Boston type 1 keratoprosthesis: the New York Eye and Ear experience.

PURPOSE: The Boston keratoprosthesis has had variable success rates in the past. However, significant modifications to design and management have recently led to successful outcomes. This study was undertaken to evaluate the outcomes of the Boston type 1 keratoprosthesis at our institution. METHODS: A retrospective chart review was performed of all Boston type 1 keratoprosthesis procedures conducted at a single practice at the New York Eye and Ear Infirmary from December 2006 to August 2010. Outcome measures included visual acuity, retention rates, and complications. RESULTS: In all, 58 eyes of 51 patients who received a Boston type 1 keratoprosthesis were included. The most common indication for the keratoprosthesis was failed penetrating keratoplasty (PK) (81.0%; mean 2.4±1.3 PKs per eye). Glaucoma was the most common comorbidity (75.9%). Pre-operative best corrected visual acuity (BCVA) was <20/400 in 87.9% of eyes. At last follow-up, 43.1% of eyes had a BCVA of 20/200. Retention rate was 87.9% over an average follow-up of 21.5±11.4 months (median 22 months, range 3-47 months). Complications increased with time, with 65.5% of eyes experiencing at least one event by 6 months and 75.9% by 1 year. The most common post-operative complication was retroprosthetic membrane formation (50.0%). CONCLUSIONS: The Boston type 1 keratoprosthesis provides visual recovery for eyes with multiple PK failures or with poor prognosis for primary PK, showing excellent retention rates. However, there is a trend towards a decline in visual acuity with time and the development of late complications, highlighting a need for longer-term studies.

Pars plana tube insertion of glaucoma drainage implants and penetrating keratoplasty in patients with coexisting glaucoma and corneal disease.

PURPOSE: To determine the efficacy and associated complications of glaucoma drainage implant (GDI) surgery with pars plana tube insertion and penetrating keratoplasty (PK) in eyes with glaucoma and corneal disease. DESIGN: Retrospective, interventional case series. PARTICIPANTS: All patients who underwent both GDI surgery with pars plana tube insertion and PK before September 1997 were included. METHODS: The medical records of 34 consecutive patients (34 eyes) who had undergone GDI (Baerveldt, Pharmacia & Upjohn, Kalamazoo, MI; Molteno, IOP INC:, Costa Mesa, CA; Krupin, Hood Laboratories, Pembroke, MA; or Ahmed, New World Medical, Rancho Cucamonga, CA) insertion before, concurrent with, or after PK were reviewed retrospectively. All corneal grafts were clear before GDI surgery for patients who underwent glaucoma surgery after PK. Outcomes were evaluated using Kaplan-Meier life-table analysis. MAIN OUTCOME MEASURES: Clinical outcome assessment included corneal graft clarity, intraocular pressure (IOP), visual acuity, and identification of complications. RESULTS: Mean follow-up after completion of both GDI surgery and PK was 12.1 +/- 8.4 months (range, 0-31.8 months). Twelve- and 24-month life-table rates for complete success after both GDI and PK were 63% and 33%, respectively. Twelve- and 24-month life-table success rates for IOP control and corneal graft clarity were 85% and 62%, and 64% and 41%, respectively. Final postoperative visual acuity was the same as or better than (> or =2 Snellen lines) the preoperative level in 29 patients (85%). One or more posterior segment complications occurred in 15 (44%) patients. CONCLUSIONS: Pars plana tube insertion of GDIs is a reasonable option for patients who have undergone PK or in whom PK is anticipated, despite the need for a complete pars plana vitrectomy. Although complications related to limbal tube placement are avoided, the incidence of posterior segment complications may be higher for pars plana insertion. The potential for enhanced corneal graft survival with pars plana versus anterior segment tube placement warrants further investigation.

A devastating ocular pathogen: beta-streptococcus Group G.

