Communicating with laser vision correction patients.

Laser vision correction or LASIK has a long and excellent history with significant benefits and unlikely risks. Adequately educating patients should allay their fears and allow good candidates to enjoy the life changing benefits of improvement in the natural vision through laser vision correction.

Serious complications of topical mitomycin-C after pterygium surgery.

BACKGROUND: The use of topical mitomycin (mitomycin-C) as a medical adjunct to pterygium and glaucoma surgery is increasing. METHODS: The authors report on a series of 10 patients who experienced serious, vision-threatening complications associated with the use of this drug after pterygium surgery. RESULTS: Complications included severe secondary glaucoma (4 patients), corneal edema (3 patients), corneal perforation (1 patient), corectopia (2 patients), iritis (8 patients), sudden onset mature cataract (2 patients), scleral calcification (1 patient) and incapacitating photophobia and pain (8 patients). Two patients required penetrating keratoplasties and a third required three lamellar keratoplasties. Another patient underwent four additional surgeries including a conjunctival Z-plasty, scleral patch grafting, and conjunctival autografting before his intractable pain and photophobia resolved 15 months after the original surgery. Because of these complications, 6 patients required a total of 20 return visits to the operating room after their original pterygium surgery. In 5 eyes, visual acuity remained at 20/200 or less. Three of the six patients with the most severe complications had concomitant chronic external diseases (rosacea [3 patients], ichthyosis [1 patient], keratitis sicca [1 patient]). CONCLUSION: The authors urge extreme caution in the use of mitomycin. If mitomycin is used, the lowest possible concentration should be applied for the shortest time period in an effort to avoid these complications. A prospective multicenter study of the ophthalmic use of this medication is needed.

Giant papillary conjunctivitis and meibomian gland dysfunction blepharitis.

In this prospective pilot study we saw 42 consecutive giant papillary conjunctivitis (GPC) patients (80 eyes), all of whom were found to have some meibomian gland dysfunction blepharitis. Severity of GPC at presentation correlated with severity of meibomian gland dysfunction blepharitis (Kendall's tau b averaged 0.246 across the adjusted statistical analyses). Thirty-two patients (63 eyes) were refit after treating meibomian gland dysfunction blepharitis. Twenty-eight of these patients (55 eyes; 87%) continue to wear contact lenses, maintaining an improvement in GPC (mean follow-up 21 months; range 11-36 months). We hypothesize that meibomian gland dysfunction blepharitis may play a role in the pathogenesis of GPC and suggest that a large, controlled, multi-observer study be performed to further investigate this possible association.

Corneal decompensation after argon laser iridectomy.

Five eyes of three patients developed generalized corneal decompensation after undergoing argon laser iridectomy for angle closure glaucoma. Factors possibly associated with corneal decompensation include episodes of angle closure glaucoma with pressure elevations and inflammation, corneal guttate, diabetes, and the need for multiple treatments requiring a high-laser energy. It is important for ophthalmologists to inform their patients of the rare risk of developing bullous keratopathy after argon laser iridectomy and to consider obtaining prelaser specular microscopy to document the corneal status in high-risk patients.

Topical retinoid therapy for squamous metaplasia of various ocular surface disorders. A multicenter, placebo-controlled double-masked study.

In a prospective, double-masked clinical study, the authors evaluated the efficacy and safety of topically applied tretinoin ophthalmic ointment (0.01%) versus placebo in the treatment of squamous metaplasia associated with various ocular surface disorders involving dry eyes. Study parameters consisted of graded symptoms and signs, and serial impression cytologies. A total of 161 patients were enrolled in the study. Of these patients, 116 who had a minimum of 4 to 8 months of follow-up qualified for final statistical analysis. These patients were classified into two major groups: (1) keratoconjunctivitis sicca (KCS) and (2) conjunctival cicatricial diseases (Stevens-Johnson syndrome, inactive pemphigoid, radiation-induced dry eye, drug-induced pseudopemphigoid, and toxic epidermal necrolysis). An analysis of adjusted mean changes for KCS patients showed no statistically significant differences between active drug and placebo. A similar analysis of patients with conjunctival cicatricial diseases indicated a statistically significant (P less than 0.05) reversal of conjunctival keratinization in the temporal bulbar site after treatment with active drug, however, clinical symptoms and signs showed no significant improvement with active drug relative to placebo. Side effects were limited to blepharoconjunctivitis and were reversible upon tapering or stopping the drug.

Continuing corneal endothelial loss in intracapsular surgery with and without Binkhorst four-loop lenses: a long-term specular microscopy study.

