Biomedical subjects

F R Hu

Publications and source records attributed to F R Hu.

At least 19 recordsLinked to original sources

PubMed2001

Laser in situ keratomileusis for the correction of myopia and myopic astigmatism.

PURPOSE: To evaluate the efficacy, safety, predictability, and surgically induced astigmatism (SIA) of laser in situ keratomileusis (LASIK) for the correction of myopia and myopic astigmatism. SETTING: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. METHODS: This retrospective study comprised 69 eyes that had LASIK to correct myopia and 74 eyes that had LASIK to correct myopic astigmatism. The excimer laser keratectomy was performed using a Summit Apex Plus machine. Refraction, visual acuity, and computerized corneal videokeratography data from the preoperative and postoperative examinations were collected. The astigmatic change was calculated by the Alpins vector analysis method. RESULTS: The preoperative spherical equivalent at the glasses plane in the myopia and myopic astigmatism groups was -8.08 diopters (D) and -9.73 D, respectively. At 6 months, the spherical equivalent and residual corneal astigmatism were -0.25 D and 0.85 D, respectively, in the myopia group and -0.71 D and 0.82 D, respectively, in the myopic astigmatism group. In the myopia group, 88% of eyes were within +/-1.0 D of the intended myopia correction and in the myopic astigmatism group, 85% were within +/-1.0 D of the targeted spherical equivalent and 90% were within +/-1.0 D of the intended astigmatism correction. The uncorrected visual acuity was 20/40 or better in 94.1% of eyes in the myopia group and 92.5% of eyes in the myopic astigmatism group. The SIA magnitude was 0.66 D with the axis randomly distributed in the myopia group. The mean astigmatism correction index was 0.97, the mean magnitude of error was 0.13 D +/- 0.62 (SD), and the mean angle of error was -3.70 +/- 13.73 degrees in the myopic astigmatism group. CONCLUSION: Laser in situ keratomileusis had similar predictability, safety, and efficacy in the treatment of myopia and myopic astigmatism. The astigmatism correction was effective, but the results suggest that subjective astigmatism of less than 1.0 D need not be treated with the Summit Apex Plus laser.

Adult↗

PubMed2001

Changing indications for penetrating keratoplasty in Taiwan from 1987 to 1999.

PURPOSE: To determine the leading indications for penetrating keratoplasty and to identify changing trends in these indications during the past 12 years. METHODS: We retrospectively performed a chart review of the hospital records of all patients undergoing penetrating keratoplasty at the National Taiwan University Hospital during a 12-year period (1987-1999). When possible, the clinical indication was corroborated by the pathologic report. RESULTS: A total of 770 corneal transplants were performed. The leading indications for penetrating keratoplasty. in order of decreasing frequency, were corneal scars (27.9%), regraft (21.0%), acute necrotizing and ulcerative keratitis (17.9%), pseudophakic or aphakic bullous keratopathy (17.6%), Fuchs' dystrophy (4.5%), and keratoconus (2.5%). A trend of increasing frequency of regraft and acute necrotizing and ulcerative keratitis, a decreasing frequency of corneal scar, and an initially decreasing then increasing frequency of pseudophakic and aphakic bullous keratopathy were found during the 12-year study period. Acute necrotizing and ulcerative keratitis was found to be the most frequent indication for regraft. CONCLUSION: In this series, corneal scars, regraft, and acute necrotizing and ulcerative keratitis were the leading indications for penetrating keratoplasty. A changing incidence of pseudophakic and aphakic bullous keratopathy noted during the study period was related to the type of intraocular lens implanted and the method of cataract surgery performed. This study found a comparatively high frequency of acute necrotizing and ulcerative keratitis and an extremely low frequency of keratoconus compared with previous reports.

Adolescent↗

PubMed2001

The cornea in young myopic adults.

