Amniotic membrane transplantation: indications and results.

PURPOSE: To describe amniotic membrane transplantation indications and results at the authors' institution. METHODS: In this study, chart review of 108 patients who underwent amniotic membrane transplantation between January 2002 and April 2006 was performed. The survival rate of corneal integrity was compared, using Kaplan-Meier survival analysis, as a measure of success rate. RESULTS: The mean age of the patients was 55.2+/-20.1 (6-87 years, 75 female, 51 male). The patients underwent amniotic membrane transplantation for six different diagnoses: nontraumatic corneal perforation (32 eyes, Group 1), persistent epithelial defect (29 eyes, Group 2), aphakic/pseudophakic bullous keratopathy (18 eyes, Group 3), infectious ulcer resistant to treatment (14 eyes, Group 4), necrotizing keratitis secondary to endophthalmitis (10 eyes, Group 5), and caustic injury (5 eyes, Group 6). The mean survival of corneal integrity was similar in all groups (p=0.156). CONCLUSIONS: Amniotic membrane transplantation is a successful adjunctive method in achieving corneal epithelization in the study indications.

Chitosan-coated alginate membranes for cultivation of limbal epithelial cells to use in the restoration of damaged corneal surfaces.

Some chemicals or thermal burns may result in abnormal reepithelialization by conjunctival epithelial cells and it causes different types of damage on the cornea surface. When reepithelialization does not occur, chronic inflammation and neovascularization develop, often leading to stroma scarring and/or ulceration. The aim of this study is to restore the human corneal surface with autologous corneal epithelial sheets generated by serial cultivation of the limbal epithelial cells over the different compositions of composite membranes. The composite membranes were prepared by coating the alginate membrane with chitosan. In this method, alginate membrane was prepared by precipitation of the sodium alginate solution in calcium chloride solution. Alginate membranes were washed, dried and immersed into the chitosan solutions to prepare composite membranes. The composite membranes were characterized based on their morphology, hydrophilicity, swellability, and chemical structure. In the last part of the study, composite membranes were used as base matrices for limbal epithelial cell cultivation. The cell cultivation on polymeric membranes was investigated as the in vitro studies. In these studies cell attachment, spreading and growth on polymeric membranes were evaluated.

Conjunctival impression cytology and tear-film changes in patients with psoriasis.

PURPOSE: In this study, we evaluated ocular-surface changes and tear-film functions in patients with plaque-type psoriasis. METHODS: This study was performed on two groups. Group I included 100 eyes of 50 subjects with chronic plaque-type psoriasis whose diagnoses were confirmed with skin biopsy. Group II included 100 eyes of 50 healthy volunteers who were in the same age and sex distribution. Ocular-surface changes were evaluated on the cell content of the surface conjunctival epithelium by conjunctival impression cytology and tear-film functions by the Schirmer I test and break-up time (BUT). RESULTS: Of the patients with psoriasis, 50% had a grade 0, 30% had a grade I, and 20% had a grade II conjunctival impression cytology differentiation compared with 95, 3, and 2%, respectively in the control group (p < 0.001). Snake-like appearance of nuclear chromatin in conjunctival epithelial cells was demonstrated in 12% of eyes in group I but in 2% of eyes in group II. The Schirmer's test results showed that average values were 10.1 +/- 5.8 mm in group I and 12.6 +/- 5.5 mm in group II (p > 0.001). The mean break-up time was 7.8 +/- 3.7 s in group I and 12.5 +/- 4.6 s in group II (p < 0.001). CONCLUSIONS: We showed the early conjunctival changes in patients with psoriasis. According to these results, primary etiologic factors may contribute to ocular lesions in psoriasis.

Microbial keratitis following penetrating keratoplasty.