We analyzed pre- and postoperative corneal endothelial photographs of 17 intracapsular cataract extractions (ICCE) with Binkhorst four-loop intraocular lens (IOL) eyes and found 11.6% mean cell loss at 2 months (previously reported by Hirst et al) increasing to 42.4% after 5 years (p less than 0.05) and 51.8% at 7 years. Eleven ICCE eyes without IOLs similarly examined showed a 15.6% mean cell loss at 2 months (previously reported by Hirst et al), increasing to 33.4% at 5 years (p less than 0.005, paired t-test). Our results appear to indicate long-term continuing cell loss after ICCE, both with and without Binkhorst four-loop iris clip IOLs, and statistically significant greater cell loss (p less than .001, unpaired t-test) with IOLs than without.

Treatment of Mooren's and Mooren's-like ulcer by lamellar keratectomy: report of six eyes and literature review.

Three cases of Mooren's ulcer (four eyes) and one case of marginal corneal ulcer associated with relapsing polychondritis (two eyes) are presented with decrease in ocular inflammation following extensive lamellar keratectomy or lamellar keratoplasty. Tissue adhesive was needed in two cases to maintain ocular integrity. The procedure may work by the removal of a corneal antigenic stimulus to a self-perpetrating auto-immune phenomenon that causes corneal melting. More cases are needed to evaluate the therapeutic efficacy of lamellar keratectomy for Mooren's and Mooren's-like corneal ulcers.

Endothelial damage from retrocorneal mode-locked neodymium:YAG laser pulses in monkeys.

Laser pulses were focused 0.85 to 1.60 mm from the rhesus monkey corneal endothelium using a mode-locked laser at 3.3 and 4.5 mJ. Sixteen slightly off-axis pulses were applied with no contact lens on the eye. Corneal damage was studied clinically and by scanning electron microscopy. The retrocorneal distance for a 50% incidence of endothelial damage (LD 50 = lesion distance, 50%) for 3.3 mJ mode-locked pulses was found to be 1.60 mm. All mode-locked pulses of 4.5 mJ focused 0.85 to 1.60 mJ from the endothelium caused damage. In comparison, Q-switched pulses of 12 mJ or less are not likely to damage the cornea if focused more than 0.75 mm from the endothelium. The severe, early effect of mode-locked pulses is edema of endothelial cells in a 0.2- to 0.3-mm diameter circular zone surrounding a 0.1-mm diameter denuded zone with a small central break of Descemet's membrane. By two months, mild and moderate lesions heal with little or no distortion of the endothelial mosaic. Irregular enlargement of endothelial cells surrounding and covering the previously denuded area of severe lesions is caused by both mode-locked and Q-switched treatment. In no case was there clinically significant, persistent damage in the healed monkey corneas.

Endothelial damage thresholds for retrocorneal Q-switched neodymium:YAG laser pulses in monkeys.

Laser pulses were focused within 1 mm of the rhesus monkey corneal endothelium using the Coherent Model 9900 laser at energies of 3, 6, 9, and 12 mJ. Sixteen slightly off-axis pulses were applied with no contact lens on the eye. Corneal damage was studied clinically and by scanning electron microscopy. Q-switched pulses of 12 mJ or less are not likely to damage the cornea if focused more than 0.75 mm from the endothelium. The retrocorneal focal distance for a 50% incidence of endothelial damage for 6, 9, and 12 mJ pulses was found to be less than 0.5 mm. For 3 mJ pulses, it was less than 0.25 mm. The severe early effect of suprathreshold pulses is edema of endothelial cells in a 0.2- to 0.6-mm diameter circular zone surrounding a small central pit through Descemet's membrane. At two months, irregular enlargement of endothelial cells surrounding and partially covering the persistent pit exists at sites of severe damage. The extent of the longer-term change is proportional to the severity of the original insult, but in no case was there clinically significant, persistent damage in the healed corneas.

Corneal crystalline deposits and drusenosis associated with IgA-kappa chain monoclonal gammopathy.

An unusual case is presented in which corneal deposits in mid-to-deep stroma with Doyne's posterior pole drusenosis are the initial signs of an IgA-kappa monoclonal gammopathy. The case has several unique features. Corneal deposits have been described previously with IgG and IgM-kappa light chain gammopathies, but to our knowledge have not been described before with IgA-kappa monoclonal gammopathy. Corneal stromal deposits and associated macular drusen have been described with IgM monoclonal gammopathy, but not previously with IgA monoclonal gammopathy. Bietti described superficial perilimbal corneal deposits with fundus albipunctatus, whereas the present case shows diffuse central deep corneal deposits with macular drusen.

In vivo incorporation of palmitic acid and galactose in glycolipids of Trypanosoma cruzi epimastigotes.

