compare the effectiveness of a modified and previous fitting guide for multifocal (MF) contact lenses that share a common optical design, lotrafilcon B, nelfilcon A, and delefilcon A, in current soft contact lens (CL) wearers needing presbyopia correction.Methods: This international multicenter, prospective, randomized, subject-masked study assessed the superiority of the modified guide relative to the previous guide as determined by the number of MF CLs needed to successfully fit each eye at the screening/fitting visit.Results: A total of 183 presbyopic subjects were randomized to fitting using the modified (n = 99) and previous (n = 84) MF CL fitting guides. The mean ± SD numbers of lenses required to fit each eye at the screening/fitting visit using the modified and previous fitting guides were 1.2 ± 0.5 and 1.4 ± 0.5, respectively. The least-squares mean difference (0.2) met predetermined criteria for superiority of the modified fitting guide. At the screening/fitting visit, 82.8% (164/108) and 65.1% (105/166) of presbyopic eyes were fit with one pair of MF lenses using the modified and previous guides, respectively, and 98.0% (194/198) of eyes were fit with 1–2 pairs of MF lenses using the modified guide. A higher percentage of eye care practitioners gave the highest ratings for ease of fit for the modified than for the previous fitting guide (63.6% [7/11] vs 33.3% [3/9]).Conclusions: The modified fitting guide was superior at reducing the number of MF lenses required to successfully fit each presbyopic patient. 相似文献
4.
Keratoconus is a bilateral degenerative disease characterized by a non-inflammatory, progressive central corneal ectasia (typically asymmetric) and decreased vision. In its early stages it may be managed with spectacles and soft contact lenses but more commonly it is managed with rigid contact lenses. In advanced stages, when contact lenses can no longer be fit, have become intolerable, or corneal damage is severe, a penetrating keratoplasty is commonly performed. Alternative surgical techniques, such as the use of intra-stromal corneal ring segments (INTACS) have been developed to try and improve the fit of rigid contact lenses in keratoconic patients and avoid penetrating keratoplasties. This case report follows through the fitting of rigid contact lenses in an advanced keratoconic cornea after an INTACS procedure and discusses clinical findings, treatment options, and the use of mini-scleral and scleral lens designs as they relate to the challenges encountered in managing such a patient. Mini-scleral and scleral lenses are relatively easy to fit, and can be of benefit to many patients, including advanced keratoconic patients, post-INTAC patients and post-penetrating keratoplasty patients. 相似文献
5.
The performance and benefits as well as the risks and complications of disposable soft lenses (single use disposable or re-used 2-4 weeks) are reviewed in relation to corneal physiology. Modern designs and advanced technology have resulted in disposable lenses providing excellent visual performance. Fewer subjective symptoms (e.g. dryness and grittiness), slit-lamp findings (such as injection and tarsal abnormalities), and inflammatory responses (papillary conjunctivitis; contact lens-induced acute red eye) have been reported with disposable lenses than with conventional soft lenses. The risk of contact lens-induced keratitis (CLIK) has been reported to be higher for daily wear of disposable lenses than for other lens types by UK investigators. Other studies have shown the risk of CLIK with disposable lenses to be equal to that with conventional soft lenses, and in two extensive Swedish studies, the incidence of severe keratitis was found to be significantly lower for daily wear (DW) of disposable lenses than for DW of conventional soft and rigid gas permeable lenses. Both the total complication rate and the number of unscheduled visits are found to be significantly lower for disposable lenses than for conventional soft lenses in several studies. Comfort has been reported to be significantly better and overall satisfaction significantly greater with disposable lenses than with conventional soft lenses according to many studies. These may be important reasons why the success rate for disposable lens wear is reported to be fairly high, generally 70-90%. The importance of appropriate care for 're-usable disposable lenses' must be stressed. One day disposable lenses, if used as directed, will eliminate the risk factors of inadequate cleaning and disinfection as well as contaminated lens cases. 相似文献
6.
