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Biomedical subjects

H Dwight Cavanagh

Publications and source records attributed to H Dwight Cavanagh.

At least 19 recordsLinked to original sources
PubMed2007

Microbial keratitis pathogens and antibiotic susceptibilities: a 5-year review of cases at an urban county hospital in north Texas.

PURPOSE: To review the epidemiology, risk factors, microbiologic spectrum, and outcomes of microbial keratitis and to compare cases in which a causative organism is identified to those determined to be sterile during a 5-year period at a large county hospital in north Texas. METHODS: A retrospective chart review of cases of microbial keratitis at Parkland Memorial Hospital between January 2000 and December 2004. RESULTS: During this 5-year period, 132 eyes of 131 patients underwent 139 corneal scrapings for presumed microbial keratitis and an organism was reported in 73 (52.5%) cultures. Including abnormal confocal microscopy results, a causative organism was determined in 78 (56.1%) cases. At least one risk factor was present in 115 (87.1%) cases, with the most common risk factors being preexisting ocular disease, contact lens wear, and a history of trauma. Nearly 5% of patients reported a history of cocaine use. Gram staining correctly identified the organism in 20 (28.6%) culture-positive cases, and Pseudomonas aeruginosa was the most common isolate, followed by Staphylococcus aureus. The rate of S. aureus resistance to fluoroquinolones (15.4%) was similar to rates previously reported from the early to mid 1990s, but less than those reported from the late 1990s. Severe complications were more common in the nonsterile subgroup (34.2%) than in the sterile (16.9%) subgroup (P=0.041). Although the rate of acute intervention was higher in the nonsterile subgroup (27.4%) than in the sterile subgroup (20.3%), this difference was not statistically significant (P=0.461). Mean logMAR visual acuity was 1.451 (Snellen equivalent, 20/563) at presentation and 1.062 (20/231) at the last follow-up visit (P<0.001). Presenting and final visual acuities were significantly better in the sterile subgroup than in the nonsterile subgroup (P<0.001 and P=0.002, respectively). CONCLUSIONS: When a causative organism is not identified in microbial keratitis, visual acuity is not as severely affected, and fewer severe complications occur. Antibiotic resistance to fluoroquinolones and aminoglycosides, though not common, still deserves consideration in the treatment of microbial keratitis.

Adolescent↗
PubMed2007

Updates in Acanthamoeba keratitis.

PURPOSE: Acanthamoeba keratitis is a potentially blinding microbial disease that has been increasing in incidence during the past two decades. Prognosis of this serious disease had been dismal, but improvement in diagnosis, a better understanding of the natural course of the disease, and recent introduction of multiple and effective therapeutic agents have resulted in improvement of visual outcomes. METHODS: A review of literature pertaining to Acanthamoeba keratitis. RESULTS: Contact lens wear and exposure to contaminated water sources remain the most important risk factors; however, in vivo confocal microscopy and improved biomicroscopic screening have proven instrumental in accurate early diagnosis. Complications of Acanthamoeba keratitis include dacryoadenitis, corneal melting and scarring, severe secondary glaucoma, cataract, and chronic anterior segment inflammation that can rarely lead to reactive blinding retinal ischemia. Combination chemotherapeutic agents have been shown to be more effective than monotherapy, whereas rehabilitative surgery such as penetrating keratoplasty is best performed on a quiet eye free of ocular inflammation and with no residual amoebae. CONCLUSIONS: Increased suspicion by clinicians for Acanthamoeba and confocal microscopy have allowed more rapid and accurate diagnosis; treatment with multiple antiamoeba drugs is essential to disease resolution. Provided there are no residual amoebae after treatment, penetrating keratoplasty has been successful in visual rehabilitation. Secondary glaucoma occurs frequently and may require drainage procedures for control of intraocular pressure. Posterior complications are rare but may lead to ischemic retinitis.

Acanthamoeba↗
PubMed2006

Severe reactive ischemic posterior segment inflammation in acanthamoeba keratitis: a new potentially blinding syndrome.

