Assessment of macular thickness and Assessment of macular thickness and function by optical coherence function by optical coherence

tomography and multifocal tomography and multifocal electroretinogram in uncomplicated electroretinogram in uncomplicated

cataract surgerycataract surgery

Yang Li, Jason Dilly, Michael Ober, Gary TrickYang Li, Jason Dilly, Michael Ober, Gary TrickDepartment of Ophthalmology, Henry Ford Department of Ophthalmology, Henry Ford

Hospital, Detroit, MIHospital, Detroit, MI

Authors have no financial interestAuthors have no financial interest

PurposePurpose

To determine whether there is an increase To determine whether there is an increase of macular thickness and /or impairment of of macular thickness and /or impairment of photoreceptor function in patients following photoreceptor function in patients following uncomplicated cataract surgery.uncomplicated cataract surgery.

To determine whether there is an To determine whether there is an association between changes in macular association between changes in macular thickness and photoreceptor function.thickness and photoreceptor function.

MethodsMethodsProspective studyProspective study12 patients undergoing uneventful small–12 patients undergoing uneventful small–incisional cataract surgeryincisional cataract surgeryPatient’s mean age: 69 years Patient’s mean age: 69 years Pre-op evaluation and post-op evaluation at 2 Pre-op evaluation and post-op evaluation at 2 weeks & 3 monthsweeks & 3 months

- - Complete ophthalmic examinationComplete ophthalmic examination - OCT (Stratus 3) - OCT (Stratus 3)

- - mfERG (Veris 5.0.5): the mfERG responses were mfERG (Veris 5.0.5): the mfERG responses were analyzed within the 3 central concentric rings which analyzed within the 3 central concentric rings which correspond to the foveal and parafoveal area correspond to the foveal and parafoveal area measured by the OCTmeasured by the OCT

Results: Post-op 2 weeksResults: Post-op 2 weeksOCTOCT

- Pre-op central retinal thickness was 221.3 ± 4.7µm - Pre-op central retinal thickness was 221.3 ± 4.7µm (mean ± standard error of mean(mean ± standard error of mean [SEM]).[SEM]).

- In 6 of 12 patients (50%) retinal thickness increased by - In 6 of 12 patients (50%) retinal thickness increased by at least 2 SEM at 2 weeks post-op. In this group the at least 2 SEM at 2 weeks post-op. In this group the central retinal thickness increased from 218.5 ± 4.1 µm central retinal thickness increased from 218.5 ± 4.1 µm to 234.9 ± 3.7 µm.to 234.9 ± 3.7 µm.

mfERGmfERG - - Ten of 12 patients (83.33%) had an increased mfERG Ten of 12 patients (83.33%) had an increased mfERG

response (mean = 32.88%) post-op. response (mean = 32.88%) post-op. - Two of 12 patients (16.67%) had decreased mfERG - Two of 12 patients (16.67%) had decreased mfERG

response (mean = 19.8%) post-op. response (mean = 19.8%) post-op.

OCT : mfERGOCT : mfERG - Both patients with decreased photoreceptor - Both patients with decreased photoreceptor

responses exhibited increased central retinal responses exhibited increased central retinal thickness.thickness.

- In patients with increased central retinal thickness the - In patients with increased central retinal thickness the change in mfERG amplitude (20.03%) was less than change in mfERG amplitude (20.03%) was less than in the patients with no increase in central retinal in the patients with no increase in central retinal thickness (28.17%). Excluding one mfERG outlier thickness (28.17%). Excluding one mfERG outlier (pre-op mfERG substantially lower than other (pre-op mfERG substantially lower than other subjects) the difference between the two groups is subjects) the difference between the two groups is significantly increased (5.28% vs 28.17%).significantly increased (5.28% vs 28.17%).

Pre-op: 228um Post-op: 241um

A patient with increased central retinal thickness

Pre-op: 237um Post-op: 240um

A patient with unchanged central retinal thickness

Pre-op Post-op: 2 weeksA patient with decreased mfERG response 2 weeks post-op

Pre-op Post-op: 2 weeks

A patient with increased mfERG response 2 weeks post-op

Results: post-op 3 monthsResults: post-op 3 months

OCTOCT - - Pre-op central retinal thickness was 221.9 ± 5.4µm Pre-op central retinal thickness was 221.9 ± 5.4µm

(mean ± SEM).(mean ± SEM). - In 3 of 6 patients (50%) retinal thickness increased - In 3 of 6 patients (50%) retinal thickness increased

by at least 2 SEM at 3 months post-op. In this group by at least 2 SEM at 3 months post-op. In this group the central retinal thickness increased from 224 ± the central retinal thickness increased from 224 ± 8.7µm to 247 ± 21.6µm.8.7µm to 247 ± 21.6µm.

mfERGmfERG - Four of 6 patients (66.67%) had an increased - Four of 6 patients (66.67%) had an increased

mfERG response (mean = 22.78%) post-op. mfERG response (mean = 22.78%) post-op. - Two of 6 patients (33.33%) had decreased mfERG - Two of 6 patients (33.33%) had decreased mfERG

response (mean = 8.46%) post-op. response (mean = 8.46%) post-op.

OCT : mfERGOCT : mfERG

- - Both patients with decreased photoreceptor Both patients with decreased photoreceptor responses exhibited increased central retinal responses exhibited increased central retinal thickness.thickness.

- In patients with increased central retinal - In patients with increased central retinal thickness the change in mfERG amplitude (-thickness the change in mfERG amplitude (-1.50%) was less than in the patients with no 1.50%) was less than in the patients with no increase in central retinal thickness (26.22%).increase in central retinal thickness (26.22%).

ConclusionsConclusionsSubclinical central retinal thickening occurs in Subclinical central retinal thickening occurs in many patients after uncomplicated standard many patients after uncomplicated standard small–incisional cataract surgery.small–incisional cataract surgery.

In most patients, the mfERG response In most patients, the mfERG response increases or remains unchanged after increases or remains unchanged after uncomplicated cataract surgery.uncomplicated cataract surgery.

Even mild increase in central retinal thickness Even mild increase in central retinal thickness on OCT (subclinical CME) may be associated on OCT (subclinical CME) may be associated with decreased retinal function as manifested with decreased retinal function as manifested by decreased mfERG amplitude. by decreased mfERG amplitude.