AIMS: To further understand the effect of refractive error on the corneal dimensions and function. METHODS: Corneal curvature, corneal thickness, and axial length measurements were performed, as well as specular microscopy and fluorophotometry, on patients with various refractive statuses. 216 subjects, mean age 22.2 (SD 4.2) years, were examined. Patients with previous contact lens wear history, external eye diseases, as well as previous ocular surgeries, were excluded. RESULTS: The corneas were flatter in eyes with longer axial length (r = -0.22, p = 0.003). Eyes with more myopic spherical equivalent had longer axial length (r = -0.90, p <0.001) as well as less corneal endothelial density (r = 0.20, p = 0.037). Corneal endothelial density decreased in eyes with longer axial length (r = 0.24, p = 0.019); however, it correlated neither with corneal thickness (r = -0.06, p = 0.59) nor with corneal curvature (r = -0.07, p = 0.52). The corneas had a mean corneal thickness of 533 (SD 29) microm and were thinner in more myopic eyes (r = 0.16, p = 0.021). The corneas tended to be thinner in eyes with longer axial length. However, the correlation did not reach statistical significance (r = -0.11, p = 0.14). Besides, there was no significant correlation between the corneal thickness and the corneal curvature (r = -0.13, p = 0.093) and the endothelial permeability (r = 0.042, p = 0.69). The corneas with higher endothelial density had larger corneal transfer coefficient (r = 0.26, p = 0.024) and higher permeability to fluorescein molecules (r = 0.28, p = 0.014). Nevertheless, the corneal endothelial permeability did not correlate significantly with either the axial length (r = -0.18, p = 0.11) or the degree of myopia (r = 0.12, p = 0.26). CONCLUSION: Changes in the anterior segments as the eyeball elongates in myopia progression included flatter corneal curvature, decreased corneal thickness, as well as decreased endothelial density. These factors should be considered in refractive surgery.

Adult↗

PubMed2000

Mechanism of abnormal elastin gene expression in the pinguecular part of pterygia.

Elastodysplasia and elastodystrophy are two known manifestations in the conjunctival, ie, pinguecular, part of pterygia. But the mechanisms are still not understood. The purpose of this study is to investigate the mechanism of enhanced elastin gene expression in fibroblasts from the pinguecular part of pterygia, which is related to abnormal elastic fiber expression in the pinguecular part of pterygia. Elastin in surgical specimens of normal conjunctiva and the pinguecular part of pterygia from age-matched patients was detected by immunohistochemical staining. Northern hybridization and quantification of radiolabeled tropoelastin were performed in conjunctival fibroblasts cultured under different doses of ultraviolet (UV) B irradiation, and in cultured pinguecular fibroblasts from pterygia. In vitro translation was also performed to analyze the tropoelastin production in rabbit reticulocyte lysate. The level of tropoelastin in reticulolysates from UV-treated conjunctival and pinguecular fibroblasts of pterygia was higher than in normal conjunctival fibroblasts. The coding sequence and 3'- untranslated region of tropoelastin mRNAs were amplified by reverse transcription-polymerase chain reaction, and mutations were checked by DNA sequencing. Immunohistochemical staining revealed elastin in pinguecular subepithelial connective tissues of pterygia, but not in normal conjunctiva. Tropoelastin mRNA levels were not elevated in cultured pinguecular or conjunctival fibroblasts with or without ultraviolet B irradiation. However, tropoelastin synthesis was enhanced in culture medium of pinguecular and UV-irradiated conjunctival fibroblasts, but not in normal conjunctival fibroblasts. Direct DNA sequencing revealed mutations in the 3'-untranslated region but not in the coding sequence of tropoelastin mRNA, in both pinguecular and UV-irradiated conjunctival fibroblasts. The increased expression of tropoelastin in pinguecular and UV-irradiated fibroblasts is not a result of increased levels of steady-state mRNA, but is a result of posttranscriptional modification of tropoelastin.

3' Untranslated Regions↗

PubMed2000

Surgical results of photorefractive keratectomy with different operative modes.

PURPOSE: To compare the predictability, efficacy, and safety of photorefractive keratectomy (PRK) using different operative modes. SETTING: National Taiwan University Hospital, Taipei, Taiwan. METHODS: One hundred fifty-three eyes of 80 patients who had PRK for myopia with a follow-up of at least 6 months were studied. All patients were sequentially assigned to 1 of the following surgical modes: mode 1: PRK with the Summit OmniMed excimer laser; mode 2: PRK with the Summit Apex Plus laser; mode 3: PRK with the Summit Apex Plus laser with anti-central-island pretreatment. RESULTS: Six months after treatment, a homogeneous topographic pattern was seen in 76% of mode 1 eyes, 70% of mode 2 eyes, and 88% of mode 3 eyes. In the low myopia group (< or =-6.0 diopters [D]), the mean residual refractive error was -0.79 D +/- 0.59 (SD) in mode 1, -0.94 +/- 1.02 D in mode 2, and -0.31 +/- 0.42 D in mode 3. In the high myopia group (>-6.0 D), it was -1.93 +/- 1.51 D, -1.54 +/- 0.88 D, and -0.70 +/- 0.81 D, respectively. Uncorrected visual acuity of 20/25 or better was achieved in 81% of mode 1 eyes, 56% of mode 2 eyes, and 89% of mode 3 eyes in the low myopia group, and in 48%, 28%, and 72%, respectively, in the high myopia group. CONCLUSIONS: Photorefractive keratectomy appears to be a predictable and effective procedure. The best results were achieved with the Summit Apex Plus laser with anti-central-island pretreatment, followed by the Summit OmniMed laser. The Summit Apex Plus laser without anti-central-island pretreatment produced less satisfactory results.

