Corneal neovascularization after penetrating keratoplasty

The purpose of this study was to delineate the patient and surgical factors that contribute to the development of corneal neovascularization (CNV) after penetrating keratoplasty (PK). Thirty-six eyes of 36 patients with no antecedent CNV were enrolled in the study. Grafts were sutured to the host with 16 10-0 nylon sutures with the knots buried alternately in either the host or donor corneal stroma. Multiple perioperative factors were recorded for each patient, and at each postoperative visit systematic corneal drawings were used to follow the development of neovascularization. The stroma adjacent to each suture of each graft was given a neovascularization score based on the extent of vessel growth toward the wound interface. Univariate and multivariate analyses were performed, including generalized estimating equations logistic regression where each eye is considered a cluster of observations. Thirty-four patients without preoperative CNV or inflammation were followed prospectively for 6-9 (mean, 7) months after PK. Fourteen eyes (41%) developed some degree of CNV. Indication for keratoplasty, age, gender, phakic status, and size of donor button were not risk factors for CNV development. The most significant risk factor identified for any degree of CNV was placement of the suture knot in the host stroma (p = 0.00007), with the overall relative risk of CNV associated with these knots over 2 (95% confidence interval, 1.1-4.2). Furthermore, the mean recipient size in eyes with postoperative CNV was larger than eyes that did not develop neovascularization (p = 0.015), and active blepharitis was associated with a fivefold increase in the risk of developing CNV to the wound edge (p = 0.008). Embedding suture knots in the host stroma, active blepharitis, and a large recipient bed are significantly associated with postkeratoplasty CNV.     

Retrephination keratoplasty for high astigmatism after penetrating keratoplasty

PURPOSE: We report preliminary results of a new procedure for correcting high astigmatism after penetrating keratoplasty. METHODS: The procedure entails full-thickness trephination along the original donor-recipient junction with careful suturing in a combined interrupted and running fashion. Four eyes of four patients with severe astigmatism and myopia after penetrating keratoplasty underwent the procedure. RESULTS: High preoperative cylinder ranging from 4.50 to 16.00 D (mean 9.00 D) was reduced to 0.50 to 3.50 D (mean 1.90 D) at the last examination (between 3 to 6 months). Spherical equivalent myopia ranging from -2.00 to -10.25 D (mean -4.90 D) was essentially unchanged at plano to -9.00 D (-4.70 D) at the last examination. Overall, there was a mean refractive cylinder reduction of 7.10 D (79%). CONCLUSION: Retrephination after penetrating keratoplasty appears to be an acceptable alternative for correcting high astigmatism, and had only a small effect on the level of myopia.     

Cyclocryotherapy for refractory glaucoma after penetrating keratoplasty

Twenty-eight patients (28 eyes) with secondary glaucoma following penetrating keratoplasty and failed to respond to anti-glaucoma drugs and routine filtering procedures were performed with cyclocryotherapy by nitrogen monoxide. All patients were followed up for more than one year. The results showed intraocular pressure was well controlled in 89% of the eyes, graft remained clear in 85%, and visual functions are preserved in 82% of the patients. Our study suggests that precisely controlled temperature, time, and extent of cryotherapy, and post-operative anti-rejection agents be the key factor to success. Over-treatment, which may lead to atrophy of the eye, must be avoided. It should not be given up flowing under-treatment in the initial procedure.     

Recurrent Meesmann''s corneal epithelial dystrophy after penetrating keratoplasty

Endoscopic treatment of chronic pancreatitis has drawn benefits from endoscopic procedures previously described for the main bile duct. Endotherapy is developing throughout the world. Cyst drainage procedures certainly represent the largest step forward in that non-surgical approach, whatever it is either direct (through the stomach or the duodenum) or indirect through the papilla in the duodenum. This procedure gives similar results to surgery with a lower morbidity. Pancreatic duct drainage associated with stone clearance is feasible and provides good results which have not yet been compared with those obtained thanks to surgery. Nonetheless, when the duct is not widely dilated it has been proven to be a satisfactory alternative to surgery. By contrast, chronic cholestasis does not appear to be a good indication of endotherapy.     