Purpose
To report the symptoms and experiences associated with habitual hydrogel (Hyd) and silicone hydrogel (SiHy) contact lenses (CLs) among young adults and measure their association with age.Methods
Questionnaire responses from 699 Hyd and 183 SiHy wearers were analyzed to test the association of age with features indicating struggle with CL wear. Prevalence by age was compared between groups with Pearson's chi-square and within groups with Spearman's correlation coefficient.Results
Hyd and SiHy groups were similar for sex and age distribution. Diagnosis of dry eye increased with age in the Hyd wearers from 10.6% to 21.1% (18-24 vs. 30-35 years), but was approximately 19% in the SiHy wearers across age. Adverse environments caused more discomfort with Hyd than SiHy lenses and Hyd wearers’ discomfort increased with age (smoky (p = 0.0001), dry air environments (p = 0.002), after napping or sleeping (p = 0.004). More Hyd wearers considered discontinuation of CL wear with age, from 4.6% to 14.2% (18-24 vs. 30-35 years, p < 0.04), but the proportion remained steady at 9% across age for SiHy wearers (p = 0.46).Conclusions
From 18 to 35 years, hydrogel CL wearers reported increasing struggle with CL wear and more negative ratings compared to SiHy wearers. Older hydrogel CL wearers were also more likely to consider discontinuing CL wear compared with younger hydrogel or silicone hydrogel CL wearers in general. Young adult CL wearers should be routinely queried directly about specific aspects of CL wear in order to determine whether different lens types should be prescribed to avoid abandonment of CL wear. 相似文献7.
《Contact lens & anterior eye》2020,43(6):543-552
PurposeTo compare the comfort and visual performance of corneal rigid gas permeable contact lenses (CoL) and scleral rigid gas permeable contact lenses (SL) in participants with corneal ectasia, successfully wearing “habitual” CoL.MethodsIn a randomised controlled trial (RCT) with a 2 × 2 crossover, 34 participants were recruited and randomised into two groups. Group 1 (sequence AB), were fitted in period 1, with new CoL and after a 4-week washout period, in which habitual CoL were worn, were fitted with and crossed-over to SL, period 2. Group 2 (sequence BA), were first fitted with SL in period 1 and after a washout period of 4 weeks, crossed-over to new CoL, period 2. The median lengths in weeks of Periods 1 and 2 were: 17.5 (IQR 12.4) and 14.5 (IQR 6.2) respectively. The outcome measures for visual performance were best corrected visual acuity and the contrast sensitivity function. Vision related quality of life (Qol) was assessed using the National Eye Institute Visual Function Questioannaire-25 and reported subjective perception of vision (SPV) and reported subjective perception of comfort (SPC) scores, recorded on a scale from 1–10. The final outcome measure was the selection of the preferred lens type at the completion of the RCT.ResultsFor the 30 who completed the trial, significantly higher SPC scores were found for SL compared to CoL (p = 0.002). Significantly higher SPC scores for CoL were found in participants who selected CoL as their preferred lens for future use, compared to those who selected SL (p = 0.009). All other outcomes exhibited no significant difference between the experimental lenses. There was no significant difference (p=0.86) in the proportion preferring CoL (53%) and SL (47%).ConclusionSignificantly better comfort was reported for SL compared with CoL. Significantly higher comfort in CoL was found in those who preferred CoL, than those who preferred SL. Successful CoL wearers whose SPC in CoL is <7 are likely to achieve better comfort with SL. On average, successful CoL wearers found SL more comfortable and there are unlikely to be any significant visual or visual Qol advantage or disadvantage in refitting successful CoL wearers with keratoconus and other corneal ectasia disorders, with SL and vice versa. 相似文献
8.
《Contact lens & anterior eye》2022,45(5):101594
PurposeThe aim of this study was to evaluate the types of contact lenses fitted by hospital optometrists within the Midlands region of the United Kingdom (UK).MethodA questionnaire was sent to all the lead optometrists of the Midlands Hospital Optometry Group (MHOG). This group includes optometry hospital eye departments within the Midlands region of the UK. The questionnaire requested information of their last ten contact lens fitting appointments. Details of the patient’s age, gender, lens type, wearing times, and presenting condition were retrospectively taken from the patients’ records using the appointment diary to identify the last ten patients fitted with contact lenses.ResultsDetails from a total of 109 contact lens fits were collected. This included 45 females and 64 males with a mean age of 39.4 ± 17.4 years. The mean wearing time was 6.3 ± 1.0 days per week and 10.7 ± 5.1 h per day. Sixty-one percent of the contact lenses fitted were for patients with keratoconus and over half of all the contact lenses fitted were corneal rigid gas permeable lenses.ConclusionThis study highlighted that the main reason for fitting contact lenses in hospital contact lens practice is primary corneal ectasia, and mainly keratoconus. Whilst most patients with keratoconus were fitted with corneal rigid gas permeable contact lenses, around 1 in 6 were fitted with soft contact lenses. This study addresses a gap in the literature about contact lenses fitted in UK hospitals and how they differ from community contact lens practice. 相似文献
9.