PURPOSE: To investigate the prevalence of microbial keratitis, predisposing risk factors and treatment modalities in patients who developed keratitis following penetrating keratoplasty (PK). PATIENTS AND METHODS: The records of 285 patients who had undergone PK between January 1991 and December 1995 in a tertiary care center were reviewed. Patients who developed postoperative microbial keratitis were evaluated for predisposing risk factors, microbiological etiology, response to broad spectrum antibiotic therapy and subsequent PK. Patients were mainly treated with fortified topical antibiotics with or without repeat PK. RESULTS: Of the 285 patient records reviewed, microbial keratitis developed in 21 eyes of 21 patients (7.4%). Seventy-one percent of infections occurred within 6 months after grafting. Keratitis initially began from the donor-recipient border in 16 cases (76.2%) and were central or paracentral in 5 patients. Predisposing risk factors included loose or exposed suture (9), suture removal (1), persistent epithelial defect (3), graft failure (3), contact lens wear (1), Stevens-Johnson syndrome (1). Fifteen (71.4%) patients were culture-positive consisting of Streptococcus pneumoniae (7), Staphylococcus aureus (5), Pseudomonas aureginosa (2), and Hemophilus influenzae (1). Forty-three percent of patients were successfully treated with medical therapy only. Seven patients underwent second PK for visual rehabilitation and 4 for tectonic purposes. After medical and surgical therapy, graft clarity was achieved in 17 (81%) of patients. CONCLUSIONS: The microbial keratitis following PK is a major postoperative problem affecting the long term prognosis. Careful selection of patients, and preoperative and postoperative control of risk factors, may decrease the frequency of this complication. Several factors, including loose or exposed sutures, epithelial defects, ocular surface disorders, and graft failure, may predispose patients to develop microbial keratitis following PK.

The results of trabeculectomy with and without mitomycin C in young patients.

The results of primary trabeculectomy with and without mitomycin C (MMC) were evaluated in young glaucoma patients. The patients, 15-40 years of age, were divided into two main groups and two subgroups. In group IA, primary Cairns type trabeculectomy was performed in 24 eyes of 24 patients with juvenile glaucoma; in group IB, trabeculectomy + MMC 0.4 mg/ml in 3 min was done in 20 eyes of 20 patients with juvenile glaucoma; in group IIA, primary trabeculectomy was performed in 20 eyes of 20 patients with developmental glaucoma, and in group IIB, trabeculectomy + MMC 0.4 mg/ml in 3 min was performed in 16 eyes of 16 patients with developmental glaucoma. The success rate of the surgery was 75% in group IA, 90% in group IB, 50% in group IIA, and 75% in group IIB. There was no statistically significant difference among the groups in terms of success rates of trabeculectomies (p > 0.05).

Comparison of the anti-inflammatory effects of diclofenac and flurbiprofen eye drops after cataract extraction.

PURPOSE: A clinical double-blind study was performed in patients who had undergone extracapsular cataract extraction and intraocular lens implantation (ECCE+IOL) to compare the anti-inflammatory effects of diclofenac sodium 0.1% and flurbiprofen 0.03% eye drops. METHODS: The diclofenac group included 21 eyes of 21 patients and the flurbiprofen group included 22 eyes of 22 patients. The parameters compared were pachymetry of the cornea, corneal surface changes, intraocular pressure (IOP) and the degree of inflammation of the anterior chamber at one, three and six weeks after cataract surgery. RESULTS: There was no statistically significant difference between the two treatment groups in corneal pachymetry, corneal surface changes, IOP and the anterior chamber inflammation (p>0.05). CONCLUSION: Both drugs were well tolerated and may be safely used to reduce inflammation for cataract surgery.

The SRKII formula in the calculation of intraocular lens power.

This study compares the predictive accuracy of the SRKII formula for groups with average axial length and long eyes. 344 eyes which underwent cataract extraction with implantation of a posterior-chamber intraocular lens were included in the survey; 246 eyes had an average axial length (22.0-24.49 mm), and 98 eyes had an axial length of more than 24.50 mm. Mean absolute errors were 0.26+/-0.68 dpt in the first group and 1.16+/-1.78 dpt in the second group. 94.3% of the average eyes were within 1.0 dpt of the expected refraction, 98.8% within 2.0 dpt, whereas in the long-eye group 58.2% were within 1.0 dpt and 84.7% within 2.0 dpt. The results show that the SRKII formula performed credibly in average-length eyes; in the long eyes the ratio of large refractive deviations was greater than that of the other group.

