Posterior capsule opacification.

Posterior Capsule Opacification (PCO) is the most common complication of cataract surgery. At present the only means of treating cataract is by surgical intervention, and this initially restores high visual quality. Unfortunately, PCO develops in a significant proportion of patients to such an extent that a secondary loss of vision occurs. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens. The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. However, on the remaining anterior capsule, lens epithelial cells stubbornly reside despite enduring the rigours of surgical trauma. This resilient group of cells then begin to re-colonise the denuded regions of the anterior capsule, encroach onto the intraocular lens surface, occupy regions of the outer anterior capsule and most importantly of all begin to colonise the previously cell-free posterior capsule. Cells continue to divide, begin to cover the posterior capsule and can ultimately encroach on the visual axis resulting in changes to the matrix and cell organization that can give rise to light scatter. This review will describe the biological mechanisms driving PCO progression and discuss the influence of IOL design, surgical techniques and putative drug therapies in regulating the rate and severity of PCO.

Immediate sequential bilateral cataract surgery: The rationale, implementation, and beliefs of ophthalmic surgeons across Europe.

PURPOSE: To assess the attitudes and beliefs held toward immediate sequential bilateral cataract surgery (ISBCS), including estimating the incidence of European Society of Cataract and Refractive Surgeons (ESCRS) members currently performing ISBCS, exploring the barriers of ISBCS implementation, and assessing the relevance of these findings to practice in the United Kingdom. SETTING: European consultant members of the ESCRS. DESIGN: Survey-based questionnaire. METHODS: The survey was sent and collected electronically. An initial screening question directed the rest of the survey; participants were asked to rate the importance of several factors with regard to performing ISBCS. Free text options were also available. Descriptive analysis was performed. RESULTS: Of the 2200 recipients, 303 (13.7%) responded, of which 247 were eligible for analysis. Of the 247 eligible respondents, 166 (67.2%) reported performing ISBCS, 71 (28.7%) said they did not perform ISBCS, and 10 (4.0%) said they had previously done so but have since stopped. Of those who were currently practicing ISBCS, the three most important factors to consider were all directly related to infection risk. Of those who did not perform ISBCS, the most important reasons for not performing the surgery were a risk for endophthalmitis (69.0%) and the medicolegal issues should ISBCS go wrong (57.8%). The most common reason for stopping ISBCS was that the respondent no longer believed in the benefit of ISBCS (n = 4). CONCLUSIONS: The survey reflects ophthalmologists' concerns regarding infection and medicolegal risks; however, reports of bilateral endophthalmitis are extremely rare when the correct recommendations are followed. The findings from this survey could be used to inform service provision of ISBCS in the U.K., taking into consideration the voices of colleagues overseas.

Detection of laminar resorption in osteo-odonto-keratoprostheses.

PURPOSE: To compare the clinical examination and computerized tomography (CT) scanning methods for the detection of laminar resorption in eyes with osteo-odonto-keratoprosthesis (OOKP). METHODS: Patients who developed laminar resorption after OOKP surgery and had at least one CT scan of the lamina during the follow-up were included. Case records and CT images and reports were retrospectively reviewed. Each lamina of the eye was regarded as a case. The imaging and clinical data were collected in Microsoft Excel, and statistical analysis was performed on Stata-v14. The agreements and sensitivities of both the methods were compared. RESULTS: Forty patients out of 64 were found to have laminar resorption. A total of 48 laminae were studied, which had data on the presence or absence of resorption. The sensitivity and specificity of clinical detection of resorption were 87.5% (CI 68%-97%) and 37.5% (CI 8.5%-75.5%), respectively. Whereas, the sensitivity and specificity of CT scan were 81% (CI 61%-93%) and 50% (CI12%-88%), respectively. Both the methods have detected resorption in 21 out of 32 laminae having both the clinical and CT scan data. There is a fair agreement between the two techniques in the identification of thinned laminar sites. CONCLUSIONS: Clinical detection of laminar resorption in OOKP eyes is equally sensitive to the CT scanning. Resorption can be detected even in its early stages by clinical palpation in experienced hands. Frequent CT scanning is not indicated to detect laminar resorption. Both methods complement each other. Thinned laminar segments should be compared and correlated with both the methods for full evaluation of resorption.