《Contact lens & anterior eye》2022,45(4):101472
PurposeAs presbyopia occurs, new visual demands create a need for clear vision at multiple distances. Many spectacle wearers adapt into progressive addition lenses (PAL) in order to see clearly at distance, intermediate, and near. A multifocal contact lens provides the ability to see at these same distances without the prismatic effects of a spectacle lens or the peripheral obstruction of a spectacle frame. No studies have been done to date comparing the effect of these types of presbyopic vision correction on a variety of tests of visual performance representative of everyday tasks.MethodsA battery of visual performance tasks were completed by subjects while wearing their habitual PAL spectacles. These subjects were then fit with a multifocal contact lens and wore lenses for 2 weeks or more before completing the tasks again. These functional vision tests included assessments of coincidence anticipation timing, peripheral search and hand-eye coordination, and dynamic visual acuity. Following functional vision testing, subjects completed a preference survey comparing both types of refractive correction while performing common activities of daily living.ResultsPerformance on the majority of the tests of visual performance were equivalent (P < 0.05) when comparing PAL spectacles and multifocal contact lenses. Survey results demonstrated a preference for multifocal contact lenses overall.ConclusionPAL spectacles are widely prescribed for presbyopic patients. The findings of this study suggest that in addition to providing excellent vision, multifocal contact lenses provide functional vision performance equal to PAL spectacle wear and patients may prefer them over PAL spectacles. 相似文献
10.
Improving your spectacle patients’ in-practice experience with contact lenses during frame selection
《Contact lens & anterior eye》2019,42(4):406-410
PurposeA market research survey was conducted to assess the impact of offering complimentary contact lenses (CLs) to spectacle-only wearing patients during frame selection with regards to their in-office experience, the transaction amount for their eyewear purchase and the likelihood of proceeding with a comprehensive contact lens fitting.MethodsFive optometry offices in the US participated. An initial interviewing phase served as a control during which optometrists treated spectacle-only wearing patients in the usual manner for frame selection. After this, the offices transitioned into a test phase where patients were offered the opportunity to wear CLs while selecting new spectacle frames. Only patients 18 or older who had not expressed an interest in CLs were invited to participate. A brief survey was completed on an iPad following the visit by all patients in both control and test phases.Results410 patients (205 test, 205 control) participated. 63% of the test group elected to wear CLs (40% spherical, 20% toric, 35% multifocal, 5% monovision). Patients wearing CLs spent more on their eyewear purchase ($708 vs $593, p = 0.04), were greater than 2.5X more likely to have received or scheduled a CL fit (p = 0.01), and were greater than 3X more likely to consider scheduling a CL fitting in the future (p = 0.0003). Additionally, 93% reported that they were highly satisfied with the experience and 86% said they would wear CLs to select frames again (86%).ConclusionsOffering CLs to spectacle-only patients positively impacts eyewear selection and purchase and can grow the overall CL business. 相似文献
11.
