Long-term anatomical and functional outcomes after autokeratoplasty.

BACKGROUND: To evaluate the anatomical and functional outcomes of autologous contralateral penetrating keratoplasty (autokeratoplasty). METHODS: Kaplan-Meier survival analyses were retrospectively performed. Anatomical failure was defined as regraft or graft permanently cloudy at any time during follow-up. Functional failure was defined as the final best-corrected visual acuity (BCVA) <20/400. RESULTS: Thirty-one eyes of 31 patients (19 men), with a mean age of 52±18 years (range 15-81 years) were studied during a mean follow-up of 11.3 years (from 13 months to 48 years). At 12 months postoperatively, all the recipient eyes showed a transparent cornea, but 23% showed functional failure. At the final followup, 16 recipient eyes (52%) showed anatomical and functional success. Twenty-three eyes (74%) showed a clear cornea and 68% reached a better BCVA when compared with preoperative measurements. Nevertheless, 13/31 eyes (42%) displayed functional failure. The accumulative probabilities for anatomical success were 100%, 72% and 48% and 77%, 59% and 29% for functional success at 1, 10 and 40 years, respectively. The most common risk factor for failure was progression of previous glaucoma in 50% of the anatomical failures and in 77% of the functional failures. CONCLUSIONS: Autokeratoplasty could be a successful long-term option in patients having one eye with a clear cornea but with irreversible visual dysfunction and the contralateral eye having favourable visual potential limited only by a completely opacified cornea. Progression of previous glaucoma was the most important risk factor for long-term cornea decompensation and visual functional failure in the sample.

VITRECTOMY FOR ENDOPHTHALMITIS IN EYES WITH OSTEOKERATOPROSTHESIS.

PURPOSE: To analyze functional and anatomical results of pars plana vitrectomy (PPV) to treat endophthalmitis in eyes with osteokeratoprosthesis. METHODS: An observational, retrospective study of five eyes suffering from endophthalmitis, after an osteokeratoprosthesis implantation, which underwent PPV associated with intravitreal antibiotics. The minimum follow-up after PPV was 6 months. A descriptive study and a Kaplan-Meier survival analysis for anatomical (attached retina during the follow-up) and functional success (visual acuity ≥20/400) were performed. RESULTS: Best-corrected visual acuity during the final follow-up was 20/100 in 1 case (20%), hand movement in another case (20%), and no light perception in 3 cases (60%). The anatomical survival rates were recorded at 80%, 60%, and 40% at 1, 6, and 8 months respectively, and this last value was maintained at 12 months after PPV. The functional survival rates were recorded at 40% and 20% at 1 month and 8 months, respectively, and this last value was maintained at 12 months after PPV. CONCLUSION: Endophthalmitis in eyes with previous osteokeratoprosthesis is a very severe complication with a reserved prognosis. Pars plana vitrectomy associated with intravitreal antibiotics leads to maintaining or increasing visual acuity in a small proportion of patients who otherwise would end up blind.

Osteo-odonto-, Tibial bone and Boston keratoprosthesis in clinically comparable cases of chemical injury and autoimmune disease.

PURPOSE: To compare anatomical and functional results between three types of keratoprosthesis (KPro) in chemical injury and autoimmune disease. METHODS: 70 clinically comparable cases were included as follows: Boston KPro Type 1 25 eyes, osteo-odonto-keratoprosthesis (OOKP) 23 eyes, Tibial bone KPro 22 eyes. Survival times for anatomical and functional success were evaluated with Kaplan-Meier estimations and Log-rank tests. KPro exchange was considered a complication, not as failure. RESULTS: Prosthesis retention in chemical injury group at 5 years was 86% for OOKP, 100% for Tibial bone KPro, and 65% for Boston KPro (p = 0.09), while in the autoimmune disease group it was 66% for Tibial bone KPro and 50% for Boston KPro (p = 0.19; OOKP only one case). Functional success in the chemical injury group at 5 years was 86% for OOKP, 84% for Tibial bone KPro and 71% for Boston KPro (p = 0.38), while in the autoimmune group, it was 44% for Tibial bone KPro and 15% for Boston KPro (p = 0.15; OOKP only one case). The post-operative complications in all groups were: retinal detachment, vitreous hemorrhage, endophthalmitis, retro-prosthetic membrane, uncontrolled glaucoma, the last two being more common in Boston KPro. CONCLUSIONS: For both diagnoses, chemical injury and autoimmune diseases, there was a tendency for better long-term anatomical and functional results with Tibial bone KPro followed by OOKP and Boston KPro Type 1. However, these results were not statistically significant.