Vitreoretinal complications of osteoodontokeratoprosthesis surgery.

PURPOSE: To describe the vitreoretinal complications in a cohort of patients with osteoodontokeratoprosthesis (OOKP) and discuss surgical management. METHODS: Review of notes of 35 OOKP cases performed at the Sussex Eye Hospital (Brighton, United Kingdom) between January 1999 and December 2005 was performed. RESULTS: The overall incidence of vitreoretinal complications was 22.8%, which included vitreous hemorrhage (3 patients), rhegmatogenous retinal detachment (3 patients), endophthalmitis with retinal detachment complicating lamina resorption and optic extrusion (2 patients), and intraoperative choroidal hemorrhage (1 patient). Preexisting aphakia was associated with rhegmatogenous retinal detachment (P < 0.05, chi2 = 4.36). Five patients required pars plana vitrectomy, which was performed either endoscopically (two cases) or using a binocular indirect viewing system (three cases) with one case requiring removal of the OOKP and insertion of a temporary keratoprosthesis. Retinal detachment repair was attempted on four of five patients but was successful for only one. Vitreous hemorrhage without retinal detachment required vitrectomy in one case, while two cases cleared spontaneously. CONCLUSIONS: Eyes receiving OOKP are prone to vitreoretinal complications, with retinal detachment associated with a poor prognosis. Thicker OOKP laminae and lamina bulk screening will hopefully reduce the risk of endophthalmitis due to unexpected resorption.

Cataract surgery by appointment--a pilot study.

BACKGROUND: "Cataract Surgery by Appointment" is a new method of delivery of cataract surgery that reduces the time a patient spends in hospital by their direct arrival at the operating theatre, having self-prepared for surgery, thus avoiding admission to the ward or time spent in the Day Case Unit. The patient can stay as little as 20 minutes from their arrival to going home. We describe the process in detail, and seek to evaluate the visual outcome, safety and patient satisfaction of same. METHODS: Visual outcome and safety data were obtained from patients' medical records, prospectively. Patients were also surveyed by a questionnaire to determine their satisfaction with the service and viability as a prospect for providing a more efficient cataract surgery service. RESULTS: In 2002, fifty-one eyes of 39 consecutive patients underwent "Cataract Surgery by Appointment". There were 16 male and 23 female. The pre-operative best-corrected visual acuity was 6/9 or better in 17 (33%) eyes. The post-operative best-corrected visual acuity was 6/9 or better in 44 (86%) eyes. There were no per-operative complications. Post-operative complications occurred in 3 (6%) eyes. The average number of days from surgery to final discharge was 14.5 days. Twenty-eight (72%) completed questionnaires were returned. The results show that the majority of patients were satisfied with their overall experience of this mode of delivery for cataract surgery. CONCLUSION: "Cataract Surgery by Appointment" performed under local anaesthesia by a skilled ophthalmic surgeon appears to be safe and effective for highly selected cases. This method of delivery gave a high level of patient satisfaction, and is the ultimate form of day case cataract surgery. The method may gain widespread use should per-operative intracameral pupil dilatation prove to be effective and acceptable. Attention should be paid to risk-stratification, so complex cases are allocated more time on the operating list.

A brief review of Boston type-1 and osteo-odonto keratoprostheses.