Incubation of epimastigote forms of Trypanosoma cruzi with (3H)-palmitic acid and (3H)-galactose, respectively, results in the incorporation of both precursors into the lipopeptidophosphoglycan (LPPG) and in at least two glycosphingolipids. Palmitic acid was incorporated into sphinganine and sphingenine, identified after hydrolysis, respectively, of the major and the minor glycosphingolipid. The purified glycosphingolipids labeled with either precursor migrated with a Rf similar to that of a sample labeled by periodate oxidation and borotritide reduction in which sialic acids have been previously characterized. This, together with the fact that the palmitic acid labeled glycosphingolipids were partially hydrolysed with neuraminidase favors a ganglioside-like structure for these compounds.

Carbonic anhydrase inhibitors for prevention of space motion sickness: an avenue of investigation.

Space motion sickness (SMS) is an important medical problem facing NASA's space shuttle program. Two theories that have been advanced to explain SMS are the "fluid shift theory" and the "vestibulo-ocular sensory conflict theory". The "fluid shift theory" pre-supposes an active or passive shift of body fluid to the central nervous system (CNS) and vestibulo-auditory mechanisms. In contrast, the "sensory conflict theory" hypothesizes that unfamiliar accelerational and gravitational inputs from the middle ear conflict with visual inputs and lead to SMS. Carbonic anhydrase inhibitors (CAHI) are known to suppress active production of CSF and may be able to inhibit production of perilymph in the semi-circular canals. Therefore, CAHI may be able to diminish the hypothesized fluid shift to the CNS and inner ear under the fluid shift theory. It is suggested that carbonic anhydrase inhibitors merit clinical investigation to test their usefulness for prophylaxis of space motion sickness and to test the veracity of the fluid shift theory.

Sialoglycolipids in Trypanosoma cruzi.

Mild oxidation of epimastigote forms of T.cruzi followed by sodium borotritide reduction incorporates radioactivity into glycolipid fractions. Column chromatography on silica gel of the chloroform:methanol (2:1) extract separated two main peaks of radioactivity. Treatment with neuraminidase released 30% and 18% of the radioactivity, respectively. Paper chromatography showed peaks of radioactivity with relative migration to NANA7 of 1.33 in fraction A and 1.33 and 1.51 in fraction B. When unlabeled cells were submitted to a Folch extraction, thin layer chromatography of the upper phase showed at least two components detected with the resorcinol-copper reagent. Enzymatic and mild acid hydrolysis released a sialic acid with a migration relative to NANA of 1.22. These results suggest that a substituted sialic acid is present in glycolipids of the epimastigote form of T.cruzi.

Aphakic extended-wear contact lenses after penetrating keratoplasty.

Fifteen aphakic eyes in 15 selected patients who underwent penetrating keratoplasty were successfully fitted with extended-wear contact lenses three to 42 months postoperatively. After an average follow-up of 17 months, there was no graft edema, no microbial corneal ulcers, and no episode of graft rejection. Three eyes developed minor (1 to 2 mm) graft neovascularization; the neovascularization was stable and did not require discontinuation of the contact lenses. Fourteen of the 15 patients had postoperative visual acuities of 20/70 or better; the one patient whose visual acuity was worse than 20/70 had a clear graft but also had senile macular degeneration.

Ocular copper deposition associated with pulmonary carcinoma, IgG monoclonal gammopathy and hypercupremia. A clinicopathologic correlation.

Hypercupremia with central deposition of copper in Descemet's membrane and lens capsule has been reported previously in lymphoproliferative disorders in two cases. A 60-year-old white man presented with visual acuity loss and was found to have an iridescent brown corneal and lenticular discoloration. Laboratory investigation revealed hypercupremia secondary to a poorly differentiated adenocarcinoma of the lung. Presence of copper in the eye was confirmed by specific atomic absorption spectra and histochemical stains of ocular tissue. This appears to be the first report of a carcinoma with associated hypercupremia presenting initially with ocular copper deposition.

Extended-wear soft contact lenses for aphakic correction.

Evaluation of an extended-wear perfilcon A soft contact lens (Permalens) in 299 eyes of 244 patients showed that 266 eyes (89%) were successfully fitted and wore the lenses without important complications (mean follow-up, 23 months; range, four to 48 months). Use of the lens in 33 eyes was discontinued because of transient lens-related problems. "Overcorrected" acuity of 6/12 (20/40) or better (with spectacles plus the contact lens) was achieved in all patients who were without vitreous, retinal, or optic nerve disease. Seventy-six percent of patients could wear the lens for longer than one-month intervals, and 30% removed the lens at four- to six-month intervals. There were no cases of infectious corneal ulcers or scarring or permanent visual loss. Our more limited experience with lidofilcon B lenses (Sauflon PW) (24 eyes) and the silicone lenses (Silsoft) (25 eyes) also showed beneficial results.