Limbal cell autograft transplantation for severe ocular surface disorders.

Background: Limbal cell transplantation may improve the visual outcome after chemical trauma and ocular surface diseases.

Methods: Nine eyes of nine consecutive patients (eight males and one female, age 9-60 years), underwent limbal autograft transplantation (LAUT). In five cases LAUT was done for severe chemical burns in the acute stage (group 1).

Vitreoretinal surgery assisted by the 193-nm excimer laser.

Purpose: Ablating and cutting vitreoretinal membranes using a 193-nm excimer laser-based microsurgical system.

Methods: A 193-nm microsurgical system enables delivery of the beam into a fluid medium to cut preretinal and subretinal membranes. Two patients with proliferative diabetic retinopathy and one patient with proliferative vitreoretinopathy were treated with this new device.

Efficacy of topical gentamicin treatment after 193-nm photorefractive keratectomy in an experimental Pseudomonas keratitis model.

Background: The treatment of Pseudomonas keratitis has many limitations, and further investigation to identify more effective approaches is required. We therefore studied the possible contribution of the debridement effect of 193-nm excimer laser on Pseudomonas keratitis in rabbit eyes.

Methods: Pseudomonas keratitis was induced in 30 rabbit eyes by inflicting controlled central corneal scratches and applying a drop of Pseudomonas aeruginosa suspension.

The use of a silicone strip over the sclerotomy in vitreous surgery.

We have developed a technique to prevent enlargement and distortion of the sclerotomy wound during vitreoretinal surgery. The technique involves the use of a silicone strip temporarily attached to the sclera. The strip and the sclera are pierced with a lance-tipped blade and surgery is done by entering through the silicone strip and then through the resulting scleral opening.

Vitreoretinal ablation with the 193-nm excimer laser in fluid media.

Purpose: To ablate retina and vitreous membranes using the 193-nm argon fluoride excimer laser in a fluid medium.

Methods: A special delivery system for the 193-nm excimer laser was developed that enabled the delivery of the laser into high-absorption liquid environments. The system was tested on the retina in an in vitro cup preparation of cow's eyes, and also in vivo on retina and vitreous membranes of rabbit eyes.

Silicone oil tamponade for retinal detachment and delayed treatment of retinal tears.

Four patients underwent a vitrectomy procedure for retinal detachment associated with anterior and posterior proliferative vitreoretinopathy (D-1 type). In each patient, an internal tamponade was achieved with 1000-centistoke silicone oil. Preretinal and/or subretinal hemorrhage that was difficult to remove during surgery, as well as remnants of subretinal fluid, prevented complete intraoperative treatment of the retinal tears or the retinotomy with endolaser photocoagulation.

The effect of the ArF excimer laser on Candida albicans in vitro.

Candida albicans colonies in Sabouraud agar plates were irradiated with the excimer laser as follows: (a) at 10 Hz, power densities of 115-300 mJ/cm2 and 200-3000 pulses, and (b) power density of 115 mJ/cm2 and 200 pulses at 10-50 Hz. Additional colonies were irradiated with a power density of 200 mJ/cm2 at 10 Hz and 500 pulses. Each colony was cultured and the visible colony forming units were counted after 24 h.

The effect of topical indomethacin on subjective symptoms in chronic corneal edema.

The authors conducted a masked randomized study of 15 patients to evaluate the effect of administration of topical indomethacin 1% suspension on complaints in chronic corneal edema. Patients who complained of photophobia, pain, itching, burning sensation, foreign body sensation and tearing, were treated with topical indomethacin 1% or placebo and followed for eight weeks. The severity of the complaints was rated and the scores were evaluated (Wilcoxon matched-pairs test).

Extreme deepening of the anterior chamber during phacoemulsification.

An unusual deepening of the anterior chamber during a phacoemulsification procedure was observed in 3 patients with cataracts: 1 with high myopia, 1 with a lens opacification following a vitrectomy procedure, and 1 with pseudoexfoliation syndrome. This deepening hindered emulsification of the nucleus in the posterior chamber. Early delivery of the nucleus from the capsular bag allowed phacoemulsification to proceed at the pupillary level.

Microsurgery of the retina with a needle-guided 193-nm excimer laser.

This article presents a method used to guide the beam from an argon fluoride excimer laser to make it suitable for microsurgical purposes and confine it to areas that can be varied in dimension from 1 micron to tens or hundreds of microns. This approach guides the excimer laser beam with an articulated mechanical arm and confines it with variable-diameter tapered tubes, possibly allowing the use of this laser in in vitro retinal surgery with endolaser techniques. Currently, because of the lack of a delivery and focusing system for the 193-nm argon fluoride beam and its absorption by biologic liquids, this laser is used exclusively in ophthalmology for topical applications, such as corneal sculpting.

The effect of indomethacin on prostaglandin E2 in human cornea and conjunctiva.

