The Importance of Ocular Surface Assessment

At least 25% of cataract patients present to the operating theatre with clear signs of ocular surface disease, according to the 2024 ESCRS Clinical Trends Survey.

“We have to keep in mind that there are many more patients suffering from this disease,” said Ramin Khoramnia MD, PhD. “In fact, about 60% of routine cataract patients are asymptomatic dry eye patients, and finding those patients is the duty we must fulfil.”

Reviewing the Clinical Trends Survey, Dr Khoramnia observed how 66% of respondent ophthalmologists are very likely to postpone surgery in a patient with moderate dry eye—meaning that even though the biometry is not giving accurate data, 34% of surgeons do not postpone. This can lead to worse outcomes, he added, suggesting it may be important to prioritise patient assessment over surgery.

However, only 55% of cataract surgeons systematically check the ocular surface during preoperative examination. This can lead to a lot of missed diagnoses, which prompted Dr Khoramnia to urge his colleagues to carefully consider the importance of screening patients for ocular surface disease.

A slit lamp examination is the first step; evaluating film stability and tear breakup time (TBUT) and osmolarity testing are also necessary. Inflammatory marker testing, meibography, and Schirmer tests are all valuable options to assess cases of dry eye. Dr Khoramnia also underlined the importance of the Dry Eye Questionnaire.

Red flags

The ESCRS Clinical Trends Survey also revealed that 75% of respondents believe mild to moderate dry eye significantly affects keratometry and IOL calculations. Even the best surgeon implanting the best lens will never get good outcomes if the data taken prior to surgery is not compiled in an orderly fashion, Dr Khoramnia said.

Taking good and consistent preoperative measurements through multiple readings is therefore paramount, including confirming the stability of the ocular surface. If it is not the surgeon who conducts the exams directly, Dr Khoramnia said, their staff must be trained to take multiple readings and verify reproducibility.

Since data validation is important, Dr Khoramnia outlined red flags for consideration: more than one dioptre of difference between the eyes in average K should lead to further examination, as well as average K greater or less than 47.0 D, cylinder more than 2.5 D, ACD higher than 4.2 mm or lower than 2.0 mm, and axial length higher than 30.0 mm and lower than 22.0 mm.

Careful patient selection for the right kind of lens is another essential factor, Dr Khoramnia noted. Alcon’s Vivity lens is one of his IOLs of choice, thanks to the wavefront-shaping technology that leads to greater spectacle independence with lower photic phenomena.

“It’s very important that we screen the ocular surface in every patient—even if the patients are asymptomatic—and optimise the ocular surface,” Dr Khoramnia said. “We need to confirm a very stable and repeatable keratometry and look for the right lens choice. We really must optimise the surface to ensure an accurate power calculation and to achieve better vision quality. If we do all that, then the patient’s satisfaction can be as high as possible.”

Dr Khoramnia spoke at the 2025 ESCRS Congress in Copenhagen.

Ramin Khoramnia MD, PhD, FEBO is Director of Ophthalmology at the Carl Gustav Carus University Clinic of Dresden, Germany.