Adult↗

PubMed2000

Impression cytology of pterygium.

The purpose of this study was to study the morphology and cytokeratin expression in the epithelia of pterygia. Impression cytology and immunohistochemical staining with antikeratin antibodies were performed in 32 eyes of 16 patients with pterygia. TUNEL stain and electron microscopy were also performed in surgical specimens ofpterygium. Squamous metaplasia-like epithelial cells were found in all specimens of impression cytology, especially in the head part. These specimens had positive immunostaining by antipancytokeratin antibodies, but not by anti-K12 AK2 mAb. Goblet cells were found around the area of these abnormal epithelial cells. TUNEL-positive cells were found in the epithelia of the pterygial head, but not in the body of pterygia and normal conjunctiva. The expressional patterns of keratin by these epithelial cells ofpterygia are consistent with the notion that they are derived from conjunctival epithelium and mimic the process of squamous metaplasia.

Aged↗

PubMed1999

Outcomes of penetrating keratoplasty with imported donor corneas.

PURPOSE: To analyze factors influencing the surgical success of penetrating keratoplasty and long-term graft survival when using imported donor corneas. METHODS: Sixty-three donor corneas imported to Taipei from the Cincinnati Eye Bank from July 1992-June 1993 were used for penetrating keratoplasty. The corneal endothelium was examined using specular microscopy on arrival in Taiwan. The endothelial morphology and endothelial cell density (ECD) were compared with the photograph of the same cornea taken in the United States. The relationships of the surgical success rate with donor age, death to enucleation time, death to surgery time, and ECD were analyzed. The long-term graft survival and ECD of clear grafts were analyzed 4 years after surgery. RESULTS: On specular microscopic examination. the imported corneas showed diminished endothelial reflection, blurred cellular borders, and increased dark areas, which were markedly different from the pictures of the corneal endothelium taken in the United States. The average ECD before transportation was 2,525+/-267/mm2 and decreased to 1,934+/-250/mm2 after transportation (p < 0.001), with an average endothelial cell loss of 590+/-247/mm2. The overall surgical success rate was 89% and did not correlate with any of the donor factors tested except death to surgery time. The surgical success rate decreased when the time from death to surgery was >7 days (p = 0.05), mainly because of poor reepithelialization. Four years after surgery, 24 grafts remained clear. The ECD had decreased by 72+/-5% in the clear grafts. CONCLUSIONS: Our findings show that endothelial changes in imported donor corneas do occur after transportation, but the surgical success rate may not be influenced significantly if the penetrating keratoplasty is performed within 7 days after donor death. However, the ECD in the clear grafts 4 years after surgery is low.

Adult↗

PubMed1998

T-cell malignant lymphoma with conjunctival involvement.

PURPOSE: To report a rare case of T-cell malignant lymphoma involving the conjunctiva. METHODS: A 63-year-old woman had rapid onset of bilateral perilimbal congestion and chemosis. Perilimbal thickening with corneal infiltration developed 20 days later. Computed tomography incidentally disclosed a right maxillary sinus mass. Biopsy specimens from the maxillary sinus mass and the left limbus were subjected to histopathologic examination and immunohistochemical study. RESULTS: T-cell malignant lymphoma of diffuse large cell type, stage IV, was diagnosed. The patient was treated with combination chemotherapy plus 13-cis-retinoic acid and remained in remission 1 1/2 years after diagnosis. CONCLUSION: Conjunctival involvement with T-cell lymphoma may present as episcleritis and chemosis.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1998

Interferon treatment for corneolimbal squamous dysplasia.

