Evaluation Of The Cornea In Retinitis Pigmentosa Patients By Specular Microscopy

The aim of this study was to evaluate the specular microscopic features of the cornea in retinitis pigmentosa patients.

Nigde Omer Halisdemir University, Department of Ophthalmology, September 2023-October 2024.

For this purpose, RP patients without cataract surgery were divided into two groups according to inheritance pattern: Autosomal dominant (group 1, n=14, 28 eyes), autosomal recessive (group 2, n=10, 20 eyes). Group 1 consisted of 9 males and 5 females, mean age 29.6±11.8 years and group 2 consisted of 6 males and 4 females, mean age 27.0±10.5 years. The control group (group 3) consisted of 20 healthy subjects (13 males and 7 females, mean age 29.2±10.4 years). All participants underwent a detailed ophthalmologic examination. All eyes were visualized by non-contact specular microscopy (SP-1P, Topcon Co., Tokyo, Japan). Cell density (CD), Coefficient of variation (CV), Hexagonality (HEX), Central corneal thickness (CCT) data were compared.

The mean spherical equivalent (D) was similar between the groups (p=0.157). Mean visual acuity was 0.13±0.10 logMAR in group 1, 0.19±0.14 logMAR in group 2 and 0.0 logMAR in group 3. Groups 1 and 2 were similar in terms of mean visual acuity (p=0.281). Central corneal thickness (CCT, µm) was similar between groups (532.1±30.4 in group 1, 528.6±42.2 in group 2 and 536.0±26.9 in group 3, p=0.445). The mean cell density (CD, cells/mm2) was similar between the groups (2757.1±384.18 in group 1, 2758.6±389.69 in group 2 and 2800.9±387.34 in group 3, p=0.682). The mean hexagonality (HEX, %) was 63.4±5.37 in group 1, 53.2±6.21 in group 2 and 65.5±5.91 in group 3. The mean HEX was lower in group 2 compared to both groups (p=0.002 and p<0.001).

Corneal morphologic abnormalities that may affect vision may be seen especially in autosomal recessive retinitis pigmentosa patients. Future studies with advanced imaging systems that evaluate corneal morphology such as electron microscopy are needed.