In pursuit of objective dry eye screening clinical techniques

Dry eye is a multifactorial,progressive,and chronic disease of the tears and ocular surface.The disease is multi-factorial and has intermittent symptoms.Discomfort,visual disturbance,tear film instability with potential damage to the ocular surface,and increased tear film osmolarity are known associates.Dry eye is a common clinical problem for eye-care providers worldwide and there is a large number of clinical investigative techniques for the evaluation of dry eye.Despite this,however,there is no globally accepted guideline for dry eye diagnosis and none of the available tests may hold the title of the‘gold standard’.The majority of the techniques involved in the diagnosis of the disease,particularly for its early stages,has a large degree of subjectivity.The purpose of this article is to review existing dry eye investigative techniques and to present a new objective dry eye screening technique based on optical coherence tomography.

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.

Higher incidence of steroid-induced ocular hypertension in keratoconus

Background:To compare intraocular pressure(IOP)changes following topical dexamethasone administration for 1 month in keratoconic versus normal eyes.Methods:This is a retrospective,single-center,non-randomized case series evaluation of 350 eyes.Two groups were formed:normal/control Group A(n_(A)=73),eyes that underwent excimer laser photorefractive keratectomy;and keratoconic(KCN)Group B(n_(B)=277),eyes that were subjected to partial laser photorefractive keratectomy combined with collagen cross-linking(The Athens Protocol).All eyes received the same post-operative regimen of topical dexamethasone 0.1%for at least 1 month.Goldmann applanation tonometry IOP readings and central corneal thickness(CCT)measurements were monitored.Cases with induced ocular hypertension(OHT,defined as post-operative IOP higher than 21 mmHg),were identified and correlated to refractive procedure,gender,and corneal thickness.Results:At 4 weeks postoperatively,OHT was noted on 27.4%(20/73 eyes)in Group A,and 43.7%(121/277 eyes)in KCN Group B,(p<0.01).Six months post-operatively(following 5-months of discontinuing topical dexamethasone treatment and commencing treatment of IOP-lowering medications),OHT rate was 1.8%in Group A and 3.9%in the KCN Group B.Conclusion:This study demonstrates a potentially significant pre-disposition of keratoconic eyes to the development of steroid-induced OHT.