Keratohematoma leading to acquired posterior keratoconus.

We describe a patient with congenital syphilis associated with corneal neovascularization and subsequent intracorneal hemorrhage. Over time, this condition resulted in acquired posterior keratoconus. A review of our clinical case, the literature, and histologic findings is presented. To our knowledge, this is the first reported case of acquired posterior keratoconus associated with corneal vascularization and hemorrhage secondary to congenital syphilis. We also have provided histopathologic evidence for the prescence of an iron ring.

Results of penetrating keratoplasty with posterior chamber intraocular lens implantation in the absence of a lens capsule.

We studied 21 consecutive cases of posterior chamber intraocular lens implantation in the absence of an intact lens capsule performed during penetrating keratoplasty. Twenty patients had iris sutures to support the posterior chamber intraocular lenses (one required no suture). Twelve patients had closed-loop anterior chamber intraocular lenses, and five patients had other types of intraocular lenses explanted at the time of surgery. Postoperative follow-up time averaged 10 months, ranging from 2 to 19 months, with ten eyes having at least 1 year follow-up. All 21 grafts remained clear at their latest examinations. Seven eyes (33%) had 20/50 or better visual acuity, nine (43%) had a visual acuity from 20/60 to 20/150, and five (24%) had a visual acuity of 20/200 or worse at their latest examinations. All patients had improved vision postoperatively, and nine eyes (43%) achieved an improvement in vision of five lines or better. Of the ten eyes with at least 1 year follow-up, all had their sutures removed and four (40%) had 20/40 or better visual acuity. Of the remaining six patients (60%) with visual acuity worse than 20/40, all had significant retinal disease and/or glaucoma.

Organic tissue glue in the closure of cataract incisions in rabbit eyes.

We performed 7 mm scleral pocket cataract incisions in both eyes of ten rabbits. One eye of each rabbit was closed with one interrupted 10-0 nylon suture and organic tissue glue (Tisseel) and the other was closed with a conventional shoelace running 10-0 nylon suture. The eyes were examined clinically and histopathologically at various postoperative intervals. No difference in wound integrity was found between the two closures, but slightly more inflammation occurred in the eyes closed with glue than in those closed with sutures alone. Organic tissue glue may become an alternative method to suture closure of scleral pocket cataract incisions.

Inflammatory cell responses to radial keratotomy.

Radial keratotomy stimulates the influx of polymorphonuclear cells (PMNs) into the tear film and stroma. These cells do not degranulate and are gone in four days. Incisions fill with persistent epithelial plugs, and extracellular matrix (ECM) replacement does not occur. In contrast, a thermal burn stimulates a prolonged influx of PMNs into the tear film and stroma, where they degranulate and remove damaged tissue. ECM replacement in a few weeks suggests that factors released by activated PMNs may stimulate normal wound healing in the cornea.

Corneal surface ablation by 193 nm excimer laser and wound healing in rabbits.

The 193 nm argon fluoride excimer laser was used to ablate a 6 mm diameter area of the central rabbit cornea under various conditions of power, beam configuration and exposure time. High repetition rates or prolonged exposures produced charring and prevented rapid epithelial wound closure. Endothelial vacuolization, reduction in density, and displacement of cell material into Descemet's layer resulted in these experiments. A beam of low and uniform power intensity (40 pulses per second, 100 seconds at 23 mJ/cm2) reduced stromal damage, cellular infiltration, and epithelial irregularities including punctate staining and cell exfoliation. Epithelial rehealing occurred within two days. Basal lamina and hemidesmosomes were reformed by one week. Endothelial damage was not detected. Excimer laser ablation may allow removal of superficial dystrophies or scars, followed by rapid healing from normal corneal reparative processes.

Polyvinylpyrrolidone iodine: corneal toxicology and epithelial healing in a rabbit model.

Polyvinylpyrrolidone-iodine (PVP-I) is a biocompatible broad spectrum antimicrobial that is widely used as an ophthalmic pre-operative prepping agent. In order to determine if PVP-I is safe for treating corneal ulcers and conjunctivitis, we evaluated the ocular toxicity of frequent dosing in a rabbit model. We evaluated ocular irritation in 18 rabbits according to the McDonald-Shadduck method. Concentrations of 0.5% PVP-I or less were practically non-irritating when administered six times per day. We evaluated corneal epithelial wound healing in 16 rabbits with standardized abrasions. Concentrations of 0.33% PVP-I showed epithelial healing comparable to gentamicin treated eyes and untreated controls. Concentrations of 0.5% PVP-I delayed epithelial healing by one day. Because of its broad spectrum and apparently low toxicity, PVP-I may be a useful treatment for corneal ulcers, keratitis and conjunctivitis.

Organic tissue glue in the closure of cataract incisions.