Globally there are ≈4.9 million bilaterally corneal blind and 23 million unilaterally corneal blind. Majority of this blindness exists in the developing countries, where resources for corneal banking and transplant surgery are less than adequate. Survival of corneal grafts gradually declines over the long term. Corneal transplantation has poor prognosis in vascularised corneal beds, ocular surface disease and viral keratitis. Keratoprosthesis (KPro) remains as a final option for end-stage ocular surface disease, multiple corneal transplant failures and high-risk corneal grafts. Boston type-1 KPro and osteo-odonto-keratoprosthesis are the two devices proven useful in recent years. Choice of a keratoprosthetic device is patient specific based on the underlying diagnosis, ocular morbidity and patient suitability. KPro surgery demands a high level of clinical and surgical expertise, lifelong commitment and extensive resources. Improvements in techniques and biomaterials may in the future provide retainable KPros that do not need regular follow-up of patients, have low complications but high retention rates and may be produced at a low cost on a mass scale to be available as 'off the shelf' devices. Because KPros have the potential to effectively address the burden of surgically treatable corneal blindness and may also eliminate the problems of corneal transplantation, more research is required to develop KPros as substitutes for corneal transplantation even in low-risk cases. In those countries where corneal blindness is a major liability, we need a two pronged approach: one to develop eye donation, eye banking and corneal transplantation and the second to establish centres for keratoprostheses, which are affordable and technically not challenging, in a population where default on follow-up visits are high. Until the latter is achieved, KPros should be viewed as a temporary means for visual restoration and be offered in national and supraregional specialised centres only.

Comparison of 640-Slice Multidetector Computed Tomography Versus 32-Slice MDCT for Imaging of the Osteo-odonto-keratoprosthesis Lamina.

PURPOSE: To investigate the efficacy of 640-slice multidetector computed tomography (MDCT) for detecting osteo-odonto laminar resorption in the osteo-odonto-keratoprosthesis (OOKP) compared with the current standard 32-slice MDCT. METHODS: Explanted OOKP laminae and bone-dentine fragments were scanned using 640-slice MDCT (Aquilion ONE; Toshiba) and 32-slice MDCT (LightSpeed Pro32; GE Healthcare). Pertinent comparisons including image quality, radiation dose, and scanning parameters were made. RESULTS: Benefits of 640-slice MDCT over 32-slice MDCT were shown. Key comparisons of 640-slice MDCT versus 32-slice MDCT included the following: percentage difference and correlation coefficient between radiological and anatomical measurements, 1.35% versus 3.67% and 0.9961 versus 0.9882, respectively; dose-length product, 63.50 versus 70.26; rotation time, 0.175 seconds versus 1.000 seconds; and detector coverage width, 16 cm versus 2 cm. CONCLUSIONS: Resorption of the osteo-odonto lamina after OOKP surgery can result in potentially sight-threatening complications, hence it warrants regular monitoring and timely intervention. MDCT remains the gold standard for radiological assessment of laminar resorption, which facilitates detection of subtle laminar changes earlier than the onset of clinical signs, thus indicating when preemptive measures can be taken. The 640-slice MDCT exhibits several advantages over traditional 32-slice MDCT. However, such benefits may not offset cost implications, except in rare cases, such as in young patients who might undergo years of radiation exposure.

Mitomycin-C for mucous membrane overgrowth in OOKP eyes.

PURPOSE: The aim of this study was to report the use of mitomycin-C (MMC) in the treatment of mucous membrane overgrowth in eyes with osteo-odonto-keratoprosthesis (OOKP). METHODS: Records of 4 cases with mucous membrane overgrowth after stage 2 OOKP surgery were reviewed. RESULTS: All the patients had undergone a mucous membrane trimming procedure followed by MMC application. None of the patients had any episode of recurrence of the mucous membrane overgrowth after a single application of MMC in the follow-up period that ranged from 1 to 11 years. CONCLUSIONS: MMC can successfully arrest mucous membrane overgrowth in OOKP-implanted eyes including refractory cases.

Optical functional performance of the osteo-odonto-keratoprosthesis.