PURPOSE: To report a patient with corneolimbal squamous dysplasia successfully treated with interferon therapy. METHODS: A 78-year-old man had a gelatinous and vascularized lesion involving the left cornea and adjacent limbus. Impression cytology studied with periodic acid--Schiff-hematoxylin stain disclosed severe squamous dysplasia. Topical instillation and subconjunctival injection of interferon alpha-2b was instituted. RESULTS: The gelatinous tumor mass involving the cornea and adjacent limbus completely resolved 2 months after interferon treatment. He showed no sign of recurrence during the 10-month follow-up. CONCLUSION: Interferon therapy may be a therapeutic alternative for treating corneolimbal squamous dysplasia.

Aged↗

PubMed1998

Topical ciprofloxacin for treating nontuberculous mycobacterial keratitis.

OBJECTIVE: This study aimed to evaluate the clinical efficacy of topical ciprofloxacin for treating Mycobacterium fortuitum and Mycobacterium chelonae keratitis refractory to amikacin therapy. DESIGN: A prospective clinical trial of topical ciprofloxacin treatment for nontuberculous mycobacterial keratitis was conducted. PARTICIPANTS: Eleven patients with nontuberculous mycobacterial keratitis diagnosed from 1992 to 1996 were enrolled. INTERVENTION: All 11 patients were treated initially with topical fortified amikacin, but only 2 patients responded. The other nine patients, four with M. fortuitum and five with M. chelonae keratitis, were refractory to amikacin therapy and received topical ciprofloxacin treatment. Bacterial culture and drug susceptibility tests using the broth microdilution method were performed on all 11 patients. MAIN OUTCOME MEASURES: The clinical response to amikacin or ciprofloxacin treatment was judged by corneal re-epithelialization and density and/or size of corneal infiltrates. RESULTS: M. chelonae isolates were more resistant to amikacin and ciprofloxacin than M. fortuitum isolates based on the in vitro susceptibility test. Clinically, three patients with M. fortuitum keratitis were responsive to ciprofloxacin therapy; however, only one patient with M. chelonae keratitis responded to the same therapy. CONCLUSIONS: Topical ciprofloxacin offers a therapeutic alternative for nontuberculous mycobacterial keratitis, which was refractory to amikacin treatment. However, topical ciprofloxacin was more effective for treating M. fortuitum keratitis than for M. chelonae keratitis.

Administration, Topical↗

PubMed1998

Comparison of topical antibiotics for treating Mycobacterium chelonae keratitis in a rabbit model.

PURPOSE: To investigate the effect of topical amikacin (25 mg/ml), imipenem (25 mg/ml), ciprofloxacin (3 mg/ml), clarithromycin (20 mg/ml), amikacin combined with ciprofloxacin, amikacin combined with imipenem, and amikacin combined with clarithromycin on Mycobacterium chelonae keratitis. METHODS: Ninety New Zealand albino rabbits were infected with a strain of M. chelonae for which minimum inhibitory concentration indicated in vitro sensitivity to the above antibiotics. The rabbits were treated for one or two weeks. The treatment efficacy was judged by the size of stromal infiltrate and quantitative culture of the infected corneas. RESULTS: The size of the stromal infiltrate showed no significant difference in treated eyes compared to the untreated, control eyes. However, all treatments significantly reduced the number of organisms in treated eyes compared to untreated, control eyes (all p-values < 0.05). No significant difference in treatment efficacy was found between individual treatment groups. In none of the cases were organisms eliminated from the infected eyes, even after 2 weeks of treatment. CONCLUSIONS: The results suggest that topical amikacin, imipenem, ciprofloxacin and clarithromycin had some therapeutic effect on M. chelonae keratitis; however, amikacin combined with imipenem, ciprofloxacin, and clarithromycin showed no increased efficacy over single agent therapy during 2 weeks of treatment. Long term treatment may be required to eradicate M. chelonae.

Administration, Topical↗

PubMed1998

Analysis of corneal topography after excimer laser photorefractive keratectomy.