Laser in situ keratomileusis for moderate and high myopia and myopic astigmatism

OBJECTIVE: This study evaluated the predictability, stability, and safety of laser in situ keratomileusis (LASIK) in myopia and myopic astigmatism. DESIGN: The study design was a prospective, unmasked, nonrandomized clinical trial. PARTICIPANTS: Participating were 25 patients with myopia (37 eyes) with astigmatism of less than 1.00 diopter (D), divided into 3 subgroups (-5.00 to -9.90 D, 8 eyes; -10.00 to -14.90 D, 10 eyes; -15.00 to -29.00 D, 19 eyes), and 37 patients with myopia (56 eyes) with corneal astigmatism of 1.00 to 4.50 D, divided into 3 subgroups (-5.00 to -9.90 D, 12 eyes; -10.00 to -14.90 D, 24 eyes; -15.00 to -29.00 D, 20 eyes). INTERVENTION: LASIK was performed using the Automatic Corneal Shaper and the Keracor 116 excimer laser. MAIN OUTCOME MEASURES: Visual acuity, manifest refraction, central corneal islands, ablation decentration, and patient satisfaction were measured. RESULTS: At 12 months, predictability, regression between 1 and 12 months, uncorrected visual acuity (UCVA), loss of two or more lines of corrected visual acuity, and patient satisfaction of the spherical (toric) groups are reported. Subgroups -5.00 to -9.90 D: 100% (75%) +1.00 D; regression less than or equal to 1.00 D in 100% (91.7%); UCVA greater than or equal to 20/40 in 87.5% (70%); none lost two or more lines; 100% (84%) highly satisfied. Subgroups -10.00 to -14.90 D: 60% (78.3%) +/-1.00 D; regression less than or equal to 1.00 D in 100% (87%); UCVA greater than or equal to 20/40 in 77.8% (86.4%); 10% (4.3%) lost two lines; 90% (91%) highly satisfied. Subgroups -15.00 to -29.00 D: 38.9% (21.4%) +/-1.00 D; regression less than or equal to 1.00 D in 72.2% (64.3%); UCVA greater than or equal to 20/40 in 33.3% (40%); 5.6% (7.1%) lost two lines; 78% (50%) highly satisfied. Differences of predictability and change of manifest refraction between subgroups of -5.00 to -9.90 D and -15.00 to -29.00 D were statistically significant. Central islands (decentrations) were observed in 17% (5.6%) of eyes of the spherical and in 16% (4.1%) of the toric group. Overall, the corneal interface was visible in 8.2%. CONCLUSIONS: The LASIK method used in this study showed stability of manifest refraction and adequate uncorrected central visual acuity in a large percentage of patients with myopia up to -15.00 D. Corneal stability was not as uniform. Central corneal islands were observed in a sizable minority of patients despite pretreatment. For myopia greater than 15.00 D, accuracy and patient satisfaction were sufficiently poor to advise against using the authors' treatment technique in these groups. Visually significant microkeratome and laser-related problems were noted in a smaller percentage of patients. Patients with astigmatism correction were less pleased with results than were patients who received spherical corrections.     

Laser in situ keratomileusis for myopia and astigmatism: 6 month results

The increasingly popular immunohistochemical techniques for assay of the estrogen receptor (ER) allow localization of receptor positivity to specific cell populations. Heterogeneity of the ER in tumor cell populations may have important implications for analytic cell selection and for prognosis in ER-positive carcinomas. We studied 84 tissue blocks for level-to-level and geographic heterogeneity within level of the ER and cytokeratin by staining alternate serial sections for ER and cytokeratin. Distribution of ER and cytokeratin positivity was manually assessed. Homogenous positive staining was seen in 63 of 84 cases for ER and 71 of 84 cases for cytokeratin. Distinct geographic variability constant from level to level was seen in 7 cases for ER. In each of these cases, the cell populations stained uniformly for cytokeratin. Artifactual heterogeneity seemed to be uncommon for ER. Automated image analysis and manual ER estimation resulted in more positive cases than did the dextran-coated charcoal (DCC) technique. Interobserver correlation for the manual method seemed high, as did correlation between the manual method and image analysis. Because a majority of the immunohistochemical staining heterogeneity for ER seemed to be biologic, we believe it may mark carcinomas that are less responsive to tamoxifen and more likely to progress than would be predicted by more traditional methods of ER analysis.     