《Contact lens & anterior eye》2022,45(6):101599
PurposeContact lenses offer a good option for patients with presbyopia, especially with improved optical designs available in modern multifocal contact lenses. Due to the ageing population there is good opportunity to increase contact lens penetration by managing these patients better. However, multifocal contact lenses achieve low penetration in the market.MethodsA questionnaire was administered to people aged above 40 years, to investigate their perceptions of contact lenses for presbyopia. Only people, with presbyopia, who were existing contact lens wearers or willing to try contact lenses were included. Participants were recruited from United Kingdom (UK), United States of America (USA), Netherlands, Germany, France, Spain and Italy.ResultsData from 1540 participants above the age of 40 years was collected, 57.9% were females and 42.1% males. Overall, 50.8% of the participants wore contact lenses, but contact lens wear was less common amongst older participants. Some data supported earlier studies, such as 6.1% wore gas permeable lenses. However, only 25% of the contact lens wearers used multifocal contact lenses. The reasons the participants wanted to wear contact lenses were similar to younger patient such as sports or cosmesis reasons. Reasons why participants had dropped out of contact lenses included discomfort and dry eye related issues. Poor visual performance with contact lenses was a reason to dropout of contact lenses for the older participants.ConclusionsThe study highlights some failings by eye care practitioners in the management of patients with presbyopia. It seems that patients of this age group are seeking suggestions and recommendations from their eye care practitioner including upgrading contact lenses and dual wear options. The day-to-day problems encountered by the contact lens wearers in this study seem to be, in the main, things that could be easily tackled by additional counselling and instruction from the eye care practitioners. 相似文献
12.
《Contact lens & anterior eye》2022,45(4):101493
PurposeThe purpose of this study was to compare sign identification distances and driving performance metrics in presbyopic participants while wearing multifocal contact lenses (MFCL) and while wearing progressive addition lens (PAL) spectacles.Methods19 presbyopic participants completed PAL spectacle assessments and contact lens fitting and follow up visits before driving assessments began. These assessments occurred in a simulator equipped with a full-sized sedan on a motion platform and a 260 degree screen. Participants completed the driving task with PAL and with MFCL. Participants followed a lead car and identified signs at various distances from the road. For the two wearing conditions, comparisons of the distance along the road at which signs were identified were made using repeated measures ANOVA. Paired t-tests were used to compare driving performance for the two conditions.ResultsThere was no statistical difference in sign identification distance between PAL and MFLC for signs 32.0 m from the road side of the road (182 ± 46 m for MFCL; 205 ± 45 m for PAL; P = 0.07) or 51.4 m from the side of the road (204 ± 43 m for MFCL; 216 ± 36 m for PAL; P = 0.3). Only signs 70.2 m from the roadside showed a significant difference (207 ± 42 m with MFCL; 232 ± 39 m with PAL; P = 0.01), All distances were greater than those required to safely stop a vehicle. There were no significant differences in the driving performance metrics between the refractive corrections.ConclusionDriving performance metrics were similar for MFCL and PAL spectacles. Sign identification distances with both eyewear types were well within the distances required for safe vehicle stopping. 相似文献
13.
《Contact lens & anterior eye》2020,43(4):322-332
Overnight orthokeratology lenses are approved in countries all over the world for the temporary reduction in myopia, and recently, one lens design has received regulatory approval for myopia control in Europe. The modern orthokeratology lens has a substantial history from its origins of attempting to flatten the corneal curvature with a spherical rigid contact lens to sophisticated gas permeable lenses, designed to reshape the cornea. These lenses are predominantly prescribed for children to slow myopia progression and limit axial elongation of the eye. This article reviews the peer-reviewed literature on the efficacy of orthokeratology for myopia control, sustainability after treatment is discontinued, and the safety concerns of overnight contact lens wear. Future avenues of research are discussed. 相似文献
14.
15.
Purpose
To explore the safety profile and overall visual improvement over the course of RGP contact lens wear on children with unilateral or bilateral amblyopia resulting from myopia.Methods
This was a retrospective analysis case series study. Clinical records of 15 patients who were fitted with RGP contact lenses at the Shanghai Eye and EENT Hospital of Fudan University between the period of January 2009 to December 2014 were reviewed. The inclusion criteria for review included patients with myopia of ?3.00DS or greater in one or both eyes and an initial best-corrected visual acuity (BCVA) of logMAR 0.4 or worse for 3 year olds, and logMAR 0.3 or worse for 4 years old and above. One or both myopic eyes were fitted with RGP lenses.Results
15 subjects and 22 amblyopic eyes were included. The mean baseline BCVA was logMAR 0.70 ± 0.38, which improved to a VA of 0.23 ± 0.28 at the time of review (p < 0.05). Baseline myopia also increased from ?8.18 ± 2.93DS to ?11.41 ± 3.76DS (p < 0.05). The final visual acuity at the time of this review was correlated with the initial refractive error (r = ?0.695, p < 0.05) as well as the initial BCVA (r = 0.854, p < 0.05). There was also a strong correlation between initial refractive error and initial BCVA (r = 0.?801, p < 0.05)Conclusion
RGP contact lens wear is a safe and effective refractive treatment option in young children with amblyopia due to myopia. 相似文献16.
