The refractive outcome of Toric Lentis Mplus implant in cataract surgery

AIM： To evaluate the refractive outcome of Toric Lentis Mplus intraocular lens（IOL） implant.· METHODS： This is a retrospective case series.Consecutive patients with corneal astigmatism of at least1.5 D had Toric Lentis Mplus IOL implant during cataract surgery. The exclusion criteria included irregular astigmatism on corneal topography, large scotopic pupil diameter（〉6 mm）, poor visual potential and significant ocular comorbidity. Postoperative manifest refraction,uncorrected distance visual acuity（UDVA）, best-corrected distance visual acuity（BCVA）, uncorrected intermediate visual acuity at（UIVA） 3/4 m and uncorrected near visual acuity（UNVA） were obtained.·RESULTS： There were 70 eyes from 49 patients in this study. Patients were refracted at a median of 8.9wk（range 4.0 to 15.5） from the operation date. Sixty-five percent of eyes had 6/7.5（0.10 log MAR） or better, and99% 6/12（0.30 log MAR） or better postoperative UDVA.Eighty-nine percent could read Jaeger（J） 3（0.28 log MAR）and 95% J5（0.37 log MAR） at 40 cm. The median magnitude of astigmatism decreased from 1.91 D to 0.49 D（Wilcoxon, P〈0.001） after the operation. The range of the cylindrical error was reduced from 1.5-3.95 D（keratometric） preoperatively to 0.00-1.46 D（subjective refraction transposed to corneal plane） postoperatively.· CONCLUSION： Toric Lentis Mplus IOL has good predictability in reducing preexisting corneal astigmatism.

Standard manual capsulorhexis / Ultrasound phacoemulsification compared to femtosecond laser-assisted capsulorhexis and lens fragmentation in clear cornea small incision cataract surgery

Background:Femtosecond-laser assisted clear cornea cataract surgery may hold promise in safer and more effective procedures.We decided to perform a comparative study to standard manual incision phacoemulsification surgery.Methods:This is a single-center,single-intervention,and prospective comparative data evaluation of 133 consecutive cases subjected to cataract surgery.Group-A(Phaco),manual capsulorhexis&ultrasound phacoemulsification(n=66);Group-B femtosecond-laser assisted capsulorhexis and lens fragmentation(n=67),employing the LenSx laser(Alcon Surgical,Ft.Worth,TX).All cases were evaluated for refraction,visual acuity,keratometry,tomography,pachymetry,endothelial cell counts,intraocular pressure,and type of intraocular lens(IOL)implanted.The groups were matched for age,gender,pre-operative vision metrics,and cataract grade,and were followed up to 1 year.Results:In group-A post-operative uncorrected distance visual acuity(UDVA)was 20/20 or better in 61.5%and 20/25 or better in 78.5%of the eyes.The femtosecond laser group-B had improved outcomes(p=0.075 and p=0.042,respectively):post-operative UDVA was 20/20 or better in 62.7%of the eyes and 20/25 or better in 85.1%.Linear regression scatterplots of achieved versus attempted spherical equivalent had excellent regression coefficients(r^(2)=0.983 in group-A and 0.979 in group-B).There were 75.2%cases in group-A and 80.6%in group-B(p=0.8732)within±0.50 D of targeted refractive equivalent.Slight trend of under-correction was noted in group-A.Average residual manifest cylinder in the toric subgroup-A was-0.50 D(95%Limit-of-Agreement(LoA)=-0.78 D),and in toric subgroup-B-0.45 D(LoA=-0.45 D).Conclusions:Mean spherical equivalent refraction and visual acuity are comparable with laser cataract surgery compared with manual capsulorhexis&ultrasound phacoemulsification.Improved astigmatism correction may be among the benefits of femtosecond laser–assisted cataract surgery.Transient corneal edema may be a first day transient disadvantage in femtosecond laser–assisted cataract surgery.

The art of nomograms

Background:To retrospectively analyse strategies for adjusting refractive surgery plans with reference to the preoperative manifest refraction.Methods:We constructed seven nomograms based on the refractive outcomes(sphere,cylinder,axis[SCA])of 150 consecutive eyes treated with laser in situ keratomileusis for myopic astigmatism.We limited the initial data to the SCA of the manifest refraction.All nomograms were based on the strategy:if for x diopters(D)of attempted metric,y D is achieved;we can reverse this sentence and state for achieving y D of change in the metric,x D will be planned.The effects of the use of plus or minus astigmatism notation,spherical equivalent,sphere,principal meridians notation,cardinal and oblique astigmatism,and astigmatic axis were incorporated.Results:All nomograms detected subtle differences in the spherical component(p<0.0001).Nomograms 5 and 7(using power vectors)and 6(considering axis shifts)detected significant astigmatic differences(nomogram 5,p<0.001;nomogram 6,p<0.05;nomogram 7,p<0.005 for cardinal astigmatism,p=0.1 for oblique astigmatism).We observed mild clinically relevant differences(~0.5 D)in sphere or astigmatism among the nomograms;differences of~0.25 D in the proposals for sphere or cylinder were not uncommon.All nomograms suggested minor improvements versus actual observed outcomes,with no clinically relevant differences among them.Conclusions:All nomograms anticipated minor improvements versus actual observed outcomes without clinically relevant differences among them.The minimal uncertainties in determining the manifest refraction(~0.6 D)are the major limitation to improving the accuracy of refractive surgery nomograms.

Glaucoma surgery and induced astigmatism:a systematic review

Background:The refractive outcomes of glaucoma surgeries,particularly their effect on astigmatism,are incompletely understood.Main body:Trabeculectomy is associated with a considerable amount of with-the-rule astigmatic change in the immediate postoperative period.This is followed by a gradual against-the-rule shift.These changes are altered with the use of mitomycin C(MMC).Non-penetrating surgery such as deep sclerectomy is also associated with a similar or smaller degree of induced astigmatism.Minimally invasive glaucoma surgery appears to be astigmatically neutral.There is no clear evidence regarding refractive outcomes of glaucoma drainage device surgery.Conclusions:Induced astigmatism may account for a reduction in unaided visual acuity in the early postoperative period following a successful trabeculectomy.These changes appear to stabilise at 3 months,and it would be prudent to defer the prescription of new glasses until this time.If sequential cataract surgery is to be performed,toric intraocular lenses can be a useful option for astigmatic correction.