Laser in situ keratomileusis: literature review of a developing technique

We reviewed papers published in peer-reviewed journals describing techniques and results of laser in situ keratomileusis (LASIK) and summarized the instruments used, nomograms, preoperative and postoperative refractions, predictability, outcome, safety, and complications. We performed a similar review of abstracts published in the abstract books of the 1996 meeting of the International Society of Refractive Surgery, the 1997 meeting of the Association for Research in Vision and Ophthalmology, and the 1997 meeting of the American Society of Cataract and Refractive Surgery. The number of LASIK and photorefractive keratectomy (PRK) patients described in the abstracts were sorted by city. Mean weighted latitudes were calculated and compared for each procedure. The mean preoperative refraction in the papers was -12.59 diopters (D), which was statistically higher than that in the abstracts, -8.71 D (P < .001), and the mean postoperative refraction, -1.10 and + 0.93 D, respectively. The mean percentage of cases within +/- 1.00 D was 67.0% in the papers and 82.5% in the abstracts. Uncorrected visual acuity (UCVA) of 20/40 or better was achieved in 49.2% of eyes in the papers and 83.2% of those in the abstracts; a UCVA of 20/20 or better was achieved in 22.0 and 56.6%, respectively. The portion of eyes that lost two or more lines of best corrected visual was 8.0% in the papers and 0.9% in the abstracts. Complications in the papers included irregular flap (4.0%), incomplete cut (2.5%), free cap (4.9%), perforated lenticule (2.6%), short flap (3.0%), sliding flap (1.4%), interface debris (6.8%), central island (5.3%), decentration (4.7%), epithelial ingrowth (4.3%), induced astigmatism (5.1%), wrinkles (5.9%), haze (8.7%), night vision problems (14.0%), and reoperation (8.2%), Mean latitude for LASIK cases (27.00 degrees +/- 13.73 [SD] was significantly lower than that for PRK cases (42.85 +/- 11.7 degrees). Visual outcomes of LASIK surgery show significant improvements when recent abstracts are compared with published papers. This may reflect continued improvement in the surgical techniques, surgeons' skills, and visual outcomes.     

Central focal interface opacity after laser in situ keratomileusis

BACKGROUND: The acute onset of a focal central interface opacity with visual loss following LASIK has not been described in the peer reviewed literature. Non-peer reviewed reports of various inflammatory lesions have been recorded. METHODS: We describe three cases in which an acute focal stromal interface opacification was identified within 1 week of laser in situ keratomileusis (LASIK). Each case was performed by a different surgeon on a different day, but using the same method, materials, and the Summit Apex Plus excimer laser. Immediately after surgery, all eyes were normal with good unaided vision. The appearance of the central stromal opacity was associated with acute visual deterioration. Preoperative and postoperative cycloplegic refractions, videokeratography, and postoperative slit-lamp biomicroscopy were performed. Each case was treated with intensive topical corticosteroids. RESULTS: Each case demonstrated a central circular opacity in the interface between corneal flap and stromal bed, with associated variable stromal thinning. Resolution of the pathological process followed 2 to 4 weeks of treatment with topical corticosteroids and subsequent improvement in slit-lamp biomicroscopy, corneal topography, and vision. Etiology was uncertain. CONCLUSION: Central interface opacification is a rare but visually important inflammatory complication of LASIK.     

Corneal wound healing after laser in situ keratomileusis in rabbits

BACKGROUND: The aim of this study was to characterize the cell biology of wound healing in rabbit corneas subjected to laser in situ keratomileusis (LASIK). METHODS: Rabbit corneas underwent LASIK with various multizone photoablations or only a lamellar keratotomy followed by repositioning of the flap. We looked for indications for an active wound healing process. Immunohistochemistry for the extradomain A cellular fibronectin (EDA-cFn) or tenascin (Tn) and routine histology were examined. RESULTS: Four days after LASIK or lamellar keratotomy followed by repositioning of the flap, epithelial plugs and prominent keratocytes as well as Tn and EDA-cFn immunoreactions-indicative of a wound-healing process-appeared in the wound margins. Epithelial plugs were less conspicous, and prominent, presumably activated, keratocytes were no longer identified at the wound margin at 2.5 and 5 months after wounding. However, EDA-cFn and Tn immunoreactivities could still be observed. Only the stromal cells located in the periphery of the flap and in relatively close contact with the epithelium were surrounded by scar tissue expressing immunoreactivity for EDA-cFn or Tn. The central corneal stroma was devoid of scar tissue. CONCLUSION: Results indicate that the wound healing reaction after LASIK takes place only at the periphery of the microkeratome wound, leaving the central optical zone clear.     

Pellucid marginal corneal degeneration 12 years after penetrating keratoplasty for keratoconus

Historically the divisions between the mental health and substance abuse fields have been so deep that attempts to provide coordinated treatment across service sectors for people with dual diagnoses of psychiatric disorder and substance use disorder have failed. The authors describe a program in Maine designed to develop collaboratives, or communities of providers, who work together to offer coordinated mental health and substance abuse treatment and support. Surveys of provider agencies in one collaborative conducted one year and two years after the collaborative was established showed an increase in interagency referrals, joint assessments of clients, and jointly sponsored training and client services.     

