Biomedical subjects

R D Stulting

Publications and source records attributed to R D Stulting.

At least 37 records · Page 2Linked to original sources

PubMed1997

Results of phase III excimer laser photorefractive keratectomy for myopia. The Summit PRK Study Group.

OBJECTIVE: The purpose of the study is to determine safety and efficacy outcomes of excimer laser photorefractive keratectomy (PRK) for the treatment of mild-to-moderate myopia. DESIGN: A prospective, multicenter, phase III clinical trial. PARTICIPANTS: A total of 701 eyes of 701 patients were entered in the study; 612 eyes were examined at 2 years after surgery. INTERVENTION: Intervention was photorefractive keratectomy using the Summit ExciMed UV200LA excimer laser (Summit Technology, Inc., Waltham, MA). The treatment zone diameter used was 4.5 mm in 251 eyes (35.8%) and 5 mm in 450 eyes (64.2%). Attempted corrections ranged from 1.50 to 6.00 diopters (D). MAIN OUTCOME MEASURES: Predictability and stability of refraction, uncorrected and spectacle-corrected visual acuity, refractive and keratometric astigmatism, corneal haze, contrast sensitivity, subjective reported problems of glare and halo, and patient satisfaction were the parameters measured. RESULTS: At 2 years, 407 (66.5%) eyes achieved 20/20 or better uncorrected visual acuity and 564 (92.5%) eyes achieved 20/40 or better visual acuity. Three hundred thirty-six (54.9%) eyes were within 0.5 D and 476 (77.8%) eyes were within 1.0 D of attempted correction. Stability of refraction improved with time; 86.8% of eyes were stable within 1.0 D from 6 to 12 months, 94% were stable from 12 to 18 months, and 96.3% were stable from 18 to 24 months. There was no evidence of progressive or late myopic or hyperopic refractive shifts. One hundred fourteen (18.6%) eyes gained 2 or more lines of spectacle-corrected visual acuity, whereas 42 (6.9%) eyes lost 2 or more lines; however, of the latter, 32 (76.2%) had spectacle-corrected visual acuity of 20/25 or better and 39 (92.9%) eyes had 20/40 or better. Four hundred forty-two (72.2%) corneas were clear, 138 (22.5%) showed trace haze, 20 (3.3%) mild haze, 9 (1.5%) moderate haze, and 3 (0.5%) marked haze. On patient questionnaires, 87 (29.7%) patients reported worsening of glare from preoperative baseline; 133 (50.1%) reported worsening of halo symptoms from baseline. CONCLUSIONS: Photorefractive keratectomy appears effective for myopic corrections of -1.50 to -6.00 D. Uncorrected visual acuity is maximized in most eyes by 3 months, although some patients require between 6 months and 1 year to attain their best postoperative uncorrected visual acuity and some may require from 1 to 2 years for stabilization of refraction. Refraction stabilizes progressively without evidence of late myopic or hyperopic refractive shifts. Optical sequelae of glare and halo occur in some patients treated with a 4.5- or 5-mm treatment zone.

Adult↗

PubMed1997

The effects of donor age on the outcome of penetrating keratoplasty in adults.

OBJECTIVE: The purpose of the study is to determine whether there is a higher incidence of complications in adult patients receiving corneas from pediatric donors compared to those receiving corneas from adult donors. DESIGN: The design is a follow-up of two matched cohorts. PARTICIPANTS: The outcome of penetrating keratoplasty in 29 adult patients (age 20 years of age and older) receiving pediatric donor corneas (range, 0-5 years) was compared to that of 29 control patients matched for recipient age and diagnosis who received adult donor corneas (range, 40-70 years). INTERVENTION: Chart review was performed. MAIN OUTCOME MEASURES: Graft rejection, postoperative keratometry, postoperative refractive cylinder, postoperative intraocular pressure, and graft failure due to rejection were measured. RESULTS: One or more allograft reactions occurred in 11 (37.9%) of 29 patients who received pediatric donor corneas compared to 2 (6.9%) of 29 patients who received adult donor corneas (P = 0.005, chi-square). There were a total of 20 rejection episodes in patients receiving pediatric donor corneas compared to a total of 5 rejection episodes in patients receiving adult donor corneas. The average postoperative keratometry was 46.1 diopters for the pediatric donor group and 44.0 diopters for the adult donor group (P = 0.03). There was no statistically significant difference in average refractive cylinder (P = 1.0), intraocular pressure (P = 0.26), or the incidence of graft failure due to rejection (P = 1.0) between the two groups. The average follow-up time for clear grafts was 58.3 months in the pediatric donor group and 59.9 months in the adult donor group. CONCLUSIONS: The incidence of allograft reactions and the postoperative corneal curvature is greater in adult eyes undergoing penetrating keratoplasty with young donor corneas compared to those undergoing penetrating keratoplasty with older donor corneas. There was no difference in the incidence of graft failure due to rejection between the two groups.