Comparison of long-term results between osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

PURPOSE: To compare the anatomical and the functional results between osteo-odonto-keratoprosthesis (OOKP) and keratoprosthesis using tibial bone autograft (Tibial bone KPro). METHODS: We reviewed the charts of 258 patients; 145 had OOKP whereas 113 had Tibial bone KPro implanted. Functional success was defined as best corrected visual acuity ≥0.05 on decimal scale and anatomical success as retention of the keratoprosthesis lamina. Kaplan-Meier survival curves were calculated for anatomical and functional survival as well as to estimate the probability of post-op complications. RESULTS: The anatomical survival for both KPro groups was not significantly different and was estimated as 67% for OOKP and 54% for Tibial bone KPro at 10 years after surgery. There was also no difference found after subdividing for primary diagnosis groups such as chemical injury, thermal burn, trachoma and all autoimmune cases combined. Estimated functional survival at 10 years post-surgery was 49% for OOKP and 25% for Tibial bone KPro, which was significantly different. The probability of patients with Tibial bone KPro developing one or more post-operative complications at 10 years after surgery (65%) was significantly higher than those with OOKP (40%). Mucous membrane necrosis and retroprosthetic membrane formation were more common in Tibial bone KPro than OOKP. CONCLUSION: Both types of autologous biological KPro, OOKP and Tibial bone KPro, had statistically similar rate of keratoprosthesis extrusion. Although functional success rate was significantly higher in OOKP, it may have been influenced by a better visual potential in the patients in this group.

RESULTS OF RETINAL DETACHMENT SURGERY IN EYES WITH OSTEO-KERATOPROSTHESIS.

PURPOSE: To evaluate the anatomical and functional results of pars plana vitrectomy in eyes with osteo-keratoprosthesis, who have suffered retinal detachment. METHODS: An observational, retrospective study of 18 eyes which underwent pars plana vitrectomy for retinal detachment after an implantation of an osteo-keratoprosthesis, with a minimum of 1-year follow-up. A descriptive study and a Kaplan-Meier survival analysis for anatomical and functional success were performed. Anatomical success was defined as an attached retina at the end of vitreoretinal surgery with no redetachment during the follow-up. Functional success was defined as a postoperative visual acuity of more than or equal to 20/400. RESULTS: The overall rate of anatomical success was 56%, and the anatomical survival rates were 67% and 53% at 6 months and 12 months, respectively, maintaining this last value at 24 months after pars plana vitrectomy. The overall rate of functional success was 17%, and the functional survival rates were 83%, 39%, and 14% at 6 months, 12 months, and 24 months after pars plana vitrectomy, respectively. The most frequent complication after retinal surgery was retroprosthetic membrane (33%). CONCLUSION: Despite the reserved prognosis and the severe complications, vitrectomy represents a valid method for treating retinal detachment in patients with osteo-keratoprosthesis, with good anatomical results but poor visual acuity.

Osteokeratoprosthesis Using Tibial Bone: Surgical Technique and Outcomes.

PURPOSE: To analyze the anatomical and functional results of keratoprosthesis using tibial bone autograft. METHODS: We reviewed 113 charts of patients who underwent tibial bone osteokeratoprothesis implantation at the Centro de Oftalmologia Barraquer. Kaplan-Meier survival curves with 95% confidence interval were calculated for functional success, defined as best corrected visual acuity (BCVA) ≥0.05 on the decimal scale, and for anatomical success, defined as retention of the keratoprosthesis lamina. Multivariate analysis was used to test the impact of clinical factors on anatomical and functional survival rates. RESULTS: Based on Kaplan-Meier analyses, tibial bone keratoprosthesis 5-year and 10-year anatomical survival rates were 69.5% and 53.5%, respectively. Functional survival rate at 5 years was 33% and at 10 years was 19.2%. Considering primary diagnosis, chemical burn had better anatomical and functional survival rates than autoimmune or infectious diseases. Patient age did not have a significant effect on keratoprosthesis survival rates. About 48.7% of the patients who underwent surgery had complications: keratoprosthesis extrusion, glaucoma, retinal detachment and buccal mucosa necrosis were the most frequent ones. CONCLUSION: Half of the patients with tibial bone KPro had retained the keratoprosthesis after 10 years post-surgery and one-fifth of them had visual acuity of 0.05 or better at the same period. Considering that these patients have no other way to recover their vision either because they have no canine tooth or their buccal or dental conditions are not adequate for OOKP, this modified surgery is their only hope.

The role of visual evoked potential and electroretinography in the preoperative assessment of osteo-keratoprosthesis or osteo-odonto-keratoprosthesis surgery.

PURPOSE: To determine the value of electroretinography (ERG) and visual evoked potential (VEP) in predicting visual outcome in patients undergoing osteo-keratoprosthesis (OKP) or osteo-odonto-keratoprosthesis (OOKP) surgery. METHODS: We performed a retrospective cohort study of 143 eyes in 101 patients who underwent OKP or OOKP surgery. The subjects underwent ERG, VEP testing or both up to 6 months prior to surgery. The ERG and VEP results were classified into four categories based on wave amplitude, latency and configuration. The main outcome was the maximum best-corrected visual acuity (maxBCVA) reached at any time postoperatively. RESULTS: One hundred thirty-four cases had undergone preoperative ERG, 82 VEP and 73 both examinations. The sensitivities of ERG and VEP to detect maxBCVA≥0.05 were 68.5% and 87%, respectively, while the specificity was 63.2% for ERG and 47.4% for VEP. The maxBCVA was significantly better in patients with normal ERG (p=0.033) and those with normal VEP (p=0.048), once having defined appropriate normal and abnormal cut-off levels. When comparing fellow eyes in patients who underwent surgery in both eyes, maxBCVA was better in the eyes that had better VEP results (p=0.013). CONCLUSION: Eyes demonstrating normal ERG or VEP achieved better visual outcome than those with abnormal results. In addition, VEP proved instrumental in determining the eye with the best prognosis when comparing both eyes of a given patient.