The influence of glaucoma history on graft survival after penetrating keratoplasty

BACKGROUND: It was the purpose of this retrospective study to evaluate the effect of a preoperative history of glaucoma on graft survival after penetrating keratoplasty. PATIENTS AND METHODS: Six hundred and forty-six penetrating keratoplasties with generally good prognosis were analyzed retrospectively. Indications for surgery were corneal dystrophy, degeneration and scarring. Only first keratoplasties in corneas without severe vascularization or acute inflammation were included. Surface disorders, a history of herpes or Acanthamoeba keratitis were further exclusion criteria. Keratoplasties were performed only if glaucoma seemed to be controlled preoperatively. Graft survival ratios were calculated according to Kaplan and Meier, and statistical significance was evaluated by means of the log-rank test. RESULTS: With a glaucoma history the estimated 3-year graft survival rate was 71%, in contrast to 89% without such a history. This difference was statistically significant (P < 0.001). There was no difference between the groups with respect to immune reactions. With a glaucoma history, postoperative episodes of glaucoma decompensation were responsible for half of the graft failures. CONCLUSIONS: A preoperative history of glaucoma affects graft prognosis negatively, presumably through a negative influence of postoperatively elevated intraocular pressure on a vulnerable graft endothelium, and not by an increase in immune reactions. Therefore, keratoplasties in eyes with glaucoma are high-risk procedures and glaucoma has to be monitored more efficiently pre- and postoperatively.     

Visual improvement as a function of time after lamellar keratoplasty for keratoconus

PEFR is a simple and reliable way of following patients with bronchial asthma and other obstructive airway diseases. Normal data is available for Caucasian and North Indian children but not for ethnic South Indian children. We, therefore, measured Peak Expiratory Flow Rate (PEFR) in 345 healthy South Indian children aged 4-15 years, using the Wright mini peak flow meter. A nomogram was constructed relating PEFR to height. Prediction equations for PEFR using height alone or height, age and weight were determined for both sexes. The prediction equation for boys based on height alone was PEFR = 4.08 height (cm)--284.55 and for girls was PEFR = 3.92 height (cm)--277.01.     

Positive donor rim culture in penetrating keratoplasty

A 3-year retrospective study on the risk factors of positive donor rim cultures in penetrating keratoplasty was performed. One thousand and ninety-seven consecutive donor rim cultures were reviewed from the period between June 1990 and October 1993 to determine the rate of culture positivity. The sex, age, diabetes status, use of respirator at time of death, cause of death, harvesting technique, storage time, and corneal storage medium utilized for the donors with positive donor rim culture were compared to those for 100 randomly selected culture negative donor controls. Logistic analysis was performed to eliminate confounding effects. Forty-six of the 1,097 (4.19%) donor rim cultures were positive. We found an association between the in situ technique for donor harvesting and culture negativity (p = 0.03). None of the other donor characteristics was associated with culture positivity. None of the 46 recipients who received the positive culture corneas developed endophthalmitis. In situ cornea harvesting promotes less contamination than enucleation and enriched gentamicin and streptomycin storage medium may further decrease donor rim culture positivity.     

Gelatinase B and A expression after laser in situ keratomileusis and photorefractive keratectomy

OBJECTIVE: To compare the expression of gelatinases in the corneal epithelium and stroma after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). METHODS: Rabbit eyes were treated with LASIK (n=11), PRK (n=12), or corneal flap construction (n=12); 4 eyes served as unwounded controls. Zymography was performed on the central epithelium and the stroma 1, 3, and 7 days after surgery to determine the expression of gelatinases. RESULTS: Epithelial expression of gelatinase B in the LASIK group (0%-25%) was lower than that in the PRK group at all time points (50%-100%) and was identical to the corneal flap group. Stromal expression of gelatinases A and B was similar after LASIK and PRK, but was minimal after corneal flap construction at all time points. Epithelial expression of gelatinase A was similar for the first 3 days after LASIK and PRK but not thereafter. CONCLUSIONS: Gelatinase B epithelial expression was up-regulated after PRK but not after LASIK. Gelatinase B stromal expression was up-regulated after both procedures. CLINICAL RELEVANCE: Differences in wound healing and subepithelial scarring after these 2 procedures may be related to gelatinase B.