Classification of disease severity in retinitis pigmentosa.

AIM: To develop a simple and easily applicable classification of disease severity in retinitis pigmentosa (RP). METHODS: This is a retrospective cross-sectional study. Visual acuity (VA), visual field width (VF) and ellipsoid zone width (EZ) were obtained from medical records of patients with RP. A scoring criterion was developed wherein each variable was assigned a score from 0 to 5 depending on its distribution. The cumulative score (from 0 to 15) was used to classify disease severity from grade 0 to 5. The scores were correlated with each other and the final grade. The grades were then correlated with age and disease duration. RESULTS: The median age (range) of patients (n=93) was 55 (12-87) years, 51% were female, 70% had been diagnosed within 10 years, and 50% had autosomal recessive disease. Most eyes (n=181) at least had a VA of 20/40 (67%), a VF of 20° (75%) and an EZ of 5° (76%). All scores were correlated with each other (r=0.509-0.613; p<0.001 for all) and with the final grade (r=0.790-0.869; p<0.001 for all). Except for grade 0 (5%), all grades were evenly distributed: 21% for grade 1, 23% for grade 2, 22% for grade 3, 17% for grade 4 and 12% for grade 5. Grades were correlated with both age (r=0.252; p<0.001) and disease duration (r=0.383; p<0.001). CONCLUSIONS: We present a simple, objective and easy to use disease severity classification for RP which can be used to categorise and compare patients.

Epidemiology of Primary Ophthalmic Inpatient Admissions in the United States.

PURPOSE: To determine the national estimates, demographics, and costs of inpatient eye care in the United States (US). DESIGN: Retrospective cross-sectional study. METHODS: National Inpatient Sample (NIS), a representative sample of all US community hospitals, was used to analyze inpatient admissions with a primary ophthalmic diagnosis from 2001 to 2014. National estimates of the most prevalent diagnoses were determined, and descriptive statistics were calculated for demographics and costs. RESULTS: From 2001 to 2014, there were an estimated 671 324 inpatient admissions (male patients, 51.6%; mean [standard deviation] age, 44.5 [27.3] years) in the US owing to an ophthalmic disorder-an annual rate of 16 per 100 000 population. The Mid-Atlantic region had the highest rate. Most admissions were owing to nontraumatic disorders (75.3%), classified as emergencies (41.8%), and covered by public insurance (48.9%). The median length of stay was 2 days and mortality was 0.2%. The total inflation-adjusted cost over the 14-year period was $5.9 billion. The most prevalent diagnosis was orbital cellulitis (14.5%), followed by orbital floor fracture (9.6%) and eyelid abscess (6.0%). Most diagnoses were infectious (28.0%) and the majority were attributed to external disease (24.3%). A total of 31.1% of all patients had an ophthalmic procedure, pars plana vitrectomy (4.8%) being the most common one. CONCLUSION: There were around 48 000 ophthalmic inpatient admissions in the US costing $421 million every year. Orbital pathology, namely infection and trauma, was the leading cause of admissions. Implementing interventions to decrease the incidence of these conditions may significantly reduce the burden of inpatient ophthalmic care.

Progression of Retinitis Pigmentosa as Measured on Microperimetry: The PREP-1 Study.

PURPOSE: To evaluate yearly progression of retinitis pigmentosa (RP) using microperimetry (MP) performed on Nidek MP1 (NAVIS Software v1.7; Nidek Technologies, Padova, Italy). DESIGN: Retrospective longitudinal study. PARTICIPANTS: RP patients with consecutive MP tests (using the same test settings). METHODS: Data were collected as part of the Photoreceptor Cell Death in Retinitis Pigmentosa Retrospective (PREP-1) study. Visual acuity, fixation stability, mean sensitivity, and regional sensitivity were assessed at baseline and at yearly follow-up appointments. Regional sensitivity was calculated based on 2 methods. Method 1 involved topographical division into central macula (CM) and paracentral macula (PM). Method 2 involved functional division into the edge of scotoma (ES) and the seeing retina (SR). Linear mixed-effects models were used to assess the annual rate of change for each parameter, adjusted for disease duration. MAIN OUTCOME MEASURES: Annual rate of change of visual acuity, fixation stability, and retinal sensitivities (mean sensitivity and regional sensitivities using methods 1 and 2). RESULTS: In total, 75 eyes of 39 patients (median age, 56 y; males, 57%) with a follow-up period ranging from 1 to 4 years were reviewed. Visual acuity at baseline was positively correlated with all retinal sensitivity parameters, most strongly with CM sensitivity (r = 0.545, P < 0.001). There was no change in visual acuity (P = 0.075) or fixation stability (P = 0.371) per year. All retinal sensitivity parameters had a significant decline per year (P < 0.001), with a decline of 0.4 decibel (dB) for mean sensitivity, 0.6 dB for CM, 0.3 dB for PM, 1.3 dB for ES, and 1.1 dB for SR. Method 2 identified the greatest number of cases, with a significant decline in regional sensitivity. CONCLUSION: MP can detect significant changes in regional sensitivity over a 1-year period in patients with RP, even as visual acuity and fixation remain stable. An individualized approach to analyzing retinal sensitivity derived from MP may offer a useful outcome measure for future clinical trials.