Autosomal recessive nanophthalmos.

Nanophthalmos is a rare congenital ocular malformation which is generally recognized at middle age when serious complications have already developed. In this report 7 early diagnosed nanophthalmic cases are presented and diagnostic criteria, complications, inheritance and various modalities of treatment are discussed.

Calculation of intraocular lens power with the SRK II formula for axial high myopia.

AIM: The SRK II formula has been widely used for intraocular lens (IOL) power calculations. The predictability of this formula is evaluated in axial myopic patients. METHODS: Planned extracapsular cataract extraction and posterior chamber IOL implantation (PECCE + IOL) were performed on 98 eyes of 98 patients with axial length > 24.5 mm. Cases had no preoperative complications and postoperative visual acuity was at least 0.5 (Snellen). Corneal refractive power and axial length were measured preoperatively and emmetropic IOL power calculations were made using the SRK II formula. Long-term (mean 4.7 months) visual acuities and refractions were noted postoperatively. RESULTS: The absolute refractive error was < 1.00 Diopters (D) in 57 eyes (58.2%) and < 2.00 D in 83 eyes (84.7%). The mean absolute error of the SRK II formula in axial myopia was 1.16 D +/- 0.78 SD. CONCLUSIONS: The SRK II formula is not very accurate in axial myopic patients.

Treatment of glaucoma in young nanophthalmic patients.

PURPOSE: To evaluate the criteria of diagnosis and management of secondary glaucoma in young nanophthalmic patients. METHODS: Considering the anatomic features and clinical characteristics, 22 eyes of 11 patients were identified as bilateral nanophthalmos. Intraocular pressures (IOP) were checked with Goldmann applanation or Keeler pulse-air 2000 tonometer, and Nd-Yag laser was used for iridotomies. Prophylactic V-shaped unsutured sclerectomies over the pars plana were combined with trabeculectomy, and Mitomycin C (MMC) in 0.2 mg/ml concentration was applied. RESULTS: Among 22 eyes of bilateral nanophthalmic patients 8 eyes had secondary angle-closure glaucoma. Laser iridotomies were performed in 6 eyes. Laser iridotomy and supplemental medical therapy were sufficient in 4 out of 6 eyes. Mean IOP dropped from 26.4 to 14.5 mmHg in these patients. Due to continuous increase of IOP in the other patients, they underwent trabeculectomy with V-shaped sclerostomy and intraoperative MMC application. Mean IOP dropped from 39.3 mmHg to 19.3 mmHg. Postoperative uveal effusion on other major complications were not observed. Mean age of these patients was 14.6 years during treatment. CONCLUSION: Management of glaucoma in nanophthalmus is complicated. Initial treatment is medical. If it is insufficient, laser iridotomies and V-shaped sclerostomies with filtration surgery can be performed at any age.

Effects of antiglaucoma drugs on ocular surface.

Topical medications have a very important role in chronic glaucoma treatment. Long-term use of these medications can cause significant changes on ocular surfaces. In this study, the ocular surfaces of 20 control subjects (group I), 20 primary open-angle glaucoma patients (group II) treated (mean 21.20 +/- 1.32 months) with 0.50% timolol maleate, and 20 primary open-angle glaucoma patients (group III) treated (mean 21.70 +/- 1.34 months) with 0.50% timolol maleate + 1% dipivefrin hydrochloride were evaluated. Studied parameters included Schirmer's test, tear break-up time, conjunctiva impression cytology and goblet cell density. These results suggest that long-term applications of topical anti glaucoma medications damage the ocular surface.