PURPOSE: The aim of this study was to evaluate optical and visual functional performance of the osteo-odonto-keratoprosthesis (OOKP). METHODS: Optical design and analysis was performed with customized optical design software. Nine patients with implanted OOKP devices and 9 age-matched control patients were assessed. Contrast sensitivity was assessed and glare effect was measured with a brightness acuity test. All OOKP patients underwent kinetic Goldmann perimetry and wavefront aberrometry and completed the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). RESULTS: Optical analysis showed that the optical cylinder is near diffraction-limited. A reduction in median visual acuity (VA) with increasing glare settings was observed from 0.04 logMAR (without glare) to 0.20 logMAR (with glare at "high" setting) and significantly reduced statistically when compared with the control group at all levels of glare (P < 0.05). Contrast sensitivity was significantly reduced when compared with age-matched controls at medium and high spatial frequencies (P < 0.05). Median Goldmann perimetry was 65 degrees (interquartile range, 64-74 degrees; V-4e isopters) and 69 degrees excluding 2 glaucomatous subjects. Several vision-related NEI VFQ-25 subscales correlated significantly with VA at various brightness acuity test levels and contrast sensitivity at medium spatial frequencies, including dependency, general vision, near activities and distance activities. CONCLUSIONS: The OOKP optical cylinder provides patients with a good level of VA that is significantly reduced by glare. We have shown in vivo that updates to the optical cylinder design have improved the patient's field of view. Reduction of glare and refinement of cylinder alignment methods may further improve visual function and patient satisfaction.

Black-on-clear piggyback technique for a black occlusive intraocular device in intractable diplopia.

Black occlusive intraocular devices have been used successfully for intractable binocular diplopia. We describe a novel technique of implanting both a black occlusive device and a clear poly(methyl methacrylate) intraocular lens (IOL) in the capsular bag during phacoemulsification surgery. If the need should arise at a later date, this approach will allow safer and easier explantation of the black occlusive device, avoiding the need for IOL exchange.

A retrospective study of endodontic treatment outcome between nickel-titanium rotary and stainless steel hand filing techniques.

AIM: The purpose of this study was to compare the periapical healing of molar root canal treatment using two instrumentation techniques. METHODS: A total of 225 maxillary and mandibular first and second permanent molars endodontically treated by undergraduate or postgraduate students were randomly selected from a computerized hospital database of which 110 molars had been prepared using a hybrid rotary technique with nickel-titanium instruments (group NR) and 115 with hand stainless steel files (group HF). Patients were recalled and the teeth were examined both clinically and radiographically for signs of periapical inflammation. RESULTS: Some 19% and 39% of teeth in the NR and HF group, respectively, were judged to have some form of procedural errors. A higher rate of periapical healing was noted for NR (77%) than the HF group (60%) (p < 0.05). Factors contributing favorably to treatment outcome included the use of rotary technique, maxillary molar, experienced operator, and absence of preoperative radiolucent lesion. CONCLUSION: There was a higher incidence of procedural errors and a lower success rate for primary root canal treatment of teeth prepared with stainless steel files compared with the use of NiTi instruments in a continuous reaming action.

Inferior conjunctival autograft for primary pterygia.

OBJECTIVE: Superior conjunctival graft is commonly used in pterygium surgery, which may adversely affect the outcome of future filtration surgery. We retrospectively studied the success rate of inferior conjunctival autografting for primary pterygia in our unit. DESIGN: A noncomparative, retrospective, interventional case series. PARTICIPANTS: Thirty eyes of 27 patients treated between August 1996 and February 2001 with primary pterygia. INTERVENTION: Excision of pterygium followed by conjunctival autograft harvested from the inferior bulbar conjunctiva. Surgeries were performed by an experienced surgeon (CL) in 23 patients and by trainees in the remaining four cases. MAIN OUTCOME MEASURES: Recurrence of the pterygium and complications. RESULTS: Mean follow-up was 27 months (range, 8-53). Recurrence occurred in one eye (3.3%). This was a white female in her early fifties, with recurrence detected 3 months after the surgery. Conjunctival scarring at the donor site was observed in 11 eyes (36.66%). There was no symblepharon formation. There was no restriction of up gaze. Hemorrhage under the conjunctival graft developed in three eyes, corneal dellen near the limbus developed in four eyes, and epithelial inclusion cysts at the recipient site developed in two eyes. CONCLUSIONS: Inferior conjunctival autografting is an effective technique with a low recurrence rate. This is a useful technique in cases in which it is not possible or desirable to use the superior conjunctiva as a donor source.