Your Space - Health and Fitness

From all Lasik flap complication, LASIK flap buttonholes are the ones that lead most often to loss of best-corrected visual acuity (BCVA). Why do

According to USFDA, a combination product is one composed of any combination of a drug and device; biological product and device; drug and biological product

they happen? Thin, irregular and perforated flaps seem to result from a common etiology; an inadequate coupling of the blade to the cornea. Steep

; or drug, device, and biological product and fixed dose combination would include two or more combinations of drug.

Examples of combination products may in

corneas have been compared to tennis balls that would buckle centrally upon applanating pressure. This results in a central dimple missed by the

lude drug-coated devices, drugs packaged with delivery devices in medical kits, and drugs and devices packaged separately but intended to be used together.

blade leading to a buttonhole. Another theory is that higher keratometric values offer increased resistance to cutting when applanated, leading to

here is enormous increase in the number of combination products entering the market in the recent years. Combination products have proven advantages but fixe

upwards movement of the blade.

The latter is probably more applicable to keratomes with lower oscillation rates. Similarly, flat corneas may res

d dose combinations are still in the process of convincing regulatory authority on their advantages over the single ingredient formulations.

Combination pro

ult in a thin and/or small flap as they could be below the adequate cutting level in certain locations. Inadequate blade to cornea coupling is oft

ucts have become life saving products for the pharmaceutical companies who doesn’t have many innovative molecules in their product pipeline and have been inc

en due to poor suction (sunken globe/small diameter corneas with inadequate suction ring placement, conjunctival incarceration in the suction port

easingly used in the product life cycle management. Even the companies having product patents are trying to extend their product life cycle through the combi

…). Non-angled blades have equal chances of moving upwards towards the surface or downwards towards the stromal side if faced with resistance. On

nation products and maximize the revenues. But the companies involved in this practice are overlooking that they are burdening the patients both economically

the other hand, inferiorly angled blades are more likely to be driven towards the stroma. If a buttonhole is encountered (especially centrally), m

and physically. They need to rightly judge the benefits of the combination products and they have to even look at the risks involved when combining the produ

ost surgeons prefer to abort the procedure, replace the flap and re cut a deeper flap (20-60 ?m deeper) approximately 10-12 weeks later. While som

ts. Some of the combination products were well accepted by physicians while others suffered. Companies involved in development of combination products are fi

e advocate proceeding with scraping the epithelium and performing a PRK laser ablation, we believe this approach may not be feasible in higher myo

ding difficulty in defining their combination products and facing various challenges from selecting a combination to marketing it.

Following aspects would a

pes due to the appearance of unexpected haze.

A higher index for epithelial ingrowth should maintained around the margins of the buttonhole. The

dd to the challenges in developing combination products:

Which markets to tap where the combination products can do fairly well?
Which combination prod

incidence of perforated flaps (as well as thin and irregular ones) may be reduced if the surgeon ensures adequate suction, inspects the blades and

cts are meaningful and rational?
Which therapeutic categories to select?
Which Combinations can address unmet needs of the patients?
Do combin

adjusts the keratome plate thickness according to corneal curvature. Other helpful measures include ensuring adequate intraocular pressure before

tions increase the patient compliance?
What would be the developing cost?
How to tackle the risks encountered during combination product developmen

cutting the flap. Measurement may be most valuable with a pneumotonometer as other means were reported to provide imprecise readings at times. Ca

t?

As combination products don't fit into the traditional categories of drugs, medical devices, or biological products, the USFDA is in the process of devel

re should be taken to avoid conjunctival clogging in the suction port, which could lead to discrepancy between the intraocular pressure and the su

ping new procedures for reviewing their safety, efficacy and quality.

Professional from academic institutions, pharmaceutical industries, health care indust

ction pressure recorded on the microkeratome vacuum console. Newer microkeratomes have a safety mechanism to automatically abort the procedure or

y and representatives from various regulatory agencies are working out to design the regulatory requirements for manufacture and sale of combination products

to activate additional suction but are also prone to similar problems if IOP measurements are not obtained to ensure adequate suction. Some surgeo

.

As there is an increasing trend of the combination products companies manufacturing such products should be able to tackle the problems involved in the de

ns inspect the microkeratome blade under the operating microscope before engaging it in the suction ring in order to rule out manufacturing or oth

elopment. They need to be wiser in analyzing the market trends and the regulatory requirements.

Companies that provide selfless information through particip

er preoperative damage to the blade. It is best to keep the microkeratome away from hard surfaces after assembly to avoid subsequent blade damage.

tion in industry events and feedback to regulatory authorities would be able to face the challenges and will be successful in developing combination products

HTTP = HTML link (for blogs, profiles,phorums):
<a href="http://www.yourspace.org.ua/article/246212/yourspace-Managing-Lasik-Flap-Buttonholes.html">Managing Lasik Flap Buttonholes</a>

BB link (for phorums):
[url=http://www.yourspace.org.ua/article/246212/yourspace-Managing-Lasik-Flap-Buttonholes.html]Managing Lasik Flap Buttonholes[/url]

There are three reasons that you might have missed a payment on your credit card: either you can’t afford to pay, the payment didn’t get there in time or you just plain forgot. For whatever reason, there’s one thing you need to do, and quickly – get on the phone.

You will need to determine what should be stored off-site during a hurricane emergency and which computer systems and services will need to be kept running at a hot site...

Tags

Links

Your Space - Managing Lasik Flap Buttonholes

Related Articles: