Eye Injury

Over 1 million people suffer eye injuries each year. Cuts to the eye, chemical burns and foreign bodies in the eye are among the most frequently seen cases in hospital emergency rooms. Many of these incidents can result in serious injuries or loss of vision. However, the ability to give proper first aid for an eye injury can be an important step in saving sight.

What steps should be taken when an eye injury occurs?

When an eye injury occurs, it is important to determine the severity of the damage. This can be difficult because even an eyelash or speck of dirt in the eye can cause extreme discomfort. In all cases, it is better to be safe than to risk vision loss. After first aid has been administered, the eye should be examined by an eye doctor or emergency medical professional.

Why is correct first aid for an eye injury important?

Correct first aid treatment intermediately following an eye injury can make a vital difference to the success of further medical treatment and can prevent loss of sight.  However, first aid is only the treatment given first until experienced medical help is available. After first aid is completed, medical help should be obtained, especially if there is pain, impaired vision,or any question as to eye damage.

Although first aid is important, with a badly injured eye,it is better to do too little than too much. When in doubt about either the nature of the injury or the kind of treatment required, apply a sterile eye pad or clean handkerchief over the injured eye and seek immediate medical help.

What is the first aid treatment for foreign bodies in the eye?

Foreign bodies that enter the eye (eyelash, speck of dirt, piece of glass) can often be removed by tearing and blinking. However, if this is not sufficient to remove the irritant, lift the upper lid over the lower lid, allowing the lower lashes to brush the particle off the inside of the upper lid. Do not rub the eye, as a speck or foreign particle may become embedded in or scratch the eye. If further blinking and tearing do not remove the speck, keep the eye closed or patch it loosely and seek medical help. Bandaging both eyes may help to limit eye movement and damage to the eye.

Blows to the eye?

Whether intentional or unintentional, blows or injuries to the eye may result in a swollen and discolored eye or eyelid. Apply a cold compress to the eye immediately for 15 minutes to relieve pain and swelling. Do not apply ice directly to the eye, as this may cause further damage. Repeat cold compresses every two to three hours. After 48 hours, alternate warm and cold compresses. If pain persists or if a black eye or blurred vision is present, professional attention is required as internal eye damage may be present.

Cuts to the eye or eyelid?

A cut to the eye or eyelid should be bandaged lightly. Do not attempt to wash the eye or remove an object stuck in the eye. Do not rub the eye or apply hard pressure to stop any bleeding. After bandaging the eye, seek medical help immediately.

Chemical burns to the eye?

Chemical and agents such as gasoline, brake fluid, hair spray and grease can cause a painful, red, or burning eye. In such cases, the eye should be flushed with warm water immediately. Hold the eye open as wide as possible with fingers. Flush the eye continuously for 15 minutes with tap water or clean water from a container. Roll the eyeball as much as possible to wash out the eye. Do not rub the eye, bandage the eye, or use an eye cup. Seek medical help immediately.

When proper safety measure are followed, most eye injuries can be prevented. When an eye injury does occur, immediate first aid treatment can be vital in preventing vision loss. However, first aid treatment is not a substitute for professional care. Proper treatment by an eye doctor or emergency medical professional after an eye injury is most important to prevent permanent damage and loss of sight.

If you experience an eye injury or other vision problem, you should obtain a complete eye examination.

Prevention is the best medicine against eye injuries.

Nine out of ten eye injuries can be prevented. By following simple safety guidelines, most eye injuries can be avoided.

At home:

• Protect the eyes from household products by reading instructions carefully, directing all spray nozzles away from the face, and washing hands after use.
• Wear protective goggles when doing carpentry, home repairs, gardening, or using powerful chemicals.
• Make sure no one is in front of or on the side of a lawn mower in operation.

At work:

• Wear proper safety glasses when neccessary.
• Wear proper light filtering goggles when welding.

When playing sports:

• Wear protective goggles during all sports activities involving a ball of any size.
• Wear protective helmets or face protectors when appropriate.
• Observe the sport's safety rules.

Around children:

• Supervise children at play with toys or games that can be dangerous.
• Educate children on safety measures when they are using potentially dangerous equipment, such as scissors or a BB gun.

Around fireworks:

• Wear safety goggles when lighting fireworks.
• Do not light fireworks near others.
• Do not put firecrackers in containers such as bottles, cans, or clay spots which can shatter.
• Do not throw sparklers in the air or wave near a person's face.
• Do not allow children to ignite fireworks.

Around the car:

• Do not open the hood of a car around an open flame, match or cigarette.
• Use proper safety procedures when jump starting a car.
• Wear protective goggles when grinding metal or performing body work.

When outdoors:

• Do not stare directly into the sun.
• Wear ultraviolet filtering sun goggles in bright light.

Pachymetry Assisted Laser Keratoplasty (PALK): a new approach to an old technique

Pachymetry Assisted Laser Keratoplasty (PALK): a new approach to an old technique. By Cesar Carriazo MD.

Introduction.

Same corneal disease (e.g. leukomas, irregularities, and dystrophies) may compromise only the anterior portion of the cornea. In that scenario, it is undesirable to treat the unaffected Descemet's membrane and the endothelium. Those patients usually have been treated by lamellar resection of the anterior portion of the cornea, which is replaced by a donor lamellar graft. These techniques are called lamellar keratoplasty or homoplastic lamellar keratomileusis.

The advantages of lamellar keratoplasty (LK) over penetrating keratoplasty (PKP) are: (1) shorter visual rehabilitation; (2) decrease in astigmatism induction; (3) lower risk of infection and graft rejection; (4) lower incidence of intraoperative complications; and (5) the possibility of using stored donor tissue. Despite all these advantages, eyes treated with LK usually do not present the same optical quality achieved with PKP. The host-donor interface is frequently irregular which leads to irregular astigmatism and poor visual outcomes.  Additionally, technical difficulties prevent it from being a popular procedure.

In this chapter we  present a new technique for lamellar keratoplasty, using excimer laser ablation guided by pachymetric data (pachymetry asisted laser keratoplasty; PALK). This technique has all the advantages of lamellar procedures but it also provides a uniform corneal thickness due to a smooth receptor surface leading to a good optical performance.

Surgical Technique - Pachymetry Assisted Laser Keratoplasty (PALK)

DONOR LENTICULE

In conventional automated lamellar keratoplasties a corneal donor disk is obtained from a whole ocular globe or from an artificial chamber-mounted corneal scleral button, using a microkeratome system without stopper.  Corneal scleral buttons must have at least a 16mm diameter to fit an artificial chamber. Thickness and diameters of the corneal lamellar cut can be determined by using different microkeratome heads and suction rings.

In our technique (PALK) we use the same procedure for pathologies like leukomas or irregularities of the corneal anterior surface (<300 microns of depth). In case where the posterior layers of the cornea are compromised or a corneal ecstasy is found, we use a trephine that creates a full thickness donor disc with vertical edges that fulfill the requirements of the patient. The desired thickness of the lenticule is then obtained using an excimer laser (Esiris, Schwind, Germany). The laser is applied onto the endothelial face with the PTL program.  The depth of deep stromal ablation is calculated to match the patient's requirement.

Diagrammatic illustration of surgical procedure

HOST CORNEA

This procedure is performed using topical anesthesia since we need the patient's collaboration in order to get the laser fixation. The ablation guided by pachymetry can be achieved manually or automatically.  In the manual procedure, the host cornea is marked with violet dye.  A marker presenting eight radial and two circular lines is used. After this, we measure the thickness of the cornea in 17 predetermined points using a Sonogage pachymeter. These results, along with clinical and personal data, are transferred to a computer software (Pachy-Link Software). The diameter of the Optical Zone, the pachymetric values, and the position of the 17 points are the most relevant data. If needed, the number of thickness mesasurements can be altered by the surgeon.

In the automatic system we use a slit-lamp-based (via rotating camera) full map pachymeter - the Oculus Pentacam. After this informacion is obtained it is processed directly by the PACHY-LINK software in its own pachymetric map, which automatically generates the ablation profile map that is going to be used on the patient.

The target posterior stromal bed thickness and the optical zone are selected by the surgeon and depend on the preoperative evaluation (e.g. corneal disease, depth of compromised area).

As the excimer laser used works with a flying spot beam, the peripheral borders of the ablation are not perfectly regular, and we recommend using a plastic protector ring of 0.5 mm smaller diameter than the selected ablation zone. This ensures that the peripheral border created is vertical and well defined. Once the posterior stromal bed thickness has been selected the corneal tissue of the receptor cornea is removed by the pachymetry guided laser ablation. This procedure requires an eye tracking system. In patients with keratoconus, this procedure takes between 7 and 8 minutes using the Scwind Esiris laser, which works at 400 Hertz per second.

The donor corneal disk is placed on to the residual stromal bed of the receptor. If the donor corneal disk is thinner than 200um, sutures are not needed. However, when using thicker lenticules sutures are required.

POSTOPERATIVE CLINICAL SIGNS

During the first weeks some posterior folds can be present. In two out of 40 patients in whom the manual system was used we had a micro perforation and obtained a pseudo-chamber in the interface. We have not had any micro perforation cases using the computerized pachymetric map system.

With PALK we did not observe: (1) endothelial rejection (2) endothelial cell loss greater than 10% (in stromal beds of  >100um), (3) decentration of the ablation (an indicator that the eye tracking system is suitable for this procedure), (4) intraocular complications (e.g. infections, glaucoma, cataracts), or (5) high postoperative astigmatism. Patients treated with PALK presented a faster postoperative recovery.

The first keratoconus patient was operated in the year 2000. Nowadays, we have performed surgery with the same technique in 55 patients (2006). In the first cases we reached an average visual acuity recovery of 70% due to the fact that there was no thickness uniformity because of technical limitations of the manual system.  In the last procedures - which were made automatically - the visual acuities are superior, having patients with 20/20 best spectaclecorrected visual acuity (BSCVA). This occurs once the residual aberrations are corrected.

Another important observation is that visual recovery is inversely proportional to age and directly proportional to the interfaxe integration. The corneal structure reassembled in the immediate postoperative period, and the donor-host interface becomes imperceptible in a couple of months.

Pachymetric map in a patient with keratoconus

DISCUSSION

Excimer lasers are capable of performing corneal ablations with a high degree of accuracy. Excimer laser corneal surgery is currently performed in three different ways: phototherapeutic keratectomy (PTK), photorefractive keratectomy (PRK And LASEK) and laser in situ keratomileusis (LASIK).

In the particular case of PTK, the intention is to smoothen irregular corneal surfaces and/or to remove opaque superficial corneal tissue. In this technique the surgeon chooses the diameter and depth of the desired ablation and in all cases the ablation is made in parallel planes.

Currently, LK can be performed using manual or automated keratectomy. Accidental corneal perforation can occur, specially in manual procedures with deep resections. Corneal irregularities induced by an uneven interface are also of concern.

The PALK technique is a new approach that can be used in cases of severe corneal irregularities of the receptor eye and where the classical techniques are not the best option. The use of automatic multipoint corneal pachymetry allows surgeons to measure laser ablation depth from a fixed surface, avoiding microperforations during the procedure, to obtain a uniform thickness in the host cornea.

By providing a map of the cornela thickness across the ocular globe, multipoint corneal pachymetry effectively provides a cross-sectional view of the corneal bed. With PALK, it is possible to precisely control the depth of the treatment during the ablation of the host area. In the future, the duration of treatment will be reduced because new laser machines higher ablation speeds are being introduced.

Summarizing, we present a new approach for LK technique that we believe is safer and more predictable than manual or automated procedures. To the best of our knowledge, this is the first paper describing pachymetry assisted laser keratoplasty (PALK).

REFERENCES

Barraquer JI. Cirugia Refractiva de la Cornea. Tomo I Instituto Barraquer de America, Bogota, 1989.

Polack FM. Lamellar keratoplasty; Malbran's peeling off technique. Arch ophthalmol 1971.

Anwar M. Dissection techniques in Lamellar Keratoplasty. Br J Ophthalmol 1972.

Von Hipple A Ueber die Operative Behadlung Totaler Stationarer Hornhaut - trubungen. Albrecht V Graefes Arch Ophthal 1877.

Castroviejo R. Electrokeratome for the dissection of lamellar grafts. Am J Ophthalmol 1959.

Seiler T. Wollensak J. Myopic photorefractive keratectomy with the excimer laser: one year follow up. Ophthalmology 1991.

Rashad KM. Laser in situ keratomileusis for myopic astigmatism. J Cataract Refract Surg 1999.

Vasco Posada J. Homoqueratoplastia Interlaminar. Rev Soc Col Oftal 1973.

Tuunanen TH, Tervo TT. Results of photorefractive keratectomy for low, moderate and high myopia. J Cataract Refract Surg 1998.

Arenas Archila EA. Deep lamellar keratoplasty dissection of host tissue with intrastromal air injection. Cornea 1985.

Arenas Archila EA: Deep Lamellar Keratoplasty Dissection of Host Tissue with Intrastromal air injection. Abstracts from World Congress on the Corena III, April 27 to May 1, 1987, Washington DC. Cornea 1897.

Pachymetry Assisted Laser Keratoplasty (PALK)

An innovative, ground-breaking method for corneal transplantation developed by Dr. Cesar Carriazo, Centro Oftalmológico Carriazo, Colombia as a result of a close and long-term cooperation with SCHWIND eye-tech-solutions. With the SCHWIND AMARIS, the pachymetry assisted laser keratoplasty (PALK) is an easy, safe and extremely precise procedure. It is suited for patients who need corneal transplants and whose endothelium is intact.
The comprehensive diagnostic measurement of corneal pachymetry combined with laser-guided ablation provide a so far unequalled level of precision in removing damaged corneal surfaces, homogeneity of residual stromal bed thickness as well as a shorter surgical time. Up to now, PALK has shown excellent visual results and has significantly reduced risks associated with other techniques. “With PALK, we are broadening the spectrum of treatment provided by the SCHWIND AMARIS, thus continuously expanding the leading technological position of the TotalTechLaser“, Rolf SCHWIND, CEO of SCHWIND, points out.

PALK-CAM precisely determines the ablation volume
The surgical procedures most commonly applied in the past for transplantations replacing diseased or damaged corneas are the penetrating keratoplasty and lamellar keratoplasty. However, these methods present their own risks, complications and vision results. The PALK technique developed by Dr. Carriazo in cooperation with SCHWIND opens up new dimensions in corneal transplantation.
A module of the SCHWIND-CAM software (PALK-CAM) available for the SCHWIND AMARIS laser precisely determines the ablation volume of the host cornea based on a detailed pachymetry map. At a high resolution in all dimensions, the AMARIS laser then ablates the calculated volume. This technique combines all advantages of lamellar keratoplasty, but additionally provides individualized corneal ablation ensuring homogeneity of residual stromal thickness, thus leading to better postsurgical visual results. According to the clinical experience of Dr. Carriazo gathered with preliminary software versions and in pilot studies, the treated eyes had an excellent transparency at the donor-host interface and most of them had less than 15% loss of endothelial cells. No rejection of the graft was observed. In addition, it was significantly better centred as compared to non-laser based techniques.

Contact-free method
Dr. Carriazo sums up his experience with PALK like this: “Patients improved their vision in both quantity and quality and additionally have the opportunity to more effective post-keratoplasty refractive corrections because with the PALK technique, they have gained extra corneal thickness and almost normal corneas in terms of anatomy. The risks are lower than those with the traditional technique, since the incidence of complications is very low.” According to Dr. Carriazo the major advantages of laser treatment with the PALK-CAM are the contact-free
method without exerting mechanical pressure on the eye, the centring done by the eye tracking system, the minimal endothelial loss and the safety and reproducibility of the procedure, together with shorter surgical time with the SCHWIND AMARIS. “Furthermore, the PALK technique preserves endothelium and Descemet membrane of the host, and survival is increased as compared to PKP. The possibility of rejection is minimal because the transplanted immune load is lower“, Dr. Carriazo sums up.

Source: http://www.eye-tech-solutions.com/fileadmin/files/documents/pdf-files/Aktuelles/Pressemitteilungen/2009/PR_PALK_04-2009-E.pdf

Blepharoplasty - Cosmetic Eyelid Surgery

Eyelids Function

Eyelids play an important role in the protection of the eyes and distribution of tears. Nevertheless factors like aging, sun expossure, type of diet, innadecuate skin care or family traits can contribute to the appearance of crease, wrinkles, skinfolds and excessive accumulation of skin in the upper and lower eyelids. All these changes occur because the skin elasticity increases, muscles and orbital connective tissue become weaker and orbital fat prolapses.

When all these changes take place, the eyes and face acquire a "tired" or aging appearance. The patient also presents a decrease in visual field, excessive tearing and difficulties when wearing glasses because of the lower eyelid abnormalities.

How It is Treated.

The most effective way of correcting all these eyelid changes is a surgical procedure called Blepharoplasty, which is an ambulatory surgery and usually done under local anesthesia and intravenous sedation.
The procedure's main objective is to reduce excessive skin and tissue laxity of the eyelids and this includes skin, muscle and orbital fat repair without affecting the eye function nor other structures (lacrimale glands, lacrimal ducts, etc)

How is the procedure done?

The incision is done in the natural eyelid crease to hide the scar after the patient is completely recovered. If eyebrows ptosis exists another special procedure is also done.
The scar is initially pigmented but within days it minimizes until it turns almost invisible. Its common that after the surgery the patient present eyelid inflammation and ecchymosis, but they are normal findings and they dissapear almost completely after the first week.

Recovery

Usually we recommend the patient absolute rest with the head raised after the surgery, and the use of cold compresses for several days to reduce the inflammation.
The area around the eyes must be healed and kept clean and the use of eyedrops is also recommended. When fine sutures are used, they may be either reabsorbed or removed after one week.
The final results depend of many factors like the extension of the area to be reconstructed, skin structure and age. Normally the patient notices the improvement of his appearance after the first week and can resume his daily activities in a short time.
Since this surgery can affect vision, an ophthalmologist trained in oculoplastic (ocular plastic surgery) should be the person who performs this procedure. This professional always looks forwards not only to improve the appearance but to maintain or recover the adequate function of the eyelids.


Carriazo Ophthalmology Center counts with all these new technology devices for the diagnosis and surgical treatment of ocular conditions.