Impact of clinical factors on the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

PURPOSE: To report the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis; to analyze the influence of clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, on the final outcome. DESIGN: Retrospective cohort study. METHODS: setting: Centro de Oftalmología Barraquer, between 1974 and 2005. PARTICIPANTS: Two hundred twenty-seven patients. intervention: Biological keratoprosthesis using osteo-odonto-keratoprosthesis or tibial bone keratoprosthesis. main outcome measures: Functional survival with success defined as best-corrected visual acuity ≥0.05; anatomic survival with success defined as retention of the keratoprosthesis lamina. RESULTS: Osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis have comparable anatomic survival at 5 and 10 years of follow-up, but osteo-odonto-keratoprosthesis has a significantly better functional success than tibial bone keratoprosthesis at the same time periods. Among the primary diagnoses, Stevens-Johnson syndrome, chemical burn, and trachoma have generally good functional and anatomic outcomes and the least favorable prognosis is for ocular cicatricial pemphigoid. Younger patients fared better than those in older age groups. The most frequent complications were extrusion (28%), retinal detachment (16%), and uncontrolled glaucoma (11%). The glaucoma group had the best anatomic success but the worst functional results, only exceeded by the retinal detachment group in terms of functional outcome. CONCLUSION: Clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, can affect the long-term anatomic and functional successes of biological keratoprosthesis. Knowledge about the impact of each of these factors on survival can help surgeons determine the best approach in every particular case.

Long-term functional and anatomical results of osteo- and osteoodonto-keratoprosthesis.

PURPOSE: To analyse the functional and anatomical results of keratoprosthesis using tooth and tibial autograft. METHODS: We reviewed 227 charts of patients that underwent osteo-keratoprosthesis (OKP) (n = 82) or osteo-odonto-keratoprosthesis (OOKP) (n = 145) at the Centro de Oftalmología Barraquer. Mean follow-up time was 8.4 years for OOKP and 3.5 years for OKP. Kaplan-Meier survival curves with 95% confidence interval (CI) were calculated for functional success, defined as BCVA >0.05. Anatomical success was defined as retention of the keratoprosthesis lamina. Visual Acuity by Time (VAT) Index with 95% CI was calculated for up to 2 years post-OKP and up to 6 years post-OOKP. Maximum visual acuity ever reached after the last step of the implantation of the keratoprosthesis was used as an indicator for the potential of the retina. RESULTS: Based on Kaplan-Meier analyses, 10-year anatomical survival was 66% (CI 57-76) for OOKP and 47% (CI 27-67) for OKP. Two-year functional survival was 63% (CI 55-71) for OOKP and 49% (CI 37-60) for OKP, and 10-year functional survival was 38% (CI 29-48) for OOKP and 17% (CI 5-28) for OKP. Multivariate analysis showed that neither surgical technique (OOKP or OKP), primary diagnosis nor age had a significant influence on the functional survival. However, a high maximum visual acuity ever reached post-op decreased the risk for functional failure. According to the VAT Index calculations, mean BCVA 2 years after OOKP was 0.33 (CI 0.28-0.41) and after OKP was 0.28 (CI 0.20-0.36). CONCLUSION: Although we found a tendency that OOKP had better anatomical results than OKP, this difference was not statistically significant up to 10 years post-op. Functional results for both techniques were not significantly different at the 2-year follow-up, but at 10 years they were. However, this difference was influenced by the retinal potential and not by the technique itself.

Keratoconus associated with corneal granular dystrophy in a patient of Italian origin.

PURPOSE: To report a rare case of keratoconus concurrent with granular dystrophy in a patient of Italian origin. It is the seventh case in the literature and the second histopathologically documented case. METHODS: Keratoconus combined with granular dystrophy developed bilaterally in a 15-year-old boy from Italy. The corneal host button of the left eye obtained during penetrating keratoplasty 8 years later was analyzed histologically, immunohistochemically, and ultrastructurally. RESULTS: Histologic evaluation showed characteristic features of keratoconus, such as breaks in Bowman's layer and typical electron-dense trapezoidal deposits ultrastructurally. Other corneal dystrophies, such as Avellino dystrophy, were excluded. CONCLUSIONS: The concurrence of keratoconus and granular dystrophy raises the possibility of a genetic linkage of the diseases, although a chance association cannot be excluded. The diagnosis of keratoconus in patients with granular dystrophy is important because impairment of vision might be the result of keratoconus and could be treated with contact lenses instead of keratoplasty. In the future, the use of computerized corneal topography might help to detect more cases of keratoconus concurrent with granular dystrophy.