OBJECTIVE: To describe a newly recognized clinical syndrome in Acanthamoeba keratitis consisting of severe reactive ischemic posterior segment vascular inflammation. DESIGN: Noncomparative, retrospective, single-institution observational case series. PARTICIPANTS: Five eyes of 5 patients with Acanthamoeba keratitis. METHODS: A retrospective review of the records of patients diagnosed with Acanthamoeba keratitis between January 1, 1995, and December 1, 2005, was conducted to identify those who underwent eventual enucleation. Five enucleated eyes of 118 eyes with Acanthamoeba keratitis were identified. MAIN OUTCOME MEASURES: History, clinical examination results, available laboratory study results, and histopathologic examination results. RESULTS: Histopathologic examination showed Acanthamoeba cysts in the cornea in 4 eyes, whereas it failed to demonstrate amebic cysts or trophozoites in the posterior segment of all eyes studied and unexpectedly revealed chronic chorioretinal inflammation with perivascular lymphocytic infiltration and diffuse neuroretinal ischemia in 4 of 5 eyes. Retinal artery thrombosis was present in 3 of the 4 involved eyes, and central retinal artery and vein thrombosis was found in 1 eye. Hematologic studies in 3 patients showed abnormal anticardiolipin antibody levels in 1 patient and factor V Leiden deficiency in another. CONCLUSIONS: Prolonged Acanthamoeba keratitis can result in a severe sterile ischemic posterior segment inflammation that is potentially blinding, especially in patients with underlying hypercoagulation disorders.

Acanthamoeba Keratitis↗
PubMed2006

Current concepts: contact lens related Pseudomonas keratitis.

Despite the development of silicone hydrogel lenses, Pseudomonas aeruginosa (PA) continues to be the leading cause of contact lens related microbial keratitis. Understanding the pathogenesis of PA-mediated corneal infection is critical to the development of new prevention and treatment strategies. Recently intracellular invasion of surface corneal epithelial cells by PA has been revisited as an important element in the infection process. This review identifies the mechanisms involved, and examines the roles of the lens, hypoxia alone, PA stain, cystic fibrosis transmembrane receptor protein (CFTR), and membrane lipid rafts in mediating intracellular invasion in both in vitro and in vivo conditions. Non-toxic blockade of raft formation in vitro or in vivo effectively abrogates PA internalization and may represent a unique, new strategy to prevent or ameliorate lens-related PA microbial keratitis.

Animals↗
PubMed2006

Ocular surface restoration using non-surgical transplantation of tissue-cultured human amniotic epithelial cells.

PURPOSE: To assess the effect of tissue-cultured human amniotic epithelial cells (AECs) in restoring the ocular surface, transplanted using a collagen shield seeded with AECs supported by a soft contact lens. DESIGN: Prospective interventional single-institutional case series with crossover controls. METHODS: Three eyes in three patients were identified with persistent corneal epithelial defects (PEDs) refractory to medical therapy. Two cases were secondary to neurotrophic keratopathy, while one case was attributable to longstanding alkali injury. AECs were isolated from serologically screened donor human placenta, seeded onto collagen corneal shields, and incubated in tissue culture medium for 7 days. These collagen shields were placed over the PED and supported by an overlying soft contact lens. The collagen shields dissolved by 72 hours, and the contact lenses were removed after this time. This cycle was repeated every week until healing was achieved. As a crossover control, collagen shields without AECs were placed in the same eye 1 week before placing collagen shields containing AECs. The PED was assessed by vital staining and slit-lamp color photography. RESULTS: The PEDs had a mean duration of 4 months and involved 20% to 37% of the corneal surface area, one case secondary to longstanding alkali injury and two cases attributable to neurotrophic keratopathy. No change in PED size was observed in those control eyes receiving collagen shields without AECs. Complete resolution of the PED was seen after two cycles of AEC-seeded collagen shield in one case, and four cycles in two cases, from 7 to 12 weeks following treatment in all patients. No loss of visual acuity was seen and clinical improvement was maintained in all cases, with a mean follow-up of 6.3 months. CONCLUSIONS: Nonsurgical transplantation of tissue-cultured AECs on a collagen shield provides a promising approach to restoring the ocular surface in cases of PED.

Adult↗
PubMed2006

Confocal assessment of the corneal response to intracorneal lens insertion and laser in situ keratomileusis with flap creation using IntraLase.

