Table 4.

Top 20 keywords related to intraocular lens power calculation formulas

Rank	Keyword	Frequency	Total link strength
1	Cataract	231	241
2	Cataract surgery	189	204
3	Intraocular lens	127	157
4	Astigmatism	95	134
5	Biometry	94	142
6	Axial length	93	155
7	Phacoemulsification	84	113
8	IOL power calculation	61	80
9	Keratometry	45	77
10	Myopia	45	56
11	Anterior chamber depth	44	76
12	Intraocular lens power	38	45
13	Toric intraocular lens	33	47
14	Intraocular lens power calculation	32	36
15	Optical biometry	31	54
16	Refractive error	31	42
17	High myopia	29	40
18	Refractive surgery	28	40
19	Presbyopia	27	27
20	Prediction error	26	44

Note: The total link strength attribute indicates the total strength of the co-occurrence links of a given keyword with other keywords [21], representing the number of publications in which two keywords occur together [22].