Visual Field Characteristics of Type I Boston Keratoprosthesis Patients Without Glaucoma

Abstract

Purpose: To determine visual field findings in Boston type 1-KPro (BI-KPro) patients without glaucoma. Characterize normal threshold values and global indices using standard automated perimetry and characterize visual field amplitude using Goldmann's manual perimetry.Methods: This cross-sectional prospective noninterventional study included patients (n = 6 patients, 6 eyes) with BI-KPro who had normal optical coherence tomography and fundoscopic evaluation of the optic disc and retina. None had a previous history of glaucoma. Visual acuity, reliable and reproducible standard automated perimetry (24-2 and 30-2), and manual perimetry examinations were obtained from all patients. Each patient answered the National Eye Institute Visual Function Questionnaire, and the results were correlated with visual field indices.Results: The mean visual acuity was 0.35 ± 0.31 logMAR (0.84 to 0.10). All visual fields had good reliability indices. The standard automated perimetry mean deviation values were −7.25 ± 3.63 decibels (dB) and −7.75 ± 3.23 (24-2 and 30-2 values, respectively), whereas pattern SD values were 2.72 ± 0.82 and 3.30 ± 1.13 (24-2 and 30-2, respectively). The manual visual field mean values of the 4 quadrants (superior, temporal, inferior, and nasal), were 39.7 ± 4.5, 61.8 ± 6.2, 54.0 ± 4.3, and 48.2 ± 7.6 degrees, respectively. The authors found a significant correlation between the VFQ-25 indexes of general sight and close-range activities with the values of total deviation at 10 degrees. VFQ-25 peripheral vision indexes also correlated significantly with values of total deviation at 30 degrees (outermost locations in the 30-degree area).Conclusions: Patients with BI-KPro presented reliable and reproductive visual field measurements. The authors found a consistent reduction in visual field extension and a global sensitivity reduction in these patients. Despite visual field changes, our patients had a good quality of life scores. Overall, these results could be useful to improve early glaucoma diagnosis and to follow-up BI-KPro patients.

Glaucoma management in patients with penetrating keratoplasty or keratoprosthesis

“…Visual field testing should also be attempted in all keratoplasty patients preoperatively and postoperatively, although poor visual acuity often impairs surveillance by this method [32]. Goldmann visual field (GVF) testing is commonly used to monitor visual fields in KPro eyes, with digital planimetric quantification of GVFs being investigated as a novel method for quantitative surveillance [33].…”

Challenges of Glaucoma Management in Patients with Type I Boston Keratoprosthesis

“… 27 A cross-sectional study that included 6 eyes that received the KPro device with no previous history of glaucoma, concluded that Goldmann manual perimetry was a reproducible test will all eyes showing good reliability indices. 30 Akpek et al tested the reliability of different glaucoma investigations in patients after Boston type 1 KPro implantation versus eyes with penetrating keratoplasty as controls. 31 They concluded that the Humphrey 10–2 visual field test and RNFL thickness with the OCT are both repeatable and reliable for detecting glaucomatous progression in KPro eyes.…”