We report our initial studies with a new organic tissue glue (Tisseel) in the closure of cataract incisions made in fresh cadaver eyes. We made two types of cataract incisions, posterior beveled and scleral pocket, and closed them with nylon sutures, glue, or a combination of both. The 11-mm posterior-beveled incision required eight nylon sutures, with or without glue, to maintain wound integrity at high intraocular pressures. We found the 7-mm and 11-mm pocket-type incisions to be essentially self-sealing and to leak only when posterior scleral lip pressure was applied. Once glue was added, even high posterior pressure did not disrupt the wound. This glue may thus present an alternative to suture closure of scleral pocket cataract incisions.

Corneal incisions produced with the fourth harmonic (266 nm) of the YAG laser.

The fourth harmonic wavelength (266 nm) of a neodymium YAG laser was used to cut precise grooves on the surface of the human cornea. Well-controlled cuts were made using the laser operating at 1.3 kHz. The width of the grooves was 2-3 micron. The depth could be controlled by varying the amount of laser exposure.

Clinical evaluation of the Humphrey automatic refractor.

A new automatic objective refractor was used on healthy adults. In the absence of cycloplegic drugs, spherocylindrical objective refractions performed with the instrument provided 20/20 acuity 96% as often as with standard subjective techniques. No instrument-induced accommodations effects were seen. One hundred percent of instrument spherical findings were repeatable within 0.50 diopters; all cylindrical findings were repeatable within 0.37 D. This result represents a higher level of repeatability than that reported for standard subjective refraction under clinical conditions. In the absence of cycloplegic drugs, the correlation coefficient between the instrument's findings and standard subjective spherical findings was .97 v .98 between two practitioners' subjective refractions. The average difference between cylindrical findings of the instrument and those of an experienced practitioner was 0.04 D larger than the average difference seen between two practitioners using subjective techniques.

Unusual superficial confluent form of granular corneal dystrophy.

A 53-year-old Japanese woman had corneal opacification due to granular dystrophy (GCD) since childhood. Clinically, unusual bilateral confluent dense granular opacities with a peripheral rim of clear cornea were observed. Her mother and daughter have a milder form of GCD, with circumscribed opacities separated by clear stroma. Light and electron microscopy of the patient's corneal button showed that the opacities involved the corneal epithelium as well as the stroma.

Forskolin, a potent adenylate cyclase activator, lowers rabbit intraocular pressure.

To our knowledge, this is the first report of a topically applied, specific adenylate cyclase activator that reduces intraocular pressure. Forskolin, a novel adenylate cyclase activator, is reported to increase cyclic adenosine monophosphate (AMP) in intact cells. Cyclic AMP levels are increased with various antiglaucoma agents. Intraocular pressure in rabbits was significantly reduced with two concentrations of forskolin, 0.1% and 0.05%. Ocular hypertension was noted with 0.05% and 0.2%. No change in IOP was noted with 0.01% forskolin. The IOP lowering with 0.1% and 0.05% forskolin lasted approximately six hours. Mild, transient conjunctival chemosis was noted in the doses that decreased IOP. The contralateral control eye showed decreases in IOP, but the differences between control and tested eyes were significant by the Student's paired t test.

Unusual superficial confluent form of granular corneal dystrophy.

A 53-year-old Japanese woman had corneal opacification due to granular dystrophy (GCD) since childhood. Clinically, unusual bilateral confluent dense granular opacities with a peripheral rim of clear cornea were observed. Her mother and daughter have a milder form of GCD, with circumscribed opacities separated by clear stroma. Light and electron microscopy of the patient's corneal button showed that the opacities involved the corneal epithelium as well as the stroma.

Surgical advances and results of keratoconus.

We analyzed 82 eyes of 53 patients who underwent penetrating keratoplasty for keratoconus. Despite meticulous attention to microsurgical technique, and the use of the corneal punch. 10-0 monofilament nylon double continuous suture, and the surgical keratometer, and sizing the donor graft to recipient bed, we found a postoperative astigmatism of about 4.0 diopters. The percentage of clear grafts is now high and the complication rate low. However, we still have not developed a technique that ensures an anastigmatic cornea after keratoplasty for keratoconus.

Localization of intraocular foreign bodies by computed tomography.

An experimental model is presented and the smallest sized metal intraocular foreign body that could be accurately detected by computed tomography was found to be 1 mm in diameter. A 1/2-mm intraocular foreign body was not detected by the computed tomography scan. Computed tomography is an effective method for the precise localization of intraocular foreign bodies.

A clinicopathologic study of autosomal dominant optic atrophy.

Of a family with 40 members, 12 had autosomal dominant optic atrophy. The affected members were aware of reduced vision from the first decade. Visual loss was moderate to severe, 6/12 (20/40) to 3/60 (10/200). The affected members showed similar centrocecal scotomata. Most affected patients had severe unclassified color defects. Electroretinography measurements were normal in all but one patient who had a small reduction in the scotopic response. The pathologic changes in a patient with autosomal dominant optic atrophy showed diffuse atrophy of the ganglion cell layer of the retina with a loss of myelin and nerve tissue within the optic nerves. We suggest that autosomal dominant atrophy is a primary degeneration of retinal ganglion cells.