We studied the inhibitory effect of topical 1% indomethacin aqueous suspension on prostaglandin E2 in 20 conjunctivae extracted during cataract surgery and 16 corneas extracted during penetrating keratoplasty. Thirty minutes before each surgical procedure, indomethacin or placebo (0.9% sodium chloride solution) was instilled into the eye to be operated on in a masked fashion for conjunctiva and selectively for cornea.

The effect of topical administration of indomethacin on symptoms in corneal scars and edema.

We conducted a masked randomized study of 50 patients to evaluate the effect of administration of topical indomethacin 1% suspension on symptoms in corneal scars, edema, infiltrates, and erosions. Patients with symptoms (photophobia, pain, itching, burning sensation, foreign-body sensation, and tearing) were treated with topically administered indomethacin 1% or placebo and monitored for eight weeks. The severity of the complaints was rated and the scores were evaluated (Wilcoxon rank-sum test).

Controlled lens formation with unapertured excimer lasers: use with organic polymers and corneal tissues.

A theoretical model is developed which allows for well-defined lenses to be formed with different dioptric properties using lasers that are known to ablate a variety of materials. With the theoretical development as a guide an experimental arrangement is defined for the ArF excimer laser and this arrangement is used to form lenses with highly smooth surfaces in three polymeric materials (polymethyl methacrylate, polycarbonate, and polyvinyl chloride) to test the validity of the theory. As part of the procedure to obtain these lenses, ablation curves (etch depth per pulse vs log of the laser fluence) were measured for each of these polymers and these curves are also reported.

Assessment of intraocular lens power on the basis of precataract refractive measurements.

Assessment of intraocular lens (IOL) power may rely, when biometric measurements of the eye are not available, on refraction previous to cataract development. Such an assessment, however, is generally considered unreliable. To improve the predictability of this method, we correlated refraction measurements with predictions of IOL power.

[Age-related macular degeneration after retinal detachment surgery].

We studied a group of 157 patients who had retinal detachment surgery in one eye with successful anatomical reattachment and a fellow eye without a retinal detachment. In a group of 7 out of 8 patients who had a retinal detachment that included the macula and who underwent surgery, we found that the development of macular degenerative changes was much less pronounced in the operated eye than in the fellow, control eye. In a group of 3 patients who had retinal detachment without macular involvement, the appearance of macular degenerative changes appeared to be rather symmetric in the operated and in the fellow eye.

Use of fibrin glue in ocular surgery.

Cryoprecipitate and thrombin were used to prevent bleeding and induce permanent conjunctival attachment in ten cases of retinal detachment, 40 cases of extracapsular cataract extraction, and ten cases of strabismus. This method proved to be a good alternative to suturing the conjunctiva in each of the above-mentioned surgical procedures, and appears to result in a better and more comfortable postoperative course.

Correlations between ocular optical components, height and head circumference.

Correlations between the ocular optical components, height and head circumference were investigated in 144 subjects. Refraction had a higher correlation with axial length than with corneal curvature. On the other hand, height and head circumference had a higher correlation with corneal curvature than with axial length.

The choice of a syringe for manual cortex aspiration.

The friction force of 5-ml, 2-ml, and 1-ml syringes used for manual aspiration of cortex material in extracapsular cataract extraction (ECCE) were compared. It was found that for a 5-ml syringe the force was 500 g, for a 2-ml syringe it was 250 g, and for a 1-ml tuberculin-type syringe it was only 50 g. The ease and duration of cortex aspiration in 30 cases of ECCE were compared using each of the above syringes partially filled with fluid, connected to a 25-gauge Gill's type cannula, and a closed anterior chamber technique.

Promoting effect of n-decylmethyl sulfoxide on the penetrability of the optic nerve for lidocaine HCl in cats.

We examined the effect of n-decylmethyl sulfoxide (n-decylMSO) on the resistance of the optic nerve sheath to the penetration of lidocaine hydrochloride. Three series of experiments were carried out in living cats, administering lidocaine with and without n-decylMSO. The visual evoked potential (VEP) and optic nerve response (ONR) were measured.

Prevention of clot formation in cat retinal vein by systemic and subconjunctival urokinase.

The thrombolytic effect of urokinase was tested on cat retinal vein thrombus induced by argon laser photocoagulation. At various time intervals after thrombosis, intravenous infusion or subconjunctival injections were given. Subconjunctival normal saline injections were used for controls.

Use of infant and child corneas for grafting.

Six corneal transplants, for which donor material was taken from infants or children, were grafted in adults with different types of corneal pathology. Acceptable mean keratometric readings of 45.8 diopters were obtained 6 months after surgery, very similar to those of grafted corneas taken from adults.

Controlled retrobulbar anesthesia for ECCE and IOL implantation.

A method of controlled retrobulbar anesthesia was used in 20 patients undergoing extracapsular cataract extraction with intraocular lens implantation. The method includes: leaving the pupil undilated before anesthesia; applying topical anesthetic to the conjunctiva; injecting about 0.25 ml of anesthesia through the non-sensitive conjunctiva into the muscle cone, then waiting until the pupil becomes dilated before injecting an additional 1.