Excimer laser photorefractive keratectomy (PRK) is an effective treatment for myopia. We investigated the magnitude of optical zone decentration and qualitative patterns of corneal topography after this treatment. We performed computer-assisted videokeratography on 44 myopic eyes (29 patients) that had undergone PRK before and 1, 6, and 12 months after the procedure. Associations of clinical outcomes with decentration and topographic patterns were assessed. The normalized scale of the topography 1 month postoperatively showed a mean decentration of 0.33 +/- 0.23 mm (range 0-0.9). Thirty-four eyes had decentration of less than 0.50 mm; 10 had an ablation zone decentered from 0.5 to 0.9 mm. Analysis of geometric mean visual acuities between eyes with less than 0.5 mm decentration and those with 0.5 to 0.9 mm decentration demonstrated minimal differences. No eye was decentered more than 1 mm. Four main ablation patterns were noted on subtraction analysis: homogeneous, semicircular, keyhole, and central island. Over time, the number of eyes with a homogeneous pattern increased. Eyes with a homogeneous ablation pattern had significantly better uncorrected visual acuity than those with other patterns. The mean visual acuity was 20/29.1 in the homogeneous group and 20/38.5 in the pooled irregular group 1 month postoperatively (p < 0.05). There was no significant difference among the four ablation patterns at 6 or 12 months after PRK. Topographic patterns were not significantly associated with best-corrected vision.

Cornea↗

PubMed1997

Shewannela putrefaciens endophthalmitis after penetrating keratoplasty.

PURPOSE: To report a case of Shewannela putrefaciens endophthalmitis after penetrating keratoplasty. METHODS: Case report. Vitreous of the recipient and the preservative medium of donor cornea were cultured. RESULTS: Vitreous of the recipient eye and the donor eye corneal preservative medium both grew S putrefaciens. The patient failed to respond to intravitreal, topical, and systemic amikacin and cefotaxime. Vision was lost rapidly. Evisceration was performed. CONCLUSION: Shewannela putrefaciens should be considered as a potential pathogen contaminating donor cornea. Shewannela putrefaciens endophthalmitis is devastating and responds poorly to medical treatment.

Adult↗

PubMed1997

The antimicrobial susceptibility of Mycobacterium chelonae isolated from corneal ulcer.

PURPOSE: To determine the in vitro susceptibility of Mycobacterium chelonae isolates from corneal ulcers to various traditional and newly-developed antimicrobial agents, alone or in combination. METHODS: Fifteen strains of M. chelonae isolated from corneal ulcers were collected at the National Taiwan University Hospital from 1989 to 1993. Susceptibility to antimicrobial agents was tested by the broth microdilution method to determine the minimum inhibitory concentration (MIC). The antimicrobial effects of combinations of antimicrobial agents were assessed by the checkerboard titration method to determine the fractional inhibitory concentration (FIC) index. RESULTS: The MIC results showed that traditional antituberculous drugs had poor activity against M. chelonae. In the aminoglycoside group, tobramycin and amikacin had better activity than gentamicin. Among macrolides, clarithromycin was especially effective, with an MIC ranging from 0.125 to 1 microgram/ml. Among various beta-lactam antibiotics, imipenem was the only one to demonstrate good anti-mycobacterial activity. Of the quinolone group, ciprofloxacin was the most effective, with an MIC ranging from 0.5 to 16 micrograms/ml. Combination of an aminoglycoside with imipenem, ciprofloxacin or clarithromycin all showed antagonistic effect. CONCLUSIONS: The results suggested that amikacin, clarithromyicn, imipenem and ciprofloxacin had good in vitro antimicrobial activity against M. chelonae. However, no synergistic effect could be demonstrated for combinations of an aminoglycoside with other effective drugs.

Anti-Bacterial Agents↗

PubMed1997

Effect of shaking of corneal endothelial preservation.