PURPOSE: To assess the response of the cornea to hydrogel intracorneal lens (ICL) insertion or laser in situ keratomileusis (LASIK) with IntraLase (IntraLase Corp.) at the cellular level. SETTING: Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. METHODS: Twenty patients (29 eyes) were evaluated by in vivo confocal microscopy 1 to 6 months postoperatively: 20 eyes had LASIK with flap creation by IntraLase, and 9 eyes had ICL insertion (8 following IntraLase). RESULTS: For LASIK with IntraLase, keratocyte activation and/or interface haze was detected in 8 of 20 eyes. The remaining eyes had interface particles but no cell activation. Keratocyte activation was generally limited to a few cell layers adjacent to the interface. However, 2 patients exhibited multiple layers of activation and increased extracellular matrix (ECM) reflectivity (haze) surrounding the interface by confocal microscopy. Both patients also had clinical haze and photophobia. For ICLs, following insertion, 5 of 9 eyes had activated keratocytes adjacent to the implant surfaces. The largest amount of cell activation and ECM haze detected by confocal microscopy was in 2 patients with significant clinical haze. Structures with an epithelioid morphology were detected on some implant surfaces. Epithelial thickness was 33.3 microm +/- 2.3 (SD) in the ICL eyes and 49.2 +/- 6.5 microm in the LASIK with IntraLase eyes. CONCLUSIONS: Both LASIK with IntraLase and ICL insertion following IntraLase induced keratocyte activation, which may underlie clinical observations of haze in some patients. Intracorneal lens implant also induced thinning of the overlying corneal epithelium.

Biocompatible Materials↗
PubMed2006

Tandem scanning confocal corneal microscopy in the diagnosis of suspected acanthamoeba keratitis.

OBJECTIVE: To evaluate the role of in vivo corneal tandem scanning confocal microscopy (TSCM) in the definitive diagnosis of suspected Acanthamoeba keratitis (AK). DESIGN: Noncomparative interventional single-institution case series. METHOD: A retrospective case review of patients consecutively referred with suspected AK and undergoing corneal TSCM was performed. RESULTS: A total of 63 cases that met the inclusion criteria for the study were referred for diagnostic evaluation. Tandem scanning confocal microscopy demonstrated Acanthamoeba cysts/trophozoites in 54 cases and fungal hyphae in 2, whereas 1 case was positive for both Acanthamoeba and fungus. Culture of the cornea or contact lenses was carried out in 35 cases, 9 of which were positive for Acanthamoeba. Six of the TSCM-positive cases also underwent corneal biopsy, being positive for Acanthamoeba in only 2. Six patients were negative for Acanthamoeba on TSCM, the etiology being fungal in 1 case, as shown by subsequent culture. One patient was positive on culture for Acanthamoeba but falsely negative by TSCM, which was limited by poor cooperation during the examination. Two cases initially masqueraded as Acanthamoeba keratitis but showed fungus on TSCM. Mean follow-up was 14 months. CONCLUSION: In vivo corneal TSCM can establish the diagnosis of Acanthamoeba keratitis rapidly and noninvasively, particularly when conventional microbiology is inconclusive.

Acanthamoeba Keratitis↗
PubMed2006

Bcl-2 and Bax regulation of corneal homeostasis in genetically altered mice.

PURPOSE: The antiapoptotic protein Bcl-2 and its proapoptotic counterpart Bax may play an important role in the regulation of corneal epithelial renewal. To understand the physiologic importance of Bcl-2 and Bax in the healthy cornea, epithelial and stromal thickness, proliferation, and surface cell exfoliation rates were examined in the central cornea of genetically altered mice overexpressing Bcl-2 and lacking Bax. METHODS: Adult Bcl-2 transgenic (n = 55) and Bax knockout (n = 82) mice and wild-type controls were clinically prescreened at no less than 2 months of age for any ocular developmental abnormalities. Polymerase chain reaction was used to confirm genotype. Corneal epithelial renewal was examined by in vivo tandem scanning confocal microscopy to measure total corneal and sublayer thickness and by immunohistochemistry on whole mount corneal tissues to determine basal epithelial cell proliferation using 5-bromo-2-deoxyuridine (BrdU) and surface cell exfoliation with a Calcein AM-Ethidium homodimer assay (live/dead). Stained corneas were scanned with a laser scanning confocal microscope, and images were digitized, and cell counts were obtained. Levels of Bcl-2 protein were assessed by Western blots. RESULTS: No significant changes in proliferation or cell death were found in either group compared to wild-type littermate controls; however, epithelial and stromal thicknesses were greater in the Bcl-2 transgenic group compared to wild-type and decreased in the Bax knockout. Western blotting confirmed that there was no change in the level of Bcl-2 expression in the corneal epithelium in the Bcl-2 transgenic or Bax knockout strains. CONCLUSIONS: The significant difference in epithelial and stromal thickness suggests a functional role for Bcl-2 and Bax in the maintenance of corneal homeostasis; however, the lack of significant alterations in proliferation, cell exfoliation, and levels of Bcl-2 protein in the adult corneal epithelium suggest that these phenotypic changes are a result of a new stable homeostatic equilibrium (proliferation + migration = shedding). Additional experiments to delineate the role of Bcl-2 and Bax during development and in the adult cornea are necessary.