Adult↗

PubMed1997

The role of topical corticosteroids in the management of Acanthamoeba keratitis.

PURPOSE: To clarify the role of topical corticosteroids in the management of Acanthamoeba keratitis. METHODS: The records of 38 patients diagnosed with Acanthamoeba keratitis at three institutions were retrospectively reviewed. RESULTS: After medical therapy alone, patients diagnosed within 1 month of symptom onset had an increased likelihood of being cured (p = 0.02) and attaining visual acuity of 20/60 or better (p < 0.01). Fourteen (73.7%) of 19 patients treated with topical corticosteroids at any time were cured after antiamoebal therapy alone, whereas five (26.3%) patients required penetrating keratoplasty for either persistent infection (n = 3) or perforation (n = 2). The mean antiamoebal therapy duration, excluding duration after keratoplasty if applicable, was 38.5 weeks. Thirteen (76.5%) of 17 patients treated with antiamoebal therapy without topical corticosteroids were medically cured, whereas four (23.5%) required penetrating keratoplasty for either persistent infection (n = 2) or perforation (n = 2). The mean antiamoebal therapy duration was 20 weeks. Although the mean antiamoebal therapy duration in the steroid-treated group was significantly longer than that in the non-steroid-treated group (p = 0.02), outcome after medical therapy between the groups was not significantly different. CONCLUSIONS: Topical corticosteroids were not associated with a higher rate of medical treatment failure in patients with Acanthamoeba keratitis. Rather, poor outcome was significantly related to diagnostic delays. Therefore prudent use of corticosteroids in selected patients with severe pain not responsive to analgesics or severe corneal or anterior chamber inflammation appears justified.

Acanthamoeba↗

PubMed1997

Prospective, randomized comparison of simultaneous and sequential bilateral LASIK for the correction of myopia.

PURPOSE: To study the safety and efficacy of simultaneous bilateral laser in-situ keratomileusis (LASIK) METHODS: Data were obtained from 254 consecutive patients that were randomized to simultaneous or sequential bilateral LASIK. RESULTS: 146 patients were enrolled in the simultaneous group and 108 patients were enrolled in the sequential group. Mean follow-up was 10 months (range 6-18). There was no significant difference in intraoperative complication rate (p = 0.34), loss of two or more lines of spectacle corrected visual acuity (p = 0.9), or percentage of eyes within +/- 0.50 D of intended (p = 0.63) between simultaneous and sequential groups. CONCLUSIONS: The risk of performing bilateral simultaneous LASIK is not significantly different from that of sequential treatments.

Adolescent↗

PubMed1996

Congenital entropion and congenital corneal ulcer.

PURPOSE: We studied a case of corneal ulceration in utero from lower eyelid entropion. METHODS: A 3-week-old male infant was referred for examination of a left corneal ulcer that was present at birth and unresponsive to antibiotics. RESULTS: Examination disclosed a lower eyelid entropion that was treated surgically by a nonincisional method, leaving a central leukoma after re-epithelialization. CONCLUSION: Congenital lower eyelid entropion should be included in the differential diagnosis of congenital corneal opacities.

Corneal Opacity↗

PubMed1996

Late onset of corneal scar after excimer laser photorefractive keratectomy.

