Real-world comparison between the Tonopen and Goldmann applanation tonometry in a university glaucoma clinic.

PURPOSE: To determine whether Tonopen intraocular pressure (IOP) measurements by Ophthalmic technicians are interchangeable with Goldmann applanation tonometry (GAT) by a specialist in our glaucoma clinic. METHODS: Ophthalmic technician Tonopen and glaucoma specialist GAT IOP measurements were performed on both undilated eyes of 300 consecutive patients during the same visit to our glaucoma clinic. RESULTS: Among all 600 eyes of 300 patients (age 65.4, range: 23-92 years, male: 44.3%), Tonopen and GAT IOPs were similar (15.5 ± 0.6 vs. 15.4 ± 0.7 mmHg, respectively, p = 0.63) and directly correlated (r2 = 0.58, p < 0.0001). However, among 120 patients with bilateral primary open-angle glaucoma GAT IOP was significantly higher than Tonopen in the right eyes (17.1 ± 1.1 vs. 16.2 ± 0.9 mmHg, p = 0.024) and in the left eyes (17.0 ± 1.0 vs. 16.3 ± 1.0 mmHg, p = 0.029). In all 300 right eyes, Tonopen underestimated IOP in 48.3% of eyes and overestimated in 39% (difference range: ( - )14 to ( + )12 mmHg), with IOP difference > ± 3 mmHg in 34% of eyes. In eyes with GAT IOP ≥ 22 mmHg, Tonopen IOP was significantly lower (24.7 ± 2.6, range: 11-43 mmHg vs. 28.2 ± 2.2, range: 22-43 mmHg, p = 0.0002, mean difference: - 3.6 ± 1.7 mmHg), and the Tonopen measured IOP ≤ 21 mmHg in 33.3% of eyes. In eyes with Tonopen IOP ≤ 10 mmHg GAT measured IOP of 11-17 mmHg in 65.7% of eyes. CONCLUSIONS: Tonopen may mask a third of eyes with elevated IOP and two third of eyes with potentially above-goal IOP. The Tonopen may not be interchangeable with GAT or sufficiently reliable for patient management or screening in our glaucoma clinic. However, further study is recommended to assess the limitations of the Tonopen IOP measurements in eyes with higher or lower GAT IOPs. CLINICAL TRIALS REGISTRATION: The Institutional review board, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY does not require this retrospective study to register.

Influence of eyelid pigmentation on the diagnosis of meibomian gland dysfunction.

PURPOSE: To determine whether reliance on eyelid margin vascularization as a diagnostic criterion for meibomian gland dysfunction (MGD) results in underdiagnosis of MGD in individuals with dark skin pigmentation. PATIENTS AND METHODS: This cross-sectional study enrolled consecutive cornea clinic patients in Buffalo, New York. Eyelid margin vascularization was graded qualitatively from slit-lamp photos. Skin pigmentation was quantified from digital photos using red/green/blue (RGB) pixel analysis and dichotomized using the RGB median. MGD was defined as abnormal quantity or quality of meibum or increased pressure required to express meibum. Additional testing included infrared meibography, Schirmer's testing, and a dry eye questionnaire. Sensitivity of MGD diagnosis by visualization of vascularization, compared to diagnosis by expression of meibum, was estimated with and without stratification by skin pigmentation. RESULTS: Among 47 participants, 15-79 years old, meibomian gland truncation/dropout, abnormal tear production, and dry eye symptoms affected individuals of all skin pigmentations. Eyelid margin vascularization was less common in subjects with dark (n=21%) compared to light pigmentation (65%; p=0.002), although the prevalence of MGD assessed via clinical evaluation did not vary significantly between those groups. Use of eyelid margin vascularization alone was not sensitive (33%) for MGD diagnosis. The sensitivity was 17% when limited to those with dark pigmentation. CONCLUSION: Our findings highlight the importance of gland expression and suggest limiting reliance on eyelid margin vascularization for MGD diagnosis, especially in those with dark eyelid skin pigmentation.

Granulomatosis with polyangiitis: seeing the diagnosis.

A 41-year-old woman presented to her primary doctor with nausea, back pain and lower extremity oedema. Initial labs showed elevated serum creatinine and white blood cell count (WBC), which her doctor attributed to ibuprofen use and a recent upper respiratory infection. Five days later, she presented to the eye clinic with eye pain, redness and blurred vision. She was diagnosed with iritis, conjunctivitis and keratitis. The inflammatory eye disease with decreased renal function prompted the ophthalmologist to initiate systemic autoimmune and infectious disease work-up. Before laboratory testing was complete, she developed severe haemoptysis. Diagnosis of granulomatosis with polyangiitis (GPA) was confirmed using blood testing, radiological imaging and kidney biopsy. She received plasmapheresis, then cyclophosphamide and prednisone with good effect. This case highlights the need to consider GPA in the differential when patients present with inflammatory eye disease with decreased renal function and the need for multispecialty collaboration including ophthalmologists in the diagnosis of GPA.