Animals↗
PubMed2006

Prolonged hypoxia induces lipid raft formation and increases Pseudomonas internalization in vivo after contact lens wear and lid closure.

PURPOSE: To investigate the effects of hypoxia on lipid raft formation and Pseudomonas aeruginosa internalization by the corneal epithelium with and without the physical effects of contact lens wear. METHODS: One eye of each rabbit was randomly fitted with a low-Dk rigid gas-permeable contact lens (LDCTL) or closed with sutures, with the other as a control. After 1 day or 3 days, the rabbits were killed and bacterial invasion was assessed by gentamicin survival assay. Lipid rafts were identified by staining with FITC-conjugated beta subunit of cholera toxin. Corneal epithelial Bcl-2 expression was detected by Western blotting; surface epithelial cell size and thickness (epithelium and stroma) were measured by confocal microscopy. RESULTS: One-day hypoxia induced no significant changes in P. aeruginosa internalization, Bcl-2 expression, or lipid raft formation except in one of four eyelid-closed eyes. After 3 days, P. aeruginosa internalization was increased significantly (P < 0.05) in LDCTL-wearing eyes and not significantly (P = 0.10) increased in eyelid-closed eyes. Both 3-day test conditions also induced lipid raft-forming cells that bound P. aeruginosa, albeit in different regions of the cornea (peripherally in LDCTL-wearing eyes and centrally in closed eyes); did not alter epithelial thickness or surface cell size; and appeared to decrease epithelial Bcl-2 expression. CONCLUSIONS: This is the first direct comparison in vivo between two different methods inducing hypoxia on the corneal surface. Association of P. aeruginosa internalization with lipid raft formation in both conditions suggests a critical link among prolonged hypoxia, lipid raft formation, and susceptibility to P. aeruginosa infection. However, different distribution patterns of lipid raft-forming cells suggest physical effects of contact lens wear may direct localization of lipid raft-associated P. aeruginosa internalization on the corneal surface.

Animals↗
PubMed2006

Risk factors for infectious disease in corneal transplant screening.

PURPOSE: To identify potential medical and behavioral risk factors associated with infectious disease seropositivity in potential corneal donors using an extensive questionnaire completed by the next of kin. METHODS: Retrospective review of medical history and behavioral risk assessment questionnaire and microbiology data for potential corneal donors seropositive for hepatitis B, hepatitis C, human immunodeficiency virus, human T-cell leukemia virus and syphilis as compared to controls. RESULTS: Tobacco use, cigarette smoking, chest pain and heart disease are each associated with corneal donor seropositivity (P < 0.05). Vaccination in the last twelve months is inversely associated with infectious disease (P < 0.05). Statistically significant factors associated with hepatitis C positive donors include: cigarette use, illicit drug use, chest pain, cardiac medications, kidney stones and lung disease (P < 0.05). Factors most often associated with transmission of this disease panel (such as intravenous drug use, sexual contact with prostitutes and history of blood transfusion) are often not identified by the next of kin in the questionnaire. CONCLUSIONS: While there are questionnaire identified risk factors associated with seropositivity in this study, their clinical usefulness is unclear. Many factors crucial to the elimination of potentially infectious donor tissues are not identified in the posthumous history typically completed by next of kin. These questionnaires alone do not provide exclusion criteria for elimination of potentially infectious tissues from the donor pool.

Communicable Diseases↗
PubMed2006

Confocal assessment of the effects of fourth-generation fluoroquinolones on the cornea.

PURPOSE: To evaluate the toxicity of fourth-generation fluoroquinolone antibiotic solutions on the rabbit corneal epithelium. METHODS: In vivo confocal microscopy was used to assess epithelial structure in 18 rabbits, and tight junction integrity of superficial epithelial cells was evaluated with ZO-1 labeling in 10 rabbits. Eyes were bathed with commercial solutions of moxifloxacin (Vigamox) or gatifloxacin (Zymar) solution for 3 minutes, rinsed with balanced salt solution, and immediately examined. Balanced salt solution rinsing alone served as the control. RESULTS: A decrease in epithelial cell size was observed after treatment with Zymar (P < 0.05, two-way repeated-measures analysis of variance), but not with Vigamox or the control. Normal ZO-1 organization was observed in controls and eyes treated with Vigamox. ZO-1 staining in eyes treated with Zymar was disrupted, patchy, and generally weaker than that in control eyes. CONCLUSIONS: After short-term, intensive exposure to Vigamox, corneal epithelial integrity and tight junction organization are maintained. Zymar induces a loss of superficial epithelial cells and breakdown of tight junctions under similar conditions.