PURPOSE: We studied the occurrence of late scarring after photorefractive keratectomy and its response to topical corticosteroids and debridement during the course of follow-up of 950 eyes that had photorefractive keratectomy with excimer laser. METHODS: Five eyes of four patients developed localized corneal scars, decreased visual acuity, and increased myopia after five to 33 months of good visual acuity, with trace haze. In two eyes, scars were removed by debridement alone. In these two eyes, recurrent scars were treated by debridement, followed by aggressive treatment with topical corticosteroids. Two other eyes were treated with topical corticosteroids alone. The fifth eye, which developed a scar after debridement to correct a subjective visual distortion after photorefractive keratectomy, was treated with debridement followed by aggressive topical corticosteroids. RESULTS: Treatment with topical corticosteroids alone in two eyes improved uncorrected visual acuity slightly and decreased myopia, although the scars remained unchanged. Debridement without aggressive topical corticosteroid use resulted in rapid return of the scars and a decrease in visual acuity. Subsequent debridement after aggressive topical corticosteroid treatment resulted in resolution of scars and no recurrence after discontinuation of corticosteroids in one case. In another case, the scar recurred eight months after discontinuation of topical corticosteroids. In Case 4, the scar has not recurred as the topical corticosteroid dosage has been reduced. CONCLUSIONS: Patients who undergo photorefractive keratectomy should be counseled concerning the risk of late scarring, reexamined frequently after photorefractive keratectomy, and treated with topical corticosteroids after corneal trauma. Long-term treatment with topical corticosteroids may be required to prevent the recurrence of scars after debridement.

Adult↗

PubMed1996

The effect of photorefractive keratectomy on the corneal endothelium.

PURPOSE: The authors prospectively investigated the effect of excimer laser photorefractive keratectomy (PRK) for myopia on the corneal endothelium. METHODS: Quantitative computer-assisted morphometric analysis of central and peripheral corneal endothelial cells was performed on 142 myopic eyes before and at 3 months, 1 year, and 2 years after PRK. The mean age of the subjects was 37 years (range, 21-66 years). Ninety-one (64%) of them had a history of contact lens wear. Mean attempted correction was -3.9 diopters (range, -1.6 to -6.0 diopters). RESULTS: The mean preoperative endothelial cell density was 2660 cells/mm2 centrally and 2776 cells/mm2 peripherally. There was no change in central endothelial cell density at any of the postoperative examinations. The peripheral cell density decreased 4.1% (P = 0.003) at 3 months and 6.2% (P = 0.0001) at 1 year. However, the peripheral cell density was not significantly different from the preoperative value at 2 years. The peripheral coefficient of variation of cell size was 7.8% lower 2 years postoperatively than it was preoperatively, and this improvement was attributable to cessation of contact lens wear after PRK. The decrease in peripheral endothelial cell density at 1 year correlated with the amount of attempted correction, but there was no correlation between attempted correction and the change in central or peripheral endothelial cell density 2 years postoperatively. CONCLUSION: For the correction of up to 6.0 D of myopia, PRK causes no detectable changes in central corneal endothelial cell density, but it does cause a transient, modest loss of peripheral corneal endothelial cells at 1 year. Variations in endothelial cell shape caused by contact lens wear resolve after PRK.

Adult↗

PubMed1996

Risk factors for herpes simplex virus epithelial keratitis recurring during treatment of stromal keratitis or iridocyclitis. Herpetic Eye Disease Study Group.

AIMS: Possible risk factors were evaluated for herpes simplex virus (HSV) epithelial keratitis in patients with stromal keratouveitis. METHODS: The study population included 260 patients who had active stromal keratitis and/or iridocyclitis without epithelial disease and who were enrolled in one of three clinical trials of the Herpetic Eye Disease Study. Study treatment involved a 10 week course of topical placebo, topical prednisolone phosphate, or topical prednisolone phosphate with oral acyclovir. All groups received topical trifluridine four times daily for 3 weeks then twice daily for another 7 weeks. Patients were examined for HSV epithelial keratitis for 16 weeks. RESULTS: Dendritic or geographic epithelial keratitis occurred in 12 (4.6%) study patients. Adverse effects attributable to trifluridine prophylaxis were acute allergic blepharoconjunctivitis in 10 (3.8%) study patients and corneal epithelial erosions in 11 (4.2%) study patients. No significant difference in the occurrence of HSV epithelial keratitis was found among the study treatment groups: one (2.0%) of 49 topical placebo treated patients, nine (6.5%) of 138 patients treated with topical corticosteroids without acyclovir, and two (2.7%) of 73 patients treated with topical corticosteroids and oral acyclovir. Univariate exponential models suggested that patients with a history of previous HSV epithelial keratitis and non-white patients were more likely to develop HSV epithelial keratitis during treatment of stromal keratouveitis. CONCLUSION: Individuals with prior HSV epithelial keratitis and certain ethnic groups may have a higher rate of recurrent epithelial keratitis during the acute treatment of HSV stromal keratouveitis.

