Anterior segment optical coherence tomography in the long-term follow-up and detection of glaucoma in Boston type I keratoprosthesis.

PURPOSE: To evaluate the role of anterior segment (AS) optical coherence tomography (OCT) as a standardized method of imaging Boston type I keratoprosthesis (KPro) after surgery, particularly in the visualization of iris and angle structures. DESIGN: Prospective case series. PARTICIPANTS: Twenty patients who underwent KPro implantation in 1 eye. METHODS: Patients underwent AS OCT imaging before surgery. After KPro implantation, patients were imaged using the AS single, dual, and quad scans to obtain transverse images of the eye every 15° over 360°. High-resolution, corneal quad, and anterior chamber scans were also obtained. This imaging protocol allowed juxtaposition and comparison of the same imaging coordinates obtained before surgery and 3, 6, and 12 months after surgery. MAIN OUTCOME MEASURES: Postoperative visual acuity (VA), glaucoma progression on clinical examination and formal visual field testing, and anatomic angle changes on AS OCT defined by angle closure, peripheral anterior synechiae (PAS), iris-KPro backplate touch, and graft-host interface changes over time. RESULTS: Mean follow-up was 18.8±3.2 months. The average preoperative VA was 1.9±0.5 logarithm of the minimum angle of resolution. After surgery, VA improved to 1.0±0.9 at last follow-up (P = 0.002). Fourteen of 20 patients had glaucoma before surgery. After surgery, 5 of these patients deteriorated clinically and 1 de novo diagnosis of glaucoma was made. On OCT, the average total degrees of angle closure for all patients increased from 158.5±158.9° before surgery to 205.4±154.0° after surgery (P = 0.04). The number of eyes with 360° of PAS increased from 6 of 20 before surgery to 9 of 20 after surgery. Iris-backplate touch was demonstrated in 5 of 20 patients, with an average area of involvement of 24.2±36.2°. Overall, of the 12 of 20 patients with clear signs of anatomic angle narrowing and synechiae progression on imaging, 3 had glaucoma deterioration detected by clinical examination. In the other 9 patients, angle changes on OCT were not accompanied by any detectable clinical signs of glaucomatous deterioration. CONCLUSIONS: Anterior segment OCT can be used to observe anatomic changes after KPro implantation that cannot be detected otherwise. We were unable to demonstrate a correlation between anatomic features and clinical progression.

Assessment of the Role and Timing of Glaucoma Surgery in Boston Keratoprosthesis Type 1 Patients.

PURPOSE: To determine the role and optimal timing of glaucoma surgery in relation to Boston keratoprosthesis type 1 (KPro) implantation. DESIGN: Retrospective, comparative, nonrandomized clinical study. METHODS: Single-center study of a total of 100 eyes (100 patients) implanted with a KPro between 2008 and 2017, and diagnosed with glaucoma before or after KPro. Patients were separated into 2 groups: those with preexisting glaucoma and those who developed de novo glaucoma after KPro. Groups were then divided based on whether patients were medically or surgically managed. Glaucoma surgery included glaucoma drainage device (GDD) implantation, trabeculectomy, and cyclophotocoagulation (CPC). Primary outcomes included best-corrected visual acuity (BCVA), glaucoma progression, and complications. Differences in outcomes were compared using parametric and nonparametric tests, as well as log-rank test to compare time-to-outcome events. RESULTS: Among 72 eyes with preexisting glaucoma, 27 (38%) had glaucoma surgery before KPro (18 GDD), whereas 45 (62%) were medically managed only. Among the latter, 19 (42%) needed glaucoma surgery post-KPro (16 GDD). Among 28 eyes with de novo glaucoma, 12 (43%) had glaucoma surgery post-KPro (9 GDD). For eyes with preexisting glaucoma, glaucoma progression was greater with glaucoma surgery performed post-KPro (100%) compared with pre-KPro (74%, P = .016) and to medical management (54%, P = .002). No increase in complications were observed with glaucoma surgery compared to medications only (P > .05), whereas fewer eyes maintained a BCVA of 20/200 or better over time with medical management (P = .013). Eyes with de novo glaucoma had similar progression, BCVA, and complications between medical and surgical care (P > .05). CONCLUSIONS: Glaucoma surgery should be performed before or at the same time as KPro implantation in eyes with preexisting glaucoma. Complication rates are not increased when glaucoma surgery is performed in KPro eyes with either preexisting or de novo glaucoma. To ensure optimal glaucoma control, glaucoma surgery should be performed as early as possible in KPro eyes with good visual potential.

The effect of pharmacological pupillary dilation on intraocular pressure measurement.

OBJECTIVE: To measure the difference in intraocular pressure (IOP) before and after pharmacologic mydriasis in normal subjects using Goldmann applanation tonometer (GAT) and the Diaton transpalpebral tonometer (DT). DESIGN: Prospective case series study. PARTICIPANTS: Sixty-seven adult patients attending a tertiary general ophthalmology eye care center. METHODS: Patients were recruited based on a lack of glaucoma history and normal anterior segment on slit lamp examination. IOP measurements predilation and postdilation were collected. Predilation, both eyes were measured using GAT followed immediately by DT. Forty-five minutes post pharmacologic mydriasis, the measurements were repeated sequentially in the same order. Central corneal thickness (CCT) and additional parameters were also collected to corroborate the absence of glaucoma. RESULTS: Using GAT, the mean IOP predilation was 16.7 ± 3.1 mm Hg OD and 16.12 ± 3.0 mm Hg OS. The mean difference between predilation and postdilation time-points was -1.1 ± 2.5 mm Hg in the right eye and -0.7 ± 2.3 mm Hg in the left eye. Using DT, the mean IOP predilation was 12.8 ± 3.8 mm Hg OD and 13.2 ± 3.5 mm Hg OS. The mean difference between predilation and postdilation time points was -0.8 ± 4.0 mm Hg in the right eye and -0.7 ± 3.6 mm Hg in the left eye. There was a larger fluctuation of postdilation measurements using DT. The difference in IOP measured by the 2 instruments was statistically significant both predilation and postdilation (paired sample analysis pre-correlation 0.38 p = 0.002; post correlation 0.40 p = 0.001). CONCLUSIONS: The use of pharmacologic mydriasis affected the reliability of IOP measurements which was decreased when taken postdilation by both GAT and DT. The poor agreement between GAT and DT values indicates an intrinsic difference between the two types of instrumentation.