《Contact lens & anterior eye》2019,42(5):512-519
Therapeutic contact lenses were developed from bacterial cellulose (BC) by the Institute of Chemistry at Brazil’s São Paulo State University (UNESP). In a previous study, cyclodextrins (CD) and medications such as ciprofloxacin (CP) and diclofenac sodium (DS) were incorporated into the lenses to provide therapeutic properties and control drug release. However, significant opacity was seen in the material inherent to cellulose. In order to achieve full material transparency, the lenses were coated with an organic-inorganic hybrid compound containing aluminum alkoxide and glycidoxypropyltrimethoxysilane (GPTS)(H), or chitosan (Q) nanoparticles. This study evaluated the toxicity of these contact lenses to ensure the safety of these materials for future availability to the medical device industry. Lenses composed of BC and coated with either GPTS (H) or chitosan (Q), incorporating ciclodextrin (CD) to release diclofenac sodium (DS) or ciprofloxacin (CP), were submitted to cytotoxicity assays (XTT and Clonogenic Survival), genotoxicity (Comet Assay) and mutagenicity (Cytokinesis-blocked micronucleus assay) directly in cell culture. Statistical analyses were performed using the Tukey and Dunnett or Kruskal-Wallis and Dunn tests. All of the nanoparticles used in the lense coatings did not show cytotoxic effects by the XTT test (p > 0.05; Dunnett). Only materials associated with diclofenac sodium (BC-H-CD-DS and BC-Q-CD-DS) presented significantly different survival fractions compared to negative control (p < 0.001; Dunnett). Genotoxicity evaluation revealed a genotoxic effect in BC-H-CD-DS (p < 0.05; Dunn). All tested lenses did not present any mutagenic effect. These results indicate that improvements in DS incorporation are needed to eliminate toxicity. We demonstrated promising results in the safety of employing BC lenses functionalized with a drug delivery system permitting the bioavailability of ophthalmic drugs. Further studies utilizing other specific tests, such as corneal lineage are required before safe and efficient ophthalmologic use. 相似文献
17.
《Contact lens & anterior eye》2020,43(2):130-136
PurposeTo study the light distortion effects of soft multifocal contact lenses and the influence of different pupil size and shape.MethodsA total of 14 eyes of 7 healthy contact lens users (mean age 28.6 ± 8.5 years) were recruited. The “Light Disturbance Analyser” device was employed for light characterization. The selected lenses were the monthly disposable “Biofinity multifocal” (CooperVision, CA, USA), both centre-distance and centre-near designs (addition power +2.50 D). Two circular pupils of 3 mm and 5 mm of diameter, and an elliptical shape (3 horizontal and 5 vertical mm) were used. Metrics such as the light distortion index (LDI), best-fit circle radius and its irregularity were analysed, among others.ResultsThe LDI was generally higher with multifocal lenses, varying from 3.7 ± 0.3 % of the single vision lens to 6.1 ± 3.3 % of the multifocal centre-distance design and the 5-mm pupil. Larger pupils gave higher LDI values, changing from 4.5 ± 2.0 % (3 mm) to 6.1 ± 3.3 % (5 mm) with the centre-distance design. The elliptical pupil produced the largest discrepancy in the distortion size between the vertical and horizontal directions. The centre-distance and centre-near designs behaved similarly in terms of light distortion.ConclusionsThe multifocal contact lenses of the study increased light distortion effects under low light conditions, especially with larger pupils. The shape of the distortion pattern is associated with the shape of the pupil. It seems that not all, but a big percentage of light distortion would be produced by the presence of the out-of-focus images given by a multifocal lens. 相似文献
18.