Acyclovir↗

PubMed1995

Primary corneal graft failure. A national reporting system. Medical Advisory Board of the Eye Bank Association of America.

OBJECTIVES: To describe a national eye banking registry and to assess the effects of donor age, cause of donor death, time from death to procurement, storage time, and distance between the points of recovery and transplantation on the reported occurrence of primary corneal graft failure. DESIGN: We performed a retrospective case-control study to estimate the odds ratios of five donor factors for cases of primary graft failure voluntarily reported to a national registry using controls from selected eye banks. We also performed a nested case-control cohort study to compare cases of primary graft failure that occurred in both corneas from the same donor with those of nonmated corneas in which primary graft failure was reported to assess odds ratios for the same donor factors. PATIENTS: One hundred forty-seven patients developed primary graft failure in penetrating keratoplasty transplantations performed between January 1, 1991, and December 31, 1993. These cases were reported to the Adverse Reaction Registry of the Eye Bank Association of America, Washington, DC. Controls included 7240 donor corneas distributed by nine eye banks during 1992. RESULTS: Of the 147 donor corneas that developed primary graft failure, 17 (12%) were obtained from donors who were aged 70 years and older, 39 (27%) came from donors who died of trauma, 13 (9%) had a cadaver time longer than 12 hours, 10 (7%) had a storage time longer than 7 days, and 38 (26%) were distributed outside the eye bank's region. Compared with controls, these donor corneas were more likely to have a storage time longer than 7 days (odds ratio, 2.4; 95% confidence limits, 1.2 and 4.6) and to come from donors aged 70 years and older (odds ratio, 2.4; 95% confidence limits, 1.4 and 4.0). The 22 corneas (15%) in which primary graft failure occurred in both recipients from the same donor were 8.5 times (95% confidence limits, 1.1 and 51.5) more likely to be preserved beyond 1 week than were nonmated corneas with primary failure but were not from significantly older donors. Logistic regression analysis showed that the association between prolonged storage time and primary graft failure in mated corneas remained significant even when the analysis was controlled for other donor factors. CONCLUSIONS: No clearly defined donor or eye banking factor accounted for most cases of primary graft failure, although prolonged corneal storage and advanced donor age may increase its risk. Ophthalmologists are urged to report to their eye bank all cases of primary graft failure and other adverse events that might be attributable to donor eye tissue.

Adult↗

PubMed1995

Patient-reported symptoms associated with graft reactions in high-risk patients in the collaborative corneal transplantation studies. Collaborative Corneal Transplantation Studies Research Group.

The Collaborative Corneal Transplantation Studies (CCTS) were designed to evaluate the effect of donor-recipient histocompatibility matching and cross-matching on the survival of corneal transplants in high-risk patients. We now report on the role of symptoms in the detection of corneal allograft reactions in the CCTS and on the relationship between symptom reporting and graft survival. The 456 patients transplanted in the CCTS were followed for a minimum of 2 years or until graft failure. The follow-up protocol included 11 scheduled examinations in the first year, four examinations during the second year, and examinations every 6 months thereafter. Interim examinations were performed in response to patient-reported symptoms. At every examination, patients were asked specifically if they had redness, sensitivity to light, loss of vision, or pain (RSVP). Of the 456 patients transplanted, 62% had at least one graft reaction. Patients diagnosed with reactions at scheduled visits in the first postoperative year were 2.5 times more likely to report symptoms than those without reactions. Reports of red eye and vision loss were strongly associated with allograft reaction. However, these symptoms were neither highly sensitive nor specific for reaction (sensitivity = 46%, specificity = 70% at 6 months). The severity of reaction influenced the reporting of symptoms: 69% of patients with severe reactions reported symptoms versus 48% of patients with mild reactions (p < 0.001). The only patient characteristic associated with reliable symptom reporting was age, with younger patients with reactions being more likely to report symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Phototherapeutic keratectomy for the treatment of nodular subepithelial corneal scars in patients with keratoconus who are contact lens intolerant.