PURPOSE: To report the clinical findings, treatment, and outcomes of four cases of beta-streptococcus Group G (BHS-G) ocular infection. METHODS: The medical and microbiologic records of four cases of BHS-G ocular infection were retrospectively reviewed. RESULTS: Two cases of BHS-G endophthalmitis and two cases of BHS-G keratitis were recorded. Three patients developed fulminant infection within 12 hours of the onset of symptoms. One patient's history was incomplete. One patient developed endophthalmitis from a contaminated donor button; another following cataract surgery. One developed keratitis in a keratoplasty suture tract; and another patient developed a corneal abscess after being struck with a tree branch. The patient with the contaminated donor button developed overwhelming endophthalmitis resulting in no light perception vision, severe pain, and evisceration. The postoperative cataract patient developed a purulent endophthalmitis and is still hypotonus with light perception vision. The second keratitis patient developed a significant suture abscess with marked stromal loss but eventually healed. The traumatic keratitis patient developed a large ulcer with hypopyon and descemetocele but was lost to follow-up. CONCLUSIONS: This is the first report of a series of BHS-G ocular infections. The ocular infections were characterized by rapid onset, extreme inflammation, and--despite in vitro antibiotic sensitivity--a poor or sluggish response to antibiotic therapy.

Laser in situ keratomileusis for correction of myopia and astigmatism after penetrating keratoplasty.

PURPOSE: To determine the safety and effectiveness of laser in situ keratomileusis (LASIK) for visual rehabilitation of residual myopia and astigmatism after penetrating keratoplasty. DESIGN: Prospective, noncomparative case series. PARTICIPANTS: LASIK was performed on 23 eyes of 22 patients unable to wear glasses or contact lenses after penetrating keratoplasty due to anisometropia, high astigmatism, and/or contact lens-intolerance. METHODS: All patients underwent LASIK for visual rehabilitation after penetrating keratoplasty. Uncorrected visual acuity and best spectacle-corrected visual acuity, degree of anisometropia, and corneal transplant integrity were recorded before surgery, as well as at 1 month, 3 months, 6 months, and 12 months after LASIK surgery. RESULTS: The mean spherical equivalent before surgery was -7.58+/-4.42 diopters (D), which was reduced to -1.09+/-2.01 D, -0.79+/-1.84 D, -0.77+/-1.25 D, and -1.57+/-1.20 D, respectively, at 1, 3, 6, and 12 months after LASIK. The mean cylinder before surgery was 3.64+/-1.72 D, which was reduced to 1.98+/-1.15 D, 1.64+/-1.14 D, 1.48+/-0.92 D, and 1.29+/-1.04 D, respectively, at 1, 3, 6, and 12 months after LASIK. Spherical equivalent anisometropia was reduced from a mean of 6.88+/-4.4 D to 1.42+/-1.05 D at the final examination. Best-corrected visual acuity remained the same or improved in 21 of 23 eyes and decreased by 1 and 3 lines in 2 patients. There were no surgical flap or corneal transplant complications. CONCLUSIONS: LASIK is a viable treatment alternative for myopia and astigmatism after penetrating keratoplasty in patients who are contact lens-intolerant. LASIK is more effective in treating myopia than astigmatism after penetrating keratoplasty.

Recurrent bleb infections.

AIM: To report the patient characteristics, causative organisms, and clinical outcomes in patients with recurrent bleb related ocular infections. METHODS: The medical records of all patients diagnosed with bleb related ocular infection at the New York Eye and Ear Infirmary over a 10 year period were reviewed. Recurrent bleb infection was defined as at least two episodes of bleb purulence with or without associated intraocular inflammation separated by a quiescent period of at least 3 months. RESULTS: Recurrent bleb infections developed in 12 eyes of 12 patients (10 men, two women) a mean of 16.3 (SD 17.9) months (range 3-51 months) after the initial infection. Two patients developed a third episode 3 and 20 months, respectively, after the second infection, yielding a total of 14 recurrent infection episodes. Recurrent infection developed after trabeculectomy in 11 eyes (adjunctive 5-fluorouracil, nine eyes; mitomycin C, one eye; no antifibrosis agent, one eye) and following cataract extraction with inadvertent bleb formation in one eye. Four (36.4%) of the filtered eyes had undergone trabeculectomy at the inferior limbus. The mean follow up time from filtering surgery to the first bleb related infection was 28 months for the nine patients treated with 5-fluorouracil and 14 months for the single patient treated with mitomycin C. 11 (78.6%) cases had a documented bleb leak in the 4 week period before or at the time of recurrent infection. Topical, prophylactic antibiotics had been used in 7/14 (50%) cases. The same organism was cultured from the initial and recurrent infections in 2/14 (14.3%) cases. CONCLUSION: Eyes that have been successfully treated for bleb related infection remain at risk for recurrent infection. No apparent correlation exists between organisms responsible for the initial and recurrent infections. The increased rate of recurrent bleb related infection in patients receiving adjunctive 5-fluorouracil compared to mitomycin C may have been related to the longer follow up of the 5-fluorouracil eyes.