《Contact lens & anterior eye》2019,42(2):200-205
PurposeTo evaluate the perception of light disturbances (LD) in children wearing Dual Focus (DF) MiSight® contact lenses (CLs) for myopia control compared with children wearing single vision spectacles (SV).MethodsThis was a randomized, controlled clinical trial involving subjects aged 8–12 with myopia of -0.75 to -4.00D and astigmatism <1.00D allocated to MiSight® study CLs group or control group wearing SV. LD was determined at baseline, 12 and 24 months visit with a validated device, Light Disturbance Analyzer (LDA) to determine the shape, size and regularity of the LD phenomena with parameters of Light Disturbance Index (LDI) Best Fit Circle (BFC) and Standard Deviation between LD and BFC (BFCIrreg.SD).Results74 children completed the study, 41 in the CL group and 33 in the SV group. SV group didn´t show any significant differences between monocular and binocular LD measurements throughout the study. Binocular BFCRadius was smaller at 24 months visit compared with 12 month visit (p < 0.05) and for BFCIrreg.SD was significantly smaller at 24 month visit compared with baseline (p < 0.05). In MiSight® group, binocular and monocular LDI, BFCRadius and BFCIrreg.SD measurements didn’t show any significant change between 12 and 24 month visits (p > 0.05). However, monocular BFCIrreg. as well as monocular and binocular BFCIrreg.SD showed a significant decrease at 24 month visit compared with 12 month visit.ConclusionsDF lenses increase the monocular light disturbance perception compared with a single vision spectacle correction. However, this effect decreased over the follow-up time and presented a significant binocular attenuation effect. 相似文献
19.
《Contact lens & anterior eye》2021,44(3):101333
PurposeTo investigate the current patterns of diagnosis and referral in keratoconus.MethodsA retrospective chart review was performed of patients who had recently been diagnosed with keratoconus and attended dedicated clinics at Antwerp University Hospital, Belgium and Maria Middelares General Hospital, Ghent, Belgium between June 2013 and February 2018. Exclusion criteria included longstanding keratoconus diagnosis, reduced cognitive capabilities and prior surgical procedures (corneal crosslinking, penetrating keratoplasty or any type of refractive surgery).ResultsThree-hundred and ninety-nine patients (722 eyes) were included in this study. The mean age was 24.7 ± 6.5 years and the average maximal keratometry was 51 ± 5.2 D for the better eye and 58.4 ± 9.6 D for the worse eye. Upon diagnosis, 233 eyes (32.2 %) and 51 eyes (7.1 %) had a thinnest pachymetry <450 and <400 μm, respectively. At 6-month follow-up, 58 % of patients had been fitted with specialty contact lenses. During follow-up, 199 eyes (27.6 %) underwent corneal crosslinking. One patient underwent corneal graft surgery of his worse eye due to contact lens intolerance and insufficient visual acuity.ConclusionDespite advances in diagnostic tools, keratoconus is often diagnosed at a relatively late stage. Earlier detection of keratoconus would increase the overall clinical benefit of corneal crosslinking. Further research into screening strategies is required to develop cost-effective screening programs. 相似文献
20.
《Contact lens & anterior eye》2020,43(5):493-496
PurposeAccommodative micro-fluctuations (AMF) are small dioptric changes during accommodation. The aim of this study was to evaluate and compare changes in AMF when wearing silicone hydrogel contact lenses of two different optical designs.MethodsA multi-centre, randomised, cross-over, non-dispensing study was conducted on 68 adapted contact lens wearers aged 25–35 years to compare AMF responses to a spherical and aspheric silicone hydrogel (comfilcon A) lens designs. A Righton Speedy “i” series Auto Refractometer in accommodation analyser mode was utilized before and after reading a standard text in font size 8 on an iPhone 5 for 20 min at a 25 cm viewing distance. Phone screen brightness was set by automatic adjustment mode and ambient illumination was controlled at all sites.ResultsMean ± SD AMF change from before to after the reading task was 2.25 ± 5.6 and 0.13 ± 5.7 (relative values) for the spherical and aspheric lens designs, respectively. The difference was statistically significant (P = 0.017, Paired t-test).ConclusionsThe smaller change in AMF when using an aspheric lens design suggests reduced ciliary muscle stress when reading print on a smart phone at a close distance for short periods (20 min). Contact lens wearers who frequently use digital devices and are experiencing eye strain may benefit from switching from a spherical design to one that incorporates aspheric optics. 相似文献