Animals↗
PubMed2006

Secondary glaucoma associated with advanced acanthamoeba keratitis.

PURPOSE: To describe the association of acanthamoeba keratitis and glaucoma, to establish an incidence of glaucoma in patients with acanthamoeba keratitis, to discuss treatment options and outcomes in these patients, and to describe the histopathologic findings and pathogenesis of glaucoma secondary to acanthamoeba keratitis. METHODS: After Institutional Review Board approval, the charts of all patients suspected of having acanthamoeba keratitis at Aston Ambulatory Center at The University of Texas Southwestern Medical Center were reviewed. Inclusion criteria were as follows: diagnosis of acanthamoeba keratitis by positive confocal microscopy or culture, diagnosis of glaucoma or ocular hypertension secondary to acanthamoeba keratitis, and at least 6 months of follow-up. Exclusion criteria included a previous diagnosis of glaucoma or ocular hypertension and any history of intraocular surgery before the development of glaucoma. The date of keratitis development, pneumotonometry on initial and follow-up examinations, glaucoma medications used, and surgical procedures performed were tabulated. RESULTS: Twenty patients (20 eyes) were included. Six (30%) eyes developed secondary glaucoma during the review period. Of the patients treated for glaucoma with medication alone, the visual acuity of three (75%) of four became light perception or no light perception. Three of six patients required glaucoma drainage device implantation for intraocular pressure control. Of these, the vision of one eye became no light perception, and the other two eyes maintained better than 20/100 vision. Histopathologic examination showed chronic inflammation of the trabecular meshwork and angle closure. No acanthamoeba organisms were found in the angle structures. CONCLUSIONS: The development of secondary glaucoma is not uncommon in acanthamoeba keratitis and is a poor prognostic sign in patients with acanthamoeba keratitis, because most progress to light perception or no light perception vision. Histopathologic findings suggest an inflammatory angle-closure mechanism, apparently without direct infiltration of the organism. The glaucoma associated with acanthamoeba keratitis is often severe and frequently requires surgical intervention for intraocular pressure control and vision preservation.

Acanthamoeba↗
PubMed2006

Evaluation of intrastromal lipid deposits after intacs implantation using in vivo confocal microscopy.

PURPOSE: To assess the structure and location of intrastromal lipid deposits after implantation of Intacs by using in vivo confocal microscopy. METHODS: Seven eyes of six patients were examined by in vivo confocal microscopy 5 years (n = 6) or 2 months (n = 1) after uncomplicated implantation of Intacs for the correction of mild myopia. Selected images from all corneal layers were qualitatively evaluated for structural changes, with special attention paid to areas surrounding the Intacs implants. RESULTS: In the peripheral cornea of eyes examined 5 years after surgery, epithelial and endothelial cell layers appeared normal. Tandem scanning confocal microscopy showed stromal haze surrounding the implants in all eyes examined, but no keratocyte activation was seen. Reflective amorphous or crystalline structures consistent with lipid deposition were detected in all eyes with long-term implantation of Intacs. Deposits were localized to the inner and outer edges of Intacs segments and to the region anterior to the implant. Confocal microscopy did not show any deposits in the eye examined 2 months after surgery, although the region anterior to the implant appeared hazy and edematous. Areas central to the implant appeared normal in all eyes. CONCLUSIONS: The mechanical and physiologic stresses introduced by the implantation of Intacs lead to the accumulation of lipid deposits in the extracellular matrix. By using in vivo confocal microscopy, the location and structure of these deposits can be determined.

Adult↗
PubMed2006

Regulation of Pseudomonas aeruginosa internalization after contact lens wear in vivo and in serum-free culture by ocular surface cells.