A unique case of Cryptococcus laurentii keratitis spread by a rigid gas permeable contact lens in a patient with onychomycosis.

PURPOSE: We report the first case of fungal keratitis caused by Cryptococcus laurentii, a nonneoformans species. METHODS: A case of C. laurentii keratitis in a diabetic, gas permeable contact lens wearer was diagnosed after microbiologic evaluation of the corneal button after emergent keratoplasty. The excised cornea was also culture positive for Staphylococcus aureus and Fusarium solani. The medical history was significant for onychomycosis of the right great toe 2 months previously. Cultures of the toenail and of the contact lens case were also positive for C. laurentii and F. solani. RESULTS: An initial penetrating keratoplasty with histopathologically clear margins was unsuccessful in preventing intraocular spread of the fungal infection. Despite a repeat limbus-to-limbus therapeutic keratoplasty, pars plana vitrectomy, multiple anterior chamber washouts, intravitreal antifungal injections, and systemic antifungal treatment, the eye was ultimately lost due to ongoing inflammation, ocular hypotony, and a total retinal detachment. Histopathologic examination of the enucleated eye demonstrated filamentous fungi but no yeast forms. CONCLUSIONS: C. laurentii, a nonneoformans species, should be included in the differential diagnosis of fungal keratitis. This unique case also demonstrates the importance of a thorough clinical history and proper contact lens hygiene, particularly in a diabetic patient.

New patterns of infecting organisms in late bleb-related endophthalmitis: a ten year review.

PURPOSE: To report the risk factors, causative organisms and visual outcomes in patients with late-onset bleb-related endophthalmitis. METHODS: Medical records of all patients with the clinical diagnosis of late-onset bleb-related endophthalmitis undergoing vitreous aspirates for culture at our institution from January 1987 to July 1996 were reviewed. Late-onset bleb-related endophthalmitis was defined as conjunctival injection, bleb purulence and intraocular inflammation developing at least 1 month following filtering surgery. RESULTS: Forty-nine cases of bleb-related endophthalmitis developed in 42 patients (23 men, 19 women). Mean patient age was 62.1 +/- 19.3 years (range 5-94 years). Thirty-nine patients underwent prior filtering surgery (superior trabeculectomy, 24 eyes; inferior trabeculectomy, 10 eyes; combined superior trabeculectomy/cataract extraction, 4 eyes; posterior lip sclerectomy, 1 eye) and 3 had inadvertent blebs following cataract extraction. Endophthalmitis developed an average of 25.4 +/- 23.5 months (range 1-96 months) post-operatively. Antifibrosis agents were used in 25 of 39 eyes undergoing filtering surgery (mitomycin C, 13 eyes; 5-fluorouracil, 12 eyes). Bleb leaks were documented in a total of 32 of 49 (65%) cases either before or at the time of endophthalmitis diagnosis. Vitreous cultures were positive in 42 of 49 (86%) cases. The most frequently cultured organisms were Staphylococcus aureus (13), Staphylococcus epidermidis (12), Streptococcus species (8) and Haemophilus influenzae (2). A final visual acuity of 20/400 or better was achieved in 32 of 49 (65%) cases. CONCLUSIONS: Staphylococcal species were the most frequently cultured organisms in this series and may be associated with better visual outcomes. Although a causal relationship cannot be established, these results suggest a strong association between bleb leaks and endophthalmitis.