Late detachment of Descemet's membrane after penetrating keratoplasty for pellucid marginal degeneration.

PURPOSE: we report a case of late spontaneous large detachment of Descemet's membrane in recurrent pellucid marginal degeneration after penetrating keratoplasty. OBSERVATIONS: a 73-year-old man presented to clinic with spontaneous detachment of his Descemet's membrane 30 years after penetrating keratoplasty for pellucid marginal degeneration. Efforts were made to bubble the membrane back into place without success. The patient then underwent endothelial keratoplasty with successful restoration of cornea clarity. CONCLUSIONS AND IMPORTANCE: this condition may cause diagnostic and treatment dilemmas if not properly identified and managed. In addition this case has information for both the use of scleral contact lens and the success of endothelial keratoplasty in an extremely steep cornea.

Long-term outcomes in a series of idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome.

OBJECTIVE: Idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome is a rare entity with a potentially poor visual prognosis. Our objective is to review the clinical presentation and long-term outcomes of patients with IRVAN syndrome. DESIGN: This is a retrospective case series. METHODS: We reviewed the charts of all the patients diagnosed with IRVAN syndrome at our tertiary care centre from 2002 to 2015. RESULTS: We included the long-term clinical outcomes of 7 eyes (5 patients) diagnosed with IRVAN syndrome. After a mean follow-up of 84.9 months, best-corrected visual acuity was 20/40 or better in the majority of eyes (70%). Four (57.1%) patients had systemic conditions, namely, multiple sclerosis, ischemic stroke, and positive antiphospholipid titres. All eyes were treated with laser photocoagulation. Four (40%) eyes received adjunctive intravitreal bevacizumab injections. CONCLUSION: IRVAN is an important diagnosis for clinicians to recognize. When treated in a timely manner, long-term visual outcomes can be favourable.

Outcomes following Boston type 1 keratoprosthesis implantation in aniridia patients at the University of Montreal.

PURPOSE: To describe outcomes after Boston Type 1 Keratoprosthesis (KPro) surgery in aniridic eyes. DESIGN: Retrospective, interventional case series. SETTING: University-based tertiary care institution. PATIENT POPULATION: Twenty-six aniridic eyes of 19 patients who underwent KPro implantation by a single experienced surgeon (M.H.-D.) between October 27, 2008 and January 16, 2012. MAIN OUTCOME MEASURES: Preoperative and postoperative best-corrected visual acuity (BCVA), intraoperative and postoperative complications, and keratoprosthesis retention. RESULTS: Mean age was 56 years (range, 28-72); 10 patients were male. Seven patients had bilateral procedures. No intraoperative complications were encountered. Preoperatively, BCVA was 20/300 or worse in all eyes. After a mean follow-up time of 28.7±13.5 months (range 4-50), the most recent BCVA was 20/200 or better in 14 eyes. Visual potential was limited by preexisting terminal glaucoma (n=2), phthisis after retinal detachment (n=4), and suprachoroidal hemorrhage (n=2). Other postoperative complications included retroprosthetic membrane formation (n=15), infectious keratitis (n=1), extrusion (n=2), and corneal melt (n=4). Uncomplicated vitritis was reported in 6 eyes. No endophthalmitis occurred in this series. Most eyes have glaucoma and are on medical treatment. The overall retention rate of the initial prosthesis was 77%. CONCLUSIONS: The prognosis in aniridic patients after KPro is variable. Meticulous follow-up and a subspecialty team approach are of utmost importance.

Pre- versus post-dilation changes in intraocular pressure: their clinical significance.

OBJECTIVE: To measure the difference in intraocular pressure (IOP) before and following pharmacologic mydriasis with a cycloplegic-mydriatic combination agent in normal subjects using the Goldmann applanation tonometer. DESIGN: A prospective, university hospital-based, nonrandomized interventional case series. METHODS: We recruited 67 normal subjects without glaucoma. Data were collected on the patients' IOPs before and 45 minutes after pharmacologic mydriasis in both eyes using the Goldmann applanation tonometer. Central corneal thickness and additional parameters were measured to further confirm the absence of glaucoma and to study the correlation between IOP fluctuations and these characteristics. RESULTS: The IOP was measured in 127 eyes. The mean difference between pre- and post-dilation time points was 1.1 ± 2.5 mm Hg in the right eye and 0.7 ± 2.3 mm Hg in the left eye. Post-dilation, the maximum deviation was a change of 6 mm Hg.; 35% of patients had a post-dilation variation of >2 mm Hg (clinically significant). Of these, 31.1% of changes were IOP increases, and 68.9% of changes were IOP decreases after dilation. Central corneal thickness and other parameters showed no correlation with IOP changes. CONCLUSIONS: The use of pharmacologic mydriasis prior to IOP measurement affected the reliability of IOP measurements taken post-dilation in our group of patients. Thus, we believe that the stringent measurement of IOP prior to dilation is the responsible method of measuring and following IOP in every single patient.