They used the same viscoelastic devices and intraocular lenses, exactly as described in a former report from our group [ 15 ]. For detailed presentation of SDI and its validation process please refer to a former publication from our group [ 15 ]. An a priori power analysis was performed. For an effect size of 0. The normality of measured data was evaluated by the Kolmogorov-Smirnov test. Non-parametric data were assessed with Mann—Whitney U test. All statistical analyses were performed with the Medcalc version 9.
One hundred eighty patients 82 men and 98 women, mean age No parameter demonstrated significant differences between the two groups preoperatively. While 0. With respect to CCS, participants in both groups demonstrated reduced corneal sensitivity at all postoperative examination points. However, despite the overall reduction in CCS, 0. At the 3rd and 6th weeks both 0. Significant increase in the Schirmer test was detected at the 3rd and 6th weeks. Non-significant differences could be detected between groups at all timepoints Fig.
Regarding the subjective discomfort as expressed by our study participants, 0.
Phacoemulsification is considered the most prevalent surgical procedure in ophthalmology both in developed and in developing countries [ 17 , 18 ]. Despite the advances in cataract-extraction technology, this common surgical technique has been associated with a series of intraoperative and postoperative adverse-effects and complications. Transient corneal edema and reduced corneal sensitivity are two of the mild adverse-effects. Among the more severe ones is the permanent corneal decompensation due to endothelial cell damage. The impressive visual capacity following cataract extraction surgery is not only associated with the removal of the opaque crystalline lens and its replacement with an artificial intraocular lens IOL , but also due to the integrated properties and characteristics of the IOLs which attempt to address the majority of pre-existing refractive errors and aberrations.
It is no surprise that modern cataract-extraction surgery has become part of refractive surgery [ 20 ]. Within this context, corneal surface and tear-film have become of major importance to cataract surgeons as it was traditionally for refractive surgeons. However, published experience suggests that the majority of post-cataract patients experience DED-like symptoms that vary in severity and duration [ 11 , 21 — 25 ].
Among them are foreign body sensation, burning, stinging sensation, itchiness, tearing, blinking discomfort and pain. Our previous report presented the validation process of a novel surface discomfort index SDI , which quantified, in a scale from 1 to 10 best , the overall subjective discomfort feeling that post-cataract patients experience. SDI was constructed by four of the most commonlyexperienced symptoms which acted as components to the parameter foreign body sensation, blinking discomfort, stinging sensation, and tearing sensation. Moreover, our previous report confirmed former studies and suggested that an artificial tear preparation should be added to the postoperative regime since it alleviates DED-like symptomatology.
In fact, 0. On the other hand, recent artificial tears preparations doubled the concentration of sodium hyaluronate to 0. However, no comparative clinical trials have been published to confirm a potential additional beneficial impact on DED due to the increased sodium hyaluronate concentration over the standard 0. Exploring the potential superiority of 0. Regarding sodium hyaluronate, we do know that its viscoelastic properties facilitate the prolonged adhesion of the tear film layer [ 26 ].
Moreover, it has excellent moisturization properties and increases the total thickness of the lacrimal film [ 27 ].
On the other hand, it also mimics the rheological properties of the aqueous tear layer resulting in its stabilization [ 28 , 29 ]. In vitro reports demonstrated its antioxidant properties, which minimize the oxidative stress due to the intraoperative procedure and due to the preservatives and active ingredients of the standard postoperative medication [ 30 ].
In fact, sodium hyaluronate stimulates ocular surface tissue healing by humidifying the surface of the eye and restores the integrity of the corneal and conjunctival epithelium [ 31 ]. Recent reports indicated that sodium hyaluronate is equally efficient to 0. Although no comparative clinical trials have been published regarding the potential superiority of 0.
Nonsuperiority of 0. However, some parameters, such as staining score and adverse effects, presented better scores in 0.
Shop by category
Of note, even higher concentrations of sodium hyaluronate 0. Our study outcomes indicated a potential overall superiority of the 0. Last but not least, the overall surface discomfort that phacoemulsification patients experience was significantly less in 0. It seems that the increased concentration of sodium hyaluronate has an additional beneficial impact on the stinging sensation and the foreign body sensation, since these were the parameters of SDI that were significantly improved in study group patients. A robust feature of our study is the number of participants that populated the study and control groups and the multi-centered design.