The management of keratoconus with contact lenses may be complicated by punctate epithelial keratopathy, epithelial breakdown, and nodular, raised subepithelial scars. We report four consecutive cases of contact lens intolerance due to pain in patients with keratoconus and raised, nodular scars. Excimer laser phototherapeutic keratectomy (PTK) was used to treat all patients. Follow-up ranged from 7 to 14 months (mean: 10 months). All patients resumed rigid gas permeable (RGP) contact lens wear 2 to 4 weeks after surgery. Visual acuities ranged from 20/40 to 20/70 before surgery and improved to 20/25 or better in all patients postoperatively. PTK flattened the central cornea by an average of 5.43 D (range: 1.13-10.19 D); and refractive cylinder was reduced an average of 4.00 D (range: 3.25-5.25 D). We conclude that PTK may delay or avoid penetrating keratoplasty in selected patients with keratoconus who are contact lens intolerant due to nodular subepithelial scars.

Cicatrix↗

PubMed1994

Complications of hexagonal keratotomy.

We examined 15 eyes of ten patients with complications of hexagonal keratotomy, which included glare, photophobia, polyopia, fluctuation in vision, overcorrection, irregular astigmatism, corneal edema, corneal perforation, bacterial keratitis, cataract, and endophthalmitis. Wound healing abnormalities and anterior displacement of the central cornea adjacent to the incisions were common. Eight eyes lost best-corrected visual acuity of two or more Snellen lines. Three eyes required penetrating keratoplasty for visual rehabilitation. Histologic analysis of two of these corneas disclosed variations in wound depth and abnormalities of wound configuration, including considerable wound gaping. Hexagonal keratotomy appears to be an unpredictable, unsafe surgical procedure with a high complication rate, and it should be abandoned until well-controlled experimental trials establish its safety and efficacy.

Adult↗

PubMed1994

Calcific band keratopathy associated with the use of topical steroid-phosphate preparations.

OBJECTIVE: To report a possible adverse effect of topical steroid-phosphate preparations and to identify factors that may contribute to the development of this effect. DESIGN: The medical records of five patients who developed calcium deposition in the cornea were reviewed and analyzed for possible contributing factors. PATIENTS: Five cases of calcium deposition in the cornea associated with the use of topical steroid-phosphate preparations are described. Scrapings from the cornea and/or specimens obtained at keratoplasty were available in all cases. These cases had the following characteristics in common: use of steroid-phosphate preparations (n = 5); multiple topical drops (n = 5); penetrating keratoplasty (n = 3); presence of epithelial defects (n = 4); history of herpetic stromal keratitis (n = 3) [corrected]; and history of iritis (n = 3). A hypothesis explaining calcium deposition in association with steroid-phosphate preparations is presented. CONCLUSIONS: We recommend withdrawal of steroid-phosphate preparations in patients who develop band keratopathy.

Administration, Topical↗

PubMed1994

Penetrating keratoplasty with anterior or posterior chamber intraocular lens implantation.

OBJECTIVE: To compare the outcome of anterior chamber (AC) intraocular lens (IOL) implantation with the outcome of posterior chamber (PC) IOL implantation at the time of penetrating keratoplasty in the absence of capsular support. DESIGN: Retrospective study of 122 eyes that underwent secondary IOL implantation without capsular support at the time of penetrating keratoplasty. Ninety eyes received an AC IOL and 32 received a PC IOL sutured to the iris or the ciliary sulcus. RESULTS: Survival analysis showed the probability of a clear graft to be 86% for eyes with an AC IOL and 90% for eyes with a PC IOL at 1 year. Intraocular pressure rose by 5 mm Hg or more in 30% of eyes with AC IOLs and 5% of eyes with PC IOLs. Visual acuity was better than 20/200 in 48% of eyes with AC IOLs and 68% of eyes with PC IOLs. CONCLUSION: This study demonstrated a trend for a better outcome with PC IOLs than AC IOLs for secondary implantation at time of penetrating keratoplasty in the absence of capsular support.

Adult↗

PubMed1994

Risk factors for corneal graft failure and rejection in the collaborative corneal transplantation studies. Collaborative Corneal Transplantation Studies Research Group.