PURPOSE: To determine the effects of contact lenses (CLs) and Pseudomonas aeruginosa (PA) infection on localization of cystic fibrosis transmembrane conductance regulator (CFTR) on corneal surface epithelial cells and the association between lipid raft formation and CFTR in mediating PA binding and internalization in ocular surface epithelium. METHODS: CFTR immunolocalization was evaluated in vivo in rabbit corneal-conjunctival epithelium (with/without CL wear) before and after PA exposure and in serum-free human corneal epithelial cell culture (hTCEpi). Lipid raft formation was visualized with Alexa555-conjugated cholera toxin beta-subunit. Lipid raft involvement in PA internalization was assayed in vivo by gentamicin survival assays after topical filipin pretreatment. Involvement of CFTR in PA binding and internalization was evaluated by blockade with CFTR peptides or LPS. RESULTS: CL wear in vivo enhanced anti-CFTR staining, but CFTR localization did not correlate with the PA binding by ocular surface cells. Conjunctival epithelial cells stained for CFTR but did not bind or internalize PA. Corneal epithelial cells in vivo did not stain for CFTR unless challenged by contact lens-induced hypoxia. PA internalization by hTCEpi was significantly inhibited by LPS (P < 0.01), but not by CFTR peptides. Remarkably, normal conjunctival epithelial cells showed lipid raft formation and CFTR staining but did not bind PA. Inhibition of raft formation by filipin blocked PA internalization in vivo after CL wear. CONCLUSIONS: CFTR is not the predominant receptor for ocular surface PA infection, and after hypoxic CL challenge, neither lipid rafts nor CFTR localization alone predicts PA binding; however, lipid rafts are critical to CL-mediated PA internalization.

Animals↗
PubMed2005

Results of penetrating keratoplasty for visual rehabilitation after Acanthamoeba keratitis.

PURPOSE: To assess the results of penetrating keratoplasty in quiet eyes after resolution of Acanthamoeba keratitis. DESIGN: A retrospective interventional case series. METHODS: Penetrating keratoplasty was undertaken in 13 eyes of 13 patients with an average age of 29 +/- 13 years and a history of Acanthamoeba keratitis that was diagnosed by culture and/or confocal microscopy between January 1995 and September 2004. All eyes were observed for at least 3 months (average, 5 months) after the discontinuation of antiamebic therapy that had been administered for at least 4.5 months. In vivo confocal microscopy was used to ensure that no residual amoeba were present before the operation. Two keratoplasties were combined with a valve insertion; five keratoplasties were combined with cataract extraction, and one keratoplasty was preceded by a ciliary laser ablation. RESULTS: Postoperative best-corrected visual acuity ranged from 20/40 to 20/15, with the exception of one eye with advanced glaucoma that did not improve from a preoperative vision of light perception. No eye experienced rejection or amoebic recurrences, and 12 grafts remained clear throughout the follow-up period (8 months to 9 years; median, 23 months). One graft failed at 4 months because of uncontrolled glaucoma. The eye was regrafted, and the graft remained clear during the 28 months of follow-up evaluation. Two eyes with preoperatively diagnosed glaucoma needed subsequent surgery to control their intraocular pressure. CONCLUSION: Penetrating keratoplasty for visual restoration after Acanthamoeba keratitis appears to have an excellent long-term prognosis, provided amoebic infection has resolved and concurrent glaucoma is controlled.

Acanthamoeba↗
PubMed2005

Hyperopic laser in situ keratomileusis in eyes with previous radial keratotomy.

PURPOSE: To assess the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) in eyes with previous radial keratotomy (RK). SETTING: Zale Lipshy University Hospital Laser Center for Vision, University of Texas Southwestern Medical Center, Dallas, Texas, USA. METHODS: Thirty-eight eyes of 25 patients were treated with LASIK for secondary hyperopia after RK using a Visx Star S2, S3, S4, or LADARVision excimer laser. Retreatment was done in 7 eyes. The main outcome measures were manifest refraction spherical equivalent (MRSE), uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), predictability of treatment, and complications. RESULTS: Preoperative mean MRSE was +2.39 diopters (D) +/- 1.28 (SD) (range +0.87 to +6.00 D). At the last visit (25 eyes with minimum follow-up of 12 months, including retreatments), the mean follow-up was 23.3 +/- 7.3 months (range 12 to 34 months), the mean MRSE was +0.11 +/- 0.71 D, and the UCVA was 20/40 or better in 24 eyes (96%). Although no significant change in the mean MRSE was observed, the postoperative mean refractive cylinder showed a gradual increase over the follow-up period. No eye lost more than 2 lines of BSCVA. CONCLUSIONS: Laser in situ keratomileusis was a safe and effective treatment with good predictability for the correction of consecutive hyperopia after RK. Cylindrical errors were difficult to correct, and astigmatic correction tended to regress over time. Retreatments are safe when old flaps were relifted.

Adult↗