Among the potential weaknesses is the limited number of parameters that were evaluated i. Nevertheless, our study outcomes suggest that 0. This research followed the tenets of the Declaration of Helsinki. Approval was obtained by the Ethics committee of the University Hospital of Alexandroupolis.http://clublavoute.ca/wylov-retiro-citas-en.php
Basic and Clinical Science Course (BCSC) Series by American Academy of Ophthalmology
All participants provided written informed consent. No financial support was received for this study.
- Algebraic K-Theory, Number Theory, Geometry, and Analysis: Proceedings.
- The New Russian Business Leaders (New Horizons in Leadership Studies Series).
- Basic and Clinical Science Course (BCSC) Series.
None of the authors has any proprietary interests or conflicts of interest related to this submission. This manuscript is not simultaneously being considered for publication at any other journal. PN collected data and wrote the manuscript. GL designed the study, supervised the study, and critically revised the manuscript.
All authors read and approved the final manuscript. National Center for Biotechnology Information , U. It is estimated that this process occurs every 7 to 10 days The present study showed that said centripetal migration is completed in D6, but no emphasis was given to the microscopic appearance of this phenomenon. There is a difference in the electric potential of 6 mV between the cornea and the posterior pole of the eye. Thus, the human eye behaves like a dipole, oriented on the anteroposterior axis, the cornea being the positive pole.
Once the cells suffer influence of the electromagnetic field for having iron ions and ionic currents inside, they tend to be organized in concentric circles A similar aspect was presented in the theory known as "Hurricane and Blizzard Keratopathy" , which describes that the corneal reepithelization occurs through the distribution of epithelial cells of spiral mode and clockwise influenced by the electromagnetic field of the eye during the process of basal epithelium "turnover" The corneal reepithelization in a large circular lesion occurs in a non-uniform way.
There is a progressive decrease in the deepithelized area with the formation of epithelial leaflets from different areas of the edge of the circumference of the lesion advancing to the center and forming the convex front lines. These convex lines are in the center of the lesion, forming a single line of contact in shape of the letter Y, which soon disappears The exam carried out on slit lamp in D6 also showed the presence of this scar in Y in most patients.
In this study, the occurrence of these events may have been changed by modifying the format of the deepithelization area, as suggested in one report found in the literature concerning the modification of the format of the corneal deepithelization in PRK and its influence on VA When you change the format of the deepithelization from circular to oval, there was a better visual acuity at D6, both in the subjective evaluation perceived by the patient Possibly, this process for better recovery of VA is due to the different distances that the migration of epithelial cells travels, and due to not reaching the center at the same time, forming a fainter line contact at the center of the cornea, and it may even be offset from the visual axis.
The healing rate of the epithelial defect has been related to the area of injury. Large lesions heal faster than smaller lesions Based on this theory, the circular technique deepithelization a larger area In the oval technique, the epithelial defect area is smaller The significant results observed in this study are unprecedented because there are no studies in the literature assessing if deepithelization formats different from circular in the surgical procedure of PRK change the time of recovery of the postoperative visual acuity.
This study showed that changing the format of the corneal deepithelization in photorefractive keratectomy PRK from circular to oval provides better recovery of visual acuity using simple, easy-to-use instruments with a significant impact in the result of this refractive procedure in the first postoperative days. Censo Brasileiro de Cirurgia Refrativa. Arq Bras Oftalmol.
Excimer laser. In: Tratado brasileiro de catarata e cirurgia refrativa. Cochrane Database Syst Rev [Internet] Recovery of uncorrected visual acuity after laser in situ keratomileusis or photorefractive keratectomy for low myopia. Ophthalmol Manag [Internet] NSAID regimen important in perioperative care of laser surface ablation patients: Experts in the field shared their drug choices and dosing regimens for pain control. Ocular Surgery News U. Edition [Internet] Comparison of 3 silicone hydrogel bandage soft contact lenses for pain control after photorefractive keratectomy.
J Cataract Refract Surg.
Rev Bras Oftalmol. PRK: Feeling better and healing faster. EyeNet Magazine. September; Available from. Corneal epithelial wound healing. Br J Ophthalmol. Section 13, Newsletter Refractive Outlook [a Internet]. Visions of Health Understanding Iridology.