Colletotrichum graminicola: a new corneal pathogen.

PURPOSE: We report the first case of an ocular infection with the fungus Colletotrichum graminicola causing keratitis in a 27-year-old man. METHODS: Twenty-four months after a postoperative course complicated by recurrent fungal keratitis requiring two penetrating keratoplasties, two anterior chamber washouts, a conjunctival flap, and medical treatment with topical natamycin, intracameral amphotericin B, and oral fluconazole. RESULTS: The patient has shown no signs of fungal recurrence despite a failed corneal graft. CONCLUSIONS: C. graminicola is a new corneal pathogen and should be included in the differential diagnosis of mycotic keratitis.

Effect of doxycycline hyclate on corneal epithelial wound healing in the rabbit alkali-burn model. Preliminary observations.

We examined the effects of doxycycline hyclate on epithelial healing in vivo in the rabbit alkali-burn model. Twelve 2-3-kg Dutch belted rabbits were divided into three groups and received standard bilateral alkali burns (1 N sodium hydroxide for 30 s in an 11-mm circular plastic well). In group 1, two rabbits (four eyes) served as untreated controls. In group 2, five rabbits (10 eyes) received doxycycline hyclate (1.5 mg/kg) orally daily for 14 days. In group 3, five rabbits (10 eyes) received doxycycline hyclate (5 mg/kg) orally daily for 14 days. The epithelial defects were drawn and photographed on alternate days, after fluorescein staining. At conclusion, extracts of the corneas were evaluated for collagenase activity. At 14 days, the mean percentage of epithelial defects results in groups 1-3 were 50.0, 50.7, and 7.1%, respectively. Using the Wilcoxon rank sum test (two tailed), the differences were found to be statistically significant (p = 0.0015). Preliminary data indicated that oral doxycycline administration also decreased the collagenase activity in corneas obtained from these animals. Our preliminary findings indicated that systematically administered doxycycline hyclate, 5 mg/kg/day, promotes corneal reepithelialization in the rabbit alkali-burn model, a result, perhaps, of the drug's ability to inhibit excessive collagenase activity.

Chronic postoperative endophthalmitis from Staphylococcus aureus.

We recently treated a patient with chronic postoperative endophthalmitis caused by Staphylococcus aureus, which usually presents with a fulminant clinical course. Because of the chronic course, the initial treatment was high dose steroids followed by lensectomy and vitrectomy. However, this was not effective, and intravitreal antibiotics and steroids were ultimately required. We now recommend that in patients with chronic postoperative inflammation unresponsive to high dose steroids, intraocular cultures followed by injection of intraocular antibiotics be considered.

Donor failure after corneal transplantation surgery.

Donor failure refers to graft edema present within the first 24 h after penetrating keratoplasty that persists in spite of maximal medical therapy. We reviewed the case histories of 1,351 penetrating keratoplasties. Of these, 17 (1.2%) were considered donor failures. Five cases were histopathologically consistent with Fuchs' dystrophy. Seven cases demonstrated mechanical stripping of the endothelium. Five cases, all from the same eye bank, revealed an absence of posterior stromal keratocytes. Storage medium at the eye bank of origin was found to have an alkaline pH. Careful preoperative evaluation of donor corneas is emphasized, but if an apparent "epidemic" of donor failure occurs, a thorough investigation of the eye bank methodology should be initiated.

Penetrating keratoplasty for herpes simplex keratitis and keratoconus. Allograft rejection and survival.

To determine the relationship between corneal allograft rejection and failure, we studied patients who underwent penetrating keratoplasty for herpes simplex keratitis (n = 82) and keratoconus (n = 345), two frequent indications for keratoplasty in young patients, using survival analysis. For first grafts for herpes, the probability of survival was significantly less than it was for keratoconus (P less than 0.0001). For second grafts, this difference was less pronounced, and for three or more grafts, the difference in survival was not significant. The incidence of rejection episodes was similar in first grafts for herpes (16.6%) and keratoconus (18.5%) (P greater than 0.05). However, the incidence of rejection episodes in regrafts for herpes was significantly greater than in keratoconus (23.7 versus 17%, P less than 0.01). The incidence of failure after rejection episodes (first grafts and regrafts combined) was significantly greater in grafts for herpes (52.4 versus 16.2%, P less than 0.001). Because survival after multiple regrafts in both groups is poor, additional measures, such as tissue matching, may be necessary to improve the likelihood of success in these high-risk cases.