PURPOSE: To evaluate comprehensively the magnitude of suspected risk factors for corneal graft failure from any cause, failure from rejection, and immunologic reaction in patients at high risk for graft failure after corneal transplantation. METHODS: The records of the 457 participants in the Collaborative Corneal Transplantation Studies were reviewed. All participants had at least two quadrants of stromal vascularization and/or a history or previous graft rejection. Patients were followed for 2 to 5 years. Characteristics of the patient, study eye, donor, donor-recipient histocompatibility, and surgical procedure were examined for their association with the graft outcomes of failure from any cause, rejection failure, and immunologic reaction. Multivariate survival analysis techniques were used to estimate rates of graft outcome events and to estimate the magnitude of risk factors. RESULTS: Many apparent risk factors did not maintain their association with graft outcomes after adjustment for other risk factors. Young recipient age, the number of previous grafts, history of previous anterior segment surgery, preoperative glaucoma, quadrants of anterior synechiae, quadrants of stromal vessels, a primary diagnosis of chemical burn, and blood group ABO incompatibility were among the strongest risk factors identified for graft failure. Donor and corneal preservation characteristics had little influence on graft outcome. CONCLUSIONS: Risk of graft failure varies substantially, even within a high-risk population. The number of risk factors present should be considered by the patient and surgeon when contemplating transplantation and planning follow-up.

Adolescent↗

PubMed1994

Six-month results of the multicenter phase I study of excimer laser myopic keratomileusis.

We report six-month results of the Summit Technology Myopic Keratomileusis Phase I multicenter study. Fifty-seven eyes of 57 patients had keratomileusis to correct high myopia. A microkeratome was used for the primary keratectomy and the excimer laser was used to ablate the stroma of the resected lenticle (cap) or the stromal bed (in situ). At six months, 31 of the 47 eyes available for follow-up (65.9%) had uncorrected visual acuity of 20/40 or better; 16 (34.0%) had uncorrected acuity of 20/25 or better. Thirty-seven eyes (78.7%) maintained the same (+/- one Snellen line) best corrected visual acuity as before surgery; seven (14.9%) lost two lines and three (6.4%) lost more than two lines. In addition to the six-month multicenter study results, we report two year results in a subset of 28 eyes (22 from the multicenter study and six fellow eyes). At six months, 17 of the 24 eyes available for follow-up (70.9%) had uncorrected visual acuity of 20/40 or better and nine (37.5%) had uncorrected acuity of 20/25 or better, including eyes that had worse than 20/80 best corrected visual acuity preoperatively. At 24 months, five of the seven eyes available for follow-up (71.4%) had uncorrected acuity of 20/25 or better. Only one patient lost two lines of best corrected vision at six months and no patient lost more than two lines; at 24 months, all patients maintained (+/- one line) best corrected vision.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Effect of genetically determined host factors on the efficacy of vidarabine, acyclovir and 5-trifluorothymidine in herpes simplex virus type 1 infection.

The susceptibility of Herpes simplex virus (HSV) to acyclovir (ACV), 5-trifluorothymidine (TFT) and vidarabine (Ara-A) in HSV-infected embryo fibroblasts from BALB/c and C57BL/6 mice as well as Vero cells were measured. Ara-A and TFT (at its highest concentration) were more effective in Vero cells and BALB/c mouse embryo fibroblasts (MEF) than in C57BL/6 MEF. In contrast, ACV was more effective in C57BL/6 MEF than BALB/c MEF and Vero cells. These data suggest that genetically determined differences in the ability of host cells to support the replication of HSV influence the activity of antiviral drugs.

Acyclovir↗

PubMed1993

Bacterial and fungal endophthalmitis after penetrating keratoplasty.

We analyzed 1,010 consecutive penetrating keratoplasties to determine the incidence of postoperative endophthalmitis, the frequency of positive donor rim cultures, and whether a correlation between these two factors exists. There were three cases of bacterial endophthalmitis, all caused by streptococci, and one case of Candida albicans endophthalmitis. In all cases except one case of streptococcal endophthalmitis, the same organism was cultured from the donor rim. We cultured 138 organisms from 128 of 932 donor rims (14%). A remarkable percentage of gram-positive organisms were resistant to gentamicin, the only antibiotic contained in corneal storage media. On the basis of our data and previously published data, we believe that donor material is frequently the source of microorganisms in endophthalmitis after penetrating keratoplasty.

Adult↗