PURPOSE: To investigate the effect of shaking on corneal endothelial preservation. METHODS: Thirty-six dog corneal buttons were obtained under standard eye bank procedure, after the animals had been sacrificed for cardiovascular experiments in the surgical department. They were equally divided into two groups. In Group I, buttons were put in Dexsol preservative medium and preserved at 4 degrees C. In Group II, buttons were put in Dexsol preservative medium and shaken in a shaking incubator at a speed of 5 rpm. at 4 degrees C for 10 h. After shaking, they were returned to a 4 degrees C refrigerator until examination. Three buttons from each group underwent specular microscopy, scanning electron microscopy (SEM), and alizarin red with trypan blue stain examinations on days 0, 1, 3, 5, 7 and 9, respectively. RESULTS: In Group I, intercellular borders became blurred under specular microscopy, beginning on day 5. However, endothelial cell count did not change significantly until day 9. Intercellular digitations and wrinkling of intercellular borders were seen under alizarin red with trypan blue stain and SEM examination, beginning on day 3. Pleomorphism and ill-defined intercellular junctions were seen under SEM on day 7. There was no obvious denudement of the endothelial sheet, but a few scattered exfoliations were seen in Group I. In Group II, endothelial cell count did not decrease on day 1, but an endothelial image could not be obtained by specular microscopy 3 days after treatment. Alizarin red with trypan blue stain and SEM examination revealed that the endothelial cells were denuded from the Descemet's membrane three days after shaking. Severe stromal edema was seen under SEM five days after shaking. CONCLUSIONS: The results showed that shaking had a detrimental effect on endothelial cell preservation. Vigorous shaking should be avoided during transportation of corneal buttons. It is advisable to perform penetrating keratoplasty as soon as possible upon receiving transported donor corneas.

Animals↗

PubMed1997

Clinical features and outcome of Acanthamoeba keratitis.

We retrospectively reviewed 11 patients with culture-proven Acanthamoeba keratitis who presented at the National Taiwan University Hospital between 1989 and 1996. We assessed predisposing factors, initial diagnosis, clinical presentation, treatment, and outcome. A history of contact lens-wear, poor contact lens hygiene, intractable eye pain, and ring infiltrates in the cornea were the most prominent characteristics and clinical manifestations. Acanthamoeba keratitis was often misdiagnosed, with herpetic keratitis (7/11) being the most common initial diagnosis from referring hospitals. These patients were usually treated on the basis of the inaccurate diagnosis for more than 1 month (range 1-8 mo) before referral. All patients ultimately received penetrating keratoplasty because of poor response to delayed medical treatment. We suggest that inadequate contact lens hygiene may be important in Acanthamoeba keratitis. This condition is often misdiagnosed and, as early diagnosis is a major factor for successful medical treatment in such patients, awareness in clinical practice is critical.

Acanthamoeba Keratitis↗

PubMed1996

Nocardia brasiliensis keratitis successfully treated with therapeutic lamellar keratectomy.

A 36-year-old man sustained an indolent keratitis following a minor corneal trauma. Nocardia brasiliensis was isolated from cultures of the corneal scrapings. Fortified topical antibiotics, based on in vitro drug sensitivity testing, were intensively applied for weeks without clinical improvement. The patient underwent therapeutic lamellar keratectomy, which led to a rapid and complete resolution. The site of the keratectomy reepithelialized within 2 days and became a faint subepithelial haze thereafter. The visual acuity improved to 20/20 and there was no evidence of recurrence during the subsequent follow-up. It appears that lamellar keratectomy is a valuable treatment alternative for localized chronic nocardial keratitis.

Adult↗

PubMed1996

Corneal epithelial recovery following photorefractive keratectomy.

AIMS: To further understand the morphological and functional recovery of corneal epithelium following excimer laser photorefractive keratectomy (PRK). METHODS: The right eyes (group 1) of 15 male, New Zealand white rabbits weighing 2-3 kg underwent PRK. The left eye of each rabbit (group 2) underwent simple mechanical de-epithelialisation and were examined as treated controls. Both eyes of another eight rabbits (group 3) served as untreated controls. All eyes underwent a corneal epithelial permeability study by fluorophotometry at 2, 4, and 8 weeks after surgery. Five animals in groups 1 and 2 were sacrificed at 9, 10, and 12 weeks after surgery. The animals in group 3 were sacrificed at the end of the 12 week experimental period. Both eyes of each sacrificed animal were enucleated immediately and processed for both haematoxylin and eosin stain and electron microscopic study. The electron micrograph was magnified to 14,000x and the extent of hemidesmosome formation was quantified and analysed. RESULTS: The corneal epithelial barrier to sodium fluorescein was subnormal and returned to a normal barrier state 4 weeks after PRK in group 1 whereas it was normal in group 2 throughout the examination period. The extent of hemidesmosome formation was abundant yet subnormal in both groups 1 and 2 up to 12 weeks, when compared with that in group 3. CONCLUSION: The corneal epithelium regained its functional barrier 4 weeks after PRK in rabbits while the extent of hemidesmosome formation was still subnormal 12 weeks after mechanical de-epithelialisation, with or without PRK.

Animals↗