Systemic tetracycline treatment of alkali-induced corneal ulceration in rabbits.

Recent evidence has demonstrated a marked anticollagenolytic effect for the tetracycline antibiotics. We have examined the efficacy of systemic tetracycline hydrochloride in a rabbit model of corneal ulceration. A standard alkali burn (1N sodium hydroxide for 40 s) was delivered to 62 eyes (31 rabbits). Animals were then divided into three groups: group 1 (controls) (ten rabbits [20 eyes]) received no treatment; group 2 (ten rabbits [20 eyes]) received 10 mg/kg/d of tetracycline hydrochloride, given intramuscularly; and group 3 (11 rabbits [22 eyes]) received 50 mg/kg/d. Ulceration occurred in 85% (17/20) of control eyes. The higher dosage of tetracycline was more effective in preventing ulceration than the lower dosage (9.1% vs 55%). Eyes with higher levels of tetracycline in ocular tissues were less likely to ulcerate.

Survival of corneal grafts from donors supported by mechanical ventilation.

Eighty-five patients undergoing penetrating keratoplasty with tissue from donors supported by mechanical ventilation (Ventilator group) were compared to a surgeon- and diagnosis-matched group (Control group). Age at surgery, duration of follow-up, and sex of recipient patients were similar in the two groups. The mean donor age in the Ventilator group (26.4 years) was significantly less than in the Control group (45.8 years, P less than 0.0001). Mean time on the ventilator was 99.4 hours (range, 4 hours to 21 days). Overall graft survival rates in the Ventilator and Control groups were similar (P greater than or equal to 0.72). Time on the ventilator did not affect graft survival. Cultures of corneoscleral donor rims were positive more often in the Ventilator group than in Controls (39.7 versus 23.1%), but the difference was not significant (P = 0.09). Prolonged ventilator time was not associated with a higher rate of positive corneoscleral rim cultures, nor did positive cultures affect graft survival. The most common cause of graft failure in both groups was allograft rejection. In no case could postoperative bacterial infection be attributed to contamination of the donor material. One case of primary donor failure occurred in the Ventilator group, but the incidence (1.2%) is similar to that of previously reported studies. The data indicate that corneal tissue from ventilator-supported donors should be considered for use in penetrating keratoplasty.

Systemic tetracycline hydrochloride as adjunctive therapy in the treatment of persistent epithelial defects.

Recent evidence shows tetracyclines have anticollagenolytic activity that may be clinically effective in disease treatment. This led us to use systemic tetracycline (oral tetracycline hydrochloride 1 g daily divided into 4 doses) as adjunctive therapy in treating 18 patients with persistent corneal epithelial defects. Fourteen of 18 patients healed their defects; within 48 hours (9 patients) and within two weeks (the other 5 responding patients). Two patients showed no effect and two showed disease progression.

Neodymium:YAG laser iridectomy and acute cataract formation in the rabbit.

The Q-switched Neodymium:YAG (Nd:YAG) laser in the single pulse mode was used to perform iridectomies in pigmented and albino rabbits. Seventy-one iridectomies were attempted. Seventy-six percent (54/71) of these were patent at the time of enucleation. Iridectomy closure was not noted during the 24-day study period. Lenticular damage was not detected in any case. Patency rates in pigmented (70%) and albino (78%) irides were similar. Energy levels of 6 mJ or greater resulted in a higher rate of patency. Settings below 6 mJ were associated with more significant bleeding and had a low rate of success. The histology of acute Q-switched Nd:YAG laser iridectomy is characterized by fragmentation of the stroma and wide dispersion of the pigment epithelium. Minimal healing occurs with retention of normal iris architecture without atrophy or fibrosis. Results indicate that this procedure can be performed with minimal operative complications and without a tendency for closure.